Research from the Nurses’ Health Study, one of the largest and longest-running studies of women’s health in America, shows that what you eat, how active you are, and other lifestyle choices can stack the reproductive deck in your favor, especially if trouble with ovulation—the maturation or release of a mature egg each month—is at the root of your problems conceiving.
What We Know about Health
It is common knowledge that what you eat and how you live affect the health of your heart and blood vessels, your chances of developing certain kinds of cancer, your eyesight, the strength of your bones, and more. It only makes sense that diet and health affect the ability to get pregnant and stay pregnant. After all, reproduction is just one of many systems in the body, all of them subject to similar rules and influences.
What is astonishing is that this is news. While millions upon millions of dollars have been spent developing and perfecting reproductive technologies, almost no attention has been paid to connections between diet and fertility. This oversight speaks volumes about medicine in America—a laserlike focus on drugs, devices, or procedures that can generate revenue and often total disregard for self-help measures that anyone can do for free.
Farmers, ranchers, and animal scientists know more about how nutrition affects fertility in cows, pigs, sheep, chickens, and other commercially important animals than fertility experts know about how it affects reproduction in humans. To be sure, hints are scattered across medical journals. But there have been few systematic studies of this crucial connection in people.
We set out to change this sad state of affairs with the help of more than 18,000 female nurses from all across the United States. These women are part of the Nurses’ Health Study. They have provided information on their health, including pregnancies, miscarriages, and infertility, along with detailed records of their diets, physical activity, smoking habits, and other practices. All told, the women in the fertility study have contributed more than 80 million bits of data.
(More than 30 years ago, researchers from the Harvard School of Public Health hoping to answer a vitally important question—Do birth control pills have long-term health effects?—proposed a bold study. They would survey thousands of female nurses about their methods of birth control and then track their health over time. Little did they know that this study would evolve into one of the largest investigations of how diet, lifestyle, social, and biological factors affect the risk of developing heart disease, cancer, diabetes, osteoporosis, and other chronic conditions.)
The 10 Rules to Live By
From this vast mine of information, we have discovered ten simple changes that offer a powerful boost in fertility for women with ovulation-related infertility.
- Avoid trans-fats, the artery-clogging fats found in many commercially prepared products and fast foods.
- Use more unsaturated vegetable oils, such as olive oil or canola oil.
- Eat more vegetable protein, like beans and nuts, and less animal protein.
- Choose whole grains and other sources of carbohydrate that have lower, slower effects on blood sugar and insulin rather than highly refined carbohydrates that quickly boost blood sugar and insulin.
- Drink a glass of whole milk or have a small dish of ice cream or full-fat yogurt every day; temporarily trade in skim milk and low- or no-fat dairy products like cottage cheese and frozen yogurt for their full-fat cousins.
- Take a multivitamin that contains folic acid and other B vitamins.
- Get plenty of iron from fruits, vegetables, beans, and supplements but not from red meat.
- Beverages matter: Water is great; coffee, tea, and alcohol are OK in moderation; leave sugared sodas unopened.
- Aim for a healthy weight. If you are overweight, losing between five percent and 10 percent of your weight can jump-start ovulation.
- If you aren’t physically active, start a daily exercise plan. If you already exercise, pick up the pace of your workouts. But don’t overdo it, especially if you are quite lean—too much exercise can work against conception.
We didn’t mention smoking. Only a small number of women in the Nurses’ Health Study are smokers, which made it impossible for us to examine in detail its effects on fertility. We didn’t really need to, though. Scads of solid studies have established that women who smoke take longer to get pregnant on their own or with assisted reproduction and are more likely to miscarry than nonsmokers. So we’ll add an 11th recommendation: If you smoke, stop.
You may think that you’ve heard advice like this before. There are a few infertility diet books in circulation, and the Internet is rife with dietary advice for women who want to get pregnant. These are scattershot approaches based on wishful thinking and what seems like common sense. Our recommendations, on the other hand, are based on evidence from one of the most comprehensive long-term studies ever conducted.
At least for now, these recommendations are aimed at preventing and reversing ovulatory infertility. They may work for other types of infertility, but we don’t yet have enough data to explore connections between nutrition and infertility due to other causes. Because the Nurses’ Health Study doesn’t include information on the participants’ partners, we weren’t able to explore whether nutrition affects male infertility. From what we have gleaned from the limited research in this area, some of the Fertility Diet strategies might improve fertility in men, too.
These 10 tips work on many levels. They are simple. They cost a few dollars at most. They don’t have side effects, with the possible exception of twins. They are available to everyone, not just those with good health insurance. Best of all, they are every bit as good for your long-term health—and your partner’s—as they are for improving fertility. In fact, a diet built around these strategies will serve you well all through pregnancy and into old age.
Excerpted from The Fertility Diet by Drs. Jorge Chavarro and Walter Willett, reprinted with permission from McGraw-Hill Professional.