Updated: July 5, 2023

Disclaimer: I am a registered dietitian, but I am not your dietitian, nor a doctor or obstetrician. This article is meant for informational purposes only and is not intended as individual advice.

Food impacts so many factors of our health, even those that don’t always seem connected, so it’s no surprise that there is a connection between diet and fertility. While it may not always seem like it, what we choose to eat (or not eat) significantly affects how our bodies function!

This is an important topic to me as a dietitian and mom. I’d been thinking about preparing my body to have kids for years. I wanted to at least be doing what I knew I could nutritionally and physically to set myself (and husband) up for success. Fortunately, so many nutrition principles that are recommended for overall health, are also helpful for fertility!

For me, preparation meant things like incorporating healthy fats in my diet, not going too low calorie, low fat, or low carb. I avoided aiming for a very low body fat percentage (a.k.a. not losing too much weight when that was the mindset I was in). I tried to stay active, but avoid over exercising. I’d been using safer skincare and cleaning products for years to reduce exposure to endocrine disrupting chemicals. I tried to maintain lower stress levels, took the proper vitamins, and, of course, focused on consuming nutrient dense foods (especially those naturally high in folate).

But, I still wanted to dig deeper and have a better understanding of foods that can impact fertility, both positively and negatively. I’ve also been more and more questions on this topic more recently, and continue to find myself working with women diagnosed with Polycystic Ovarian Syndrome (PCOS), or stuggling with some level of hormone imbalance.

Needless to say, it’s been something on my mind and that I’ve been researching a lot lately. I have read more articles and scientific studies than what’s referenced here, but the following provides an overview.

Foods that can negatively impact fertility

Added Sugars & Refined Starches

When we eat sugar (or any type of carbohydrate), the body’s goal is to break it down into its smallest form (glucose) and use it for energy within the body’s cells. To do this, the body must also produce insulin (a hormone), as insulin is what actually allows glucose into the cells.

The more sugar in the diet, the more insulin is produced. Additionally, added sugar is processed much more quickly than complex carbohydrates or fiber because it’s so simple in structure. Essentially, when a lot of added sugar is consumed at once, a lot of insulin is produce in order to store or utilize that sugar for energy.

We want this process to occur because without it, our cells wouldn’t get the proper energy! Our brain alone uses around 120 grams of carbohydrates each day. Our muscles store carbohydrates and that’s how they function without being incredibly sore and weak. Our thyroid needs active T3 hormones, which aren’t made unless insulin is produced. So, it is a necessary process. But, like anything, we don’t want too much of it.

The problem with too much insulin when it comes to fertility is that it’s similar to the ovarian hormones that help eggs mature.

…the ovaries confuse elevated insulin with their own growth factors and down-regulate the production of reproductive hormones. This can potentially interfere with egg maturation and ovulation…Consistently elevated insulin levels, as seen with insulin resistance, can cause the cells in the ovarian tissues to produce too much testosterone. This excess of testosterone may cause abnormal hair growth, acne, and hair loss that is sometimes associated with polycystic ovary syndrome, or PCOS (1).

Keep in mind, the problem is with excess. By choosing more whole-food carbohydrates with added fiber (like apples instead of apple juice), glucose absorption is slowed as it’s broken down, thereby producing less insulin.

A good rule of thumb is to choose carbohydrate-containing foods without a label (like whole fruit, potatoes, squash, vegetables, etc.) and aim for labeled products with a higher percentage of fiber (greater than or equal to 20% is considered “high”, while less than or equal to 5% is considered “low”) when looking at the daily value. This is especially important because refined carbohydrates are processed very similarly to added sugar and will also lead to high insulin production.

The American Heart association recommends no more than 24 grams (or 6 teaspoons: 1 teaspoon = 4 grams) for women, and no more than 36 grams (9 teaspoons) for men of added sugar per day from all sources. This includes the sugar from common sweets and sugary beverages, but also the hidden added sugars in breads, condiments, yogurt, granola/granola bars, cereal, etc.

Soda, especially, appears to greatly influence fertility:

In another prospective cohort study of 3,628 women planning to become pregnant, women who reported consuming 3 or more servings of soda per day had a 52% lower (95% CI, 0.21, 1.13) rate of pregnancy compared to women who did not report any soda consumption… Existing data suggest that high consumption of sugar is associated with lower semen quality and increased infertility among men (2).

Red & Processed Meats

Research has linked higher consumption of red and processed meats and higher animal protein intake in general with higher rates of infertility among men and women (2).

This is something I would not actually have thought of in relation to fertility. We generally don’t eat a lot of red meat because of expense and the fact that I usually only want it about once a month. We naturally don’t eat much processed meat for heart health, and I just don’t really like it (bacon tastes like I’m eating pure grease 😛 – it smells good and I like the flavor, but I just can’t do it). There is, however, a connection to conception:

Those who ate fewer than 1.5 servings of processed meats per week had a 28% better chance of achieving pregnancy compared with men who ate 4.3 servings per week.

However, men who ate the most poultry had 13% higher fertilization rates than men who ate the lowest amount of poultry (2).

Red and processed meats also tend to be higher in saturated and trans fats, which have both been shown to lower fertility (3). Lower semen concentrations in males has specifically been associated with higher saturated fat intake.

Additionally, one study found that women who ate more vegetable protein than animal protein had lower rates of infertility related to ovulation disorders (3).

As a dietitian, I generally recommend including a variety of proteins from both animal and plant sources, especially as we continue to learn how beneficial certain beans and legumes are for our gut microbiome and overall health (they also happen to be a great source of folate!).

Low-Fat Vs. High Fat Dairy Products

While saturated fats (fats coming from animal sources and tropical oils) have been linked to lower rates of fertility, full-fat dairy products have actually been shown to be beneficial for women by reducing the risk of infertility related to ovulation. Low-fat dairy products are associated with an increased risk.

Women who ate full fat dairy products at least once per day had a 25% lower risk of [in]fertility from ovulatory disorders, compared with women who ate these foods less frequently, at around once per week.

Additionally, women who ate more than two servings of low fat dairy per day were 85% more likely to experience infertility due to lack of ovulation, compared with those who ate low fat dairy only once a week (3).

For men, however, the same reduction in semen concentrations seen with saturated fat is still seen with that of dairy products. So, low-fat dairy may actually be more beneficial for male fertility, even though the opposite is seen in women.

Alcohol & Caffeine

There’s mixed information on whether or not these beverages affect fertility, and if so, how much.

Information on caffeine from Healthline:

One older 1997 study suggests that women who consume more than 500 milligrams of caffeine daily take up to 9 1/2 months longer to get pregnant.

However, other studies did not find a strong link between caffeine intake and an increased risk of infertility.

Consider limiting your caffeine intake to one or two cups of coffee per day to be on the safe side (4).

Information on alcohol from Healthline:

One 2016 study found that having more than 14 alcoholic drinks per week was associated with a longer time to get pregnant.

An older 2004 study involving 7,393 women found that a high alcohol intake was associated with more infertility examinations.

However, the evidence on moderate alcohol consumption is mixed. One older study found no link between moderate consumption and infertility, while other studies report that moderate intake can affect fertility.

Ultimately, avoiding excessive consumption of alcohol is recommended. I’ve also polled many dietitians and have seen recommendations from other RDs who suggest avoiding alcohol completely when trying to conceive.

Foods that support fertility

Antioxidant-Rich Foods

I’m a big fan of including plenty of antioxidants in the diet anyway for a multitude of health benefits, so the recommendation to so to boost fertility is not surprising!

Free radicals damage cells in the body, including sperm and egg cells. Antioxidants, however, deactivate these free radicals.

The good news? Antioxidants are present in most fruits, vegetables, nuts, seeds, and even fish. The highest sources include foods that are rich in color (because that’s what antioxidants are: colors, as well as nutrients like vitamin c, vitamin e, selenium, folate, and zinc). Think berries, beets, Battlestar Galactica (kidding – but, if you’ve seen The Office, you get it), dark leafy greens, winter squash, tomatoes, etc. So, if you are eating a healthful diet with plenty of produce and whole foods, you’re likely getting lots of antioxidants!

The bad news? Most processed foods that contain refined flour, sugar, and/or refined vegetable oils (canola, corn, soybean, cottonseed, etc.) are more prone to inflammation, which means they can contribute to the production of free radicals. So, along with consuming more antioxidant-rich foods, it would be beneficial to consume less inflammatory/processed foods as well. A word on canola oil. Cold-pressed canola oil may actually be beneficial and help reduce inflammation. Limiting vegetable oils as a whole reduces the intkae of omega-6 fats, which promote inflammation when they oxidize, or are consumed in excess of omega-3 fats. This is why I recommend sticking with extra virgin olive oil when possible. It has natural antioxidants that prevent oxidation, and it is low in omega-6 fats.

One Word: FIBER

Like antioxidants, I am always promoting fiber consumption for overall health as well! Adequate fiber intake is associated with healthy digestion, skin health, heart health, brain function, stabilizing hunger and blood sugar levels, and so much more. Including more fiber-rich foods often seems to be my answer for everything. So, again, it’s not surprising that it may aid fertility as well.

Fiber can bind excess hormones, like estrogen, to the intestines and help rid it from the body through elimination. Soluble fiber is especially beneficial as it’s associated with lower levels of estrogen. Sources of soluble fiber include whole grains (like oats), fruit, winter squash, chia seeds, beans (also a great source of folate), and avocados (4).

Fiber also helps balance blood sugar, which we already learned impairs fertility if imbalanced (like if we consume too many added sugars or refined flour).

In general, it’s recommended that women aim to consume at least 25 grams of fiber each day, while men aim for 38 grams. Wondering how to calculate this? I love using Cronometer as it tracks and adds up fiber!

Some people don’t actually need increased fiber though, so check with your healthcare provider before consuming ample amounts of extra fiber.

A Bigger Breakfast

Ahh breakfast. What a controversial topic these days. Some find they do better with it, some without. When it comes to fertility, however, it may be beneficial to not only include a morning meal, but to make it a substantial one.

One study found that for women with PCOS consuming more calories at breakfast helped balance hormones. In fact, insulin was reduced by 8%, and testosterone was reduced by 50%. Additionally, those who ate a larger breakfast ovulated more than women who ate a smaller breakfast and larger dinner (4).

Another reason that women may benefit from eating breakfast at all is due to cortisol. Cortisol is the main stress hormone that naturally rises in the morning. When we skip breakfast, this can cause a further rise in cortisol, increasing the stress in our bodies. Too much cortisol (stress) may suppress fertility and delay conception (4).

Specific Foods

This is a list from VeryWell Family of specific foods like sunflower seeds, eggs, and tomatoes, and why they are particularly beneficial for boosting fertility (5).

Like most health concerns, when it comes to nutrition eating an overall healthy diet is key, but there are often certain tweaks to ratios or certain foods to consume more of or less of depending on what’s going on. If you want more information, or individual recommendations, let’s chat!

Sources

1. How Sugar Impacts Your Fertility. Shady Grove Fertility. December 23, 2016. https://www.shadygrovefertility.com/article/how-sugar-impacts-your-fertility/.
2. Panth, Neelima; Gavarkovs, Adam; Tamez, Martha; Matei, Jossiemer. The Influence of Diet on Fertility and the Implications for Public Health Nutrition in the United States. Front Public Health. 2018; 6: 211. doi: 10.3389/fpubh.2018.00211. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6079277/.
3. Panoff, Lauren. 5 Foods to Avoid When Trying to Get Pregnant. Healthline. August 4, 2021. https://www.healthline.com/nutrition/foods-to-avoid-when-trying-to-get-pregnant
4. Borwn, Mary Jane. 16 Natural Ways to Boost Fertility. Healthline. August 13, 2020. https://www.healthline.com/nutrition/16-fertility-tips-to-get-pregnant.
5. Gurevich, Rachel. 15 Fertility Foods to Boost Your Odds of Conception. VeryWell Family. September 15, 2020. https://www.verywellfamily.com/fertility-foods-recipes-1959903.