linoleic-acid and 11-octadecenoic-acid

Conjugated Linoleic Acids (CLA) are of great interest for analysts since techniques have been developed to determine the dietary occurrence of CLA with a good accuracy. CLA is found in animal products from ruminant sources as the result of biohydrogenation of polyunsaturated fatty acids in the rumen and as the consequence of the delta-9 desaturation of vaccenic acid in animal tissues. CLA can also be obtained in the laboratory by isomerisation of linoleic acid or by total chemical synthesis. While the "natural" isomer is rumenic acid (9c,11t-18:2), synthetic mixtures contain mainly two isomers: the 9c,11t- and the 10t,12c-18:2. Although CLA have been shown to be metabolized into desaturated and chain elongated products, it remains unclear whether these so-formed conjugated metabolites may be involved in the effects of CLA on fatty acid metabolism. Experiments carried out on animal models with CLA have shown different health benefits: anticarcinogenic, antiatherosclerotic effects, modulation of body composition , the "natural" CLA (9c,11t-18:2) being closely related to the protection against cancer and the 10t,12c-18:2 to the reduction of the fat mass. Nevertheless, recent findings have suggested adverse effects in mice. Most of the studies carried out on humans concern the influence of CLA on body composition and its possible inverse association with cancer. Since the results are still controversial and since very few data dealing with the safety of using CLA in long term feeding studies have so far been published, further works are warranted to consider the benefits of CLA for humans.

Topics: Animals; Arteriosclerosis; Body Composition; Disease Models, Animal; Humans; Linoleic Acid; Linoleic Acids, Conjugated; Neoplasms; Oleic Acids; Trans Fatty Acids

The objective of this study was to examine the effect of ruminal pulse dose of free linoleic acid (LA) and free docosahexaenoic acid (DHA) on microbial populations in the rumen, duodenal fatty acid (FA) flow, milk composition, and milk FA profiles of Chinese Holstein dairy cows. Four rumen- and duodenal-fistulated Chinese Holstein cows in mid lactation (138.5 ± 10d in milk) were randomly assigned to 3 treatment groups and 1 control group in a 4 × 4 Latin square design over 4 periods (3 wk per period). Diets contained either no LA or 2.7% LA and either no DHA or 0.5% DHA in a 2 × 2 factorial arrangement of treatments. Ruminal pulse dose with DHA increased counts of Megasphaera elsdenii, decreased Fibrobacter succinogenes, but did not affect Butyrivibrio fibrisolvens or Ruminococcus flavefaciens. The pulse dose of LA at 2.7% dry matter had no effect on the population sizes of the 3 major cellulolytic bacterial species or M. elsdenii, and no interaction was observed between LA and DHA. The pulse dose of LA or DHA, either alone or in combination, increased the duodenal flow of vaccenic acid (VA). The milk VA and cis-9,trans-11 conjugated linoleic acid (CLA) contents also increased in response to the fatty acid pulse dose, and the pulse dose of both LA and DHA together had the most profound stimulatory effect. This study indicated that ruminal pulse dose of LA or DHA could be used to increase duodenal flow of VA and the milk contents of potentially health-promoting FA, such as VA and cis-9,trans-11 CLA. These results might be useful in formulating dietary interventions to improve milk cis-9,trans-11 CLA contents.

Topics: Animals; Cattle; Diet; Docosahexaenoic Acids; Duodenum; Female; Lactation; Linoleic Acid; Linoleic Acids, Conjugated; Milk; Oleic Acids; Rumen

Forty Holstein dairy cows were used to determine the effectiveness of linoleic or linolenic-rich oils to enhance C18:2 cis-9, trans-11 conjugated linoleic acid (CLA) and C18:1 trans-11 (vaccenic acid; VA) in milk. The experimental design was a complete randomized design for 9 wk with measurements made during the last 6 wk. Cows were fed a basal diet containing 59% forage (control) or a basal diet supplemented with either 4% soybean oil (SO), 4% flaxseed oil (FO), or 2% soybean oil plus 2% flaxseed oil (SFO) on a dry matter basis. Total fatty acids in the diet were 3.27, 7.47, 7.61, and 7.50 g/100 g in control, SO, FO, and SFO diets, respectively. Feed intake, energy-corrected milk (ECM) yield, and ECM produced/kg of feed intake were similar among treatments. The proportions of VA were increased by 318, 105, and 206% in milk fat from cows in the SO, FO, and SFO groups compared with cows in the control group. Similar increases in C18:2 cis-9, trans-11 CLA were 273, 150, and 183% in SO, FO, and SFO treatments, respectively. Under similar feeding conditions, oils rich in linoleic acid (soybean oil) were more effective in enhancing VA and C18:2 cis-9, trans-11 CLA in milk fat than oils containing linolenic acid (flaxseed oil) in dairy cows fed high-forage diets (59% forage). The effects of mixing linoleic and linolenic acids (50:50) on enhancing VA and C18:2 cis-9, trans-11 CLA were additive, but not greater than when fed separately. Increasing the proportion of healthy fatty acids (VA and CLA) by feeding soybean or flaxseed oil would result in milk with higher nutritive and therapeutic value.

Topics: Animal Nutritional Physiological Phenomena; Animals; Cattle; Diet; Dietary Fats, Unsaturated; Energy Intake; Fatty Acids; Female; Lactation; Linoleic Acid; Linoleic Acids, Conjugated; Linolenic Acids; Linseed Oil; Milk; Oleic Acids; Soybean Oil

There has been controversial evidence regarding the relationship between isomers of circulating trans-fatty acids (TFAs) and mortality. This study aimed to ascertain the relationships between plasma TFAs and overall or cause-specific mortality of the general population in two independent subsets from the US National Health and Nutrition Examination Survey (1999-2000 and 2009-2010 cycles).. Plasma TFA isomers (C16:1n-7t, C18:1n-7t, C18:1n-9t and C18:2n-6,9t) in 3439 adults free of cancer or severe cardiovascular disease were analyzed by gas chromatography/mass spectrometry. Overall, 259 died among 1376 individuals over a median follow-up of 15.6 years in the 1999-2000 cycle, and 105 died in the latter subset of 2063 subjects during a median of 5.9 years. Cox proportional hazards regression was conducted to estimate the hazard ratios of mortality. The main isomer of industrially derived TFAs, elaidic acid (C18:1n-9t) was considerably associated with long-term total mortality in the 1999-2000 cycle after adjusting for confounders, with a 54% increase in the top tertile compared with the bottom one. However, the association disappeared with halving C18:1n-9t by 2009-2010. In contrast, neither of the ruminant-derived TFAs (C16:1n-7t and C18:1n-7t) suggested any inverse correlations with all-cause death, mortality due to heart disease, cancer or other causes.. The major isomer of industrial TFAs, the higher circulating C18:1n-9t might be associated with increased long-term mortality. The associations with death risk turned slight with the reduction of TFAs consumption by half. However, dietary guidelines should rigorously identify the healthy effect of animal TFAs consumption.

Topics: Adult; Cause of Death; Diet; Eating; Fatty Acids, Monounsaturated; Female; Follow-Up Studies; Gas Chromatography-Mass Spectrometry; Humans; Linoleic Acid; Male; Middle Aged; Mortality; Nutrition Surveys; Oleic Acids; Proportional Hazards Models; Prospective Studies; Risk Factors; Time Factors; Trans Fatty Acids; United States

Previous studies on health effects of trans fatty acids (TFA) have focused mainly on cardiovascular health. Little is known about the association of TFA with brain or mental health. In this study, we examined the associations of objectively-measured plasma TFA concentrations with depression in a large population-based cross-sectional study among U.S. adults.. We included 2136 non-pregnant participants aged 20 years or older from the National Health and Nutrition Examination Survey 2009-2010. Four major TFAs, including palmitelaidic acid (C16:1n-7t), elaidic acid (C18:1n-9t), vaccenic acid (C18:1n-7t), and linoelaidic acid (C18:2n-6t, 9t), were measured in fasting plasma using gas chromatography/mass spectrometry. Depressive symptoms were assessed using the validated Patient Health Questionnaire-9.. Participants with depressive symptoms had a higher plasma concentration of total TFA compared with those without depressive symptoms (6.6 vs 6.0 μmol/g lipids, P = 0.046). After adjustment for other major risk factors, the odds ratio (OR) of depressive symptoms comparing the highest with lowest tertile of TFAs was 1.44 (95% CI, 0.86-2.39) for total TFAs (P for trend 0.15). For each individual type of TFA, the corresponding OR was 1.78 (1.03-3.07) for elaidic acid (P for trend 0.049), 1.23 (0.76-2.00) for linoelaidic acid (P for trend 0.37), 1.19 (0.75-1.87) for palmitelaidic acid (P for trend 0.46), and 1.20 (0.75-1.94) for vaccenic acid (P for trend 0.43).. The cross-sectional study design limited causal inferences of the findings.. In a nationally representative population, plasma elaidic acid, a major trans fatty acid, was positively associated with depressive symptoms in adults. A positive but non-significant association of depressive symptoms was observed for total TFAs, linolelaidic acid, palmitelaidic acid, and vaccenic acid.

Topics: Adult; Aged; Cross-Sectional Studies; Depression; Fasting; Fatty Acids, Monounsaturated; Female; Gas Chromatography-Mass Spectrometry; Humans; Linoleic Acid; Male; Middle Aged; Nutrition Surveys; Oleic Acids; Patient Health Questionnaire; Risk Factors; United States

The effect of different individual TFA isomers on cardiovascular disease (CVD) has been a limited study, especially for stroke. We aimed to investigate the relationships between four major plasma TFA isomer (elaidic, vaccenic, palmitelaidic and linolelaidic acid) concentrations and the risk of CVD, stroke and non-stroke CVD. A cross-sectional study was conducted, utilising a nationally representative sample of US adults in the National Health and Nutrition Examination Survey. Among the 3504 participants, 304 participants self-reported CVD history. The highest quintile of elaidic acid intake was associated with a 233% higher CVD risk (p = .010). Adjusted for age, gender and race, palmitelaidic acid was associated with a decreased CVD risk, but the effect size was diminished in a subsequent analysis model. For stroke risk, we failed to identify any associations. In addition to elaidic acid, the health effect of palmitelaidic acid should be paid more attention in the future studies.

Topics: Adult; Aged; Aged, 80 and over; Body Mass Index; Cardiovascular Diseases; Cross-Sectional Studies; Diet; Fatty Acids, Monounsaturated; Female; Humans; Isomerism; Linoleic Acid; Male; Middle Aged; Nutrition Surveys; Oleic Acid; Oleic Acids; Risk Factors; Self Report; Trans Fatty Acids; United States; Young Adult

A diet high in trans-fatty acids (TFA) induces insulin resistance in rodent models and primates. However, previous epidemiological studies on the association between TFAs, based primarily on self-reported intake from the diet, and diabetes in humans have yielded conflicting results. Herein we examined the associations of objectively measured plasma TFA concentrations with diabetes in a large population-based study among US adults.. We included 3801 participants aged ≥20 years from the National Health and Nutrition Examination Survey 1999-2000 and 2009-10. Four major TFAs, namely palmitelaidic acid (C16:1 n-7t), elaidic acid (C18:1 n-9t), vaccenic acid (C18:1 n-7t), and linolelaidic acid (C18:2 n-6t, 9t), were measured in fasting plasma using gas chromatography-mass spectrometry. Diabetes was defined by self-reported physician diagnosis, plasma fasting glucose ≥126 mg/dL, or HbA1c ≥6.5%.. After adjustment for other major risk factors, the odds ratios (95% confidence intervals) of diabetes comparing the highest with lowest quintile of plasma TFAs was 2.19 (1.27-3.79) for total TFAs (P. In a nationally representative population, plasma TFAs, in particular elaidic acid, were positively associated with diabetes and biomarkers of glucose metabolism.

Topics: Adult; Blood Glucose; Diabetes Mellitus; Fasting; Fatty Acids, Monounsaturated; Female; Humans; Insulin; Insulin Resistance; Linoleic Acid; Male; Middle Aged; Nutrition Surveys; Oleic Acid; Oleic Acids; Risk Factors; Trans Fatty Acids; United States

Topics: Brassica napus; Chromatography, Gas; Cotyledon; Linoleic Acid; Lipids; Magnetic Resonance Spectroscopy; Oleic Acids; Palmitic Acid; Phosphatidylcholines; Plant Oils; Seeds; Spatio-Temporal Analysis; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Time Factors; Triglycerides

Oxidative stress is a well-known cause of multiple diseases. The nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway plays a central role in cellular antioxidative responses. In this study, we investigated the effects of novel fatty acid metabolite derivatives of linoleic acid generated by the gut lactic acid bacteria Lactobacillus plantarum on the Nrf2-ARE pathway. 10-Oxo-trans-11-octadecenoic acid (KetoC) protected HepG2 cells from cytotoxicity induced by hydrogen peroxide. KetoC also significantly increased cellular Nrf2 protein levels, ARE-dependent transcription, and the gene expression of antioxidative enzymes such as heme oxygenase-1 (HO-1), glutamate-cysteine ligase modifier subunit (GCLM), and. quinone oxidoreductase 1 (NQO1) in HepG2 cells. Additionally, a single oral dose administration of KetoC also increased antioxidative gene expression and protein levels of Nrf2 and HO-1 in mouse organs. Since other fatty acid metabolites and linoleic acid did not affect cellular antioxidative responses, the cytoprotective effect of KetoC may be because of its α,β-unsaturated carbonyl moiety. Collectively, our data suggested that KetoC activated the Nrf2-ARE pathway to enhance cellular antioxidative responses in vitro and in vivo, which further suggests that KetoC may prevent multiple diseases induced by oxidative stress.

Topics: Animals; Cell Survival; Cytoprotection; Hep G2 Cells; Humans; Hydrogen Peroxide; Lactic Acid; Lactobacillus plantarum; Linoleic Acid; Male; Mice; Mice, Inbred ICR; Oleic Acids; Oxidative Stress

Differing amounts of fresh forage and concentrates fed, and level of input contributes to the differences reported in fatty acid (FA) composition of organic and conventionally produced cow milk. In many previous studies designed to investigate this phenomenon, comparisons were made between grazed organic cows and housed conventional cows. In the present study, we have investigated differences between organic and conventional milk produced using year-round pasture grazing, as practiced in New Zealand. The FA composition was determined in milk sampled at morning and evening milking in both spring and autumn. Samples were taken from 45 cows from the Massey University organic herd and compared with 50 cows from the corresponding conventional herd grazed and managed similarly at the same location. Forty-three out of 51 analyzed FA were influenced by season, whereas 28 were different between production systems. In addition, one-half were also different due to time of milking. Levels of linoleic acid and α-linolenic acid were higher in organic milk, whereas conjugated linoleic acid (CLA) and vaccenic acid were higher in conventional milk. The first 3 FA (linoleic acid, α-linolenic acid, and CLA) were more abundant in milk harvested during autumn, and the CLA concentration was also significantly influenced by time of milking. Our results confirm reports that the FA profile is affected by season and time of milking, and we also showed an effect due to the production system, when both sets of cows were kept continuously on pasture, even after taking milking time and seasonal effect into account.

Topics: alpha-Linolenic Acid; Animals; Cattle; Diet; Female; Food, Organic; Lactation; Linoleic Acid; Linoleic Acids, Conjugated; Milk; New Zealand; Oleic Acids; Seasons

The objective of this study was to examine the effects of supplemental feeding of full-fat extruded cottonseed pellets (FFECS) compared with tallow on carcass characteristics, sensory traits, retail display color, and fatty acid profiles, especially CLA isomers in finishing heifers. Twenty-one Angus heifers (450 ± 5 kg) were assigned randomly to 1 of 3 experimental diets: 1) 100% supplemental fat from tallow at 4.1% of ration DM (TAL), 2) a 50:50 ratio of supplemental fat from a combination of tallow at 2.1% and FFECS at 12.8% of ration DM (TAL/ECS), and 3) 100% supplemental fat from FFECS at 25.6% ration DM (ECS). All rations were formulated to contain 7.5% fat on a DM basis. Heifers were individually fed, ad libitum, for 82 d, and BW, G:F, DMI, ADG, and body composition via ultrasound were collected at 3 to 4 wk intervals. After 82 d on feed heifers were slaughtered under federal inspection, and carcass characteristics were measured (at 24 h). The LM was removed for retail display color (1, 3, 6, 10 d), Warner-Bratzler shear force (1, 3, 7, 14, 21 d postmortem aging), sensory analysis (1, 7, 14, 21 d postmortem aging), and fatty acid profile analysis. Subcutaneous fat, including all layers, was removed from the LM for fatty acid profile analysis, and ground beef patties (80:20) were produced with lean from the brisket and fat from the plate for retail color analysis (1, 2, 4, 7 d). Supplemental fat source did not influence feedlot performance for any of the traits measured (P > 0.12) or any carcass traits related to yield, quality, or LM color at the 12th- to 13th-rib interface (P > 0.15). Supplemental fat source did not affect Warner-Bratzler shear force or any sensory traits (P > 0.20), but LM steaks became more tender as postmortem aging time increased up to 14 d (P < 0.01). During retail display of LM steaks and beef patties, the only difference was LM steaks from ECS were darker (lower L* value) than TAL or TAL/ECS steaks (P < 0.02). As display time increased, LM steak and beef patty objective and subjective color deteriorated (P < 0.01). Although feeding FFECS compared with tallow increased linoleic acid (C18:2(n-6)) in both intramuscular and subcutaneous fat (P < 0.04), this did not lead to an increase in total CLA content (P > 0.90). Full-fat extruded cottonseed pellets are interchangeable with tallow in heifer finishing diets without impacting feeding performance, meat quality, shelf life color, or CLA content of adipose sites.

Topics: Animal Feed; Animal Husbandry; Animal Nutritional Physiological Phenomena; Animals; Body Composition; Cattle; Cottonseed Oil; Diet; Fats; Female; Linoleic Acid; Meat; Oleic Acids; Rumen

The present study on Phyllanthus virgatus, known traditionally for its remedial potential, for the first time provides descriptions of the antioxidant and inhibition of α -amylase enzyme activity first by in vitro analyses, followed by a confirmatory in silico study to create a stronger biochemical rationale. Our results illustrated that P. virgatus methanol extract exhibited strong antioxidant and oxidative DNA damage protective activity than other extracts, which was well correlated with its total phenolic content. In addition, P. virgatus methanol extract strongly inhibited the α -amylase activity (IC50 33.20 ± 0.556  μ g/mL), in a noncompetitive manner, than acarbose (IC50 76.88 ± 0.277  μ g/mL), which showed competitive inhibition. Moreover, this extract stimulated the glucose uptake activity in 3T3-L1 cells and also showed a good correlation between antioxidant and α -amylase activities. The molecular docking studies of the major bioactive compounds (9,12-octadecadienoic acid, asarone, 11-octadecenoic acid, and acrylic acid) revealed via GC-MS analysis from this extract mechanistically suggested that the inhibitory property may be due to the synergistic effect of these bioactive compounds. These results provide substantial basis for the future use of P. virgatus methanol extract and its bioactive compound in in vivo system for the treatment and management of diabetes as well as in the related condition of oxidative stress.

Topics: Acrylates; Allylbenzene Derivatives; alpha-Amylases; Anisoles; Antioxidants; Computer Simulation; DNA Damage; Linoleic Acid; Molecular Docking Simulation; Oleic Acids; Oxidative Stress; Phyllanthus; Plant Extracts

Saturated and trans fatty acids have been associated with the risk to develop cardiovascular diseases. However, health-promoting effects are associated with consumption of anhydrous milk fat (AMF) and ruminant trans fatty acids, such as conjugated linoleic acid (CLA) and vaccenic acid (VA) contained in the lipid fraction of milk and dairy products. The purpose of this study was to evaluate the effect of AMF naturally enriched with CLA and VA in spontaneously hypertensive rats (SHR), using sterculic oil to inhibit the conversion of VA into CLA. The administration of AMF to SHR during 7 weeks exerted beneficial effects on cardiovascular risk biomarkers (reduction of insulin, blood lipids, increase of adiponectin). When sterculic oil was included, some parameters were further ameliorated (reduction of insulin, increase of adiponectin). Sterculic oil alone reduced body weight and adiposity, and improved blood pressure, adiponectin and triglyceride levels.

Topics: Adiponectin; Adiposity; Animals; Biomarkers; Blood Pressure; Cardiovascular Diseases; Cyclopropanes; Diet; Dietary Fats; Fatty Acids, Monounsaturated; Hypertension; Insulin; Linoleic Acid; Linoleic Acids, Conjugated; Lipids; Male; Milk; Oleic Acids; Rats; Rats, Inbred SHR; Ruminants; Triglycerides; Weight Loss

Ricinoleic acid (RA; 12-hydroxy-cis-9-18:1) is the main fatty acid component of castor oil. Although a precursor for CLA synthesis in lactic acid bacteria, RA was found previously not to form CLA in ruminal digesta but to have some inhibitory properties. The present study was undertaken to evaluate the potential of RA to modulate ruminal biohydrogenation and methanogenesis. Ruminal digesta from 4 sheep receiving a mixed hay-concentrate diet was incubated in vitro with 0.167 g/L of linoleic acid (LA; cis-9,cis-12-18:2) or with a combination of LA and RA or LA and castor oil (LA, RA, and castor oil added to a final concentration of 0.167 g/L) in the presence and absence of lipase. The CLA rumenic acid (cis-9,trans-11-18:2) accumulated when either RA or castor oil and lipase was present. Vaccenic acid (VA; trans-11-18:1) also accumulated, and a decrease of the rate of production of stearic acid (SA; 18:0) was observed. When LA was incubated with castor oil in the absence of lipase, no effects on biohydrogenation were observed. Ricinoleic acid at 0.02 g/L did not affect growth of Butyrivibrio fibrisolvens but it inhibited growth of Butyrivibrio proteoclasticus. Butyrivibrio proteoclasticus but not B. fibrisolvens metabolized RA to 12-hydroxystearate. Linoleic acid metabolism by B. proteoclasticus appeared to be unaffected by RA addition whereas rumenic acid accumulation increased (P = 0.015 at 12 h) when RA was added. A 28% decrease (P = 0.004) in methane was obtained in 24 h in vitro incubations of diluted buffered ruminal fluid with added 0.2 g RA/L. There was no effect on the total concentration of VFA after 24 h as a result of RA addition, but the molar proportions of acetate and butyrate were decreased (P = 0.041 and P < 0.001, respectively) whereas that of propionate increased (P < 0.001). It was concluded that, at least in vitro, RA or the combination of castor oil and lipase inhibit biohydrogenation, causing the accumulation of rumenic acid and VA, with potential health benefits for ruminant products. The effect appeared to be mediated via an inhibitory effect on the biohydrogenating activity of B. proteoclasticus. An added environmental benefit could be a concomitant decrease in methane emissions. In vivo studies are now required to confirm the potential of these additives.

Topics: Animals; Butyrivibrio; Castor Oil; Diet; Fatty Acids, Volatile; Gastrointestinal Contents; Hydrogenation; Linoleic Acid; Linoleic Acids, Conjugated; Methane; Oleic Acids; Propionibacterium acnes; Ricinoleic Acids; Rumen; Sheep, Domestic; Species Specificity

The present study was designed to investigate the capability of mixed rumen protozoa to synthesize conjugated linoleic acid (CLA) from linoleic (LA) and vaccenic acids (VA). Rumen contents were collected from fistulated cows. The protozoal fraction was separated and washed several times with MB9 buffer and then resuspended in autoclaved rumen fluid. The suspensions were anaerobically incubated up to 18 h at 38.5 degrees C with substrates in the presence (P-AB) or the absence of antibacterial-agents (P-No-AB). Neither P-AB nor P-No-AB suspensions were capable of producing CLA from VA (11t-18:1). Linoleic acid was catabolized by P-No-AB to a greater extent than P-AB. Different isomers of CLA were synthesized by P-AB from LA. The 9c11t-CLA was predominant. Thirty seven percent of the maximum accumulated 9c11t-CLA was found in the P-AB suspension as early as 0.1 h into the incubation period. Accumulation of 10t12c-CLA in P-AB suspension was approximately 10.0 times lower than that of 9c11t-CLA. There were no significant productions of VA, 10t-18:1, and 18:0 in P-AB compared with the control, indicating that rumen protozoa have no ability to biohydrogenate CLA isomers. On the other hand, the concentrations of 10t-18:1, VA, and 18:0 in P-No-AB were greater (P < 0.05) compared with those in P-AB, indicating the role of symbiotic bacteria associated with P-No-AB in biohydrogenating CLA isomers. We concluded that mixed rumen protozoa are capable of synthesizing CLA from LA through isomerization reactions. However, they are incapable of metabolizing CLA further. They are also incapable of vaccenic acid biohydrogenation and/or desaturation.

Topics: Animals; Cattle; Eukaryota; Female; Hydrogenation; Isomerism; Linoleic Acid; Linoleic Acids, Conjugated; Oleic Acids; Rumen

It has been argued that a reduction in the Western diet of anti-inflammatory unsaturated lipids, such as n-3 polyunsaturated fatty acids, has contributed to the increase in the frequency and severity of allergic diseases.. We investigated whether feeding milk fat enriched in conjugated linoleic acid and vaccenic acids (VAs) ('enriched' milk fat), produced by supplementing the diet of pasture-fed cows with fish and sunflower oil, will prevent development of allergic airway responses.. C57BL/6 mice were fed a control diet containing soybean oil and diets supplemented with milk lipids. They were sensitized by intraperitoneal injection of ovalbumin (OVA) on days 14 and 28, and challenged intranasally with OVA on day 42. Bronchoalveolar lavage fluid, lung tissues and serum samples were collected 6 days after the intranasal challenge.. Feeding of enriched milk fat led to marked suppression of airway inflammation as evidenced by reductions in eosinophilia and lymphocytosis in the airways, compared with feeding of normal milk fat and control diet. Enriched milk fat significantly reduced circulating allergen-specific IgE and IgG1 levels, together with reductions in bronchoalveolar lavage fluid of IL-5 and CCL11. Treatment significantly inhibited changes in the airway including airway epithelial cell hypertrophy, goblet cell metaplasia and mucus hypersecretion. The two major components of enriched milk fat, cis-9, trans-11 conjugated linoleic acid and VA, inhibited airway inflammation when fed together to mice, whereas alone they were not effective.. Milk fat enriched in conjugated linoleic and VAs suppresses inflammation and changes to the airways in an animal model of allergic airway disease.

Topics: Allergens; Animals; Cell Survival; Chemokine CCL11; Eosinophils; Fats; Female; Hypersensitivity; Immunoglobulins; Interleukin-5; Linoleic Acid; Lung Diseases, Obstructive; Male; Mice; Mice, Inbred C57BL; Milk; Oleic Acids

Knowledge of the fatty acid profile of microbial lipids is of great nutritional importance to the animals and, subsequently, their products. This study was conducted to examine the fatty acid profiles of mixed rumen bacteria and protozoa. Bacterial and protozoal cells were isolated by differential centrifugation of rumen contents. The main fatty acids were palmitic (16:0) and stearic (18:0) in both the bacterial and protozoal fractions. Palmitic acid was 74% greater in the protozoal fatty acids than in the bacterial fatty acids, whereas bacteria had 2.25-times greater stearic acid (18:0) proportions compared with protozoa. The total odd-chain plus branched-chain fatty acids were 16.5% of bacterial fatty acids and 11.0% of protozoal fatty acids. The anteiso-17:0 proportions in bacterial and protozoal fatty acids were 1.4 and 2.9%, respectively. The most abundant trans-18:1 isomer, vaccenic acid (18:1 trans-11), was 6.6% of total fatty acids in protozoa and 2.0% of total fatty acids in bacteria. The cis-9, trans-11 CLA was 8.6-times greater in the protozoal fraction (1.32% of total fatty acids) than in the bacterial fraction (0.15%). These results suggest that the presence of protozoa in the rumen may increase the supply of CLA and other unsaturated fatty acids for lower gut absorption by ruminants.

Topics: Animals; Bacteria; Cattle; Eukaryota; Fatty Acids; Female; Linoleic Acid; Oleic Acids; Rumen

The objective of this study was to evaluate the effect of soluble carbohydrates (glucose, cellobiose), pH (6.0, 6.5, 7.0), and rumen microbial growth factors (VFA, vitamins) on biohydrogenation of linoleic acid (LA) by mixed rumen fungi. Addition of glucose or cellobiose to culture media slowed the rate of biohydrogenation;only 35-40% of LA was converted to conjugated linoleic acid (CLA) or vaccenic acid (VA) within 24 h of incubation, whereas in the control treatment, 100% of LA was converted within 24 h. Addition of VFA or vitamins did not affect biohydrogenation activity or CLA production. Culturing rumen fungi at pH 6.0 slowed biohydrogenation compared with pH 6.5 or 7.0. CLA production was reduced by pH 6.0 compared with control (pH 6.5), but was higher with pH 7.0. Biohydrogenation of LA to VA was complete within 72 h at pH 6.0, 24 h at pH 6.5, and 48 h at pH 7.0. It is concluded that optimum conditions for biohydrogenation of LA and for CLA production by rumen fungi were provided without addition of soluble carbohydrates, VFA or vitamins to the culture medium; optimum pH was 6.5 for biohydrogenation and 7.0 for CLA production.

Topics: Animals; Cattle; Cellobiose; Fatty Acids, Volatile; Fungi; Glucose; Hydrogen-Ion Concentration; Hydrogenation; Linoleic Acid; Linoleic Acids, Conjugated; Oleic Acids; Rumen; Time Factors; Vitamins

To investigate biohydrogenation of linoleic acid by rumen fungi compared with rumen bacteria, and to identify the fungus with the fastest biohydrogenation rate.. Biohydrogenation of linoleic acid by mixed rumen fungi and mixed rumen bacteria were compared in vitro. With mixed rumen bacteria, all biohydrogenation reactions were finished within 100 min of incubation and the end product of biohydrogenation was stearic acid. With mixed rumen fungi, biohydrogenation proceeded more slowly over a 24-h period. Conjugated linoleic acid (CLA; cis-9, trans-11 C18 : 2) was an intermediate product, and vaccenic acid (VA; trans-11 C18 : 1) was the end product of biohydrogenation. Fourteen pure fungal isolates were tested for biohydrogenation rate. DNA sequencing showed that the isolate with the fastest rate belonged to the Orpinomyces genus.. It is concluded that rumen fungi have the ability to biohydrogenate linoleic acid, but biohydrogenation is slower in rumen fungi than in rumen bacteria. The end product of fungal biohydrogenation is VA, as for group A rumen bacteria. Orpinomyces is the most active biohydrogenating fungus.. This is the first study to demonstrate that rumen fungi can biohydrogenate fatty acids. Fungi could influence CLA content of ruminant products.

Topics: Animals; Bacteria; Cattle; Food Microbiology; Fungi; Hydrogenation; Linoleic Acid; Linoleic Acids, Conjugated; Male; Neocallimastigales; Oleic Acids; Rumen

To increase ruminal outflow of trans-vaccenic acid (t-VA), a new strain of Butyrivibrio fibrisolvens (MDT-10) was isolated that has a great ability to hydrogenate linoleic acid (LA) to t-VA. When strain MDT-10 was added to the batch cultures of mixed ruminal microbes (1% of the total number of viable ruminal bacteria), LA conversion to t-VA increased greatly; after 3 h, t-VA levels were > 4-fold higher than the control. By 10 h, all of the t-VA was hydrogenated to stearic acid. However, when a new strain of Bifidobacterium adolescentis (HF-11), which has a high capacity for incorporation of t-VA, was added in conjunction with MDT-10 (1% of the total number of ruminal bacteria), t-VA levels after 10 h were 6 times higher than with MDT-10 alone. These results suggest that t-VA produced by MDT-10 was incorporated into HF-11 cells, resulting in protection of t-VA from t-VA-hydrogenating microbes. Similar results were obtained in a continuous culture of mixed ruminal microbes in which addition of HF-11 simultaneously with MDT-10 increased the amount of t-VA in the effluent 2.5-fold. Both MDT-10 and HF-11 appeared to grow readily in the presence of mixed ruminal microbes. Sixty-two percent of t-VA incorporated by HF-11 was present in the free form, whereas 19, 15, and 3%, respectively, were incorporated into monoacylglycerol, glycerophospholipid, and diacylglycerol fractions. Because these lipids can be digested in the small intestine, it is likely that most t-VA in HF-11 cells is absorbed. Thus, introduction of MDT-10 and HF-11 simultaneously to the rumen might increase the amount of t-VA absorbed and might consequently increase the conversion of t-VA to conjugated linoleic acid in tissue.

Topics: Animals; Bifidobacterium; Butyrivibrio; Carboxylic Acids; Escherichia coli; Fatty Acids; Feces; Goats; Humans; Hydrogenation; Lactobacillus; Linoleic Acid; Oleic Acids; Rumen; Stearic Acids

Conjugated linoleic acids (CLA) have been shown to improve human health. They are derived from the microbial conversion of dietary linoleic acid (cis-9,cis-12-18 : 2 (LA)) in the rumen. An investigation was undertaken to determine the role of ruminal ciliate protozoa v. bacteria in the formation of CLA and its precursor in animal tissues, vaccenic acid (trans-11-18 : 1 (VA)). Mixed protozoa from the sheep rumen contained at least two to three times more unsaturated fatty acids, including CLA and VA, than bacteria. Different species had different composition, with larger fibrolytic species such as Epidinium ecaudatum caudatum containing more than ten times more CLA and VA than some small species, including Entodinium nanellum. In incubations with ruminal microbial fractions (bacterial fraction (BAC), protozoal fraction (PRO)), LA metabolism was very similar in strained ruminal fluid (SRF) and in the BAC, while the PRO had LA-metabolising activity an order of magnitude lower. Using PCR-based methods, no genes homologous to fatty acid desaturase genes were found in cDNA libraries from ruminal protozoa. The absence of an alternative route of VA/CLA formation via desaturation of stearate was confirmed by incubations of SRF, BAC or PRO with [14C]stearate. Thus, although protozoa are rich in CLA and VA, they appear to lack the ability to form these two fatty acids from LA or stearate. The most likely explanation is that protozoa preferentially incorporate CLA and VA formed by bacteria. The implication of the present findings is that the flow of unsaturated fatty acids, including CLA and VA, from the rumen could depend on the flow of protozoa rather than bacteria.

Topics: Animals; Bacteria; Eukaryota; Gastrointestinal Contents; Hydrogenation; Linoleic Acid; Linoleic Acids, Conjugated; Male; Oleic Acids; Rumen; Sheep; Stearic Acids

Previous research found that docosahexaenoic acid (C22:6n-3) was a component of fish oil that promotes trans-C18:1 accumulation in ruminal cultures when incubated with linoleic acid. The objective of this study was to determine if eicosatrienoic acid (C20:3n-3) and docosatrienoic acid (C22:3n-3), n-3 fatty acids in fish oil, promote accumulation of trans-C18:1, vaccenic acid (VA) in particular, using cultures of mixed ruminal microorganisms. Treatments consisted of control, control plus 5 mg of C20:3n-3 (ETA), control plus 5 mg of C22:3n-3 (DTA), control plus 15 mg of linoleic acid (LA), control plus 5 mg of C20:3n-3 and 15 mg of linoleic acid (ETALA), and control plus 5 mg of C22:3n-3 and 15 mg of linoleic acid (DTALA). Treatments were incubated in triplicate in 125-mL flasks, and 5 mL of culture contents was taken at 0 and 24 h for fatty acid analysis by gas-liquid chromatography. After 24 h of incubation, the concentrations of trans-C18:1 (0.87, 0.88, and 0.99 mg/culture), and VA (0.52, 0.56, and 0.62 mg/culture) were similar for the control, ETA, and DTA cultures, respectively. The concentrations of trans-C18:1 (5.51, 5.41, and 5.36 mg/culture), and VA (4.78, 4.62, and 4.59 mg/culture) were also similar between LA, ETALA, and DTALA cultures, respectively. These data suggest that C20:3n-3 and C22:3n-3 are not the active components in fish oil that promote VA accumulation when incubated with linoleic acid.

Topics: Animals; Arachidonic Acids; Cattle; Erucic Acids; Fatty Acids; Fatty Acids, Omega-3; Female; Linoleic Acid; Oleic Acids; Rumen

Two experiments were undertaken to evaluate the effect on milk and cheese fatty acid composition of feeding different fresh forages to dairy sheep both in winter (experiment 1, growing stage of the forages, early lactating ewes) and in spring (experiment 2, reproduction stage of the forages, midlactating ewes). Four forage species were compared: annual ryegrass (RY, Lolium rigidum Gaudin), sulla (SU, Hedysarum coronarium L.), burr medic (BM, Medicago polymorpha L.), and a daisy forb (CH, Chrysanthemum coronarium L.). The forages were cut twice daily and offered ad libitum to 4 replicate groups of Sarda dairy sheep (groups RY, SU, BM, and CH). The CH forage was particularly rich in linoleic acid in both periods, whereas BM and SU forages were rich in linolenic acid in winter and spring, respectively. Milk fatty acid composition was affected by the forage in both experiments. Milk conjugated linoleic acid and vaccenic acid contents were higher in CH and BM groups (winter) and CH group (spring) than in the other groups. No differences were observed when comparing fatty acid profile between milk, 1-d-old cheeses, and 60-d-old cheeses within experimental groups, suggesting that the fatty acid recovery rates during cheese making and ripening were not affected by the feeding regimens. After stepwise discriminant analyses of the pooled data, the milks and cheeses sourced in the different feeding regimens differed among them. Based on these results, we conclude that it is possible to manipulate the fatty acid profile of sheep dairy produce to maximize the content of beneficial fatty acids by the use of appropriate fresh forage-based regimens.

Topics: alpha-Linolenic Acid; Animals; Cheese; Chrysanthemum; Diet; Fabaceae; Fatty Acids; Female; Food Handling; Lactation; Linoleic Acid; Linoleic Acids, Conjugated; Lolium; Medicago; Mediterranean Region; Milk; Oleic Acids; Seasons; Sheep

The pattern of biohydrogenation of fatty acids from fresh alfalfa or alfalfa hay supplemented with 3 concentrations (0, 4, and 8%) of sucrose was studied at a constant pH of 6.2. Four continuous culture fermenters were used in a 4 x 4 Latin square design to test the hypothesis that fresh forage would increase flow of vaccenic acid (VA) from the fermenters compared with the same forage in hay form and that this difference would be diminished by adding sucrose to the hay diet by changing the bacterial community profile. Effluent was collected from each of the 4 fermenters during the last 3 d of each 10-d period. Nutrient digestibility, volatile fatty acids (VFA), and fatty acids in the effluent were measured. Flow of bacterial organic matter (OM) and neutral and acid detergent fiber and acid detergent fiber digestibilities were higher for fresh alfalfa than alfalfa hay. True OM digestibility of alfalfa hay tended to linearly decrease with sucrose supplementation. However, microbial efficiency and flow of bacterial OM (g/d) linearly increased with sucrose addition. There was no change in total VFA concentration; however, proportion of acetate linearly decreased and proportion of butyrate linearly increased with sucrose addition. Fresh alfalfa increased total biohydrogenation of fatty acids compared with than hay. Vaccenic acid flow (mg/d) was much higher for fresh alfalfa compared with alfalfa hay (216 vs. 41) and VA was the predominant 18:1 isomer, followed by trans-13 18:1; however, sucrose had no effect on VA flow. The percentage of VA (of total trans-18:1) was not different between fresh alfalfa and hay, whereas percentage of trans-10 18:1 was much lower for fresh alfalfa. Therefore, the ratio of VA to trans-10 18:1 was higher for fresh alfalfa. Flow of trans-12 18:1 linearly increased, whereas flows of cis-12 and total cis-18:1 had quadratic responses to sucrose supplementation. Total biohydrogenation and biohydrogenation of linoleic and linolenic acids linearly decreased with sucrose; however, there was no effect of sucrose on total trans fatty acid flow. Sucrose may be more detrimental to the last step of biohydrogenation of VA. The effects of sucrose on biohydrogenation and concentration of VFA may have been caused by a shift in microbial population by mechanisms that are independent of pH.

Topics: alpha-Linolenic Acid; Animals; Bacteria; Dietary Fiber; Digestion; DNA, Bacterial; Fatty Acids; Fatty Acids, Volatile; Fermentation; Hydrogen-Ion Concentration; Hydrogenation; Linoleic Acid; Medicago sativa; Oleic Acids; Phylogeny; Polymorphism, Genetic; Rumen; Sucrose

Previous studies found that feeding dairy cows a blend of fish and soybean oils enhanced milk vaccenic acid (VA) and conjugated linoleic acid (CLA) concentrations more than when the oils were fed separately. In these studies, the authors concluded that a component in fish oil was stimulating ruminal VA production from other sources of unsaturated fatty acids; however, that component was not identified. The objective of this study was to determine whether docosahexaenoic acid (DHA), an omega-3 fatty acid (FA) in fish oil, is the active component that promotes trans-C18:1 FA, VA in particular, accumulation using cultures of mixed ruminal microorganisms. Treatments consisted of control, control plus 5 mg of DHA (DH), control plus 30 mg of soybean oil (SBO), and control plus 5 mg of DHA and 30 mg of SBO (DHSBO). Treatments were incubated in triplicate in 125-mL flasks, and 5 mL of culture contents was taken at 0 and 24 h for fatty acid analysis by gas-liquid chromatography. After 24 h of incubation, the level of trans-C18:1 FA (14.1 and 11.7 mg/culture) and VA (13.0 and 10.2 mg/culture) increased more with added DHA than with added SBO, respectively. Combining DHA and SBO yielded higher quantities of trans-C18:1 FA (21.3 mg/culture) and VA (19.8 mg/culture) in the cultures than either fat source alone. These data suggest that DHA is the component in fish oil that promotes VA accumulation when incubated with linoleic acid.

Topics: Animals; Bacteria; Cattle; Diet; Docosahexaenoic Acids; Linoleic Acid; Oleic Acids; Rumen; Soybean Oil

The objective of this experiment was to examine the effect of feeding fish oil (FO) along with fat sources that varied in their fatty acid compositions (high stearic, high oleic, high linoleic, or high linolenic acids) to determine which combination would lead to maximum conjugated linoleic acid (cis-9,trans-11 CLA) and transvaccenic acid (TVA) concentrations in milk fat. Twelve Holstein cows (eight multiparous and four primiparous cows) at 73 (+/- 32) DIM were used in a 4 x 4 Latin square with 4-wk periods. Treatment diets were 1) 1% FO plus 2% fat source high in stearic acid (HS), 2) 1% FO plus 2% fat from high oleic acid sunflower seeds (HO), 3) 1% FO plus 2% fat from high linoleic acid sunflower seeds (HLO), and 4) 1% FO plus 2% fat from flax seeds (high linolenic; HLN). Diets formulated to contain 18% crude protein were composed of 50% (dry basis) concentrate mix, 25% corn silage, 12.5% alfalfa haylage, and 12.5% alfalfa hay. Milk production (35.8, 36.3, 34.9, and 35.0 kg/d for diets 1 to 4) was similar for all diets. Milk fat percentages (3.14, 2.81, 2.66, and 3.08) and yields (1.13, 1.02, 0.93, and 1.08 kg/d) for diets 1 to 4 were lowest for HLO. Milk protein percentages (3.04, 3.03, 3.10, and 3.08) and dry matter intake (DMI) (25.8, 26.0, 26.2, and 26.2 kg/d) for diets 1 to 4 were similar for all diets. Milk cis-9,trans-11 CLA concentrations (0.70, 1.04, 1.70, and 1.06 g/100 g fatty acids) for diet 1 to 4 and yields (7.7, 10.7, 15.8, and 11.3 g/d) for diets 1 to 4 were greatest with HLO and were least with HS. Milk cis-9,trans-11 CLA concentrations and yields were similar for cows fed the HO and the HLN diets. Similar to milk cis-9,trans-11 CLA, milk TVA concentration (1.64, 2.49, 3.74, and 2.41 g/100 g fatty acids) for diets 1 to 4 was greatest with the HLO diet and least with the HS diet. Feeding a high linoleic acid fat source with fish oil most effectively increased concentrations and yields of milk cis-9,trans-11 CLA and TVA.

Topics: alpha-Linolenic Acid; Animal Nutritional Physiological Phenomena; Animals; Cattle; Diet; Dietary Fats; Dietary Proteins; Fatty Acids; Female; Fish Oils; Helianthus; Lactation; Linoleic Acid; Lipids; Medicago sativa; Milk; Oleic Acid; Oleic Acids; Seeds; Silage; Stearic Acids; Zea mays

Two experiments were run concurrently to determine the effect of fresh forage consumption on the production and proportions of plasma and milk fat vaccenic acid (VA), conjugated linoleic acid (CLA), and linolenic acid in diary cattle. In experiment 1, the cows consumed 50, 65, and 80% of their feed intake as pasture with the remainder of intake as a barley-based concentrate. The proportion of VA in milk fatty acids increased 12% when pasture intake increased from 50 to 65% of total dry matter intake and VA, CLA, and linolenic acid proportions increased 26, 18, and 27%, respectively, as pasture increased from 65 to 80% of dietary intake. In experiment 2, fresh forage was compared to conserved hay (cut from the same pasture the previous summer) to determine the effect on plasma and milk fat VA, CLA, and linolenic acid. Also, the effect of crushed solin seed (a flax cultivar that is high in linoleic acid) supplementation to the fresh forage diet was determined. Fresh forage compared to conserved hay in the diet, increased the proportion of CLA in the plasma very low density lipoproteins (VLDL) fraction by 71% but had no effect on linolenic acid. Supplementation of the fresh forage diet with a linoleic acid source increased VA and CLA in the plasma VLDL fraction 25 and 58% and slightly decreased the proportion of linolenic acid. Fresh forage, compared to conserved hay, increased milk fat VA and CLA proportions by 22 and 15%. Supplementing the fresh forage diet with linoleic acid from crushed solin seed further increased milk fat VA and CLA proportions 41 and 25%. Solin supplementation in a lactation diet is a superior method to increase CLA levels in milk fat than feeding fresh forage alone.

Topics: alpha-Linolenic Acid; Animals; Cattle; Diet; Fats; Fatty Acids; Female; Flax; Linoleic Acid; Lipoproteins, VLDL; Milk; Oleic Acids; Rumen

Cis 9, trans 11 (c 9, t11)-18:2 and trans 10, cis 12 (t10, c12)-18:2 are the major conjugated linoleic acid (CLA) isomers in dietary supplements which reduce milk fat content in nursing women. The present study evaluated the effects of each CLA isomer or vaccenic acid on body composition and tissue fatty acids during lactation in mice. Dams were fed 30 g rapeseed oil (control)/kg diet or 20 g control plus 10 g 18:0, trans 11-18:1 (t11-18:1), c 9, t11-18:2, or t10, c12-18:2. Dietary t10, c12-18:2 reduced food intake by 18 % and carcass fat weight of the dams by 49 % compared with the other treatments. Milk fat percentage ranked by treatment was 18:0>t11-18:1=c 9, t11-18:2>t10, c12-18:2. The sum of saturated 12:0 to 16:0 in milk fat was lower when c 9, t11-18:2 was fed compared with the control, 18:0, or t11-18:1 treatments. Dietary t10, c12-18:2 caused further reductions in milk fat 12:0 to 16:0. The proportion of CLA isomers was 3-fold greater in milk fat than in the carcasses of the dams. The pups nursing from the dams fed t10, c12-18:2 had the lowest body weights and carcass fat, protein, and ash contents. Nursing from the dams fed c 9, t11-18:2 also resulted in lower carcass fat compared with the 18:0 or t11-18:1 treatments. The ratios of cis 9-16:1:16:0 or cis 9-18:1:18:0, proxies for Delta(9)-desaturase activity, were markedly lower in the carcasses of the dams and pups fed t10, c12-18:2. The ratio of 20:4n-6:18 : 2n-6, a proxy for Delta(6)- and Delta(5)-desaturase and elongase activity, in the liver of the dams and pups fed t10, c12-18:2 also was lower. Dietary t11-18:1 enhanced the content of c 9, t11-18:2 in milk fat and carcasses. As in previous studies, the reduction in food intake by t10, c12-18:2 could not entirely account for the marked decrease in carcass fat content and milk fat concentration. T10, c12-18:2 probably had a negative effect on Delta(9)-desaturase and mammary de novo fatty acid synthesis. Although these effects need to be confirmed in lactating women, the results suggest that the consumption of supplements containing t10, c12-18:2 should be avoided during the nursing period.

Topics: Animals; Animals, Suckling; Blood Glucose; Body Composition; Body Weight; Dietary Supplements; Eating; Fatty Acids; Female; Growth; Lactation; Linoleic Acid; Lipids; Liver; Mice; Mice, Inbred Strains; Milk; Oleic Acids

Vaccenic acid (11-trans octadecenoic acid; VA), a major trans fatty acid in the fat of ruminants, is produced in the rumen and converted in tissues to rumenic acid (9-cis, 11-trans octadecenoic acid; RA), an isomer of conjugated linoleic acid, by Delta(9)-desaturase. There are indications that this conversion also occurs in humans.. The aim of this controlled intervention was to study the conversion of VA to RA in humans after consumption of diets with increasing amounts of VA.. Thirty healthy subjects consumed a baseline diet rich in oleic acid for 2 wk. The subjects were then divided into 3 groups (n = 10 per group) and provided a diet containing 1.5, 3.0, or 4.5 g VA/d for 9 d. All diets contained equal amounts of macronutrients and differed only in their fatty acid compositions. The fats were mixed into conventional foods, and nearly all food was provided during the study.. The proportion of VA in serum total fatty acids increased 94%, 307%, and 620% above baseline with the 1.5-, 3.0-, and 4.5-g diets, respectively. This was associated with a linear increase in the proportion of RA. The conversion rate was 19% on average, with significant interindividual differences with all 3 intakes of VA. The urinary excretion of 8-iso-prostaglandin F(2alpha) increased in all groups (P < 0.001).. The results quantify the desaturation of VA to RA in humans. Conversion is likely to contribute significantly to the amount of RA available to the body, and dietary intakes of VA should thus be taken into account when predicting RA status.

Topics: Adult; Animals; Diet; Dietary Fats; Dinoprost; F2-Isoprostanes; Fatty Acids; Female; Humans; Kinetics; Linoleic Acid; Lipids; Lipoproteins, VLDL; Male; Oleic Acids; Rumen; Stearic Acids; Triglycerides

Four fistulated primiparous cows (two Holstein and two Brown Swiss) averaging 102 DIM were used in a 4 x 4 Latin square with 3-wk periods to determine the effect of feeding fish oil, extruded soybeans, or their combination on fatty acid profiles of milk and rumen digesta. Experimental diets consisted of: 1) control diet; 2) a diet with 2% (DM basis) added fat from menhaden fish oil; 3) a diet with 2% added fat from extruded soybeans; and 4) a diet with 1% added fat from fish oil and 1% fat from extruded soybeans. All diets consisted of 25% corn silage, 25% alfalfa hay, and 50% concentrate. Milk yields (28.6, 29.7, 29.2, and 28.1 kg/d for control, fish oil, extruded soybeans, and combination diets, respectively) were similar for all fat supplements and control. Milk fat and protein percentages (3.49, 3.08; 3.25, 2.96; 3.47, 3.01; 3.48, 2.99 for diets 1, 2, 3, and 4, respectively) were not affected by fat supplements compared with control. Dry matter intake (23.0, 21.6, 22.7, and 21.6 kg/d) was reduced when diets containing fish oil were fed. Concentrations of conjugated linoleic acid [CLA; cis-9, trans-11 CLA, 0.40, 0.88, 0.87, and 0.80 g/100 g fatty acids (FA)] and transvaccenic acid (TVA, 1.02, 2.34, 2.41, and 2.06 g/100 g of FA) were increased in milk fat by all fat supplements, with no differences in milk CLA and TVA observed among fat supplements. As with milk fat, proportions of ruminal CLA (0.09, 0.26, 0.18, and 0.21 g/100 g of FA) and TVA (2.61, 4.56, 4.61, and 4.39 g/100 g of FA) increased with fat supplements. The effects of fat supplements on ruminal TVA and CLA concentrations were also reflected in rumen FA-salts, free fatty acids, and neutral lipids. The higher TVA to CLA ratio in the rumen compared with milk indicated that fat supplements increased milk CLA concentration mainly by increasing ruminal production of TVA, which also implied the significant role that mammary delta-9 desaturase plays in milk CLA concentrations.

Topics: Animals; Cattle; Diet; Digestion; Docosahexaenoic Acids; Eating; Eicosapentaenoic Acid; Fatty Acids; Female; Fish Oils; Glycine max; Linoleic Acid; Lipids; Medicago sativa; Milk; Oleic Acids; Rumen; Silage; Zea mays

Twelve multiparous Holstein cows averaging 65 (33 to 122) DIM were used in a 4 x 4 Latin square for 4-wk periods to determine whether feeding fish oil as fish meal would stimulate increased amounts of milk conjugated linoleic acid (cis-9, trans-11 C18:2; CLA) and transvaccenic acid (trans-11 C18:1; TVA) when the cows were fed extruded soybeans to supply additional linoleic acid. Treatment diets were 1) control; 2) 0.5% fish oil from fish meal; 3) 2.5% soybean oil from extruded soybeans; and 4) 0.5% fish oil from fish meal and 2% soybean oil from extruded soybeans. Diets were formulated to contain 18% crude protein and were composed (dry basis) of 50% concentrate mix, 25% corn silage, and 25% alfalfa hay. Intake of DM was not affected by diet. Milk production was increased by diets 2, 3, and 4 compared with diet 1 (control). Milk fat and milk protein percentages decreased with diets 3 and 4. Milk fat yield was not affected by treatments, but yield of milk protein was increased with supplemental fish meal and extruded soybeans or their blend. When diets 2, 3, or 4 were fed, concentrations of cis-9, trans-11 CLA in milk fat increased by 0.4-, 1.4-, and 3.2-fold, and TVA concentrations in milk fat increased by 0.4-, 1.8-, and 3.5-fold compared with the control milk fat. Increases in TVA and cis-9, trans-11 CLA were 91 to 109% greater when a blend of fish meal and extruded soybeans was fed than the additive effect of fish meal and extruded soybeans. This suggested that fish oil increased the production of CLA and TVA from other dietary sources of linoleic acid such as extruded soybeans.

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Cattle; Energy Intake; Fats; Female; Fish Oils; Fish Products; Glycine max; Lactation; Linoleic Acid; Milk; Milk Proteins; Oleic Acids

The objective of this study was to determine the forage:concentrate ratio that would provide the greatest duodenal flow of unsaturated fatty acids in ewes supplemented with soybean oil and to determine how diets differing in forage content affect flow of conjugated linoleic acid (CLA) and trans-vaccenic acid (18:1(trans-11)). Five mature ewes (66.5 +/- 12.8 kg) fitted with ruminal and duodenal cannulas were used in a 5 x 5 Latin square experiment. Diets were isonitrogenous and included bromegrass hay, cracked corn, corn gluten meal, urea, and limestone. Dietary fat was adjusted to 6% with soybean oil. Five ratios of forage:concentrate (18.4:81.6, 32.2:67.8, 45.8:54.2, 59.4:40.6, and 72.9:27.1) were fed at 1.3% of BW daily in equal allotments at 0630 and 1830. After 14 d, Cr2O3 (2.5 g) was dosed at each feeding for 7 d and ruminal, duodenal, and fecal collections were taken for the next 3 d. Duodenal flow of 18:0 increased linearly (P < 0.01) with dietary forage. Duodenal flow of 18:1(cis-9) and 18:2(cis-9,12) decreased (P < 0.001) but duodenal flow of 18:3(cis-9,12,15) increased (P < 0.01) with increased dietary forage. Biohydrogenation of dietary unsaturated fatty acids increased (P < 0.001) as dietary forage increased, which was concomitant with increased ruminal pH. Duodenal flow of 18:2(cis-9,trans-11) increased linearly (P < 0.01) with increased dietary forage but increased abruptly when forage was fed at 45.8%. Duodenal flow of the trans-10, cis-12 and cis-10, cis-12 CLA isomers decreased as dietary forage increased, but flow tended to increase on the highest-forage diet, resulting in both linear (P < 0.01) and quadratic (P < 0.01) effects. Duodenal flow of 18:1(trans-11) decreased from 8.28 g/d on the 18.4% forage diet to 5.47 g/d on the 59.4% forage diet then increased to 7.29 g/d on the highest-forage diet (quadratic, P < 0.1). Duodenal flow of 18:1(trans-11) was 27- to 69-fold greater than flow of CLA. We conclude that when ewes were fed a 6% crude fat diet duodenal flows of dietary fatty acids changed incrementally as dietary forage was increased, whereas changes in flows of CLA isomers seemed to be more abrupt. Biohydrogenation changes were gradual with diet, suggesting a gradual shift in ruminal microbial populations with increasing forage. Finally, the highest-concentrate diet supported the greatest duodenal flows of dietary unsaturated fatty acids, as well as the highest flow of 18:1(trans-11).

Topics: Animal Feed; Animals; Diet; Dietary Fats; Digestion; Duodenum; Fatty Acids; Female; Gastrointestinal Motility; Linoleic Acid; Oleic Acids; Rumen; Sheep

The objective of this report was to determine whether vaccenic acid (t11-18:1) is converted efficiently to conjugated linoleic acid (c9,t11-18:2, CLA) in rats via the delta 9-desaturase reaction and, if so, whether vaccenic acid could substitute for CLA as an anticancer agent. In Study 1, rats were fed 1%, 2%, or 3% vaccenic acid in their diet, and tissue levels of CLA and CLA metabolites were determined in liver and mammary gland. In general, concentrations of CLA and CLA metabolites increased proportionately with an increase in vaccenic acid intake, at least up to the 2% dose level. Beyond this dose, there was clearly a plateauing effect. Thus vaccenic acid concentration increased from an undetectable level in the control to 78.5 nmol/mg lipid in the liver of rats fed a 2% vaccenic acid diet. This was accompanied by an increase in CLA from 2.3 to 33.6 nmol/mg lipid. These changes were also mirrored in the mammary gland, where increases in vaccenic acid (from 27.5 to 163.2 nmol/mg lipid) and CLA (from 17.8 to 108.9 nmol/mg lipid) were similarly observed. Vaccenic acid at 2% produced a CLA concentration in the mammary gland that was historically associated with a positive response in tumor inhibition based on our past experience. This provided the basis for selecting 2% vaccenic acid in Study 2, which was designed to evaluate its efficacy in blocking the development of premalignant lesions in the rat mammary gland. In this experiment, formation of histologically identifiable pathology due to intraductal proliferation of terminal end bud cells of mammary epithelium was used as the end point of analysis at 6 wk after carcinogen administration. Treatment with vaccenic acid reduced the total number of these premalignant lesions by approximately 50%. We hypothesize that the anticancer response to vaccenic acid is likely to be mediated by its endogenous conversion to CLA via delta 9-desaturase.

Topics: 8,11,14-Eicosatrienoic Acid; Animals; Arachidonic Acid; Diet; Epithelium; Female; gamma-Linolenic Acid; Linoleic Acid; Liver; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Oleic Acids; Precancerous Conditions; Rats; Rats, Sprague-Dawley

The incorporation of [14C]elaidic acid (trans18:1(n-9)) in phosphatidylcholine and phosphatidylethanolamine molecular species in isolated rat liver cells has been studied, and the results compared with the incorporation, previously published (B. Woldseth et al. Biochim Biophys Acta 1993; 1167: 296-302), of [14C]palmitic acid (16:0) and [14C]stearic acid (18:0) and with that of [14C]oleic acid (cis18:1(n-9)). The pattern of incorporation in phospholipid molecular species is similar to that of [14C]stearic acid and different from that of [14C]palmitic acid. In phosphatidylcholine [14C]trans18:1-18:2 and [14C]trans18:1-20:4 were the most abundant species, and in phosphatidylethanolamine [14C]trans18:1-20:4 was the predominant species. With increasing concentration of [14C]elaidic acid increasing amounts of [14C]trans18:1-[14C]trans18:1 were found. The total incorporation in phospholipids was less than that of [14C]stearic acid, but more than that of [14C]palmitic acid. The distribution in percent of [14C]elaidic acid in phospholipid classes was 8.8% in phosphatidylinositol, 1.8% in phosphatidylserine, 59.1% in phosphatidylcholine and 30.3% in phosphatidylethanolamine with 0.1 mmol l-1 substrate concentration. More [14C]elaidic acid than [14C]palmitic acid or [14C]stearic acid was oxidized. The incorporation in phospholipids of [14C]elaidic acid was very different from that of [14C]oleic acid. The main species with [14C]oleic acid were 16:0-[14C]cis18:1 in phosphatidylcholine, and [14C]cis18:1-20:4 in phosphatidylethanolamine. In some experiments [14C]18:2(n-6) was incubated together with unlabelled elaidic or unlabelled trans-vaccenic acid (trans18:1(n-7)). In these experiments, more trans18:1-18:2 was formed from elaidic acid than from trans-vaccenic acid, especially in phosphatidylethanolamine.

Topics: Animals; Carbon Radioisotopes; Chromatography, Gas; Esterification; Fatty Acids, Monounsaturated; Linoleic Acid; Liver; Male; Oleic Acid; Oleic Acids; Oxidation-Reduction; Palmitic Acid; Phosphatidylcholines; Phosphatidylethanolamines; Rats; Rats, Wistar; Stearic Acids