09.11.2006, 11:27
N Engl J Med 2006;355:1991-2002.
Low-Carbohydrate-Diet Score and the Risk
of Coronary Heart Disease in Women
Thomas L. Halton, Sc.D., Walter C. Willett, M.D., Dr.P.H., Simin Liu, M.D., Sc.D.,
JoAnn E. Manson, M.D., Dr.P.H., Christine M. Albert, M.D., M.P.H.,
Kathryn Rexrode, M.D., and Frank B. Hu, M.D., Ph.D.
Background
Low-carbohydrate diets have been advocated for weight loss and to prevent obesity,
but the long-term safety of these diets has not been determined.
Methods
We evaluated data on 82,802 women in the Nurses’ Health Study who had completed
a validated food-frequency questionnaire. Data from the questionnaire were
used to calculate a low-carbohydrate-diet score, which was based on the percentage
of energy as carbohydrate, fat, and protein (a higher score reflects a higher intake
of fat and protein and a lower intake of carbohydrate). The association between the
low-carbohydrate-diet score and the risk of coronary heart disease was examined.
Results
During 20 years of follow-up, we documented 1994 new cases of coronary heart
disease. After multivariate adjustment, the relative risk of coronary heart disease
comparing highest and lowest deciles of the low-carbohydrate-diet score was 0.94
(95% confidence interval [CI], 0.76 to 1.18; P for trend = 0.19). The relative risk
comparing highest and lowest deciles of a low-carbohydrate-diet score on the basis
of the percentage of energy from carbohydrate, animal protein, and animal fat was
0.94 (95% CI, 0.74 to 1.19; P for trend = 0.52), whereas the relative risk on the basis
of the percentage of energy from intake of carbohydrates, vegetable protein, and
vegetable fat was 0.70 (95% CI, 0.56 to 0.88; P for trend = 0.002). A higher glycemic
load was strongly associated with an increased risk of coronary heart disease (relative
risk comparing highest and lowest deciles, 1.90; 95% CI, 1.15 to 3.15; P for
trend = 0.003).
Conclusions
Our findings suggest that diets lower in carbohydrate and higher in protein and fat
are not associated with increased risk of coronary heart disease in women. When
vegetable sources of fat and protein are chosen, these diets may moderately reduce
the risk of coronary heart disease.
Low-Carbohydrate-Diet Score and the Risk
of Coronary Heart Disease in Women
Thomas L. Halton, Sc.D., Walter C. Willett, M.D., Dr.P.H., Simin Liu, M.D., Sc.D.,
JoAnn E. Manson, M.D., Dr.P.H., Christine M. Albert, M.D., M.P.H.,
Kathryn Rexrode, M.D., and Frank B. Hu, M.D., Ph.D.
Background
Low-carbohydrate diets have been advocated for weight loss and to prevent obesity,
but the long-term safety of these diets has not been determined.
Methods
We evaluated data on 82,802 women in the Nurses’ Health Study who had completed
a validated food-frequency questionnaire. Data from the questionnaire were
used to calculate a low-carbohydrate-diet score, which was based on the percentage
of energy as carbohydrate, fat, and protein (a higher score reflects a higher intake
of fat and protein and a lower intake of carbohydrate). The association between the
low-carbohydrate-diet score and the risk of coronary heart disease was examined.
Results
During 20 years of follow-up, we documented 1994 new cases of coronary heart
disease. After multivariate adjustment, the relative risk of coronary heart disease
comparing highest and lowest deciles of the low-carbohydrate-diet score was 0.94
(95% confidence interval [CI], 0.76 to 1.18; P for trend = 0.19). The relative risk
comparing highest and lowest deciles of a low-carbohydrate-diet score on the basis
of the percentage of energy from carbohydrate, animal protein, and animal fat was
0.94 (95% CI, 0.74 to 1.19; P for trend = 0.52), whereas the relative risk on the basis
of the percentage of energy from intake of carbohydrates, vegetable protein, and
vegetable fat was 0.70 (95% CI, 0.56 to 0.88; P for trend = 0.002). A higher glycemic
load was strongly associated with an increased risk of coronary heart disease (relative
risk comparing highest and lowest deciles, 1.90; 95% CI, 1.15 to 3.15; P for
trend = 0.003).
Conclusions
Our findings suggest that diets lower in carbohydrate and higher in protein and fat
are not associated with increased risk of coronary heart disease in women. When
vegetable sources of fat and protein are chosen, these diets may moderately reduce
the risk of coronary heart disease.