Background:
Long-term safety of low-carbohydrate-diets in Asian populations, whose carbohydrate intake is relatively high, is not known.
Methods:
We examined the association of low-carbohydrate-diets with CVD and total mortality using the National Integrated Project for Prospective Observation of Noncommunicable Disease and Its Trends in the Aged, (NIPPON DATA80) database with a 29-year follow-up. At the baseline in 1980, data were collected on study participants ages≥30 years from randomly selected areas in Japan. We calculated low-carbohydrate-diet scores based on the percentage of energy as carbohydrate, fat, and protein, estimated by 3-day weighed food records. We followed 9,200 participants (56% women, mean age 51 y).
Results:
During the follow-up, there were 1,171 CVD deaths (52% in women), and 3,443 total deaths (48% in women). The multivariate-adjusted hazard ratio (HR) for CVD mortality using the Cox model comparing highest versus lowest deciles for a low-carbohydrate-diet score was 0.59 (95% confidence interval [CI], 0.38-0.92, trend P=0.019) for women; 0.74 (95% CI: 0.55-0.99, trend P=0.033) for women and men combined; HR for total mortality was 0.73 (95% CI: 0.57-0.93, trend P=0.020) for women; 0.84 (95% CI: 0.72-0.99, trend P=0.030) for women and men combined. None of the associations in men alone were statistically significant. We did not note any differential effects between animal and plant based low-carbohydrate-diets.
Conclusions:
Moderate diets lower in carbohydrate and higher in protein and fat were significantly inversely associated with CVD and total mortality in women, and women and men combined.