Nutrition Reviews

Morck, Timothy A.

doi: 10.1111/j.1753-4887.1989.tb02752.xpmid: N/A

Sacks, Frank M.

doi: 10.1111/j.1753-4887.1989.tb02753.xpmid: 2689919

Comparisons of blood pressure patterns among populations suggest that low‐fat diets or consumption of unsaturated fatty acids decrease blood pressure. However, in most single populations dietary fatty acids and total fat, as determined by diet history, are not significantly correlated with blood pressure. Dietary fatty acids, quantitated by levels in adipose tissue or plasma lipoproteins, had no consistent association with blood pressure. Dietary fatty acids and total fat were not predictive of the development of hypertension over four years in a large cohort of nurses in the United States. Although several dietary trials lacking randomized controls suggested effects of dietary fats on blood pressure, 11 of 12 controlled trials showed no significant effects. All seven double‐blind trials, and the two trials of longest duration (one and five years), showed no effect of either varying the content of total fat or of exchanging polyunsaturated for saturated fatty acids. In summary, there is little convincing evidence that the amount or type of dietary fat, varied within customary dietary patterns, affects blood pressure levels in persons with normal or mildly elevated blood pressure.

Knapp, Howard R.

doi: 10.1111/j.1753-4887.1989.tb02754.xpmid: 2689920

Omega‐3 fatty acid supplements have been reported to have hypotensive properties in humans, and it has been suggested that this effect is due to altered prostaglandin synthesis. However, such effects are inconsistently found, and interpretation of the literature is confounded by problems with study design. Epidemiologic data are often quoted as showing lower blood pressure in populations that eat large amounts of fish, but this effect also is less clear from the primary data. This review presents population studies of the relationship between consumption of omega‐3 fatty acids and blood pressure, problems involved in studying blood pressure, and the studies of lowering blood pressure and vascular reactivity with omega‐3 supplements in volunteers. Data on omega‐3 fatty acids and endogenous production of prostaglandins are also summarized, with interpretation of investigations of dietary omega‐3 fatty acids and vascular control. Recent work addressing a number of controversial points is presented, with the conclusion that pharmacologic doses of omega‐3 fatty acids can lower blood pressure in humans but probably do not do so directly via altered production of prostaglandins.

doi: 10.1111/j.1753-4887.1989.tb02755.xpmid: 2574841

Folate deficiency has been implicated in the development of a precancerous condition of the epithelial layer of the uterine cervix, the tracheobronchial tree, and, in a recently published report, the colon. In each instance the individuals have been subject to pathologic or environmental factors that predisposed them to folate deficiency, either systemic or presumed to be localized to the tissue in question. The precancerous changes (dysplasia) in the uterine cervix and in the tracheobronchial tree were partially or wholly reversed by administration of folate to the experimental subjects. Thus, a growing body of evidence suggests that under certain circumstances the prevention of folate deficiency protects against the development of dysplasia, and thereby lessens the risk of cancer.

Whitehead, Nancy; Reyner, Franklin; Lindenbaum, John

doi: 10.1111/j.1753-4887.1989.tb02756.xpmid: 2689921

doi: 10.1111/j.1753-4887.1989.tb02757.xpmid: 2689922

Recently discovered evidence suggests that members of the Franklin expedition to the Arctic (1845–1846) died as a result of contamination of their food supply with lead.

doi: 10.1111/j.1753-4887.1989.tb02758.xpmid: 2601896

The suggestion that exercise increases the basal metabolic rate for 48 h afterward has formed the basis for advocating exercise alone for weight loss. However, a recent well‐controlled, long‐term study showed no influence of exercise on basal metabolic rate.

doi: 10.1111/j.1753-4887.1989.tb02759.xpmid: 2601897

Cataractous state may increase the demand for vitamins and enzymes concerned with meeting oxidant stress.

doi: 10.1111/j.1753-4887.1989.tb02760.xpmid: 2601898

Dietary fat did not blunt the response of adipose tissue lipoprotein lipase to glucose/insulin in obese subjects as it did in controls. This undiminished activity would favor lipase triacylgylcerol storage in adipocytes and may contribute to failure to maintain weight loss.

doi: 10.1111/j.1753-4887.1989.tb02761.xpmid: 2601899

In several regions of mouse brain the concentration of glutathione peaks by three months of age and decreases by 30% between 26 and 31 months. Tissue levels of glutathione may prove to be a useful indicator of organ senescence.