21 February 2005
Which diet?
Contrary to recent reports, very-low-carbohydrate diets may not necessarily be better than standard diets, suggest US researchers. They had randomised 160 overweight or obese adults to follow for a year the dietary component of one of four popular programs: Atkins (low carbohydrate), Ornish (low fat) Weight Watchers (low calorie) or Zone (macronutrient balance). The researchers found that each of the four diets led to a similar, and modest, reduction in body weight — about 5 kg or 5% — but only in the minority of participants who decided to keep to the diet for the full year. Further, in these participants, reductions in some of the cardiac risk factors measured (LDL/HDL cholesterol ratio, and serum C-reactive protein and insulin levels) were similar, irrespective of the type of diet.
JAMA 2005; 293: 43-53
Beware the return of the fat
There is little evidence of the "real-life" effectiveness of major commercial weight loss programs, say the authors of a systematic review. In their search, they found 10 studies that met their rigorous criteria, including some randomised controlled trials of Weight Watchers and one of a medically supervised very-low-calorie diet program. In the largest Weight Watchers trial, participants lost 5% of their initial body weight in 6 months; by 2 years, the weight had crept back up to reduce this loss to 3%. In the very-low-calorie diet trial, people who completed the program lost about 15% to 20% of their initial weight, but had regained about half of this lost weight within one to two years after treatment.
Ann Intern Med 2005; 142: 56-66
Vitamin E loses its lustre
While the jury may be out on whether antioxidants, like vitamin E, can prevent chronic diseases, authors of a meta-analysis have warned that high-dose vitamin E supplementation may actually be harmful. They analysed data from more than 135 000 patients in 19 clinical trials, finding a dose-dependent relationship between vitamin E supplementation and all-cause mortality. They recommended that high-dose vitamin E supplementation (>400 IU/day) be avoided.
Ann Intern Med 2005; 142: 37-46
Overweight? Not us
Parents are poor at recognising overweight in themselves and their children, say UK researchers. The researchers studied 277 healthy children and their parents. The whole group was heavier than UK norms. Among the overweight parents, 45% of the fathers and 40% of the mothers judged that their weight was "about right". And, even when children were obese, 57% of the fathers and 33% of the mothers saw their child’s weight as being "about right". In particular, parents are less likely to identify overweight in their sons than in their daughters.
BMJ 2005; 330: 23-24
Polypill push
Remember the polypill? In 2003, Wald and Law proposed that a daily cocktail of aspirin, folic acid, a statin and three antihypertensive agents, if given to anyone with heart disease and everyone else 55 years of age or older, could dramatically reduce rates of heart attack and stroke. The original proposal, controversially, suggested a whole-population approach, without further trial or screening. Now, an expert group, despite some dissent, has generally supported the conduct of an initial, controlled trial of the polypill in people at intermediate risk of heart disease and stroke, to be followed by further trials. However, according to an extended web version of this news item, a version of the polypill is likely to appear on the market in India by the end of this year.
BMJ 2005; 330: 1065-1068
Sorting out "silicone-osis"
An Australian study has been unable to confirm that "silicone-osis" exists. It had been previously postulated that silicone-osis might be a new systemic disease, uniquely and causally linked to silicone exposure. The study compared the health status of 487 women exposed to silicone via augmentation mammoplasty for cosmetic reasons between 1979 and 1983 with that of 687 matched women who had had non-silicone-related plastic surgery. Although the existence of a multisystem disorder —characterised by night sweats, lethargy, breast pain, impaired mentation, reflux, paraesthesiae, hand muscle weakness and myalgia — was suggested in the silicone-exposed cohort, this disorder was also present, albeit at a lower frequency, in the silicone-unexposed cohort.
Int Med J 2005; 34: 668-676
Dr Ann Gregory, MJA