The foods you eat can have a significant impact on your fertility. While many foods and supplements are beneficial to fertility and can improve your chances of conceiving (see Diet for Fertility Part 1), there are also foods you should avoid. Here is a list of some foods you should aim to steer clear of in order to optimize your fertility.

Aspartame

Aspartame is a drug that is used as an artificial sweetener in some foods and beverages, such as diet soft drinks, diet yogurt, chewing gum, low-calorie sweeteners and calorie reduced foods. In the ingredients it will be listed as aspartame or as E951. Aspartame is linked to many health issues including infertility. Once aspartame enters your body it stimulates the pituitary (your master hormone-producing gland) to excrete prolactin. Prolactin is a hormone which inhibits ovulation. 

Animal-Derived and Cooked Fats

Animal fat and cooked fats can have a negative effect on reproductive health and hormone levels, whereas raw plant-derived fats boost hormones and improve reproductive health. In women, animal fats can cause oestrogen levels to become excessively high which can cause problems, including increasing your risk of breast and other hormone related cancers. For men, eating a lot of animal and cooked fats can decrease sex drive and sex hormones. Furthermore, having a diet high in fats can lead to impotence, because too much saturated and trans fats lead to plaque building up in arteries, including the arteries to the genitals and eventually blocking them. It’s best for both men and women to stay away from animal fats, and cooked fats, such as in fried food. Raw plant fats are best, such as organic cold-pressed nut and seed oils (for example olive oil).

Fish – Due to Mercury Contamination

Mercury can cause infertility in both sexes, and mercury toxicity can cause miscarriage and birth defects. The largest fish who’re at the top of the food chain contain the most mercury, however even small fish contain unhealthy levels and it’s best to stay away from eating fish altogether.

Genetically Modified Foods

Genetically Modified (GM) foods present some concerns to reproductive health. One of these is to do with promoters. Promoters are sequences of DNA that regulate the expression of a gene, essentially controlling which gene does what. Whenever a new gene is added to a plant’s DNA it has to be added along with a promoter which is supposed to control what the new gene does and how it influences the plant.

However, scientists have now realized that these promoters may also be influencing other genes that they were not intended to. It also seems as though new genes that are added can mutate in unpredictable ways resulting in proteins that weren’t intended and which have not been tested. Eating GM foods has been linked to lowered fertility in other animals, and since this field of science is relatively new and unpredictable it’s best idea for your fertility to avoid GM foods.

Herbs to Avoid

Some herbs have been suggested to lower fertility in men if taken in to high amounts, including echinacea, ginkgo biloba, and st john’s wort. There are also a few herbs that women should avoid taking (at least in high amounts) in the first trimester of pregnancy as they may increase uterine contractions and the risk of miscarrying at the embryo implantation stage. These include: blue cohosh, raspberry leaf, burdock, chamomile, fennel, sage, thyme and parsley.

Conclusion

While some foods support your fertility, others can significantly impact your hormones and reproductive organs making it much harder for you to successfully conceive a baby. Knowing what foods to avoid is an easy way you can naturally increase your fertility and support your reproductive system to be as healthy as possible.

References:

This article was based off the book “The Fertility Diet” by Sarah Dobbyn

Dobbyn, S. (2008). The fertility diet: And how to maximize your chances of having a baby at any age. Simon & Schuster.