Recently I discovered a blog called
Nourished Kitchen- if you are trying to eat local, fresh, organic foods this is the best resource I have found! They have lots of great recipes and articles, but one that caught my attention is regarding what foods to avoid when trying to get pregnant. These are all foods that aren't ideal at any time, but have been shown to have a specific impact on fertility. While any one of these foods probably won't be the single determinant in whether or not you are able to get pregnant, they should be considered in your overall plan for a healthier lifestyle.
1) Gluten- if your digestion is sensitive to gluten (a protein found in wheat, spelt, barley, and rye) this may lead to malabsorbtion of other nutrients essential for reproductive health. The incidence of gluten intolerance or Celiac Disease is higher in women diagnosed with unexplained infertility than that of the general population.
2) Low-Fat or Nonfat Dairy Products- in a study of 18,000 women, it was found that skim and low-fat dairy products may actually increase the risk of anovulatory infertility, while full-fat dairy products actually decrease the risk of infertility.* This seems to run counter to what we've always heard- low fat is always better, right? Butterfat actually contains nutrients not present in low fat dairy, such as fat-soluble vitamins A, D, E, and K. If eaten in moderation, foods such as cream, butter, and full fat milk may be better for your health.
3) Soy- soy contains xenoestrogens- plant hormones that interfere with your body's normal estrogen balance. Soy isoflavones such as genistein and daidzein have been shown to interfere with the production of HCG (human chorionic gonadotropin), the hormone which is produced by a developing embryo.** It has a vital role in ensuring the health of the fetus early in development. Avoid foods which list soy, soy lecithin, soy protein, soy flour, and texturized vegetable protein (TVP) as ingredients. Obviously one should avoid soy milk and soy-based meat substitutes such as tofu.
4) Refined Sugar- this is a definite food to avoid, especially for women with PCOS (Polycystic Ovarian Syndrome- a condition marked by irregular, anovulatory cycles). Consuming refined sugar creates a temporary spike in blood glucose levels, which then leads to an increase in insulin levels. Over time, elevated levels of insulin lead to insulin resistance. I have seen clinically that many women diagnosed with insulin resistant PCOS are able to manage their condition through diet, without neccessarily having to take Metformin (a drug to lower insulin levels). Even for women without PCOS, following a low-glycemic diet that limits consumption of refined sugars may improve fertility and pregnancy outcomes*. This includes avoiding not just candy and ice cream, but simple carbohydrates such as white bread, juices, and soda.
5) Coffee and Sodas- I tell patients that if they must consume caffeine, do so in moderation- try to limit it to one cup per day. Specifically you should know that caffeine can decrease blood flow to the uterus and may increase the risk of miscarriage. It increases anxiety levels, which can lead to increased stress hormone production. These stress hormones (cortisol and prolactin) can have quite an effect on your body's normal hormone levels, which can lead to things like delayed ovulation. In addition, since caffeine is a diuretic it can lead to decreased production of fertile cervical fluid.
To re-iterate, I encourage everyone to adopt a diet rich in whole grains, green leafy vegetables, fruit, and with moderate amounts of meat and dairy (all organic where possible). Avoid all processed foods (yes even those frozen organic enchiladas from Trader Joe's are processed) and eat foods that are fresh and in season- these are the foods with the most bang for your buck nutrition-wise.
*Source: Chavarro et al. A prospective study of dairy foods intake and anovulatory infertility. Human Reproduction. 2007. May.
**Source: Jeschke et al. Effects of phytoestrogens genistein daidzein on production of human chorionc gonadotropin in term trophoblast cells in vitro. Gynecological Endocrinology. 2005. September.