Wed, Sep-13-06, 13:59
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Senior Member
Posts: 1,162
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Plan: Atkins
Stats: 228/195/188
BF:
Progress: 83%
Location: Erie PA
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If you're interested, Dr. Mozaffarian wrote a letter to JAMA about the WHI study about low fat diets. In it he referred to this article. If you check PubMEd this article has been quoted about 3 times (in 2 years), and this was one of them. The other ones were a dismissive editorial and one by Jeff Volek I think.
Quote:
Low-Fat Diet and Cardiovascular Disease
To the Editor: In the report of the Women's Health Initiative (WHI) Dietary Modification Trial by Dr Howard and colleagues,1 reduced consumption of total fat and increased consumption of fruits, vegetables, and grains did not significantly affect the incidence of coronary heart disease or stroke among postmenopausal women during 8.1 years of follow-up. The authors' primary explanation for the negative results was that the magnitude of dietary changes may have been insufficient to significantly alter risk.
A second plausible explanation is that the dietary intervention may have failed to influence risk because it balanced beneficial effects of some dietary changes with harmful effects of other changes. Modest benefits from small increases in fruit and vegetable intake (+1.1 servings/d) and whole grain intake (+0.2 servings/d) and decreases in trans fatty acid intake (–0.6% of energy) may have been counterbalanced by modest harms from small decreases in nut consumption (–0.8 servings/wk) and monounsaturated fat intake (–3.3% of energy) and increases in intake of refined grains (+0.3 servings/d). This counterbalancing of divergent dietary effects could also account for the lack of changes in triglyceride levels, insulin sensitivity, and the ratio of total to high-density lipoprotein cholesterol.
Clinical benefit did not occur, even given slightly greater physical activity in the intervention group (+0.39 metabolic equivalent tasks/wk), suggesting that the net effect of the dietary changes may have been slightly harmful. The dietary intervention was associated with increased rates of cardiovascular events among women with established cardiovascular disease (P=.006 for interaction); while this finding may have been due to chance, it is consistent with observations that lower intake of saturated fat and possibly monounsaturated fat and greater intake of refined grains is associated with greater progression of coronary atherosclerosis among postmenopausal women with established coronary disease.2 Evaluation of changes in risk factors in this subgroup—particularly high-density lipoprotein cholesterol levels3—would be informative.
Post hoc analyses of associations of specific dietary changes with incidence of cardiovascular events would be interesting, although they may not be able to disentangle competing effects of the various dietary changes, given the strong propensity toward improved outcomes among more adherent participants in randomized trials.
Financial Disclosures: None reported.
Dariush Mozaffarian, MD, MPH
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