The association of protein intake (amount and type) with ovarian antral follicle counts among infertile women: results from the EARTH prospective study cohort

Abstract

Objective To evaluate the association between protein intake (amount and type) and antral follicle count (AFC). Design Prospective cohort. Setting Academic fertility center. Population 265 women undergoing fertility treatments at an academic fertility center and participating in an ongoing study on environment and reproductive health. Methods We measured AFC in ultrasonographic evaluation among women undergoing infertility treatments. Women completed a previously validated semi-quantitative food frequency questionnaire. We used Poisson regression to evaluate the relation between protein intake and AFC while adjusting for age, body mass index, race, smoking status, and total energy intake. Main Outcome Measures Antral follicle count. Results Among 265 women (mean age: 35.0±3.9 years, 85% Caucasian), total protein intake (% energy) was unrelated to AFC. When protein from different food sources was considered separately, we found a negative association between dairy protein intake and AFC. The mean AFC was 14.4% (3.9%–23.7%) lower for women in the highest quintile of dairy protein intake than for women in the bottom quintile after adjusting for potential confounders (p-trend=0.04). This association was stronger among women who had never smoked (p-trend=0.002) but was not observed among previous smokers (p-trend=0.36). There were no associations between protein intake from either non-dairy animal or vegetable sources and AFC. Conclusion Higher dairy protein intake (≥ 5.24% of energy) was associated with lower antral follicle counts among women presenting for infertility treatment. These findings should be further investigated in prospective studies designed to also clarify the biology underlying the observed associations.

Diet and female fertility: doctor, what should I eat?

“…Regarding protein intake from nondairy sources and its effect on reproductive outcomes, available data point toward complex interactions between dietary protein and environmental contaminants. Ovarian antral follicle counts were not affected by either vegetable or animal protein intake from nondairy sources among women attending a fertility clinic (123). However, ovulation was negatively affected by increased meat intake among NHS-II participants.…”

“…In human populations with higher per-capita consumption of milk, the decline in fertility with aging was steeper and fertility at older ages was lower (122). Similarly, higher dairy protein intake, and not total protein intake, was associated with lower ovarian antral follicle counts among women presenting for infertility treatment (123). Although these findings suggest a possible negative impact of dairy on ovarian reserve, studies evaluating its impact on either overall fertility or ovulatory infertility do not support a similar adverse effect.…”

Milk and Dairy Products and Their Impact on Carbohydrate Metabolism and Fertility—A Potential Role in the Diet of Women with Polycystic Ovary Syndrome

“…Notably, the fat content of dairy products consumed by the participants had no influence on the strength of such a relationship. Contradictory results were arrived at by Souter et al [65], who assessed the relationship between milk protein intake and antral follicle count (AFC) in a prospective group of women of reproductive age. They concluded that higher total milk protein intake (≥5.24% of energy value or ≥2.3 glasses of milk daily) was associated with lower AFC.…”

Obesity, Insulin Resistance, and Hyperandrogenism Mediate the Link between Poor Diet Quality and Ovarian Dysmorphology in Reproductive-Aged Women

“…The aMED and DASH indices emphasize reducing the intake of red meat and increasing protein intake from fish and dairy products. Previous studies have shown the benefits of dairy protein on decreasing antral follicle counts in infertile women [ 125 ] and fish consumption on blastocyst formation [ 126 ], as well as the adverse effects of red meat consumption on ovulation [ 127 ]. Decreased consumption of sugar-sweetened beverages and dietary sodium is recommended in the DASH index and was shown to increase glucose regulation [ 128 ], reduce IR [ 129 ], and abdominal adiposity [ 130 ] in women.…”