Natural Fertility: Diet
Diet and Fertility
I find this fascinating because this is what we are putting in our body and I believe that makes a huge impact. I want to do an overview of where things stand if you are trying to get pregnant.
Carbohydrates
Let’s start with carbohydrates. They are not bad. Insulin levels when high impact normal hormone function in the ovaries and they can impact egg quality or chromosome abnormalities. Diabetics who have high sugar and insulin levels have a higher risk of abnormalities and miscarriage. Refined white carbohydrates have been associated with increased rates of ovulatory infertility. Things like white rice, breakfast cereals, and potatoes were associated with lower chances of getting pregnant. Brown rice and whole grain bread were associated with higher chances of getting pregnant. They did a small IVF study of women with no blood sugar problems who failed their first IVF cycles were asked to eat fewer simple carbohydrates. This change improved their embryo quality and pregnancy rates. Some studies give carbohydrates a bad name. However, whole grains have been shown to have antioxidant and anti-inflammatory properties which have been associated with higher live birth rates. So you do not need to be carb free. Carbohydrates are a necessary part of your diet. My recommendation is to limit sugar processed and refined carbohydrates, no soda and include whole grain carbohydrates that are high in fiber. A side note is that fruit has natural sugar, but also has a lot of fiber. Fiber changes how sugar is absorbed and it helps stabilize your blood sugar levels. Please eat fruit!
Gluten
If you have celiac disease, we know you don’t process gluten well. It can cause inflammation, decreased pregnancy, and increased miscarriage rates. It is an autoimmune disease so there is some thought that other women on the autoimmune spectrum may have some gluten sensitivity even though they are not gluten intolerant. For these patients I will recommend avoiding gluten and also dairy.
Plants
It appears by evidence that eating more plants improves pregnancy outcomes. I am doing a dance because I am #EatMorePlants. Plant-based eating encourages you to take in more vitamins and nutrients and also limits your exposure to toxic hormones that are put into meat. Let’s talk about ovulation. Ovulation is essential for reproduction and an increase in vegetables protein improves ovulation pattern. In a nurses health study evaluating nutritional parameters in nurses, we got a lot of our nutritional data. The data showed that from every serving of protein sourced from vegetables instead of animals increased pregnancy rates. We also learned that during IVF cycles, consuming red meat and weight loss dieting were both associated with lower pregnancy rates and probability development of embryos. So eating red meat and having a negative energy balance or ketogenic diet for weight loss is not a healthy way to receive a pregnancy. It is worth noting that animal proteins are high in AGEs (Advanced Glycation End Products) and have been shown to cause cellular damage in multiple studies. Studies have also shown that AGE accumulation is correlated with poor follicle and embryo development thus lower pregnancy rates. This is just another example of animal proteins affecting pregnancy rates. Evidence also shows that animal products such as meat and milks have high levels of endocrine disrupting compounds which can increase the level of sex steroids in these processed foods. It can impact how our hormones function, which plays a role in getting pregnant.
Fish
Evidence suggests that diets high in omega-3s have been shown to have a shorter time to pregnancy, improved ovulation, and outcomes with fertility treatments. However, fish consumption studies give us inconsistent results. One reason is that fish consumption has the risk of environmental exposures to methylmercury. So if you are eating fish, you should limit it to 2-3 times per week and try to stick to smaller fish. Big fish eat smaller fish, so the bigger the fish, the more mercury it contains. Another good way to get omega-3s is through supplements such as fish oil or an algae based supplement if you are avoiding animal products.
Dairy
Like fish, dairy studies have been inconsistent on reproductive outcomes. It has been shown that if you do eat dairy, full fat products are better than high fat products. This is likely due to the process of removing the fat from the product and adding hormones and other substances to keep the consistency which can be harmful to your fertility.
Soy
There has been a long standing concern that soy-based products may impair your endocrine to estrogen pathways. There has been no evidence of soy intake and decreased fecundability. In addition, patients using fertility treatments had higher outcomes of pregnancy and live birth rate when consuming soy. So there is no clear evidence whether soy can increase or decrease fertility. Part of it could be that those who ate soy, ate less animal proteins.
A study published in the American Journey of Obstetrics and Gynecology in 2019 showed that a fertility diet high in supplemental folic acid, B-12, and vitamin D, had low pesticide produce, whole grains over simple carbohydrates, dairy, soy foods, and fish over red meats had higher probabilities of live birth even with IVF. Female reproduction is a hormone dependent and sensitive process. Many things have to come together and function normally. This does not mean that you need to be vegan or vegetarian, although I am a huge advocate for a plant-based diet. However, if you choose to go vegan or vegetarian you likely need to supplement your diet with vitamins and nutrients. I also believe that everyone should be taking daily supplements.
Stay tuned for the next blog post all about supplements!