Vegetarian and Depressed? You Might Be Low on Vitamin B12
Switching to a plant-based diet can be one of the best decisions you've made for your health. But, it can also carry a serious risk: Vitamin B12 deficiency. Vitamin B12 is important for producing red blood cells and DNA as well as working along with your nervous system1. It is typically found in animal products, such as fish, meat, poultry, dairy, and eggs. But it can also be found in some plant-based milks, bread, two varieties of edible algae, and some varieties of mushrooms. Unfortunately, humans are unable to absorb the vitamin B12 produced in the colon because vitamin B12 is only absorbed in the small intestine (which is upstream of the colon). The food that primates, indigenous societies, and prehistoric populations ate had enough bacteria on the surface to provide the vitamin B12 they needed. Today, we typically clean and cook our foods, thereby reducing the vitamin B12 content in the plants we eat. This is why many vegans and vegetarians are at risk of a vitamin B12 deficiency. In one study, vitamin B12 deficiency affected 86 percent of all vegans2. Vitamin B-12 and other B vitamins play a vital role in producing brain chemicals that affect mood and other brain functions. Studies suggest that having lower levels of vitamin B12 and other B vitamins may actually be linked to depression. Take a look at the studies below to learn more about the link between vegetarians and depression:
Research Linking Vegetarianism and Depression
- A 2007 study of 14,247 young women found that 30 percent of vegetarians and semi-vegetarians had experienced depression in the previous 12 months, compared to 20 percent of non-vegetarian women3.
- Researchers examined mental health issues among a representative sample of 4,116 Germans including vegetarians, predominantly vegetarians, and non-vegetarians. The subjects were matched on demographic and socioeconomic variables. More vegetarians than meat eaters suffered from depressive disorders in the previous month, the previous year, and over their lifetimes4.
- In 2014, researchers studied individuals who varied in their diets: 330 vegetarians, 330 people who consumed a lot of meat, 330 omnivores who ate less meat, and 330 people who consumed a little meat but mostly ate fruits and veggies. The subjects were matched for sex, age, and socio-economic status. The vegetarians were about two times as likely as the other groups to suffer from a mental illness such as anxiety and depression5.
- A study of 140 women found that the odds of depression were two times greater in women consuming less than the recommended intake of meat per week. (Researchers also discovered that women eating more than the recommended amount were also likely to be depressed6.)
References: 1. Cobalamin deficiency, 2012;56:301-22. doi: 10.1007/978-94-007-2199-9_16 2. The prevalence of cobalamin deficiency among vegetarians assessed by serum vitamin B12: a review of literature, 26 March 2014 3. How does the health and well-being of young Australian vegetarian and semi-vegetarian women compare with non-vegetarians?, 2007 4. Vegetarian diet and mental disorders: results from a representative community survey, 2012 5. Nutrition and Health – The Association between Eating Behavior and Various Health Parameters: A Matched Sample Study, February 7, 2014 6. Red Meat Consumption and Mood and Anxiety Disorders, 2012;81:196–198