Children raised on a vegan diet may have healthier hearts and less body fat than omnivores, but they grow up shorter and with weaker bones, a study has revealed.

Researchers from UCL Great Ormond Street Institute of Child Health and the Children's Memorial Health Institute in Warsaw, Poland, recently conducted a study that looked at the 'dangers of a vegan diet for infants'.

It focused on 187 healthy children aged five to 10 between 2014 and 2016. Of those, 63 children were vegetarians, 52 vegans and 72 omnivores.

Data was complied on growth, body composition, cardiovascular risk and micronutrient status in vegetarian or vegan children.

It was then compared to the group of children who consumed meat in their diet.

Findings of study into children raised on vegan diets

Those who followed a plant-based diet (vegan) were on average 3cm shorter than those who ate meat.

The study also found vegan children had 4-6 per cent less bone mineral content and were over three times more likely to be deficient in vitamin B12 than the omnivores.

At the same time, they also had 25 per cent lower levels of low-density lipoproteins (LDL) – the unhealthy form of cholesterol – and lower levels of body fat.

"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, co-author of the study said in a press release.

"On the other hand, their lower intakes of protein, calcium, and vitamins B12 and D may explain their less favourable bone mineral and serum vitamin concentrations."

Professor Jonathan Wells from UCL, who spearheaded the study, said people are increasingly being drawn to plant-based diets for several reasons, including promoting animal welfare and reducing our impact on the environment.

"Indeed, a global shift towards plant-based diets is now recognised to be crucial for preventing climate breakdown, and we strongly support this effort," he 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."

Vegan diet warning for kids

The study, which was published in the American Journal of Clinical Nutrition, also found that the 63 children following vegetarian diets had a lower risk of nutritional deficiencies compared to the omnivores, but 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 fibre and sugars compared to the vegans," Dr Desmond of UCL and the Children's Memorial Health Institute, explained.

"So, we are learning that just eating plant-based diets is no guarantee of health; we still need to select healthy foods."

The team highlighted the necessity for supplementary vitamin B12 and vitamin D on plant-based diets and added that parents must be aware of the risks of vegan diets.

"Our research shows that we need to provide more advice to the public as to how they can eat healthily on plant-based diets," Prof Wells said.

"This is particularly relevant for children, as they may have higher nutrient needs while they are growing. We aim to conduct further research, to help maximise the health benefits of plant-based diets in children."

text by Shireen Khalil, news.com.au