Omega-3 fatty acid intake associated with lower heart disease risk

Increased consumption of omega-3 fatty acids in the diet is associated with lower levels of inflammation and endothelial activation, according to results from a study at Harvard. Dysfunction of the endothelium, which is the inner lining of the blood vessel wall, is an early event in the development of atherosclerosis and subsequent heart disease.

Food frequency questionnaires completed in1986 and 1990 by 727 participants in the Nurses' Health study were evaluated for levels of the omega-3 fatty acids alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).

Alpha-linolenic acid consumption was found to be inversely associated with several plasma markers of inflammation, while EPA and DHA intake was inversely related to platelet aggregration.

Results of this study indicate that in addition to reducing triglycerides, platelet aggregation and heart arrhythmias, omega-3 fatty acids may also reduce the body's production of hydrogen peroxide, which is involved in the inflammatory process.

J Nutr 2004 Jul;134(7):1806-11

Low Levels of Vitamin D Are Common Among Healthy Children

According to a new study, many kids and adolescents who are otherwise healthy may have inadequate blood levels of vitamin D, a nutrient essential for normal growth and development. A vitamin D deficiency in childhood may lead to muscle weakness, defective bone mineralization and rickets. A new study published in the July 2007 issue of the American Journal of Clinical Nutrition has found that many children may be at risk for a vitamin D deficiency. Vitamin D is essential for normal growth and development and is important for immune function.

The researchers from Children's Hospital of Philadelphia assessed dietary and supplemental vitamin D intake, body mass, and measured blood levels of vitamin D in 382 healthy children between six years and 21 years of age living in the northeastern U.S. and found that more than half of the children had low blood levels of vitamin D. Of the subjects, 55 percent of the children had inadequate vitamin D blood levels and 68 percent overall had low blood levels of the vitamin in the wintertime. African Americans, children aged 9 and older, and those whose vitamin D intake was low were likeliest to have reduced serum vitamin D levels.

"The best indicator of a person's vitamin D status is the blood level of a vitamin D compound called 25-hydroxyvitamin D," Dr. Zemel, the lead investigator noted. "Vitamin D deficiency remains an under-recognized problem overall, and is not well studied in children."

The researchers added that further study is needed to determine the appropriate blood levels of vitamin D in children, as well as a review of the current recommendations for vitamin D intake.

The American Journal of Clinical Nutrition 2007 July; 86(1):150- 8.

Magnesium intake increases bone mineral density and may reduce the risk of osteoporosis

A study published in the Journal of the American Geriatric Society has shown that dietary intake of magnesium is associated with an increase in bone mineral density in older men and women. The study included 2,038 men and women aged 70-79 that were enrolled in the Health, Aging and Body Composition Study. Food frequency questionnaires were used to assess magnesium intakes and document any medications. The data also accounted for variations in age, body mass index (BMI), smoking status, alcohol use, physical activity, estrogen use, and supplemental calcium and vitamin D.

Higher magnesium intake through diet and supplements was positively associated with total - body bone mineral density (BMD) in older white men and women. For every 100 mg per day increase in magnesium, there was an approximate 2 per cent increase in whole-body BMD.

The results have important implications since osteoporosis currently affects over 10 million adults in the U.S. alone, with another 34 million suspected to have low bone mass. In addition, earlier dietary surveys have consistently shown that a large portion of adults do not meet the RDA for magnesium.

Journal of the American Geriatrics Society November 2005, Vol 53, No 11, pp 1875-1880