Omega-3 fatty acids and cardiovascular health
Observational studies and randomized controlled trials have examined the cardiovascular effects of fatty fish consumption and long-chain omega-3 polyunsaturated fatty acids (PUFAs) from dietary supplements. Several clinical trials have documented signifi-cant benefits of omega-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), for cardiovascular health. Although much has been learned, some questions remain unanswered, including: what are the precise physiological effects and molecular mechanisms that account for the ob-served benefits for cardiovascular health; and what are the magnitudes and dose-responses of effects on specific diseases and the potential differences in various populations? National and international guidelines now give consistent recommendations for the general population: to consume at least 250 mg/day of long-chain n-3 PUFA or at least two servings of oily fish per week.
Dietitians and dietary supplements
National nutrition surveys show that many Americans fall short in their consumption of several vitamins and minerals. Nutrition authorities consis-tently advocate a “food first” approach to achieving nutritional adequacy. Some, including the Academy of Nutrition and Dietetics, also recognize that dietary supplements can play a role in improving nutrient intakes to support health and wellness. While the prevalence of consumer usage of die-tary supplements is well documented, less attention has been paid to usage among health professionals and to whether they recommend dietary supplements to their patients or clients.
According to new research from the US, the risk of diseases, such as hip fractures, heart attacks and cancer, increases when the blood concentration of vitamin D falls below 20 ng/milliliter or 50 nmol/liter.
New US in vitro experiments suggest that high concentrations of certain naturally occurring molecules derived from beta-carotene may be associated with health hazards under specific conditions. An adequate intake of beta-carotene remains recommended.
