Low-carbohydrate diets and all-cause and cause-specific mortality: two cohort studies.
BACKGROUND
Data on the long-term association between low-carbohydrate diets and mortality are sparse.


OBJECTIVE
To examine the association of low-carbohydrate diets with mortality during 26 years of follow-up in women and 20 years in men.


METHODS
Prospective cohort study of women and men who were followed from 1980 (women) or 1986 (men) until 2006. Low-carbohydrate diets, either animal-based (emphasizing animal sources of fat and protein) or vegetable-based (emphasizing vegetable sources of fat and protein), were computed from several validated food-frequency questionnaires assessed during follow-up.


METHODS
Nurses' Health Study and Health Professionals' Follow-up Study.


METHODS
85 168 women (aged 34 to 59 years at baseline) and 44 548 men (aged 40 to 75 years at baseline) without heart disease, cancer, or diabetes.


METHODS
Investigators documented 12 555 deaths (2458 cardiovascular-related and 5780 cancer-related) in women and 8678 deaths (2746 cardiovascular-related and 2960 cancer-related) in men.


RESULTS
The overall low-carbohydrate score was associated with a modest increase in overall mortality in a pooled analysis (hazard ratio [HR] comparing extreme deciles, 1.12 [95% CI, 1.01 to 1.24]; P for trend = 0.136). The animal low-carbohydrate score was associated with higher all-cause mortality (pooled HR comparing extreme deciles, 1.23 [CI, 1.11 to 1.37]; P for trend = 0.051), cardiovascular mortality (corresponding HR, 1.14 [CI, 1.01 to 1.29]; P for trend = 0.029), and cancer mortality (corresponding HR, 1.28 [CI, 1.02 to 1.60]; P for trend = 0.089). In contrast, a higher vegetable low-carbohydrate score was associated with lower all-cause mortality (HR, 0.80 [CI, 0.75 to 0.85]; P for trend </= 0.001) and cardiovascular mortality (HR, 0.77 [CI, 0.68 to 0.87]; P for trend < 0.001).


CONCLUSIONS
Diet and lifestyle characteristics were assessed with some degree of error. Sensitivity analyses indicated that results were probably not substantively affected by residual confounding or an unmeasured confounder. Participants were not a representative sample of the U.S. population.


CONCLUSIONS
A low-carbohydrate diet based on animal sources was associated with higher all-cause mortality in both men and women, whereas a vegetable-based low-carbohydrate diet was associated with lower all-cause and cardiovascular disease mortality rates.


BACKGROUND
National Institutes of Health.
Fung
Teresa T
TT
Harvard School of Public Health, Boston, Massachusetts 02115, USA. teresa.fung@simmons.edu
van Dam
Rob M
RM
Hankinson
Susan E
SE
Stampfer
Meir
M
Willett
Walter C
WC
Hu
Frank B
FB
D000328:Adult; D000818:Animals; D002318:Cardiovascular Diseases / Q000401:mortality; D002423:Cause of Death; D050528:Diet, Carbohydrate-Restricted; D004041:Dietary Fats / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000401:mortality; D014674:Plant Proteins, Dietary / Q000008:administration & dosage; D055815:Young Adult
D004041:Dietary Fats; D004044:Dietary Proteins; D014674:Plant Proteins, Dietary
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