The question of whether there is a connection between diet, nutrition, and fertility is one that researchers have been trying to answer for decades. And it appears that, after a comprehensive review by the Harvard School of Public Health, there is reason to believe nutrition can impact fertility.
So what foods can help positively increase your chances of getting pregnant? And what foods should be avoided for this purpose? These are the two popular concerns we’ll be addressing in this article.
Looking at fertility as a whole
Let’s briefly examine what we mean by fertility. According to most definitions, fertility refers to the “natural capacity to conceive a child,” and approximately 12 to 15% of all couples trying to conceive will encounter a fertility issue. Most of the time, couples do not even realize there may be a fertility problem until after they have been having unprotected sexual intercourse for a year without getting pregnant. This can be the result of a “silent” fertility issue. Once investigated, however, most of the time causes of infertility can be attributed to one or more of the following risk factors:
- Being over the age of 35
- Chronic disease
- Family history of infertility
- Medication side effects (some medications can reduce your chances of conceiving)
- Hormonal imbalances
There also seems to be some evidence that, according to Vox, “many people aren’t having as many children as they would like to.” Surveys within the US indicate the ideal number of children desired by those looking to be parents has hovered around 2.5 for the past 20 years, but actual fertility rates have declined. Why would this be? Well, it’s a mix of factors.
It’s true that simultaneously: 1) people in developed nations are choosing to have children later in life, 2) many couples list economic concerns as the reason for delaying children (or having fewer children), and 3) the fact that infertility rates themselves are rising.
All this is to say: if you are concerned about your fertility, you are certainly not alone. And if you have struggled to conceive, then know that there are many individuals and couples like yourself who take a year - or longer - to get pregnant.
Indeed, conceiving may not be quite as easy as many people have been led to believe, especially if you fall into any of the ‘risk factors’ listed above. That being said, it’s important to note that just because someone may be at risk for lower fertility, does not mean they won’t be able to get pregnant or are certain to have issues.
Now let’s discuss how nutrition may be able to improve an individual’s, or a couple’s, chances of getting pregnant.
Gaps In The Research on Nutrition and Fertility
Before going into the findings of Harvard’s review, we’d like to take a moment to acknowledge that, though there has historically been a tendency to emphasize (or even blame) women’s fertility in cases of couples who have issues conceiving, the ‘root cause’ of most couple’s infertility is - statistically speaking - shared by both men and women.
In other words, according to the US Department of Health, “in one-third of infertile couples, the problem is with the man,” in another third the problem can’t be identified (or is shared), and in another third, “the problem is with the woman.”
Interestingly, though the problem of infertility is shared by both genders in heterosexual relationships, Harvard Medical School acknowledges in the majority of research they reviewed “studies did not examine the impact of paternal diet on the rate of successful pregnancies.”
So though this article is focused on women’s diets and how they can be optimized to impact fertility, it should be acknowledged that men’s diets also matter, and more research is needed in this area to give heterosexual couples the best possible chances of naturally conceiving.
Foods Linked To Improved Fertility
A review of studies carried out by Harvard School of Public Health found that for women trying to conceive naturally, the following vitamins and nutrients were linked to improved fertility:
- Folic acid
- Vitamin B12
- Omega-3 fatty acids
- Overall healthy diet
So where and how can you increase your intake of these vitamins and nutrients into your diet? Let’s first discuss food sources, and then supplements.
- Folic Acid
Folate is the natural form of B9, and it is a water-soluble vitamin naturally found in a number of foods (though you can also find it added to fortified foods).
So what does folate do?
In a nutshell: a lot. It helps to form DNA and RNA, while also playing a critical role in protein metabolism and the production of healthy red blood cells. You may have heard of folate before, as it really is spotlighted during “periods of rapid growth” - namely, pregnancy and fetal development.
Find it in the following foods:
- Dark leafy green vegetables
- Sunflower seeds
- Fresh fruits
- Whole grains
If you are choosing between folate-fortified foods and supplementation, Harvard School of Public Health recommends you opt for a supplement (at the right dosage) given that it is better absorbed by this method.
Since folate is water-soluble, some people mistakenly believe they can’t supplement ‘too much’ with this vitamin, but experts caution against this: supplementing with high levels of folate can mask a vitamin B12 deficiency (which can cause irreversible damage to one’s long-term health when occurring over a long period of time). As such, a lower range of 400mcg a day or less should be enough to meet your dietary needs, especially if consuming foods high in folate.
- Vitamin B12
Most people - except for those who have issues processing B12, or those who follow a vegan or vegetarian diet - consume enough B12 without issue through their diet. But that doesn’t mean it should be forsaken: B12 does plenty of important things in the body, not least keeping your nerve and blood cells healthy, helping produce DNA, and metabolizing cells.
B12 can be found in the following foods:
- Beef, liver, and chicken
- Fish and shellfish
- Fortified plant-based products
Similar to folate, vitamin B-12 is a water soluble vitamin, so any excess in your body will be excreted. If you follow a vegetarian or vegan diet, have issues with absorption, or exhibit signs of vitamin-B12 anemia, then you will want to consider being tested for a deficiency, and possibly taking a B-12 supplement. Since the recommended daily intake hovers around 2.4mcg, and most supplements range from 250mcg to 2500mcg, you may want to consider taking a lower dose in accordance with your doctor’s guidance, to prevent unwanted side effects from too much B-12 (namely rosacea and acne).
- Omega 3
The American diet is filled with plenty of foods rich in Omega 6 (such as meat, soybean oil, and fast food) but Omega 3’s can feel harder to come by without consciously incorporating some foods rich in this fatty acid.
According to the results of this study, Omega 3’s are linked to improved fertility (while also being excellent for reducing inflammation and offering a bunch of other health benefits!). So where can you easily find Omega 3’s? Well, first let’s discuss quickly what Omega 3’s are made up of. EPA, DHA, and ALA are all fatty acids that are part of the omega 3 family. ALA is found in plant-based foods, while DHA and EPA are found in fatty fish. So the best way to get a mix of all 3 is to choose a mix of foods from the following two lists.
For DHA and EPA-rich foods, look to:
- Limit your consumption to 2-3 servings per week, as sardines contain mercury, which can accumulate in your bloodstream.
ALA can be found in chia seeds, flax seeds, and walnuts.
Vegans and vegetarians may struggle to get DHA and EPA if they don’t consume fish, so it is recommended they try algae-oil, one of the only plant-based sources of the first two types of omega 3.
If you choose to supplement with fish oil, look for supplements that are rich in DHA and EPA, and list the quantity of these fatty acids per serving (versus other unspecified Omega 3s) on the back of the packet.
- Healthy diet
This is the most general recommendation of the Harvard Health study review, but it makes sense: when your body is healthy, energized, and has enough sustenance, it can devote resources to helping you conceive.
- Opt for more vegetables and fruits
- Particularly leafy greens, berries, and whatever else you enjoy the most
- Make sure to consume enough whole grains, protein and healthy fats
- Aim to always pair your carbohydrates with fiber, fats, and protein to prevent blood sugar spikes and crashes
This study gives the example of the Mediterranean diet as a healthy, balanced diet that may improve your fertility. If you look at what this diet consists of, you’ll see it is dominated by vegetables, fruits, healthy fats, whole grains, seafood, and dairy.
Foods That Can Negatively Impact Fertility
As you might expect, in their review, researchers from the Harvard School of Public Health and Harvard Medical School found that diets rich in trans-fat and unhealthy foods had negative effects on fertility.
Specifically, diets dominated by:
- High nitrate meats
- Sweets and other candy (when not consumed with fiber, fat, and protein to slow carbohydrate absorption)
- Sweetened beverages (when not consumed with fiber, fat, and protein to slow carbohydrate absorption)
These foods were not conducive toward increasing one’s odds of conceiving naturally. That being said, the aforementioned groups are not inherently ‘bad’ foods, and should not be villainized (oftentimes, these foods are turned to for convenience, enjoyment, or to share with friends and family). However, a high consumption of these items can crowd out more nutrient-dense foods that support fertility.
Similar to many other health goals, there is no ‘silver’ bullet for getting pregnant naturally, but there are research-backed ways you can try to improve your odds of conceiving. With the guidance of your physician or registered dietitian (or turning to a hormonal-health, female-focused resource like Allara) consider incorporating folate, B12, and omega 3s more heavily into your diet or supplement regimen, while also working in a balance of all food groups, including of protein, nutrient-dense fats, and carbohydrates (like whole grains, veggies, fruits, and legumes), as much as possible.
Interested in learning more about nutrition and the impact it has on your body? Check out our article on whether organic food really is better for you.
Allara Health provides personalized treatment for hormonal, metabolic & gynecological conditions that utilizes a holistic plan that merges nutrition, lifestyle, medication and supplementation, and ongoing, expert support to heal your body.