Diets with a high fat concentration could have a detrimental effect on the fertility of both men and women, according to results of two new studies.
The findings were presented at the American Society for Reproductive Medicine (ASRM) Annual Meeting in Baltimore.
Effect of Trans Fats on Male Fertility
According to Mariel Arvizu, MD, of the Harvard T.H. Chan School of Public Health in Boston, previous research demonstrated an inverse association between dietary trans fatty acids and total sperm count in a sample of young men and that trans fatty acid concentration present in semen was also inversely related to sperm concentration.
“However, semen samples are usually not considered good predictors of clinical outcomes in couples undergoing [assisted reproductive technologies (ART)], thus we wanted to explore the impact of trans fat consumption in males [and] clinical outcomes for the couple,” Dr Arvizu told Endocrinology Advisor.
The prospective cohort study included 141 men who were part of couples presenting to an academic fertility center for ART (n=246 cycles). Dr Arvizu and colleagues determined diet via a validated food questionnaire and culled outcomes data from medical records.
Median age of men was 36.9 years, and median total fat intake was 32% of calories per day, according to the data.
Among couples with the highest male partner intake of trans fat, researchers reported the lowest fertilization rates.
“There was a consistent inverse association between trans fat intake in males and fertilization rates among couples that supported previous findings,” Dr Arvizu said. “Additionally, we observed a decline in pregnancy, implantation, and live births when comparing higher intake of trans fat with lower intake, but those results were not statistically significant.”
Dr Arvizu noted that despite detrimental effects of trans fats being extensively associated with cardiovascular disease, evidence in reproductive health is limited.
“Although our study may suggest a role of trans [fat] intake in infertility, further studies with larger sample sizes should confirm our findings,” she said.
High-Fat Diets in Female Mice
In a separate study, also presented at the meeting, Malgorzata E. Skaznik-Wikiel, MD, FACOG, and fellow researchers from the University of Colorado, Denver sought to determine the impact of high-fat diets on ovarian function, fertility, and markers of inflammation independent of obesity.
“It is a well-known fact that obese women have an increased risk of multiple reproductive adverse effects, including anovulation, irregular menses, difficulty in achieving pregnancy, poor in vitro fertilization outcomes, and increased risk of pregnancy complications; however, it is unknown if a high-fat diet without obesity plays a role as well,” Dr Skaznik-Wikiel said in an interview.
The prospective animal study involved 5-week old mice fed either a low-fat diet with 10% fat (control) or a high-fat diet with 60% fat. At 10 weeks, high-fat diet mice were stratified into 3 groups depending on body weight.
Ten-week data suggested that mice given the high-fat diet had depleted primordial follicle numbers (ovarian reserve) regardless of obese phenotype, with the number of growing follicles not differing significantly between the 3 high-fat diet arms.
“At the beginning of the study, we were expecting to see that high-fat diet exposure in lean individuals would not have a significant effect on reproduction,” Dr Skaznik-Wikiel said.
However, she noted that they found that “high-fat diet exposure without the obese phenotype can be almost equally detrimental to fertility as obesity itself.”
Dr Skaznik-Wikiel suggested endocrinologists better counsel patients about maintaining not just a healthy weight but also a healthy diet, even if they are lean.
“Future studies should focus on explaining why high-fat diets cause ovarian dysfunction and if the changes are reversible with switching to a low-fat diet,” she said.
- Arvizu M, Tanrikut C, Hauser R, Keller M, Chavarro JE. Abstract O-271. Male Dietary Trans Fat Intake Is Inversely Associated To Fertilization Rates.
- Shaznik-Wikiel ME, Polotsky AJ, McManaman JL. Abstract O-272. High-Fat Diet Causes Compromised Fertility and Increased Pro-Inflammatory Cytokines Independent of Obesity. Both presented at: ASRM Annual Meeting; Oct. 17-21, 2015; Baltimore.