By Alex MlynekUpdated Jan 08, 2020
When I got pregnant with our second child, after almost a year of trying, I happened to be taking a break from eating added sugar. Did this coincidental timing play a role in helping me conceive?
It’s hard to say, but it may have, depending on what was going on in my body, says Toronto-based naturopathic doctor Mahalia Freed, who works with families trying to get pregnant. Reducing added sugar is thought to keep chronic inflammation away, which is just good for your overall health, and doing so may have helped regulate my blood sugar. In fact, in 2007, researchers from Harvard School of Public Health’s Department of Nutrition found a correlation between eating less sugar from carbohydrates and a reduced risk for infertility caused by ovulatory disorders. (To be clear, that doesn’t mean following a no-carb diet, it means reducing your intake of sweets, white bread and white pasta.) Their findings were published in the journal Obstetrics & Gynecology.
This potential connection was one of several ways the researchers determined women hoping to conceive may reduce the risk of infertility associated with ovulatory disorders. Eating fewer trans fats and boosting your intake of healthy monounsaturated fats (found in foods like extra-virgin olive oil and nuts) could also help. Focusing on plant-based sources of protein instead of meaty ones, and fitting in more fibre (found in dried beans, chickpeas, lentils, fruits and vegetables and whole grains), is also recommended. The researchers theorized that it's better to eat high-fat dairy products instead of low-fat ones. The more of the recommendations participants followed, the greater the risk reduction, they concluded.
But Freed says it’s important to look at these results carefully. The study participants self-reported what they ate, there was no control group, and there was no way to assess the nutritional quality of the food choices they made. This could really impact the protein question, for example. They compared a general vegetarian diet to a meat-eater’s diet, without looking at specifics. (This could mean comparing someone who ate grass-fed beef to someone who ate lentils, or it could mean comparing someone who ate lots of hot dogs to someone who loves deep-fried tofu.)
Also, the study the Harvard paper is based on began back in 1991, which was when low-fat products were more trendy anyhow, which means the women likely had very little fat in their diets. So, while the results showed that higher-fat dairy may be helpful in terms of fertility, it may just be that the increased fat it offered—more fat being good for fertility—was the key factor and not the dairy itself, Freed explains. The research wasn’t comparing people who ate no dairy to people who ate dairy, for example. “You're not controlling for all of the variables in this kind of study,” she says. “So, while those recommendations are out there, I wouldn’t hold to them.”
Registered dietitian Winny Wai Man Cheng works at the OriginElle Fertility Clinic and Women’s Health Centre in Montreal. She says while there is no concrete proof this approach to eating—or any diet, really—will help you get pregnant, it isn’t a bad thing to try, provided you are generally healthy. “It's well balanced, and will help the body get all of the nutrients that we need to support the future baby and have a healthy pregnancy,” she explains.
Al Yuzpe, a reproductive endocrinologist in Vancouver, and co-director of Olive Fertility Centre, recommends foods that are a balance between carbohydrates, fats and proteins. “Eating or eliminating one specific thing, unless there's an indication to do so, is not necessary.” He also points out that “there are women who get pregnant in every country in the world, and people in every country in the world don't eat the same way.”
Something you don’t want to do when trying to conceive, says Cheng, is to severely restrict your caloric intake. You need to nourish your body, and extreme fertility diets may not have the right balance of nutrients to do so, she explains.
Weight is another fertility factor that Caitlin Boudreau, a registered dietitian in Victoria, BC, points to. Cheng and Yuzpe agree that a woman’s weight (both “under” and “over”) is something to consider. In fact, Body Mass Index (BMI) is a standard measurement in the fertility world.
“We know that women who have a BMI of over 35 have, in general, more difficulty conceiving than women who have a BMI under 35. And women who have a BMI under 19 also tend to have more difficulty. So, the ideal is to have a BMI between 19 and 25,” Yuzpe explains.
Cheng says that being under or overweight can affect menstrual cycles, body metabolism and hormone balance.
But BMI is far from a perfect measure, says Boudreau, whose practice, Wee Nourish, focuses on child and family nutrition. “BMI is great for looking at large groups. It's not always great when you're dealing one-on-one with a client, because it doesn't take into consideration a lot of things, like cultural background, genetics and bone density.” People can be healthy at any size. “A woman who is active and eating a varied diet speaks a lot more loudly to me than somebody who is technically in the healthy weight category but isn't feeling or eating all that healthy,” says Boudreau. She also notes that it’s important to keep a balanced perspective and not overanalyze what you eat. Don’t get caught up with picking your diet apart. “I don't think women need to be told that they're doing everything wrong with their diet. Sometimes it's just some tweaking and some small changes that can really have a positive impact,” she says.
If you’re looking to make changes to boost your fertility right now, the best advice might be to increase the amount of fruits and vegetables you eat, especially antioxidant-rich berries, dark leafy greens and orange vegetables. Beyond that, there’s very little that can be widely applied as a fertility diet. “The overarching message is there is no one diet for fertility, but there are some things that are good for all of us, all the time, like eating a nutrient-dense diet,” says Freed.