Many health organizations recommend plant-based diets as good for people and the planet, and it’s true that most could benefit greatly from adding more vegetables to their diets. However, there are risks involved when you move from eating a diet rich in plant foods to one that is strictly plant based.
Nutrient deficiencies not only are possible with a strict plant-based diet but probable, depending on your diet, with choline being among them. Choline, a B vitamin known for its role in brain development, is an essential nutrient that humans must get from dietary or supplement sources.
Animal foods are a major contributor of choline to the diet, and Emma Derbyshire, director of Nutritional Insight, a consultant firm specializing in nutrition and health science, suggested in BMJ Nutrition, Prevention & Health that the increasing tend toward plant-based diets could be leading to a potential “choline crisis.”1
Why Choline Is Important
While your liver produces small amounts of choline, it’s not enough to meet the demands your body has for this essential nutrient, making additional dietary sources critical. Your body uses choline to keep your cell membranes functioning properly and it plays a role in nerve communications. Derbyshire explained:2
“Physiologically, choline is critical for a number of functions across the life cycle which include wide-ranging roles in human metabolism from neurotransmitter synthesis to cell structure and methylation, with choline deficiency being linked to liver disease, offspring cognitive function and potential neurological disorders.
Functionally choline in its oxidised form (the metabolite glycine betaine) contributes to S-adenosylmethionine synthesis – a chief methyl donor involved in DNA and histone methylation which play a central role in regulating gene expression and potentially modulating brain function.
Choline also influences liver function, with shortfalls linked to defective lipoprotein metabolism, abnormal phospholipid synthesis and oxidative damage.”
During pregnancy, choline is transported to the fetus and plays a role in cognitive development and outcomes. “This nutrient is particularly critical during fetal development as it modifies brain and spinal cord structure (via apoptosis and stem cell proliferation) influencing the risk of lifelong memory function and possible risk of neural tube defects,” Derbyshire wrote.3
Even in adulthood, people with higher choline intakes were shown to have better cognitive performance, doing better on tests of verbal and visual memory, than those with low intake.4 In fact, some of the symptoms associated with low choline levels include memory problems and persistent brain fog.
Choline is still being explored, and research continues to uncover new roles for this nutrient. Among them, emerging evidence suggests choline may be an epigenetic modifier of the genome, altering “gene methylation, expression and cellular function.”5 If levels are low during fetal development and infancy, it may have a lifelong effect, altering memory function and stress-related disorders later in life.
Choline also appears to be a key controlling factor in preventing the development of fatty liver by enhancing secretion of very low density lipoprotein (VLDL) particles in your liver,6 required to safely transport fat out of your liver.
Most People Don’t Get Enough Choline
According to a study published in the journal Nutrients, only 8% of U.S. adults are getting enough choline (including only 8.5 percent of pregnant women) by meeting the Institute of Medicine’s Adequate Intake (AI) level of 550 milligrams (mg) a day for men and 425 mg/day for women (this rises to 450 mg/day during pregnancy and 550 mg/day while breastfeeding).7,8
There is evidence that people with certain genetic factors may require even more intake than other individuals, which could mean that even more people are at risk of low choline.
As noted by Derbyshire, “[A] growing body of evidence exists suggesting that choline requirements may depend on the presence of several genotypes and that individuals with these could well have choline requirements higher than current recommended intakes.”9
Animal Foods Are a Primary Source of Choline
Based on unit weight, animal foods contain more choline than plant sources, with beef, eggs and salmon among the most concentrated sources.10 Further, in Europeans, the main food groups contributing choline to the diet were meat, milk, grain, eggs and their derived products and fish.11 Yet, even with these foods, most of the population groups had average choline intake below the AI level.
Research has also found that eating eggs is one of the best ways to improve choline intake, and it’s difficult to get enough of this essential nutrient if you don’t consume them. According to a study published in the journal Nutrients,12 among egg consumers more than 57% met the AI levels for choline, compared to just 2.4% of people who consumed no eggs.
The researchers concluded that it’s “extremely difficult” to get enough choline unless you eat eggs or take a dietary supplement. Another study, this one published in the British Journal of Nutrition, found that the main dietary sources of choline among pregnant and lactating women in Canada were dairy products, eggs and meat.13
Women who consumed at least one egg daily not only had higher choline intake overall but were two to eight times more likely to meet choline intake recommendations compared to women who did not consume eggs.14
Trends Toward Plant-Based Diets Could Harm Choline Intake
Derbyshire noted that choline is largely overlooked in the U.K., being excluded from U.K. food composition databases, major dietary surveys and dietary guidelines. She wrote:15
“The mounting evidence of choline’s importance makes it essential that it does not continue to be overlooked in the UK. This is now more important than ever given that accelerated food trends towards plant-based diets/veganism could have further ramifications on choline intake/status.
… Eggs, milk and meat appear to be major dietary providers and further movements away from the consumption of these could have unintended consequences for choline intake/status … More needs to be done to educate health care professionals and consumers about the importance of a choline-rich diet and how to achieve this.
… 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.”
This isn’t new advice. In 2009, researchers from the University of North Carolina at Chapel Hill expressed concern that choline intakes were far below the AI level and suggested “dietary guidance should be developed to encourage the intake of choline-rich foods.” Again, they noted eggs and meat as “rich sources of choline in the North American diet, providing up to 430 milligrams per 100 grams.”16
Healthy Sources of Choline
As mentioned, organic, pastured eggs are one of the best sources of choline you can eat. One hard-boiled egg may contain 147 mg of choline.17 Make sure to eat the yolk, where this nutrient is concentrated. Other healthy choline sources include:
Krill oil — One 2011 study found 69 choline-containing phospholipids in krill oil, including 60 phosphatidylcholine substances, which helps protect against liver disease (including hepatitis and cirrhosis in alcoholics), reduce digestive tract inflammation and lessen symptoms associated with ulcerative colitis and irritable bowel syndrome18
Grass fed beef liver
While some believe most people get enough choline from their diets and deficiency only occurs in rare cases, it's important to identify your choline food sources to determine whether your intake is sufficient to meet your daily needs. This is especially true if you follow a strict vegetarian or vegan diet, in which case supplementation may be necessary.
Plant-Based Diets Linked to Depression
While many people choose to eat a vegetarian or vegan diet for health reasons, research following vegetarianism may be associated with depression. In a study of 9,668 vegetarian (including a small number of vegan) men, vegetarians were nearly twice as likely to suffer from depression as meat eaters, even after adjusting for variables like job status, family history and number of children.19
The study couldn’t show causation, but it did have a number of theories for why the association may exist. The association may exist because people with depression may be more likely to change their dietary preferences, or it could be related to higher blood levels of phytoestrogens, particularly among those who eat a lot of soy, or even pesticides, a consequence of consuming a lot of nonorganic produce, the researchers said.
But, more likely, it has to do with nutrient levels. Vegetarians tend to have lower intakes of omega-3 fats, vitamin B12 and folate, which could affect depression risk. Vegans or strict vegetarians who abstain from animal products and do not supplement their diet with vitamin B12 may become deficient and may face increased risks of neuropsychiatric and neurological problems as a result.
When 100 vegetarians were compared to 100 omnivores, the vegetarians had significantly lower B12 levels as well as increased rates of depression, peripheral neuropathy, paresthesias (pins and needles sensation) and psychosis.20
Obsessive-compulsive disorder has also been linked to B12 deficiency (and elevated homocysteine).21 Neurological problems, in particular, are a possibility even at the "low normal" range at or just below 258 picomoles per liter (pmol/L). A level of 148 pmol/L or less is considered a deficiency state. As noted by the USDA:22
"Deficiency can cause a type of anemia marked by fewer but larger red blood cells. It can also cause walking and balance disturbances, a loss of vibration sensation, confusion and, in advanced cases, dementia. The body requires B12 to make the protective coating surrounding the nerves. So, inadequate B12 can expose nerves to damage."
Eating a plant-rich diet is generally excellent for your health, but if you’re a strict vegetarian or vegan, be sure you make a point to supplement where needed, including for choline, omega-3s, folate and vitamin B12.
Even if you’re not following a plant-based diet, ensuring your choline intake is optimal by consuming organic pastured eggs and other healthy choline-rich foods will go a long way toward protecting your mental and overall health.