Low-Carb Diets May Worsen Fertility by Lowering Testosterone in Pre-Menopausal Women

High Protein Diet Leads to Low Testosterone in Pre-Menopausal Women

Picnic table with meat to BBQ.October 19 , 2015
by: ASRM Office of Public Affairs
Published in ASRM 2015 Annual Meeting Press Release

Baltimore, MD – A diet high in protein, especially animal protein, is significantly associated with reduced testosterone levels in healthy women. Research supported by the National Institute of Child Health and Human Development (NICHD) and presented at the 71st Annual Meeting of the American Society for Reproductive Medicine suggests that, in healthy pre-menopausal women, consumption of high levels of protein- especially animal protein- is inversely related to testosterone levels.

In a prospective cohort study, 259 healthy, premenopausal women were followed using fertility monitors for up to two menstrual cycles. The women were tested for hormone levels up to eight times per cycle with testing visits timed to menstrual cycle phases. The researchers evaluated the association between protein intake and reproductive hormone levels. The hormones measured were estradiol, progesterone, lutenizing hormone, follicle-stimulating hormone, and testosterone.

Women were asked up to four times per cycle to recall their protein consumption within the last 24 hours- percent energy from total protein, animal protein and vegetable protein were assessed. Women with higher protein consumption, specifically animal protein, were observed to have lower testosterone levels.

Divided into three groups, the women with the highest percentage of energy consumed from total protein intake had lower testosterone concentrations compared to those in the group with the lowest protein intake. No association was observed between protein intake and other hormone levels and no association between protein intake and ovulation.

ASRM President-elect Owen Davis, MD remarked, “In the complex and delicately calibrated balance of hormones supporting the process of mammalian reproduction, abnormally low testosterone levels can have a deleterious effect on a female’s reproductive capacity. We look forward to more findings and more detailed findings from the Biocycle Study.”

O-1 S.L. Mumford et al, “Dietary Protein Intake and Reproductive Hormones and Ovulation: The Biocycle Study”