A US study has found that the intake of one or more sugar-sweetened beverages per day – by either partner – associated with a decreased chance of getting pregnant.
The amount of added sugar in the US diet has increased dramatically over the last 50 years. Much of that increase comes from higher intake of sugar-sweetened beverages, which constitute approximately one-third of the total added sugar consumption in the US diet. While consumption of these beverages has been linked to weight gain, type 2 diabetes, early menstruation, and poor semen quality, few studies have directly investigated the relationship between sugary drinks and fertility.
“We found positive associations between intake of sugar-sweetened beverages and lower fertility, which were consistent after controlling for many other factors, including obesity, caffeine intake, alcohol, smoking, and overall diet quality,” says lead author Dr Elizabeth Hatch, professor of epidemiology at Boston University. “Couples planning a pregnancy might consider limiting their consumption of these beverages, especially because they are also related to other adverse health effects.”
About 15% of couples in North America experience infertility. Identifying modifiable risk factors for infertility, including diet, could help couples conceive more quickly and reduce the psychological stress and financial hardship related to fertility treatments, which are associated with more than $5bn in annual US healthcare costs.
Through the Pregnancy Study Online (PRESTO), an ongoing web-based prospective cohort study of North American couples, the researchers surveyed 3,828 women aged 21 to 45 living in the US or Canada and 1,045 of their male partners. Participants completed a comprehensive baseline survey on medical history, lifestyle factors, and diet, including their intake of sugar-sweetened beverages. Female participants then completed a follow-up questionnaire every two months for up to 12 months or until pregnancy occurred.
Both female and male intake of sugar-sweetened beverages was associated with 20% reduced fecundability, the average monthly probability of conception. Females who consumed at least one soda per day had 25% lower fecundability; male consumption was associated with 33% lower fecundability. Intake of energy drinks was related to even larger reductions in fertility, although the results were based on small numbers of consumers. Little association was found between intake of fruit juices or diet sodas and fertility.
“Given the high levels of sugar-sweetened beverages consumed by reproductive-aged couples in North America, these findings could have important public health implications,” the authors concluded.
Lauren Wise, BU professor of epidemiology, was senior author on the study. Other co-authors from Boston University School of Public Health include: Amelia Wesselink, doctoral student in epidemiology; Kristen Hahn, former postdoctoral fellow in epidemiology; James Michiel, former MPH student; and Kenneth Rothman, professor of epidemiology. Other co-authors from Aarhus University Hospital in Denmark include: Ellen Mikkelsen, senior researcher; and Henrik Toft Sørensen, head of the clinical epidemiology department.
Dietary factors, including sugar-sweetened beverages, may have adverse effects on fertility. Sugar-sweetened beverages have been associated with poor semen quality in cross-sectional studies, and female soda intake has been associated with lower fecundability in some, but not all, studies. We evaluated the association of female and male sugar-sweetened beverage intake with fecundability among 3828 women planning pregnancy and 1045 of their male partners in a North American prospective cohort study. We followed participants enrolled between June 2013 and May 2017 until pregnancy or for up to twelve menstrual cycles. Eligible women were aged 21-45 years (male partners ≥21), attempting conception for ≤6 cycles, and not using fertility treatments. Participants completed a comprehensive baseline questionnaire, including questions on soda (sugar-sweetened and diet), fruit juice, energy, and sports drink consumption during the previous 4 weeks. We estimated time-to-pregnancy from follow-up questionnaires completed every 2 months by the female partner. We calculated adjusted fecundability ratios (FR) and 95% confidence intervals (CIs) according to intake of sugar-sweetened beverages using proportional probabilities regression. Both female and male intakes of sugar-sweetened beverages were associated with reduced fecundability (FR= 0.81; 95% CI: 0.70, 0.94 and 0.78; 95% CI: 0.63, 0.95 for ≥ 7 sugar-sweetened beverages per week compared with none, for females and males, respectively). Fecundability was further reduced among those who drank ≥7 servings per week of sugar-sweetened sodas (FR= 0.75, 95% CI: 0.59, 0.95 for females and 0.67, 95% CI: 0.51, 0.89 for males). Diet soda had little association with fecundability.
Hatch, EE; Wesselink, AK; Hahn, KA; Michiel, JJ; Mikkelsen, EM; Sorensen, HT; Rothman, KJ; Wise, LA