phytosterols and Cognition-Disorders

The proportion of elderly is growing worldwide. This trend is in parallel to an increase in diseases, such as cardiovascular disease (CVD). Plant sterols and stanols (PS) consumption is known to decrease low-density lipoprotein-cholesterol (LDL-C) levels by 5-15%, and thus lower CVD risk. Yet, the effect of PS on LDL-C levels differs between individuals. Furthermore, PS have recently been investigated for the prevention of other age-related diseases. The objective of this review is to examine the benefits of PS on CVD as well as ageing-associated diseases. PS have the ability to significantly lower LDL-C; yet, the large inter-individual variability in the lowering of LDL-C may be due to subject characteristics, food matrix of PS, dose of PS, dietary background, frequency of intake of PS, the additive effect of other foods or drugs, as well as genetic factors. Further, PS may also have other potential beneficial effects including anti-atherogenic, anti-inflammatory, antioxidant and anti-cancer activities. Overall, dietary intervention strategies, such as incorporating PS into a healthy diet, should be recommended and implemented in older adult populations in order to prevent ageing-associated diseases and hence promote healthy ageing.

Topics: Aged; Aging; Cardiovascular Diseases; Cognition Disorders; Eye Diseases; Food, Fortified; Humans; Inflammation; Meta-Analysis as Topic; Neoplasms; Oxidative Stress; Phytosterols; Randomized Controlled Trials as Topic

The oil palm (Elaeis guineensis) is native to many West African countries, where local populations have used its oil for culinary and other purposes. Large-scale plantations, established principally in tropical regions (Asia, Africa and Latin America), are mostly aimed at the production of oil, which is extracted from the fleshy mesocarp of the palm fruit, and endosperm or kernel oil. Palm oil is different from other plant and animal oils in that it contains 50% saturated fatty acids, 40% unsaturated fatty acids, and 10% polyunsaturated fatty acids. The fruit also contains components that can endow the oil with nutritional and health beneficial properties. These phytonutrients include carotenoids (alpha-,beta-,and gamma-carotenes), vitamin E (tocopherols and tocotrienols), sterols (sitosterol, stigmasterol and campesterol), phospholipids, glycolipids and squalene. In addition, it is recently reported that certain water-soluble powerful antioxidants, phenolic acids and flavonoids, can be recovered from palm oil mill effluent. Owing to its high content of phytonutrients with antioxidant properties, the possibility exists that palm fruit offers some health advantages by reducing lipid oxidation, oxidative stress and free radical damage. Accordingly, use of palm fruit or its phytonutrient-rich fractions, particularly water-soluble antioxidants, may confer some protection against a number of disorders or diseases including cardiovascular disease, cancers, cataracts and macular degeneration, cognitive impairment and Alzheimer's disease. However, whilst prevention of disease through use of these phytonutrients as in either food ingredients or nutraceuticals may be a worthwhile objective, dose response data are required to evaluate their pharmacologic and toxicologic effects. In addition, one area of concern about use of antioxidant phytonutrients is how much suppression of oxidation may be compatible with good health, as toxic free radicals are required for defence mechanisms. These food-health concepts would probably spur the large-scale oil palm (and monoculture) plantations, which are already seen to be a major cause of deforestation and replacement of diverse ecosystems in many countries. However, the environmental advantages of palm phytonutrients are that they are prepared from the readily available raw material from palm oil milling processes. Palm fruit, one of only a few fatty fruits, is likely to have an increasingly substantiated place in human health

Topics: Africa, Western; Alzheimer Disease; Arecaceae; Cardiovascular Diseases; Cataract; Chronic Disease; Cognition Disorders; Dietary Fats, Unsaturated; Flavonoids; Food, Organic; Fruit; Humans; Lipid Metabolism; Macular Degeneration; Neoplasms; Nutritive Value; Oxidation-Reduction; Palm Oil; Phenols; Phytosterols; Plant Oils; Polyphenols

Accumulating epidemiological and experimental studies have confirmed that a high-cholesterol diet is detrimental to cognitive performance in animal models. Phytosterols, a class of naturally occurring structural components in plant foods, have been demonstrated to possess cholesterol-lowering and antioxidant effects. Phytosterol esters (PSE) are esters of phytosterol. The aim of this study was to evaluate the neuroprotective effects of PSE on cognitive deficit induced by a cholesterol-enriched diet in aged rats, and to explore their underlying mechanisms for these effects. Based on their Morris water maze performance, the latencies differed by <1.5 standard deviations (SDs) on days 3-5 of testing, 60 rats were chosen from 12-month-old female Sprague Dawley aged rats and were randomized into three groups, which were fed either a control diet, a high cholesterol diet (HCD) or a high-cholesterol diet supplemented with 2% PSE (HCD + PSE) for 6 months. In our study, we found that PSE treatment maintained the body weight balance, reduced the serum lipid levels, and improved the cognitive performance of aged rats in the Morris water maze test, as evaluated by shortened escape latencies. Importantly, histological and immunohistochemical results in the brain showed that PSE supplementation may have a neuroprotective effect that alleviates neuroinflammation in aged rats. This neuroprotective effect significantly inhibited degeneration, resulting in a significant increase in the number of pyramidal cells and an apparent decrease in the number of astrocytes compared to rats that were fed only a HCD. Furthermore, PSE improved cholinergic activities by restoring the acetylcholine (ACh) content and decreasing acetylcholinesterase (AChE) activity in the cerebral cortex, as well as by elevating choline acetyl transferase (ChAT) activity in the hippocampus and the cerebral cortex. These results suggest that PSE can play a useful role in alleviating cognitive deficit induced by a cholesterol-enriched diet and ageing.

Topics: Aging; Animals; Brain; Cholesterol; Cognition; Cognition Disorders; Esters; Female; Humans; Neuroprotective Agents; Phytosterols; Rats; Rats, Sprague-Dawley

A high-fat, high-energy (HFE) diet may be deleterious to the cardiovascular system and mental health. We previously reported that serum cholesterol levels and escape latency were significantly increased in mice by feeding them an HFE diet from gestation onward. In this study, we examined whether an HFE diet supplemented with phytosterols fed to pregnant C57BL/6j dams and their offspring would protect the HFE-diet-induced compromise of the offspring's learning capability. We measured serum cholesterol levels, brain N-methyl-D-aspartate receptor (NMDAR1) mRNA and protein expression and liver sterol 27-hydroxylase (Cyp27a1) mRNA expression, as well as a Morris water maze performance. The results showed that, compared to mice consuming the HFE diet alone, those also consuming phytosterols (the HFE + PS diet) significantly decreased mean serum low-density lipoprotein cholesterol levels and altered brain NMDAR1 mRNA and protein expression and liver Cyp27a1 mRNA expression. The Morris water maze experiments indicated that dietary phytosterol supplementation slightly decreased the escape latency (p = 0.07). Collectively, these observations suggest that consumption of phytosterols from early in life may help alleviate the detrimental effects of HFE diets in mice.

Topics: Animals; Anticholesteremic Agents; Behavior, Animal; Cholesterol, LDL; Cognition Disorders; Diet, High-Fat; Dietary Supplements; Energy Intake; Female; Hypercholesterolemia; Lactation; Learning Disabilities; Male; Maternal Nutritional Physiological Phenomena; Maze Learning; Memory Disorders; Mice; Mice, Inbred C57BL; Phytosterols; Pregnancy; Random Allocation; Weaning

We examined the associations between extracerebral markers of cholesterol homeostasis and cognitive decline over 6 years of follow-up, and studied the modifying effect of apolipoprotein E (ApoE) e4. Data were collected in the Longitudinal Aging Study Amsterdam (n = 967, with longitudinal data on cognition, ages ≥ 65 years) and analyzed using linear mixed models. General cognition (Mini-Mental State Examination; MMSE), memory (Auditory Verbal Learning Test), and information processing speed (Coding task) were measured. The results show that ApoE e4 was a significant effect modifier. Significant associations were found only in ApoE e4 noncarriers (n = 718). We found a nonlinear negative association between the ratio of lanosterol to cholesterol (≤ 189.96 ng/mg), a marker for cholesterol synthesis, and general cognition. Lower cholesterol absorption, i.e., lower ratios of campesterol and sitosterol to cholesterol, as well as a higher rate of cholesterol synthesis relative to absorption were associated with lower information processing speed. In ApoE e4 carriers, the negative association between the ratio of campesterol to cholesterol and memory reached borderline significance. Future research should focus on the interaction between (disturbed) cholesterol homeostasis and ApoE e4 status with respect to dementia.

Topics: Aged; Aged, 80 and over; Apolipoprotein E4; Brain Chemistry; Cholesterol; Cognition Disorders; Down-Regulation; Female; Follow-Up Studies; Genetic Carrier Screening; Homeostasis; Humans; Longitudinal Studies; Male; Middle Aged; Phytosterols