So the media has waded in again with a scare-story about the perils of a vegan diet.
This time the focus is choline, a substance found in meat and eggs – also in beans, grains and vegetables.
But is there any substance to the story or are the meat industry scraping the barrel?
This smacks of desperation, the meat industry are clearly on the back foot now that there have never been so many vegans and meat sales are dropping.
The study in question was published in the BMJ Nutrition, Prevention and Health journal, written by Nutritionist Emma Derbyshire who is a member of the Meat Advisory Panel – which receives funding from the meat industry.
Derbyshire writes: “This is now more important than ever given that accelerated food trends towards plant-based diets or veganism could have further ramifications on choline intake."
So where’s the evidence that vegans are missing out? There is none. In fact, in the US it seems that 90 percent of people are falling short, so clearly eating meat, eggs and dairy is no guarantee.
This is a yet another scare story for which there is no solid evidence.
Don’t be swayed – all the major health bodies agree that a varied vegan diet can provide all the nutrients you need for good health while lowering your risk of disease. That includes choline – soya milk, tofu, quinoa and broccoli for example, are all good sources.
Choline is an essential nutrient involved in several body functions. We produce some in our livers, but not enough, so we need some in our diets.
Unlike other vitamins and minerals though there’s no agreed recommended daily intake for choline. In 1998, the US set an ‘Adequate Intake’ (AI) of 550 milligrams per day for men and 425 for women (450 during pregnancy, 550 while breastfeeding).
This was based on a single study in men taking just 50 milligrams a day. So intakes below the AI don’t necessarily indicate inadequacy.
In 2016, The European Food Safety Authority (EFSA) published slightly lower AI values of 400 milligrams per day for all adults (480 during pregnancy, 520 while breastfeeding).
Studies show that average choline intakes for older children, men, women and pregnant women in the US fall short of their AI. In the UK, a 2015 study in the British Journal of Nutrition found average intakes of 407 milligrams per day in men and 294 in women.
So sufficient for men and just a little below the EFSA AI for women. However, deficiency is very rare, it could be that the amount in the diet is topped up by the choline the body synthesises.
Research suggests that meat-eaters may require more choline than vegans because the bacteria in their guts (microbiome) convert choline, before it’s absorbed, into a substance called TMA, which is converted in the liver to the inflammatory molecule TMAO which contributes to the build-up of fatty plaques in the arteries, increasing the risk of heart disease and stroke.
The type of bacteria found in the guts of vegans typically don’t convert choline to TMA, so vegans tend to have substantially lower levels of TMAO (which may explain why vegans have much lower rates of heart disease and stroke). This also means that vegans may actually need less choline than meat-eaters.
Meat and eggs
High intakes of choline from meat and eggs are not desirable for other reasons too. Research from the Harvard School of Public Health, the University of California in San Francisco, Brigham and Women’s Hospital and Harvard Medical School found that out of nearly 50,000 men, those with the highest choline intake had a 70 per cent increased risk of lethal prostate cancer.
Choline is thought to protect from Alzheimer’s disease possibly by lowering levels of a harmful substance called homocysteine. But people who follow a healthy plant-based diet have a lower risk of dementia and Alzheimer’s, so it seems likely they are not falling short of choline. Deficiency in choline causes fatty liver disease – but again, this is significantly lower in vegans than meat-eaters. Taken together, the evidence suggests that vegans need not worry about choline.
'More harm than good'
Many different nutrients are required for a healthy brain and body and the typical Western diet, based on meat, fish, eggs and dairy, is doing a lot more harm than good.
We are in the midst of a public health crisis – with more people suffering from obesity and diabetes than ever before. One in two people will get cancer in their lifetime and children may, for the first time, not outlive their parents. Trying to scare mums-to-be into eating meat and eggs is misleading and irresponsible, for our health and the environment.
We know that livestock farming is destroying the rainforests and is a major contributor to the climate crisis. The healthiest option, for us and the planet, is to eat a varied vegan diet including plant-based sources of choline – cruciferous vegetables such as broccoli, soya milk and tofu, nuts, seeds and wholegrains such as quinoa.
A last word on the subject of IQ, a study published in the British Medical Journal found that people who are vegetarians by the age of 30, had an IQ five points higher than average when they were 10.
This might explain why people with a higher IQ are healthier – vegetarians generally suffer less heart disease, high blood pressure, obesity, diabetes, various cancers, diverticular disease, bowel disorders, gallstones, kidney stones and osteoporosis.