Diet for Pregnancy: Eat Healthy When You’re Expecting | Chris Kresser
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Diet and Pregnancy: How to Eat Healthy When You’re Expecting

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A 10-year-old girl with ADHD. A 30-year-old man with prostate cancer. A 50-year-old woman with heart disease and osteoporosis.

The connection between diet and pregnancy can span all three generations of the women pictured here.
Your diet during pregnancy can determine your child’s future health—and continue to impact your family for generations. iStock/pixelfit

On the surface, it may seem like they wouldn’t have much in common. But although these three individuals are dealing with such varied diagnoses, at vastly different stages of life, it’s possible their conditions all originated from the same place at the same time: their mother’s womb before they were born.

Thanks to ongoing research into the origins of health and disease, we now know more than ever before about diet and pregnancy. And the science is clear: A mother’s dietary choices during pregnancy—and even before conception and after birth—not only affect her baby’s health, they also help determine her growing child’s susceptibility to disease later in life. What’s more, the impact of her nutritional status can extend across future generations.

If you’re pregnant or planning to become pregnant, read on for the latest research into the connections between maternal diet and fetal health, plus a list of the nutrients I believe most deserve your focus during this critical time.

How We Know That Health Begins in the Womb—and Even Before

The idea that the nutritional environment we encounter in the womb affects our health from birth throughout the rest of our lives has come to be known as the developmental origins of health and disease theory, or DOHaD. (You may also see it referred to as the Barker Hypothesis.)

British research David Barker proposed this theory in the 1980s after concluding his now landmark study, which found that the biggest predictor of whether a person would develop cardiovascular disease wasn’t smoking or another expected lifestyle cause; rather, it was their weight at birth. (1, 2) His follow-up research supported and expanded this finding, concluding that babies born small to malnourished mothers are at a higher risk for hypertension and coronary heart disease, as well as type 2 diabetes, later in life. (3)

New Nutritional Research: A Look at the Latest Studies

Fortunately for us all, and particularly for mothers-to-be, Barker’s work has been reproduced and broadened over the past 30 years. While the theory originally focused on how maternal and fetal malnutrition contributes to heart and metabolic conditions, newer DOHaD studies have identified additional diseases that can result from maternal and fetal under- or overnutrition and have tied these conditions to very specific dietary choices. (4) Here’s a quick roundup of just some of the literature on the subject.

Diabetes and Obesity

Research indicates that a mother’s consumption of a Western-style diet (high in sugar, refined carbohydrates, and trans fats) may cause her child to develop diabetes and obesity, as well as several related conditions. (5) Although observational, one study found an association between high maternal gluten intake and type 1 diabetes in children. (6)

Cognition

Maternal high-sugar diets, especially those high in sugar-sweetened beverages, have been linked with poorer childhood cognition, including poorer nonverbal ability and poorer verbal memory. (7) Conversely, a mother’s high intake of fatty fish has been linked to improved neurodevelopment, while increases in maternal choline intake during pregnancy may produce cognitive benefits for offspring. (8, 9, 10)

Cancer

Studies in laboratory rats name maternal low-protein diets as potential risk factors for the development of slow-growing prostate cancers in offspring later in life. (11, 12) This isn’t the first time maternal diet has been connected to cancer development: a 2006 study suggested susceptibility to breast cancer might be predetermined in utero, with diet an influencing factor. (13)

ADHD

Several studies make connections between maternal nutrition and attention-deficit hyperactivity disorder, or ADHD. One recent cohort study showed that low maternal high-density lipoprotein levels (HDL cholesterol) were associated with an increased risk for ADHD, particularly in boys. (14) In another, an “unhealthy” diet high in fat and sugar from processed foods was linked to ADHD symptoms in children who display behavioral problems early in life. (15) A Western diet may also elicit behavioral changes in children, including ADHD and depression and anxiety. (16)

Osteoporosis

Emerging evidence strongly suggests that maternal nutrition has long-term influences on bone metabolism in children, with nutritional inadequacies starting in pregnancy putting a child at higher risk for osteoporosis and fractures later in life. (17, 18, 19)

Why Your Diet Can Be a Danger to Your Child and Even Grandchild

If these studies alone aren’t enough to give you pause over what you put on your plate during pregnancy, consider that researchers have determined that the consequences of poor maternal nutrition status can persist through three generations. (20)

How is this possible? As humans, we’re able to adapt to our environment. But there is a critical period in which that adaptation happens: in utero.

During pregnancy, a developing baby’s epigenetic marks—the “traffic lights” on human DNA that can turn certain genes off and on—undergo substantial changes. These modifications are influenced by nutrients in the mother’s blood at the time of conception and can be passed down from generation to generation. Some changes enable the production of genetic expressions that make us better matched to the environment we are likely to find ourselves in once we’re born, while others set the stage for disease. (21, 22)

What Should You Eat Before, During, and After Your Pregnancy?

It’s clear that consuming the Standard American Diet isn’t a recipe for giving birth to a healthy baby who grows into a healthy adult. Eating like our ancestors did, however, is. While there isn’t one optimal human diet, we’re genetically adapted to eat whole, nutrient-dense plant and animal foods.

An ancestral diet rich in these foods can help you avoid deficiencies in the nutrients outlined below—nutrients that are critical for a developing fetus and that may influence gene expression, tipping the scales either toward health or disease.

Here are a few of my pregnancy diet recommendations.

Favor the Fat-Soluble Vitamins A, D, and K2

Unfortunately, vitamin A has developed a reputation for being dangerous in pregnancy, but it’s actually a crucial nutrient for fetal development; for example, it prevents deafness and internal organ displacement. It can be toxic in extremely high doses when vitamins K2 and D are inadequate, but when these vitamins are sufficient, the toxicity threshold for vitamin A is very, very high. Vitamin D helps placental function, plays a role in fetal lung development, and also protects a newborn’s cardiovascular health, while vitamin K promotes healthy development of the face, skull, and nervous system.

Vitamin A, D, and K2-Rich Foods:

  • Liver, beef, and goose (A, K2)
  • Full-fat dairy products (A, K2)
  • Cod liver oil (D)
  • Salmon (D)
  • Dark leafy greens, including kale, spinach, and collard, mustard, and beet greens (K2)

The Recommended Daily Allowance (RDA) of 2,600 international units (IU) a day of vitamin A is woefully inadequate. In addition to enjoying liver and dairy products, I recommend supplementing with between 20,000 and 25,000 IU during pregnancy. This dose has proven to be safe and may even prevent birth defects. The RDA for vitamin D is also pitifully low; I consider a good target between 2,000 and 4,000 IUs per day from supplements and dietary sources. There’s no specific RDA for K2 in pregnancy, but I recommend eating a liberal amount of K2-rich foods. If you need to supplement, do so at about one gram per day.

Focus on Folate

Folate is a general term for a group of water soluble B-vitamins, also known as B9, that are naturally found in foods. Folic acid refers to the synthetic compound used in dietary supplements and food fortification. Although folic acid is effective in preventing neural tube defects, it doesn’t have all the beneficial effects of natural folate.

Folate-rich foods:

  • Dark leafy greens, such as spinach and turnip, mustard, and collard greens
  • Cruciferous vegetables, including broccoli and cauliflower
  • Beets
  • Lentils and other legumes
  • Liver, calf, and chicken

If you’re planning a pregnancy, try to consume between 800 and 1,200 mcg of folate per day for several months before conception. It can be difficult to obtain this amount from diet alone, which is why I recommend supplementing with 600 to 800 mcg of folate daily, depending on your dietary intake. Look for products that list “5-methyltetrahydrofolate” or “5-MTHF” on the label. And check your multivitamin, because most multis contain folic acid, not folate.

Concentrate on Choline

Choline plays essential roles during growth and development, especially in regards to cognition. The body’s need for choline increases during pregnancy. Yet sadly, an estimated 90 to 95 percent of pregnant women fail to meet recommended choline intakes.

Choline-rich foods:

  • Beef, liver, and muscle meat
  • Eggs, whole (whites and yolks)
  • Cruciferous vegetables, such as cauliflower
  • Potatoes

Pregnant women need roughly 450 mg of choline per day, while lactating women require more, around 550 mg. If you can’t get sufficient choline from dietary sources, I recommend supplements containing the (phosphatidyl)choline form; most prenatal supplements and multivitamins do not contain choline.

Opt for Omegas

Long-chain omega-3 fatty acids, particularly DHA, are required for healthy brain development. DHA concentrates in babies’ eyes and gray matter, protecting their brain from oxidative damage. It’s a misconception that we can meet all of our DHA needs from plant foods like flax; we need DHA from seafood sources. And while it’s true that mercury levels in fish can be potentially harmful, low-mercury fish and fish high in selenium (which prevents the adverse effects of mercury toxicity) are good options, with data indicating that the benefits of eating fish during pregnancy far outweigh any risks.

Pregnancy-safe omega-3-rich foods: (23, 24)

  • Salmon
  • Sardines
  • Cod and cod liver oil

Insist on Iron

Anemia is a common problem during pregnancy, one that can be avoided by adequate iron intake. But that doesn’t necessarily mean you should supplement: indiscriminate supplementation during pregnancy has been shown to be harmful. Instead, amp up the amount of iron in your diet.

Iron-rich foods: (25)

  • Liver, especially duck and pork
  • Clams, cooked
  • Spinach and other leafy greens
  • Dried herbs

And What Foods Should You Absolutely Avoid?

Unsurprisingly, if you’re trying to conceive and have a healthy pregnancy, you should avoid those foods responsible for the negative fetal health outcomes mentioned in the studies above, foods which had no place in the diets of our hunter–gatherer ancestors. Of course, avoiding these toxic foods is applicable to overall health as well:

  • White sugar
  • White flour and other cereal grains, including whole wheat
  • Processed soy products, such as soy milk and soy protein
  • Industrial seed oils like soy, corn, and canola
Important note: Although DOHaD research typically highlights the first 1,000 days of life, beginning at conception, as the most critical for positive dietary exposures, your diet in the months and even years leading up to conception is also important.

Here’s to your child’s good health—and yours as well.