Fertility is influenced both by uncontrollable genetic factors and modifiable lifestyle factors, such as exercise, smoking, excessive alcohol consumption and diet. If you have struggled with infertility or would simply like to improve your chances of conceiving and carrying a healthy pregnancy, there are a few modifiable risk factors that you can control. One of the most impactful ways to increase your fertility is for both partners to adopt a whole food plant based diet. Let’s take a deep dive and find out what exactly the link is between plant based diets and fertility.
1. Increased ovulatory fertility
According to a 2018 study in the journal Human Reproduction, lower intake of fruit and higher intake of fast food in the period before conception are associated with a longer time to conceive and decreased fertility.
Women who ate fruit less than one to three times a month in the month before conception took two weeks longer to conceive on average than women who ate fruit three or more times a day. From the lowest to highest categories of fruit intake, time to conceive increased from 0.6 to 0.9 months, while infertility increased from 4% to 8%. Over 5500 women of the general population were studied.
A 2008 study in the American Journal of Obstetrics and Gynecology concluded that replacing animal sources of protein with vegetable sources of protein may reduce ovulatory infertility risk. Ovulatory infertility was nearly 40 percent more likely in women who ate the highest amount of animal proteins, compared to vegan women who get most of their protein from nuts, soy, and beans.
2. Improved sperm quality
A 2021 study in the Journal of Human Reproductive Sciences showed that total sperm count and motility were significantly higher in the vegan group. Additionally, the proportion of sperm with DNA damage was significantly higher in the non-vegan group.
Higher intake of omega-3 fatty acids is also positively related to sperm morphology. You can get omega-3s from walnuts, chia, flax and hemp seeds, as well as algae oil, without the drawbacks of heavy metals in fish. Some fruits and vegetables can also maintain or improve semen quality.
3. Avoiding heavy metals found in seafood and meat
A 2022 study in the International Journal of Molecular Sciences concluded that a “strong adherence to a healthy dietary pattern based mainly on plant foods and fish is positively correlated with indicators of sperm quality.”
However, fish and other aquatic life often contain high levels of mercury and other toxins, which are linked to infertility. Common types of seafood, such as tuna, scallops and shrimp, contain mercury, cadmium, lead and other toxic heavy metals. The highest cadmium levels are found in tuna, while the highest lead levels are found in shrimp and scallops.
Heavy metal exposure (e.g. cadmium and lead) has been observed to be significantly associated with a reduction in fertility, requiring increased time to conceive for couples with higher exposure.
Even if you had adopted a plant based diet as a child, though, it may have been too late to avoid all exposure. As early as in utero and nursing, children who are exposed to relatively low dioxin doses can experience permanently reduced sperm quality. Maternal beef consumption and possibly xenobiotics in beef may even alter a man’s testicular development in utero and negatively impact his reproductive capacity, as beef can also be contaminated by cadmium and lead.
Ideally, you would eliminate fish from your diet at least five years before conceiving to significantly reduce children’s exposures to heavy metals in utero and while breastfeeding. Research has predicted that substituting plant foods for fish would reduce prenatal and breastfeeding mercury exposures by 37% each and childhood exposures by 23%.
4. Reduced saturated fat consumption
A 2012 study in Human Reproduction found that high intake of saturated fats was negatively related to sperm concentration. Increasing saturated fat intake by just 5% of total calories is associated with a 38% lower sperm count. Xenoestrogens build up in animal fat, especially fish, and can negatively impact fertility. While red meat negatively impacts sperm count too, male fertility is not just about sperm count. Meat consumption also negatively impacts sperm quality. It’s also about sperm quality, including factors such as sperm motility.
According to a 2009 study in Fertility and Sterility, frequent intake of high fat foods like meat or milk may negatively affect semen quality, while some fruits and vegetables can maintain or improve semen quality.
Increased saturated fat intake by 5% is associated with 38% lower sperm count. Increased consumption of xenobiotics, mainly xenoestrogens or certain anabolic steroids, are associated with poor semen quality. Xenoestrogens can accumulate in fat-rich foods, such as meat, and may be partly responsible for the decline in semen quality.
Frequent intake of fatty foods like meat and dairy may negatively affect semen quality in humans.
5. Increased intake of antioxidants
Crowding out the consumption of animal based foods, which lack antioxidants, typically means eating more antioxidant-rich fruits and vegetables and less saturated fat. A 2011 study in Fertility and Sterility found that higher intake of antioxidants and micronutrients have a positive impact on sperm quality. It also found that intake of vegetables led to a higher implantation chance. Additionally, dietary antioxidants have been shown to help reduce sperm DNA damage.
But does soy increase infertility?
Many men on plant-based diets are likely to consume more soy products, such as tofu, tempeh, edamame and soy milk. You might have heard rumors about soy and male infertility and think you or your male partner should avoid soy while trying to conceive.
The study that generated this concern was a 2008 study in the Journal of Human Reproduction. While the media reported that increased soy consumption decreased sperm concentration, it failed to mention the other details. Soy appears to stimulate the prostate to create more ejaculate fluid. Increased soy consumption appears to increase the volume of ejaculate fluid, but does not impact the actual number of sperm.
According to a 2010 study published in Fertility and Sterility, consumption of soy protein of low or high isoflavone content does not adversely affect semen quality in a sample of healthy adult men. Additionally, a meta-analysis in the same journal showed that soy foods and isoflavone supplements from soy do not affect testosterone levels in men.
Finally, a 2015 study found that soy consumption was unrelated to IVF treatment outcomes, further suggesting that soy may have little to no impact on overall sperm quality.
Other lifestyle factors to increase fertility
Plant-based diets have also been shown to be effective in reducing the risk of becoming overweight or obese, as well as aiding in weight loss. In this way, plant-based diets also indirectly increase fertility, as being overweight or obese has a strong negative impact on fertility.
Other lifestyle factors that can negatively impact fertility include smoking, excessive alcohol consumption, use of recreational drugs and maternal and paternal obesity. Additionally, increased consumption of foods with high glycemic index and trans fats are associated with higher risk of ovulatory infertility.
Of course, in addition to adopting a plant based diet, be sure to take B12, vitamin D, and any prenatal vitamins your doctor recommends to ensure the healthiest pregnancy possible.
5 ways plant based diets and fertility are connected
So, now you can enumerate exactly how plant based diets and fertility are connected. Studies show that by improving ovulatory fertility, increasing sperm quality, avoidance of heavy metals, reduced saturated fat intake and increased antioxidant consumption, whole food plant based diets can help increase your fertility.
And if anyone challenges your decision to adopt a whole food plant based vegan diet prior to conceiving, have this fact up your sleeve: “It is the position of the Academy of Nutrition and Dietetics that appropriately planned vegetarian, including vegan, diets are healthful, nutritionally adequate, and may provide health benefits for the prevention and treatment of certain diseases. These diets are appropriate for all stages of the life cycle, including pregnancy, lactation, infancy, childhood, adolescence, older adulthood, and for athletes.”
Whether for fertility, prevention of chronic disease, or sustainability, plant-based diets take the (vegan) cake.
