An awful lot of things can affect fecundability — that is, the probability of conceiving within a single menstrual cycle — but can soda really decrease your chances of getting pregnant? A new study suggests that it might, although it turns out that there’s a surprising twist at play here, too: According to the study, which was led by researchers from the Boston University School of Public Health and published recently in the journal Epidemiology, soda might have an effect on a couple’s fertility no matter which partner drinks it.
Now, it’s worth noting that the study didn’t focus on soda specifically; it zeroed in on sugar-sweetened beverages more generally, examining a range of options of which soda was just one. (Others included fruit juice, energy drinks, and sports drinks.) But given that a Gallup poll from 2012 found that about half of American adults reported drinking at least one glass of soda a day, and in 2016, about half of American adults drank a sugar-sweetened beverage every day, according to the Centers for Disease Control and Prevention (CDC) — well, it seems that when it comes to our sweet drinks, soda (or pop, if you prefer) is one of our very top picks.
The study’s participant pool encompassed 3,828 cisgender women between the ages of 21 and 45 who were trying to conceive (without the use of fertility treatments) and 1,045 of their cis male partners who were at least 21 years of age or older. The researchers followed the participants between June of 2013 and May of 2017 for up to 12 menstrual cycles or until pregnancy occurred.
The research itself was conducted primarily with questionnaires, with participants first answering a baseline questionnaire which included items about how much soda, juice, energy drinks, and sports drinks they had consumed during the past four weeks. Then, the women participants completed follow-up questionnaires every two months, which allowed the researchers to estimate time-to-pregnancy. They were also able to “adjusted fecundability ratios (FR) and 95 percent confidence intervals (CIs) according to intake of sugar-sweetened beverages,” according to the paper.
The researchers found that consuming at least seven sugar-sweetened beverages per week, or about one per day, was associated with reduced fecundability, regardless as to which partner was drinking them; what’s more, drinking more than seven sugar-sweetened drinks per week resulted in an even lower rate of fecundability. Said lead author and professor of epidemiology Elizabeth Hatch according to Science Daily, “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.” She continued, “Couples planning a pregnancy might consider limiting their consumption of these beverages, especially because they are also related to other adverse health effects.”
I’ll be honest: At first, I was… skeptical. There is a lot of bad science journalism out there, full of oversimplifications and misinterpretations of what a study is actually saying — and the assertion that drinking soda can stop you from getting pregnant, no matter which partner is drinking it, seems like the kind of idea that’s ripe for this kind of oversimplification and misinterpretation. But it turns out that it does actually line up with previous research about how diet in general and sugar intake in particular can affect fertility and pregnancy in people of all genders.
A 2009 study based off the Nurse’s Health Study, for example, examined how the consumption of carbohydrates affects fertility in people with uteruses — and the researchers did, in fact, find a “positive association between the quality of carbohydrate and ovulatory infertility.” Writing in Newsweek, study author Jorge E. Chavarro, M.D. elaborated on the findings, noting (emphasis mine), “Eating lots of easily digested carbohydrates (fast carbs), such as white bread, potatoes, and sugared sodas, increases the odds that you’ll find yourself struggling with ovulatory infertility,” while “choosing slowly digested carbohydrates that are rich in fiber can improve fertility.” Why does this happen? Because carbs are one of the major determinants of our levels of blood-sugar and insulin — and when these levels get too high,they mess with our hormones, which in turn messes with ovulation.
What’s more, a study conducted by British researchers and presented at the American Society for Reproductive Medicine congress in 2016 found a link between consuming artificial sweeteners of the variety used in diet sodas and lower rates of ovulatory fertility — and one between consuming sugar in drinks like regular soda or taken with coffee and poor egg and embryo quality.
Meanwhile, a 2014 study, of which Dr. Chavarro was again a co-author, found an association between drinking lots of sugary drinks and low sperm motility. Drinking things like soda or sports drinks regularly didn’t have an affect on sperm concentration or shape or in ejaculation volume — but apparently the little things just don’t swim as well when you drink a lot of sugar-sweetened beverages.
So, despite my initial skepticism, it seems that there’s likely some truth to the matter — although it’s also worth keeping in mind that there are a lot of other things that can affect fertility, especially when it comes to what you eat and drink. As The Daily Beast pointed out in 2011, sperm count can be affected by things like whether or not you eat soy-based foods, how much trans-fatty acids you consume, or whether you follow a Dutch diet; meanwhile, ovulatory fertility can be affected by everything from whether you eat a lot of iron-rich foods like lentils and spinach to what your dairy-consumption habits are like. Either way, though, if you’re trying to conceive, it might be worth cutting out sugar-sweetened drinks; even if it’s not a guarantee, it still might help.