Plant-Based Kids (Part 1)

In this episode, Dr. Kristine Dennis takes a deep dive into the research around raising plant-based kids! Dr. Dennis is our new Senior Research Scientist, who also happens to be a plant-based parent.

We start with a story about how eating well-balanced plant-based diets during pregnancy can reduce risks of gestational diabetes and hypertensive disorders like preeclampsia.

Over the past two decades, scientific and professional nutrition and pediatric associations have issued official statements and published position papers about adopting vegan diets during crucial life stages, including pregnancy and lactation, infancy, and childhood. While some of these associations firmly agree a well-designed vegan diet can be healthy and support normal growth and development, others are more reserved, and some caution against vegan diets for children. Those that are supportive include the American Dietetic Association, which has held this position for more than 25 years, as well as professional associations in Australia, Canada, Portugal, Italy, the UK, Finland, Germany and Norway, and Europe more broadly. More reserved opinions also came out of the UK and Europe, including Spain, and downright dismissive positions have come out of Slovenia, Germany, Italy, France, and Belgium. What does the evidence say about vegan diets in children?

Part of the challenge starts at the very beginning, with the exclusion of pregnant people from clinical trials in general. With such compelling needs, why are pregnant women largely excluded from clinical research? Often due to ethical concerns, dominated by fears of fetal harm. Even nonpregnant women of reproductive age often have to commit to contraception during the research period, and those who become pregnant must leave the study with their data excluded. That all adds up to a lack of clinical trial data on pregnant women. Paradoxically, these precautionary measures may not have made pregnant moms or their babies safer because of the resulting lack of evidence.

Some of the commentary around vegan diets for children includes this same concern about the lack of data. One researcher stated, “In children we do not have many good quality studies, and the studies we do have come mostly from vegetarian children—and they are of very varying quality.” But researchers are attempting to fill this void, starting with “to vegan or not to vegan when pregnant, lactating, or feeding young children.”

The oldest and largest association of nutrition professionals in the world, the Academy of Nutrition and Dietetics, considers a completely plant-based diet to be suitable during pregnancy, lactation, infancy, and childhood, provided it is well-planned. What exactly does well-planned mean? First of all, a diet rich in a wide variety of plant foods—grains, legumes (such as beans, lentils, split peas, and chickpeas), fruits and veggies, nuts and seeds, herbs and spices. We want to limit vegetable fats so they don’t displace more nutrient-dense foods, and if you do use them, choosing them carefully––for example, avoiding trans fats and tropical oils. Also, taking a DHA supplement, consuming enough calcium, and ensuring sufficient vitamin D––and most importantly, not forgetting about vitamin B12, as Dr. Greger has covered extensively because it is so important to ensure a regular and reliable source of vitamin B12.

Balanced plant-based diets mean eating a wide variety of plant foods in order to sufficiently meet energy requirements, and paying attention to some nutrients that may be critical, iodine included. It’s one nutrient that should also be supplemented during pregnancy and breastfeeding.

What are the impacts on the mother’s health of following a vegetarian diet during pregnancy? Gestational diabetes affects around 14% of pregnancies globally, and even more in some regions of the world. It’s also at the center of the vicious cycle of diabetes begetting diabetes. Linked not only to adverse pregnancy and birth outcomes, but greater long-term risk of cardiometabolic disorders in both moms and babies. Research suggests beneficial impacts of plant-based diets on blood sugar control. What effect might that have on risk of gestational diabetes? A systematic review and meta-analysis on the plant-based dietary patterns and gestational diabetes risk found that those who ate closer to a healthy plant-based diet had a significantly lower risk of developing gestational diabetes.

Evidence from the Harvard Nurses’ Health Study II suggests these benefits extend to hypertensive disorders, like preeclampsia, with a 20% lower risk among those eating the most plant-based diets. And this lower risk could benefit moms’ health for years to come, as hypertensive disorders during pregnancy are associated with increased risk of stroke later in life. Note that Dr. Greger has previously covered other pregnancy outcomes as well.

In our next story, Dr. Kristine Dennis looks at studies on the IQs of vegetarian children.

Many vegetarian parents believe their children are brighter than omnivorous kids, but you don’t really know until you put it to the test. And indeed, the IQ of vegetarian children tested about 16 points higher than average, and their mental age exceeded their chronological age by about a year. The researchers knew the veg kids were bright, but why were they so much more superior? There are obviously confounding factors, like maybe more highly educated parents are more likely to have vegetarian children, and they pass down both their brains and their diets.

Even if there is a cause-and-effect relationship between vegetarianism and IQ, were the children smarter because they were vegetarians, or did they become vegetarian because they were so smart? Researchers in the UK followed 8,000 kids for decades. They measured their IQ at age 10, then came back 20 years later and asked which of them had become vegetarian during that time. And indeed, the smarter kids had an increased likelihood of being a vegetarian as an adult. The researchers even quoted Benjamin Franklin saying that vegetarian diets result in “greater clearness of head and quicker comprehension.”

According to the largest and oldest association of nutrition professionals in the world, strictly plant-based diets are appropriate for all stages of the life cycle, including childhood, and may indeed provide health benefits. What about plant-based diets and growth in children? Some studies show that children raised on restrictive macrobiotic diets suffer from growth stunting, while others show that those raised plant-based may end up being up to an inch (2.5 cm) taller. In a systematic review and meta-analysis of children on vegan diets, heights were lower in vegans, but only because they included a study in which the vegan kids were significantly younger, mostly 10 to 14 years old, compared to mostly 15 to 19 years old. Once you remove the study with the age disparity, the height disparity also disappears.

What about width disparity? Population studies indicate that vegetarian diets are associated with a lower prevalence of obesity in both adults and children.