Shift to vegan diets may cause brain nutrient deficiency: Study

Shifting to plant-based and vegan diets risks worsening an already low intake of an essential nutrient involved in brain health, a study claims. Choline is an essential dietary nutrient, but the amount produced by the liver is not enough to meet the requirements of the human body.

The nutrient is critical to brain health, particularly during foetal development. It also influences liver function, with shortfalls linked to irregularities in blood fat metabolism as well as excess free radical cellular damage, according to the study published in the journal BMJ Nutrition, Prevention & Health.

The primary sources of dietary choline are found in beef, eggs, dairy products, fish, and chicken, with much lower levels found in nuts, beans, and cruciferous vegetables, such as broccoli. In 1998, recognising the importance of choline, the US Institute of Medicine recommended minimum daily intakes.

These range from 425 miligrammes (mg) per day for women to 550 mg/day for men, and 450 mg/day and 550 mg/day for pregnant and breastfeeding women, respectively, because of the critical role the nutrient has in foetal development. In 2016, the European Food Safety Authority published similar daily requirements.

Yet national dietary surveys in North America, Australia, and Europe show that habitual choline intake, on average, falls short of these recommendations, researchers said. "This is concerning given that current trends appear to be towards meat reduction and plant-based diets," said Emma Derbyshire, of Nutritional Insight, a UK-based consultancy specialising in nutrition and biomedical science.

She commends the EAT-Lancet report to compile a healthy food plan based on promoting environmental sustainability, but suggests that the restricted intakes of whole milk, eggs and animal protein it recommends could affect choline intake.

"More needs to be done to educate healthcare professionals and consumers about the importance of a choline-rich diet, and how to achieve this," Derbyshire said. "If choline is not obtained in the levels needed from dietary sources per se then supplementation strategies will be required, especially in relation to key stages of the life cycle, such as pregnancy, when choline intakes are critical to infant development," she said.