Vegan diets are becoming more popular for all ages but it may pose risks to the physical development of children according to a new study. Researchers at University College London found children on a vegan diet had better heart health than children who ate meat but had several nutritional deficiencies that stunted their growth and affected bone health.

The study consisted of 187 children in Poland between the ages of 5 and 10. The group consisted of 63 vegetarians, 52 vegans and 72 omnivores. The average duration of meatless diets was 5.3 years for the vegans and 5.9 years for the vegetarians. Omnivores were chosen to match the vegans and vegetarians as close as possible in terms of age, sex, maternal education and whether they lived in a rural or urban setting.

"We know that people are increasingly being drawn to plant-based diets for several reasons, including promoting animal welfare and reducing our impact on the climate,” UCL Professor Jonathan Wells said. "We also know that until now research into the health impact of these diets on children has been largely limited to assessments of height and weight and conducted only in vegetarian children. Our study provides a substantial insight into the health outcomes in children following vegetarian and vegan diets."

Researchers collected data on the participants related to growth, body composition, cardiovascular risk and micronutrient levels. Vegans had 25% lower levels of LDL cholesterol and lower levels of body fat, but they also were on average 3 cm shorter, had 4-6% lower bone mineral content. The findings also showed vegans were three times more likely to be deficient in vitamin B-12 than omnivores.

"We found the vegans had higher intakes of nutrients that indicated an 'unprocessed' type of plant -based diet, which is in turn linked to lower body fat and better cardiovascular risk profile,” Dr. Małgorzata Desmond said. “On the other hand, their lower intakes of protein, calcium, and vitamins B12 and D may explain their less favorable bone mineral and serum vitamin concentrations.”

Surprisingly, vegetarians had a lower risk of nutritional deficiencies compared to omnivores but at the same time they had a less healthy cardiovascular profile.

"We were initially surprised by the poor cardiovascular health profile of the vegetarian children, but their dietary data showed that they were eating a relatively processed type of plant-based diet, with less healthy levels of fiber and sugars compared to the vegans.” Desmond said. “So, we are learning that just eating plant-based diets is no guarantee of health, we still need to select healthy foods."

The study findings highlighted the need for awareness among the general population regarding supplementation for those on plant-based diets, especially when it comes to vitamins D and B-12.

"Our research shows that we need to provide more advice to the public as to how they can eat healthily on plant-based diets,” Wells added. “This is particularly relevant for children, as they may have higher nutrient needs while they are growing.”

Click here to read more in the American Journal of Clinical Nutrition.