Eating a healthy diet is one of the most powerful changes you can make to boost fertility and support a healthy pregnancy.
Many women are (understandably) confused about what constitutes proper nutrition during the pre-conception and pregnancy period. There is so much contradictory information out there, and it can be difficult for the layperson to know what to believe and who to trust. With that in mind, we'll talk about 2 common myths about nutrition for fertility, pregnancy and breastfeeding.
Myth #1: A low-fat diet is the best choice
The so-called health authorities have been promoting a low-fat, high-carbohydrate diet for decades now. Yet infertility rates are higher than they’ve ever been before - and still rising. 1 in 7 women already have trouble conceiving, and a recent study in the UK predicted that number could rise to 1 in 3 by the year 2020.
The following three arguments suggest that a high-fat - not a low-fat - diet is optimal for fertility and pregnancy.
1. Breast milk is the perfect food for infants
Human breast milk is undoubtedly the perfect food for human infants. The nutritional composition of human breast milk has evolved over 2.5 million years to supply the exact ratio of nutrients necessary for proper growth and development. What is that ratio? Human breast milk is 55% fat, 38% carbohydrate and 7% protein by calories. Breast milk, therefore, is high in fat, moderate in carbohydrate and low in protein. Logic dictates that the ideal diet for women attempting to get pregnant and those that are already pregnant or breastfeeding would have a roughly similar macronutrient breakdown.
2. Fat is the preferred energy source of the body
The lean human body is 74% fat and 26% protein by calories. Fats are structural part of every human cell and the preferred fuel source of the mitochondria, the energy-burning units of each cell. The human body stores energy from food for future use as saturated fat, which is a cleaner burning fuel source than glucose. Unlike glucose, saturated fat isn’t toxic to the body in high doses. Contrary to popular belief, our bodies are designed to run on fat - primarily saturated. If we give it the right fuel, it functions well. If we give it the wrong fuel, it will still run, but not as well. And it will be far more likely to break down.
3. Omnivorous animals naturally prefer and thrive on a high-fat diet
Animals instinctively eat a mix of foods that is healthy. They don’t have diet gurus and the internet to confuse them. When scientists let mice (omnivorous animals) choose from an unlimited supply of fat, protein and carbohydrates, mice naturally choose to get 85% of calories from fat. Yet none of these mice get fat!
Why is fat so important for fertility and pregnancy?
Saturated fat is especially beneficial for fertility. A study at Harvard found that women who ate two or more servings of low-fat or non-fat dairy per day, like skim milk or yogurt, had 85% higher risk of infertility than those that ate full-fat dairy products.
Another study found that women who eat less saturated fat have a smaller chance of becoming pregnant. More specifically, the authors found that women with oligomenorrhea, a condition of light or infrequent menstruation associated with infertility, consume significantly less saturated fat and significantly more polyunsaturated fat than women with normal menstruation and fertility.
High-fat diets improve male fertility too. Eating too many refined carbohydrates like white flour or sugar can promote insulin resistance. In men, however, insulin resistance has the opposite effect than it has in women: it causes the conversion of testosterone into estrogen. This is problematic because testosterone plays several important roles in male fertility. It’s essential to the development and maintenance of male sexual organs, and to the production, motility and volume of sperm.
But isn’t fat bad for me?
Contrary to popular belief, fat isn’t your enemy. Over the last 50 years we’ve been brainwashed to believe fat is bad for us. We’ve been told it makes us fat, raises our cholesterol and gives us heart disease. But both anthropological research and clinical studies have revealed this is false, and the low-fat, high-carbohydrate diet has been a spectacular failure. Rates of obesity, diabetes and heart disease are still skyrocketing higher each year. For more information, I’d recommend reading Eat Fat, Lose Fat, by Mary Enig & Sally Fallon, and Why We Get Fat and What To Do About It, by Gary Taubes.
Myth #2: Pregnant women shouldn’t eat fish because of high levels of mercury
Over the last decade we’ve been told it’s no longer safe to eat fish because of the high levels of mercury they contain. Pregnant women have been especially warned due to the potentially harmful effect these toxins could have on the developing fetus.
But when we examine the scientific evidence, a different story emerges. While it’s true that the levels of mercury in fish are potentially harmful, that’s only true if the fish doesn’t have adequate levels of another mineral, selenium.
Selenium has a high binding affinity for mercury. When they’re found together in nature, they connect, forming an entirely new substance. This new substance is poorly absorbed by humans, and explains why studies show that selenium protects against the adverse effects of mercury toxicity. And guess what foods are the highest in selenium? 16 of the 25 best sources are, in fact, ocean fish!
There’s only one major study showing harmful effects caused by mercury consumed in seafood, and in that study the seafood consumed was pilot whale meat. Pilot whale meat is unusual in that it contains more mercury than selenium. The good news is that most ocean and freshwater fish have more selenium than mercury. The exceptions, as the chart below illustrates, are pilot whale, marlin, swordfish, tarpon and certain species of shark.
So, as long as pregnant women avoid eating the species of fish listed above that contain more mercury than selenium, they (and their babies) will be protected against the harmful effects of mercury toxicity.
But why should a woman consume fish in the first place? Seafood contain a long-chain omega-3 fatty acid called DHA, which is exclusively found in seafood - you can’t get it anywhere else in the diet. DHA is the most important of the omega-3 fatty acids, and is primarily responsible for the benefit we get from consuming them. DHA is preferentially incorporated into the rapidly developing brain during pregnancy and the first two years of infancy, concentrating in the grey matter and they eyes. It’s also crucial to the formation of neurons, which are the functional cells in the brain, and to protecting the brain from oxidative damage.
An FDA report in 2008 found that the nutrients in fish, including DHA, can boost a child’s IQ score by 10 points! This same report suggested that pregnant women eat at least 12 ounces of fish per week. Unfortunately, Americans on average consume only 5 ounces of fish per week, and up to 14 percent of women of childbearing age consume no fish at all - despite the fact that DHA is essential to proper brain development.