NAGOYA, JAPAN — Diets containing an extreme amount of carbohydrates were associated with a higher risk of all-cause and cancer-related mortality in a study from the Nagoya University Graduate School of Medicine in Japan. However, diets containing an extremely low amount of carbohydrate had a similar association.

The study, which appeared in the August issue of The Journal of Nutrition, involved a follow-up survey over nine years with 34,893 Japanese men and 46,440 Japanese women. Daily dietary intakes of carbohydrates, fats and total calories were estimated through a food frequency questionnaire.

Results showed men who consumed less than 40% of their total calorie intake from carbohydrates experienced a significantly higher risk of all-cause and cancer-related mortality. The trend was seen regardless of whether refined or minimally processed carbohydrates were considered.

Among women with five years or longer of follow-up, those who had a carbohydrate intake of over 65% of total calorie intake had a higher risk of all-cause mortality. No clear observation was observed between refined or minimally processed carbohydrate intake and the risk of mortality in women.

Women with higher fat intake may have a lower risk of all-cause mortality.

“The finding that saturated fat intake was inversely associated with the risk of mortality only in women might partially explain the differences in the associations between the sexes,” said Takashi Tamura, leader of the study. “Alternatively, components other than fat in the food sources of fat may be responsible for the observed inverse association between fat intake and mortality in women.”