All of us here at Circle + Bloom have developed a greater interest in the dietary side of infertility. What we put into our body has a huge influence on our health and well-being, including fertility. In the upcoming months we plan to offer more blogs and recipes that focus on nutrition and fertility.
To start off our diet and nutrition focus we wanted to share with you some really interesting research that has been done examining the relationship between diet, other natural factors and our fertility. Harvard researchers, with the help of more than 18,000 women taking part in the Nurses’ Health Study, conducted a long-term research project looking at the effects of diet and other factors on the development of chronic conditions such as heart disease, cancer and other diseases. In addition, they were able to examine effects on fertility. By comparing the diets, exercise habits and other lifestyle choices of women who had some trouble getting pregnant, including hundreds who experienced ovulatory infertility, with those of women who easily got pregnant, several key differences emerged.
The research found that carbohydrate choices influence fertility. Eating a lot of rapidly digested carbohydrates that continually boost your blood-sugar and insulin levels to high levels can lower your chances of getting pregnant because when these levels rise too high they disrupt the balance of hormones needed for reproduction. This is especially true if you are eating carbs in place of healthful unsaturated fats. On the other hand, eating sources of slowly digested carbs such as whole grains, beans, vegetables and whole fruits can improve ovulation and your chances of getting pregnant. In general the researchers found that cold breakfast cereals, white rice and potatoes were linked with a higher risk of ovulatory infertility. Slow carbs, such as brown rice, pasta and dark bread, were linked with greater success getting pregnant.
The study also found that more trans fat in your diet, the greater the likelihood of developing ovulatory infertility. The research found that this negative effect existed even at daily trans fat intakes of about four grams a day, which is less than the amount the average American gets each day. Fats have powerful biological effects, such as turning genes on or off, effecting inflammation and influencing cell function. Unsaturated fats do things to improve fertility such as increasing insulin sensitivity and reducing inflammation, which is the opposite of what trans fats do. That is probably why the largest decline in fertility among participants in the study was seen when trans fats were eaten instead of monounsaturated fats.
Findings from the Nurses’ Health Study also indicate that getting more protein from plants and less from animals is another big step toward avoiding ovulatory infertility. Ovulatory infertility was 39 percent more likely in women with the highest intake of animal protein than in those with the lowest. Women with the highest intake of plant protein were substantially less likely to experience ovulatory infertility than women with the lowest plant protein intake. Eating more protein from plants and less from animals is an important strategy for overcoming ovulatory infertility.
Another interesting finding from the study is that a daily serving of whole milk and foods made from whole milk like full-fat yogurt, cottage cheese, and even ice cream seem to offer some protection against ovulatory infertility, while skim and low-fat milk do the opposite. This is because removing fat and adding protein to milk radically changes its balance of sex hormones and negatively affect fertility. The study found that the more low-fat dairy products in a woman’s diet, the more likely she was to have had trouble getting pregnant. The more full-fat dairy products in a woman’s diet, the less likely she was to have had problems getting pregnant. However, they stress that its important to keep your intake in moderation. You should aim for one to two servings of full fat dairy products a day.
The study found a strong connection between weight and fertility. Women with the lowest and highest Body Mass Indexes (BMI) were more likely to have had trouble with ovulatory infertility than women in the middle. Infertility was least common among women with BMIs of 20 to 24, with an ideal around 21. In addition, a few small studies show that overweight men aren’t as fertile as those with a healthy weight. Excess weight can lower testosterone levels, throw off the ratio of testosterone to estrogen and hinder the production of sperm cells that are good swimmers.
The study also found a link between activity and getting pregnant. 30 mins of aerobic exercise, strength training, stretching and the activities of daily living work together to control weight, guard against high blood sugar and insulin, and keep muscles flexible and strong. Exercise is also a natural stress reliever which is something almost everyone worrying about infertility can use.
Check out the book and read more about the study.