Dietary potassium deficiency in the elderly: a controlled trial.

A controlled cross-over trial of supplementary potassium was conducted in 46 elderly people whose dietary intake of potassium appeared to be no more than 45 mEq per day. Their grip strength and mental function were no better after two weeks' treatment with 48 mEq than when they received placebo tablets. It was concluded that the possible benefits of widespread potassium supplementation do not justify the risks which would be incurred.

Vitamin C supplementation of old people with low blood levels.

Ascorbic acid blood levels were estimated in 828 elderly people living in the community. 297 subjects with low blood levels were admitted to a 2-year controlled trial of vitamin C. Despite a rise in plasma and leucocyte levels, vitamin C produced no apparent benefit in terms of mortality, morbidity or mental senescence.

Peak expiratory flow rates before and after exercise in schoolchildren.

Peak expiratory flow rates (PEFR) were measured before and after 6 minutes' exercise in 12-year-old schoolchildren living in two areas. In boys, but not in girls, the mean initial PEFR was lower in asthmatics than in nonasthmatics. After exercise, children with current asthma tended to show a marked fall in PEFR.

A randomized controlled trial of acetyl salicylic acid in the secondary prevention of mortality from myocardial infarction.

The results of a randomized controlled trial of a single daily dose of acetyl salicylic acid (aspirin) in the prevention of reinfarction in 1,239 men who had had a recent myocardial infarct were statistically inconclusive. Nevertheless, they showed a reduction in total mortality of 12% at six months and 25% at twelve months after admission to the trial. Further trials are urgently required to establish whether or not this effect is real.