Rajaratnam Radhakrishnan

Bio: Rajaratnam Radhakrishnan is an academic researcher from University of Helsinki. The author has contributed to research in topics: Chylomicron & Retinyl palmitate. The author has an hindex of 2, co-authored 2 publications receiving 245 citations.

Reduction of Serum Cholesterol in Postmenopausal Women With Previous Myocardial Infarction and Cholesterol Malabsorption Induced by Dietary Sitostanol Ester Margarine Women and Dietary Sitostanol

Abstract: Background Reduction of serum cholesterol decreases mortality in primary and especially in secondary prevention. We investigated how effectively postmenopausal women with a previous myocardial infa...

AHA Dietary Guidelines Revision 2000: A Statement for Healthcare Professionals From the Nutrition Committee of the American Heart Association

Abstract: This document presents guidelines for reducing the risk of cardiovascular disease by dietary and other lifestyle practices. Since the previous publication of these guidelines by the American Heart Association,1 the overall approach has been modified to emphasize their relation to specific goals that the AHA considers of greatest importance for lowering the risk of heart disease and stroke. The revised guidelines place increased emphasis on foods and an overall eating pattern and the need for all Americans to achieve and maintain a healthy body weight (Table⇓). View this table: Table 1. Summary of Dietary Guidelines The major guidelines are designed for the general population and collectively replace the “Step 1” designation used for earlier AHA population-wide dietary recommendations. More individualized approaches involving medical nutrition therapy for specific subgroups (for example, those with lipid disorders, diabetes, and preexisting cardiovascular disease) replace the previous “Step 2” diet for higher-risk individuals. The major emphasis for weight management should be on avoidance of excess total energy intake and a regular pattern of physical activity. Fat intake of ≤30% of total energy is recommended to assist in limiting consumption of total energy as well as saturated fat. The guidelines continue to advocate a population-wide limitation of dietary saturated fat to <10% of energy and cholesterol to <300 mg/d. Specific intakes for individuals should be based on cholesterol and lipoprotein levels and the presence of existing heart disease, diabetes, and other risk factors. Because of increased evidence for the cardiovascular benefits of fish (particularly fatty fish), consumption of at least 2 fish servings per week is now recommended. Finally, recent studies support a major benefit on blood pressure of consuming vegetables, fruits, and low-fat dairy products, as well as limiting salt intake (<6 grams per day) and alcohol (no more than 2 drinks per day for men and …

AHA Dietary Guidelines Revision 2000: A Statement for Healthcare Professionals From the Nutrition Committee of the American Heart Association

Abstract: This document presents guidelines for reducing the risk of cardiovascular disease by dietary and other lifestyle practices. Since the previous publication of these guidelines by the American Heart Association,1 the overall approach has been modified to emphasize their relation to specific goals that the AHA considers of greatest importance for lowering the risk of heart disease and stroke. The revised guidelines place increased emphasis on foods and an overall eating pattern and the need for all Americans to achieve and maintain a healthy body weight (Table⇓). View this table: Table 1. Summary of Dietary Guidelines The major guidelines are designed for the general population and collectively replace the “Step 1” designation used for earlier AHA population-wide dietary recommendations. More individualized approaches involving medical nutrition therapy for specific subgroups (for example, those with lipid disorders, diabetes, and preexisting cardiovascular disease) replace the previous “Step 2” diet for higher-risk individuals. The major emphasis for weight management should be on avoidance of excess total energy intake and a regular pattern of physical activity. Fat intake of ≤30% of total energy is recommended to assist in limiting consumption of total energy as well as saturated fat. The guidelines continue to advocate a population-wide limitation of dietary saturated fat to <10% of energy and cholesterol to <300 mg/d. Specific intakes for individuals should be based on cholesterol and lipoprotein levels and the presence of existing heart disease, diabetes, and other risk factors. Because of increased evidence for the cardiovascular benefits of fish (particularly fatty fish), consumption of at least 2 fish servings per week is now recommended. Finally, recent studies support a major benefit on blood pressure of consuming vegetables, fruits, and low-fat dairy products, as well as limiting salt intake (<6 grams per day) and alcohol (no more than 2 drinks per day for men and …

Efficacy and Safety of Plant Stanols and Sterols in the Management of Blood Cholesterol Levels

Abstract: Foods with plant stanol or sterol esters lower serum cholesterol levels. We summarize the deliberations of 32 experts on the efficacy and safety of sterols and stanols. A meta-analysis of 41 trials showed that intake of 2 g/d of stanols or sterols reduced low-density lipoprotein (LDL) by 10%; higher intakes added little. Efficacy is similar for sterols and stanols, but the food form may substantially affect LDL reduction. Effects are additive with diet or drug interventions: eating foods low in saturated fat and cholesterol and high in stanols or sterols can reduce LDL by 20%; adding sterols or stanols to statin medication is more effective than doubling the statin dose. A meta-analysis of 10 to 15 trials per vitamin showed that plasma levels of vitamins A and D are not affected by stanols or sterols. Alpha carotene, lycopene, and vitamin E levels remained stable relative to their carrier molecule, LDL. Beta carotene levels declined, but adverse health outcomes were not expected. Sterol-enriched foods increased plasma sterol levels, and workshop participants discussed whether this would increase risk, in view of the marked increase of atherosclerosis in patients with homozygous phytosterolemia. This risk is believed to be largely hypothetical, and any increase due to the small increase in plasma plant sterols may be more than offset by the decrease in plasma LDL. There are insufficient data to suggest that plant stanols or sterols either prevent or promote colon carcinogenesis. Safety of sterols and stanols is being monitored by follow-up of samples from the general population; however, the power of such studies to pick up infrequent increases in common diseases, if any exist, is limited. A trial with clinical outcomes probably would not answer remaining questions about infrequent adverse effects. Trials with surrogate end points such as intima-media thickness might corroborate the expected efficacy in reducing atherosclerosis. However, present evidence is sufficient to promote use of sterols and stanols for lowering LDL cholesterol levels in persons at increased risk for coronary heart disease.

Plant sterols: biosynthesis, biological function and their importance to human nutrition.

Abstract: Plant sterols are an essential component of the membranes of all eukaryotic organisms. They are either synthesised de novo or taken up from the environment. Their function appears to be to control membrane fluidity and permeability, although some plant sterols have a specific function in signal transduction. The phytosterols are products of the isoprenoid pathway. The dedicated pathway to sterol synthesis in photosynthetic plants occurs at the squalene stage through the activity of squalene synthetase. Although the activity of 3-hydroxymethyl-3-glutaryl coenzyme A (HGMR) is rate-limiting in the synthesis of cholesterol, this does not appear to be the case with the plant sterols. Up-regulation of HGMR appears to increase the biosynthesis of cycloartenol but not the Δ5-sterols. A decline in sterol synthesis is associated with a suppression of squalene synthetase activity, which is probably a critical point in controlling carbon flow and end-product formation. The major post-squalene biosynthetic pathway is regulated by critical rate-limiting steps such as the methylation of cycloartenol into cycloeucalenol. Little is known about the factors controlling the biosynthesis of the end-point sterol esters or stanols. The commonly consumed plant sterols are sitosterol, stigmasterol and campesterol which are predominantly supplied by vegetable oils. The oils are a rich source of the steryl esters. Less important sources of sterols are cereals, nuts and vegetables. The nutritional interest derives from the fact that the sterols have a similar structure to cholesterol, and have the capacity to lower plasma cholesterol and LDL cholesterol. Since the morbidity and mortality from cardiovascular disease have been dramatically reduced using cholesterol-lowering drugs (statins), the interest in plant sterols lies in their potential to act as a natural preventive dietary product. Stanols (saturated at C-5) occur in low amounts in the diet and are equally effective in lowering plasma cholesterol and do not cause an increase in plasma levels, unlike the sterols which can be detected in plasma. © 2000 Society of Chemical Industry