PubMed Health⌕ Search

Biomedical subjects

R Shekelle

Publications and source records attributed to R Shekelle.

5 recordsLinked to original sources
PubMed1995

Dietary vitamin C and beta-carotene and risk of death in middle-aged men. The Western Electric Study.

In the Western Electric Company Study, carried out in Chicago, Illinois, data on diet and other factors were obtained in 1958 and 1959 for a cohort of 1,556 employed, middle-aged men. Nutrients included vitamin C and beta-carotene. An index that summarized combined intake of both nutrients was constructed. Mean intakes of vitamin C in the lowest and highest tertiles of the index were 66 and 138 mg/day; corresponding values for beta-carotene were 2.3 and 5.3 mg/day. A total of 522 of 1,556 men died during 32,935 person-years of follow-up, 231 from coronary heart disease and 155 from cancer. After adjustment for potentially confounding factors, relative risks (95% confidence intervals) associated with an increment of 19 points in the index (difference between means of the lowest and highest tertiles) were 0.60 (0.39-0.93) for cancer mortality, 0.70 (0.49-0.98) for coronary disease mortality, and 0.69 (0.55-0.87) for all-cause mortality. These results support the hypothesis that consumption of foods rich in vitamin C and beta-carotene reduces risk of death in middle-aged men.

Adult↗
PubMed1988

Dietary cholesterol and human coronary heart disease. The epidemiologic evidence.

For decades, dietary cholesterol has been recognized as the "materia peccans" (Anitschkow) for the induction of atherosclerosis in animals. In rabbits, chickens, and monkeys, long-term feeding of small amounts of cholesterol leads to atherosclerosis despite little or no rise in serum total cholesterol, indicating an independent contribution of dietary cholesterol to atherogenesis over-and-above its influence on serum cholesterol, possibly through effects on serum cholesterol fractions (eg, increased low-density lipoprotein-cholesterol and decreased high-density lipoprotein-cholesterol). In humans, ingestion of dietary cholesterol raises serum cholesterol, largely through its effect on low-density lipoprotein-cholesterol. Over the range of intake in usual American diets, this effect is substantial, eg, with 300 mg of cholesterol intake per 1000 kcal, rather than 100, serum cholesterol is on average about 6% to 7% higher, equivalent to a 12% to 14% greater risk of coronary heart disease (CHD). In international studies based on the Food and Agriculture Organization and the World Health Organization (Geneva) data, mean per capita dietary cholesterol levels are consistently related to CHD mortality rates. In addition, since 1981, four prospective within-population studies have shown that dietary cholesterol intake of individuals is significantly related to their long-term CHD risk, independent of and in addition to serum cholesterol, blood pressure, and cigarette use. On average, a 200-mg/1000 kcal higher intake of cholesterol at baseline was associated with a 30% higher CHD rate (95% confidence interval, 1.1 to 1.5). Conversely, lower intakes of cholesterol were associated with significantly lower risks of CHD, and of all causes mortality as well. For example, with 19 years of follow-up in the Chicago Western Electric Study, a 200-mg/1000 kcal habitual lower cholesterol intake was associated with a 37% lower risk of death from any cause, equivalent to a life expectancy longer by 3.4 years. The importance of a low-dietary cholesterol intake for prevention of CHD merits increased emphasis.

Animals↗