Low Intake of Vegetable Protein is Associated With Altered Ovulatory Function Among Healthy Women of Reproductive Age

• Published in: The journal of clinical endocrinology and metabolism 2021-07, Vol.106 (7), p.e2600-e2612
• Main Authors: Kim, Keewan, Yisahak, Samrawit F, Nobles, Carrie J, Andriessen, Victoria C, DeVilbiss, Elizabeth A, Sjaarda, Lindsey A, Alohali, Ahoud, Perkins, Neil J, Mumford, Sunni L
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Animal Proteins, Dietary - analysis; Anovulation - etiology; Clinical s; Cycle protein; Diet - adverse effects; Diet Surveys; Dietary intake; Dietary restrictions; Eating - physiology; Female; Follicle Stimulating Hormone - blood; Follicle-stimulating hormone; Food sources; Health aspects; Healthy Volunteers; High protein diet; Hormones; Humans; Low protein diet; Menopause; Ovulation - physiology; Plant Proteins, Dietary - analysis; Pregnancy; Premenopause - blood; Progesterone; Prospective Studies; Proteins; Recommended Dietary Allowances; Reproductive Health; Seeds; Vegetables; Women; Young Adult
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/clinem/dgab179

Abstract Context Diets high in plant-based protein have gained popularity due to increasing health concerns regarding consumption of animal products. Though links between intakes of certain protein-rich foods and reproductive disorders have been suggested, the relationship of overall animal and vegetable proteins with reproductive hormones among reproductive-aged women is unknown. Objective To evaluate the associations between the intake of dietary protein with reproductive hormones and sporadic anovulation among reproductive-aged women. Design A prospective cohort study, 2005–2007. Setting University at Buffalo, western New York, United States. Participants A total of 259 premenopausal women (18–44 years) without dietary restrictions. Main Outcome Measure(s) Serum reproductive hormones were determined up to 8 times per cycle for 2 cycles. Protein intake was assessed the day prior to hormone assessment at 4 visits/cycle using 24-hour recalls. Results Overall, 84% of participants met the recommended dietary allowance for total protein set for reproductive-aged women. Neither total nor animal protein intake were associated with reproductive hormones or anovulation. However, vegetable protein intake in the lowest tertile was associated with lower luteal phase progesterone (-18.0%, 95% confidence interval [CI] -30.2, -3.6), higher follicle-stimulating hormone (3.8%, 95% CI 0.2, 7.6), and a higher risk of anovulation (risk ratio [RR] 2.53, 95% CI 1.21, 5.26), compared with the middle tertile. Nuts and seeds were the only protein-rich foods associated with an elevated risk of anovulation (RR 2.12, 95% CI 1.17, 3.85). Conclusions Findings suggest that among women who meet the recommended dietary allowance for total protein, low intake of vegetable, but not animal, protein may disturb normal ovulatory function.