An excerpt from What to Eat When You Want to Get Pregnant.

I know firsthand how hard infertility can be to talk about. Personally, I struggled conceiving my second daughter, and I am an advocate for taking control of your own fertility through lifestyle and diet changes. Infertility has been seen as a taboo topic for decades, and our generation of women in society now is breaking the silence. According to the CDC, 1 in 5 women are unable to get pregnant — that means 1 in every five couples that you know and love has struggled with infertility, and the numbers are only on the rise. But why? What about our society today are we lacking, or having an abundance of, that makes it so hard for women to conceive?

What is infertility?

Infertility is defined as the inability to conceive after one full year of trying. This can be affected by an abundance of factors, affecting either the woman or man. There is a misconception that infertility only affects women, but that is simply false. Men are at the same risk of being infertile as women. In men, infertility can be a cause of abnormal sperm production, blockage of delivery, and/or low overall sperm production. In women, infertility can be attributed to inability to ovulate, reproductive structural issues, endometriosis, and/or PCOS. In the literature, there seems to be a multitude outside reasons that affect why men and women develop disorders that cause infertility, and that’s where lifestyle and diet play a major role.

What factors can cause infertility?

Since I study the effects of nutrition on health for a living, I had a pretty healthy lifestyle to begin with, but when I wasn’t able to get pregnant, and the doctors didn’t have a good answer as to why this was happening, I started asking myself if there was something that I could do, or not do, to make things happen. I started paying even more careful attention to the research studies that were out there about fertility. And I started to take a very critical look at what I was eating and putting in (and on) my body. Within this time, I realized that a lot of the things I did and used every day had ingredients that were potentially harmful to not only my health, but also to a growing baby. So, I started to clean up my (and my husband’s) diet and lifestyle even more. And, eventually, we had our daughter.

In my book, I detail the exact foods and methods we used to conceive. For example, did you know that seemingly harmless food additives like artificial sweeteners can decrease oocyte (a fancy term for an immature egg cell) quality in women, and preclinical studies suggest monosodium glutamate (MSG) may negatively impact sperm counts in men? These products are everywhere — from Chinese takeout to diet soda — and make taking a closer look at your diet daunting. Although it can be challenging at first, the results are worth more than missing a daily Diet Coke.

And it isn’t just food additives that we need to be concerned about. Even some foods that are considered healthy can be detrimental to fertility or pregnancy. For example, everyone loves the superfood flax, right? While it has powerful antioxidant properties and other health benefits, flaxseed oil can alter progesterone/estrogen ratios, which can be bad for trying to make a baby.

Another important factor I detail in my book is regarding lifestyle and environmental toxins. It isn’t just the things we eat, but also the things that encounter our food, like plastic bags and the packaging around food products, that can impact fertility. One chemical known as Surfynol, which is found in plastic, has recently been named a “reprotoxic” chemical for its ability to interfere with fertility, especially in men.

So, you are probably wondering, if all these things are bad for us and for a baby, why the heck are they allowed to be in our food supply? The answer is complicated. When the science is mixed, or when there aren’t many studies to suggest something is not safe, we often assume something is safe. The concept of being innocent until proven guilty applies to food chemicals, additives, and ingredients, just like it does to suspected criminals!

What can we do to prevent infertility?

Although we don’t hear about it in the mainstream media, there is overwhelming research on nutrition and fertility. While there may not be a one-size-fits-all plan, the evidence-based recommendations are clear when you look at the research. For example, higher intakes of omega-3 fatty acids, folate, and fiber are consistently linked to an increased chance of getting pregnant, having a successful pregnancy, and a lower chance of suffering from infertility. Clinical research shows men can add foods rich in zinc (oysters), selenium (sunflower seeds and certain mushrooms), and vitamin C to help improve sperm motility and mobility.

Omega-3s: Omega fatty acids are an all-around great nutrient to keep in your diet, especially to prevent essential fatty acid deficiency. Besides that, omega 3s When it comes to fertility, increasing your intake of omega-3s seems to be able to help. One research study (conducted in mice) found that a long-term consumption of a diet rich in omega-3 fatty acids could prolong reproductive function into an advanced maternal age. This study also showed a short-term treatment of omega-3 fatty acids could help improve egg (oocyte) quality.

Fiber: Fiber is an absorption inhibitor, meaning it helps all the nutrients you need and want from your diet be readily available for absorption. It also benefits digestion and keeps everything moving. This helps release excess hormones through bowel movements!

Folate: Taking folic acid prior to conception can ensure you have adequate stores to prevent neural tube defects. Recent research has also shown that women with obesity metabolize folate differently than normal-weight women. Increased body weight has been associated with increased risk for neural tube defects, perhaps because less folate may be available to babies of women with obesity.

Nicole Avena is a research scientist and author of What to Eat When You Want to Get Pregnant.