gamma-linolenic-acid and Obesity

Overweight and obesity are the epidemics of the 21st century in developed countries. Obesity is associated with several metabolic disorders and various diseases such as type 2 diabetes, cardiovascular disease, high blood pressure, dyslipidemia (high levels of circulating triacylglycerols and low-density lipoprotein cholesterol, and low levels of high-density lipoprotein cholesterol), commonly referred to as Metabolic Syndrome (MS). Although there is a therapeutic arsenal to combat some of these diseases, especially type 2 diabetes and cardiovascular disease, both the intake of proper diets and maintaining healthy lifestyles are considered the best preventive measures. The general population has access to a variety of dietary foods for weight loss, and to nutritional supplements. It is important to identify those foods and supplements that are effective and safe. The purpose of this review is to examine, from a critical point of view, food components currently used by health professionals and by the general population as coadjuvants in the prevention of obesity.

Topics: Anti-Obesity Agents; Dietary Fiber; Dietary Supplements; Diglycerides; Fatty Acids, Omega-3; Food; Food Analysis; gamma-Linolenic Acid; Glycine max; Humans; Linoleic Acids, Conjugated; Obesity; Phenols

This article discusses the role of diet in the management of asthma. Readers will gain an understanding of how evolution of the western diet has contributed to increased asthma prevalence and how dietary modification that includes management of dietary lipids may reduce symptoms of asthma.. Relevant studies published in English were reviewed.. Medline search to identify peer-reviewed abstracts and journal articles.. Asthma and obesity, which often occur together, have increased in prevalence in recent years. Studies suggest adaption of a western diet has not only contributed to obesity, but that increased intake of specific nutrients can cause changes in the frequency and severity of asthma. Increased asthma prevalence has also been proposed to arise from increased exposure to diesel particles or lack of exposure to infectious agents or endotoxins during childhood, generating a biased Th2 immune response, and increased cytokine and leukotriene production. Antagonists directed against these pro-inflammatory mediators include anticytokines and antileukotrienes. A reduction in the levels of inflammatory mediators associated with asthma has also been seen with dietary interventions, such as the administration of oils containing gamma-linolenic acid and eicosapentaenoic acid.. Evidence suggests elevated body mass index and dietary patterns, especially intake of dietary lipids, contribute to symptoms of asthma. Dietary modification may help patients manage their asthma as well as contribute to their overall health.

Topics: Adolescent; Adult; Arachidonic Acids; Asthma; Body Mass Index; Child; Comorbidity; Dietary Fats; Fatty Acids, Essential; Fatty Acids, Omega-3; Fatty Acids, Omega-6; Fatty Acids, Unsaturated; Female; Fish Oils; gamma-Linolenic Acid; Humans; Hypersensitivity, Immediate; Inflammation Mediators; Leukotrienes; Male; Membrane Lipids; Obesity; Prevalence; Tumor Necrosis Factor-alpha

Some research has raised the possibility that gamma linolenic acid (GLA) can increase resting metabolic rate (RMR), which can help with weight control. However, in overweight young adults with a family history of obesity, no effect on RMR was seen after a 6 weeks treatment with borage oil (880 mg GLA per day) or evening primrose oil (540 mg GLA per day). On the other hand, borage oil did lower plasma triglyceride readings and raise HDL cholesterol readings (mean starting values in normal range for triglycerides, borderline low for HDL). No effect was seen for body mass index, plasma total cholesterol, LDL cholesterol, or glucose. Thus, in the type of subjects studied here, borage oil, a source of GLA, did not show promise as a weight control aid, but could help prevent undesirable readings for two blood lipid measures.

Topics: Administration, Oral; Adult; Cholesterol, HDL; Female; Functional Food; gamma-Linolenic Acid; Humans; Male; Middle Aged; Obesity; Phytotherapy; Plant Oils; Treatment Outcome; Triglycerides; Young Adult

The purpose of this study was to determine whether gamma-linolenate (GLA) supplementation would suppress weight regain following major weight loss. Fifty formerly obese humans were randomized into a double-blind study and given either 890 mg/d of GLA (5 g/d borage oil) or 5 g/d olive oil (controls) for 1 y. Body weight and composition and adipose fatty acids of fasting subjects were assessed at 0, 3, 12, and 33 mo. After 12 subjects in each group had completed 1 y of supplementation, weight regain differed between the GLA (2.17 +/- 1.78 kg) and control (8.78 +/- 2.78 kg) groups (P < 0.03). The initial study was terminated, and all remaining subjects were assessed over a 6-wk period. Unblinding revealed weight regains of 1.8 +/- 1.6 kg in the GLA group and 7.6 +/- 2.1 kg in controls for the 13 and 17 subjects, respectively, who completed a minimum of 50 wk in the study. Weight regain did not differ in the remaining 10 GLA and 5 control subjects who completed <50 wk in the study. In a follow-up study, a subgroup from both the original GLA (GLA-GLA, n = 9) and the original control (Control-GLA, n = 14) populations either continued or crossed over to GLA supplementation for an additional 21 mo. Interim weight regains between 15 and 33 mo were 6.48 +/- 1.79 kg and 6.04 +/- 2.52 kg for the GLA-GLA and Control-GLA groups, respectively. Adipose triglyceride GLA levels increased 152% (P < 0.0001) in the GLA group at 12 mo, but did not increase further after 33 mo of GLA administration. In conclusion, GLA reduced weight regain in humans following major weight loss, suggesting a role for essential fatty acids in fuel partitioning in humans prone to obesity.

Topics: Adipose Tissue; Double-Blind Method; Female; gamma-Linolenic Acid; Humans; Male; Middle Aged; Obesity; Regression Analysis; Weight Gain; Weight Loss

Evening Primrose Oil (EPO) is a naturally occurring rich source of essential fatty acids, especially linoleic and gamma-linolenic acid. It has been suggested that it has antiobesity properties. This double-blind 12-week study was undertaken in 100 women with substantial obesity: 40 with refractory obesity, and 60 at time of initial referral to a hospital clinic. Seventy-four subjects completed the study. Those treated with EPO were comparable in age and degree of obesity with the placebo-treated group. There was no significant difference in the weight loss achieved by those taking EPO compared with placebo, either in the subjects with refractory obesity or in those treated at time of initial referral. It would appear that any antiobesity property possessed by EPO is clinically insignificant.

Topics: Adolescent; Adult; Aged; Clinical Trials as Topic; Double-Blind Method; Fatty Acids, Essential; Fatty Acids, Unsaturated; Female; gamma-Linolenic Acid; Humans; Hypolipidemic Agents; Linoleic Acids; Middle Aged; Obesity; Oenothera biennis; Plant Oils

Obesity is a medical condition with increasing prevalence, characterized by an accumulation of excess fat that could be improved using some bioactive compounds. However, many of these compounds with in vitro activity fail to respond in vivo, probably due to the sophistication of the physiological energy regulatory networks. In this context, C. elegans has emerged as a plausible model for the identification and characterization of the effect of such compounds on fat storage in a complete organism. However, the results obtained in such a simple model are not easily extrapolated to more complex organisms such as mammals, which hinders its application in the short term. Therefore, it is necessary to obtain new experimental data about the evolutionary conservation of the mechanisms of fat loss between worms and mammals. Previously, we found that some omega-6 fatty acids promote fat loss in C. elegans by up-regulation of peroxisomal fatty acid β-oxidation in an omega-3 independent manner. In this work, we prove that the omega-6 fatty acids' effects on worms are also seen when they are supplemented with a natural omega-6 source (borage seed oil, BSO). Additionally, we explore the anti-obesity effects of two doses of BSO in a diet-induced obesity rat model, validating the up-regulation of peroxisomal fatty acid β-oxidation. The supplementation with BSO significantly reduces body weight gain and energy efficiency and prevents white adipose tissue accumulation without affecting food intake. Moreover, BSO also increases serum HDL-cholesterol levels, improves insulin resistance and promotes the down-regulation of Cebpa, an adipogenesis-related gene. Therefore, we conclude that the effects of omega-6 fatty acids are highly conserved between worms and obesity-induced mammals, so these compounds could be considered to treat or prevent obesity-related disorders.

Topics: Adipose Tissue, White; Animals; Borago; Caenorhabditis elegans; CCAAT-Enhancer-Binding Proteins; Cholesterol; Diet, High-Fat; Fatty Acids, Omega-6; gamma-Linolenic Acid; Humans; Male; Obesity; Oxidation-Reduction; Peroxisomes; Plant Oils; Rats; Rats, Wistar

Non-alcoholic fatty liver disease (NAFLD) given its association with obesity and diabetes may perhaps exert distinct free fatty acids (FFA) pattern, but the understanding of this phenomenon is limited. To this effect, we evaluated FFA profiles among healthy subjects and NAFLD patients stratified by body weight, to identify FFA valuable for early diagnosis of NAFLD.. Serum FFA profiles of healthy and NAFLD (lean, overweight and obese) subjects was determined using gas chromatography-mass spectrometry (GC-MS) and distinctions in FFA patterns were evaluated using one-way ANOVA while Receiver operating characteristics (ROC) and logistic regression models were used to explore FFA significant for diagnosing NAFLD.. NAFLD patients presented significantly higher (P < 0.05) serum FFA profiles compared to healthy controls (HC). While total FFA profiles were insignificantly different between lean (2093.33 ± 558.11 μg/ml) and overweight (2420.81 ± 555.18 μg/ml) NAFLD patients, obese NAFLD (2739.01 ± 810.35 μg/ml) presented most significantly elevated (P < 0.05) total FFA profiles compared with HC. Of the four FFA; myristic acid (14:0), palmitoleic acid (16:1), γ-linolenic acid (γ-18:3) and cis-7,10,13,16,19-docosapentaenoic acid (22:5), selected in ROC analysis given their high Youden's index and AUC, only 14:0; 5.58(1.37, 22.76) and 16:1; 4.36(1.34, 14.13) had statistical significant odd ratios.. Our findings suggest 14:0 and 16:1 are promising for early diagnosis of NAFLD.

Topics: Adult; Body Mass Index; Case-Control Studies; Fatty Acids, Monounsaturated; Fatty Acids, Unsaturated; Female; gamma-Linolenic Acid; Gas Chromatography-Mass Spectrometry; Humans; Male; Middle Aged; Myristic Acid; Non-alcoholic Fatty Liver Disease; Obesity; Overweight; Thinness

The purpose of this study was to assess the individual and interactive effects of the antioxidant alpha-lipoic acid (LPA) and the n-6 essential fatty acid gamma-linolenic acid (GLA) on insulin action in insulin-resistant obese Zucker rats. LPA, GLA, and a unique conjugate consisting of equimolar parts of LPA and GLA (LPA-GLA) were administered for 14 days at 10, 30, or 50 mg. kg body wt(-1). day(-1). Whereas LPA was without effect at 10 mg/kg, at 30 and 50 mg/kg it elicited 23% reductions (P < 0.05) in the glucose-insulin index (the product of glucose and insulin areas under the curve during an oral glucose tolerance test and an index of peripheral insulin action) that were associated with significant increases in insulin-mediated (2 mU/ml) glucose transport activity in isolated epitrochlearis (63-65%) and soleus (33-41%) muscles. GLA at 10 and 30 mg/kg caused 21-25% reductions in the glucose-insulin index and 23-35% improvements in insulin-mediated glucose transport in epitrochlearis muscle. The beneficial effects of GLA disappeared at 50 mg/kg. At 10 and 30 mg/kg, the LPA-GLA conjugate elicited 29 and 38% reductions in the glucose-insulin index. These LPA-GLA-induced improvements in whole body insulin action were accompanied by 28-63 and 38-57% increases in insulin-mediated glucose transport in epitrochlearis and soleus muscles and resulted from the additive effects of LPA and GLA. At 50 mg/kg, the metabolic improvements due to LPA-GLA were substantially reduced. In summary, these results indicate that the conjugate of the antioxidant LPA and the n-6 essential fatty acid GLA elicits significant dose-dependent improvements in whole body and skeletal muscle insulin action on glucose disposal in insulin-resistant obese Zucker rats. Moreover, these actions of LPA-GLA are due to the additive effects of its individual components.

Topics: Animals; Biological Transport; Blood Glucose; Drug Combinations; Fatty Acids, Nonesterified; Female; gamma-Linolenic Acid; Glucose; Glucose Tolerance Test; Insulin; Insulin Resistance; Muscle, Skeletal; Obesity; Rats; Rats, Zucker; Thioctic Acid

Obese Zucker rats (fa/fa) have low levels of arachidonic acid (AA) in liver phospholipids (PL). We have previously shown that a 70% gamma-linolenate concentrate (GLA; an AA intermediate) fed at a fixed dose (0.07 g/day) normalized hepatic PL AA and reduced weight gain selectively in the obese animals. In a follow-up study, 16 obese (fa/fa) and 16 lean (Fa/Fa) 4-week-old male rats were randomized into 4 groups of 8 each and gavaged daily with soybean oil (SOY) containing 55% 18:2omega6 (an AA precursor) or GLA, using a progressive dose (< or = 5% of total calories) based on body weight. A defined diet with 11% of energy as SOY was fed ad libitum for 60 days. GLA obese had lower body weight (p<0.0001) and 60-day cumulative food intake (p<0.05) compared to SOY obese, but neither parameter differed between the lean groups. For the last twenty days cumulative food intake was identical for GLA obese and SOY lean, whereas SOY obese consumed 18% more (p<0.05). Thus the progressive dose of GLA selectively suppressed hyperphagia in obese Zucker rats. Erythrocytes collected at 15-day intervals showed parallel increases in AA in both genotypes over time, suggesting normal AA availability during rapid growth. Thus, the reduced PL AA in the livers from the obese rats probably reflects impaired distribution in selected tissues rather than reduced hepatic production. Due to the potential health risks of enriching tissue lipids with AA, great caution is advised in considering GLA as therapy for human obesity.

Topics: Adipose Tissue; Animals; Anti-Obesity Agents; Body Composition; Body Weight; Dietary Supplements; Disease Models, Animal; Eating; Energy Metabolism; Erythrocytes; Fatty Acids; gamma-Linolenic Acid; Genotype; Glycine max; Growth; Hyperphagia; Linoleic Acid; Lipid Metabolism; Lipids; Liver; Male; Obesity; Phospholipids; Rats; Rats, Zucker; Time Factors; Weight Gain

Below-normal proportions of phospholipid (PL) arachidonic acid (20:4 omega 6) have been reported in serum from obese humans and in liver from obese Zucker rats. This implies an abnormality of 20:4 omega 6 formation from linoleic acid (18:2 omega 6), possibly in the delta 6 desaturase step, or alternatively an abnormality in the catabolism or distribution of arachidonate. We previously speculated that a reduced proportion of 20:4 omega 6 in hepatic PL could contribute to the etiology of genetic obesity. Providing 18:3 omega 6 would bypass delta 6 desaturase and possibly normalize hepatic PL 20:4 omega 6. Therefore weanling Zucker rats were given free access to a defined diet (11% of energy as soy oil) and gavaged daily with 100 microL of either black currant oil concentrate ([BCO] 8% 18:2 omega 6 and 70% 18:3 omega 6) or soy oil ([Soy] 55% 18:2 omega 6 and < 0.1% 18:3 omega 6). Groups of eight lean and eight obese animals were randomized to receive Soy or BCO in a 2 x 2 design; 10 obese and 10 lean rats were fed a stock diet (nongavaged reference). All groups of lean rats had identical weight gain; food intake for Soy lean and BCO lean did not differ. The obese reference animals and Soy obese animals did not differ in weight gain. However, BCO obese animals ate less food (P < .06), gained less weight (P < .0001), and had lower percent body fat (P < .05) compared with the Soy obese animals. The fatty acid constituents from serum, liver, and adipose tissue showed marked differences between lean and obese animals. Hepatic PL 20:4 omega 6 was lower in Soy obese than in lean (P < .002), but was normalized by BCO gavage (diet effect, P < .007). The paucity of hepatic PL 20:4 omega 6 was not due to reduced desaturase activity, as the proportions of other desaturase products (20:3 omega 6, 20:3 omega 9, 20:5 omega 3) were significantly elevated in Soy obese rat liver and serum. Serum and hepatic cholesteryl ester 20:4 omega 6 levels were elevated in obese versus lean rats (P < .02 and P < .0001), indicating abnormal arachidonate distribution in the obese Zucker rat. Because BCO selectively reduced weight gain and percent body fat in obese Zucker rats, our results imply a role for abnormal omega 6 fatty acid metabolism in the etiology of Zucker obesity.(ABSTRACT TRUNCATED AT 400 WORDS)

Topics: Adipose Tissue; Animals; Dietary Fats, Unsaturated; Fatty Acids, Essential; gamma-Linolenic Acid; Genotype; Lipid Metabolism; Liver; Male; Obesity; Rats; Rats, Zucker; Reference Values; Triglycerides; Weight Gain

The fatty acid composition of serum phospholipids, cholesteryl esters and triglycerides was measured in 11 obese individuals before and after 2 and 4 weeks treatment with a liquid diet providing about 600 kcal and 70 g protein per day. The patients received 20g of lipid, which was either maize oil and safflower oil (6 patients) or maize oil and evening primrose oil (5 patients). During treatment serum phospholipid linoleic acid (C18:2n-6) concentration remained constant, the dihomo-gamma-linolenic acid (C20:3n-6) concentration decreased by 44 percent in the safflower oil group and by 37 percent in the evening primrose oil group and the arachidonic acid (C20:4n-6) increased by 26 percent in the safflower oil group and by 20 percent in the evening primrose oil group. The increase in phospholipid arachidonate showed a significant positive correlation with total weight loss during the treatment period. These results suggest that during weight reduction there is a increased mobilization of arachidonic acid from tissues and a decreased rate of linoleic acid desaturation and elongation, which was not significantly influenced by providing gamma-linolenic acid in the diet.

Topics: Adult; Aged; Cholesterol Esters; Corn Oil; Diet, Reducing; Energy Intake; Fatty Acids; Fatty Acids, Essential; Female; gamma-Linolenic Acid; Humans; Hypolipidemic Agents; Linoleic Acids; Lipids; Male; Middle Aged; Obesity; Oenothera biennis; Phospholipids; Plant Oils; Safflower Oil; Triglycerides; Weight Loss

Genetically obese mice (ob/ob) and their lean litter-mates were given diets iso-energetically supplemented with sucrose, hydrogenated coconut oil, safflower oil or evening primrose (Oenothera biennis) oil. Weight gain over 15 weeks was significantly greater in the evening primrose oil-supplemented obese mice than in the other groups. In all the groups of obese mice, liver total phospholipids contained proportionally less linoleic acid and more dihomo-gamma-linolenic acid and arachidonic acid than did the lean controls. As a percentage of total fatty acids, n-3 essential fatty acids (EFA) in liver and adipose tissue lipids were significantly lower in the obese mice than in the lean controls. Supplementation with EFA-rich oils (safflower and evening primrose oil) increased the proportional composition of n-6 EFA and decreased the n-3 EFA more in the liver total phospholipids of the lean than the obese mice.

Topics: Adipose Tissue; Animals; Body Weight; Epididymis; Fatty Acids, Essential; gamma-Linolenic Acid; Linoleic Acid; Linoleic Acids; Linolenic Acids; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Organ Size; Phospholipids; Triglycerides

Data were collected during a three-month double-blind trial of evening primrose oil (EPO) in 100 obese females attending a hospital obesity clinic. Initial weight was not related to subsequent weight loss. There was, however, a significant correlation between change in mood and change in weight, with weight loss being associated with improved mood state and weight gain with increased disturbance. Such associations were strongest for patients who were new to the clinic, as opposed to refractory patients, and for patients who were initially depressed, as opposed to those who were not psychologically disturbed. It is suggested that new patients have a swift psychological response to even minor changes in weight and that, because of a risk of increasing depression, particular attention should be given to obese patients who fail to show any weight loss.

Topics: Adolescent; Adult; Aged; Body Weight; Depression; Double-Blind Method; Fatty Acids, Essential; Fatty Acids, Unsaturated; Female; gamma-Linolenic Acid; Humans; Linoleic Acids; Middle Aged; Obesity; Oenothera biennis; Plant Oils