High vegetable protein intake lowers risk of early menopause
Increased consumption levels of protein from vegetable sources, equivalent to three to four servings per day of protein-rich foods, is associated with lower incidence of early onset of natural menopause, a US study suggests.
Researchers examined 85,682 women participating in the Nurses’ Health Study II cohort who were premenopausal at baseline (1991) and followed until 2011 for onset of natural menopause. Protein intake was measured using the food frequency questionnaire.
During the study period, menopause occurred early in 2,041 women. In Cox proportional hazard models, the highest quintile of vegetable protein intake (median, 6.5 percent of calories) significantly lowered the risk of early menopause by 16 percent compared with the lowest quintile of intake (median, 3.9 percent of calories; hazard ratio [HR], 0.84; 95 percent CI, 0.73 to 0.98; p=0.02).
Each 1 percent increase in vegetable protein intake was associated with a significant 6-percent reduction in the risk of early menopause. Consumption of specific foods including pasta, dark bread and cold cereal was similarly associated with a lower risk (p<0.05). In contrast, animal protein intake was not found to be related to the risk of early menopause.
Early menopause involves the cessation of ovarian function <45 years. This event occurs in about 5 to 10 percent of Western women and ups the risk of adverse health outcomes, such as premature mortality and cardiovascular disease. [Endocrinology Metabolism Clinics of North America 2015;44:543-557; Endocrine Rev 2009;30:465-493]
Moreover, women with early menopause may have reduced fertility as much as a decade prior to onset of menopause. The factors associated with natural early menopause are not well understood, and the majority of diagnoses are not attributable to genetic factors or autoimmune conditions. [Maturitas 2010;65:161-166]
Researchers said additional prospective studies are needed to investigate the potential mechanisms involved in the effect of soy- and nonsoy-based vegetable proteins on the onset of menopause.
“A better understanding of how dietary vegetable protein intake is associated with ovarian ageing may identify ways for women to modify their risk of early onset of menopause and associated health conditions,” they added.