It’s well-established now that what we eat (and don’t eat) can have a significant effect on metal health and can even cause or exacerbate anxiety and depression symptoms. (Along with several other factors, such as these).

But eating “healthy” is not that simple, especially when there’s so much conflicting nutritional advice out there: low carb, high carb, low fat, ketogenic, vegan, paleo, raw etc! Plus there’s new, conflicting studies and dubiously researched books and Netflix documentaries being published all the time!

The first and most important thing to realise is there actually isn’t ONE perfect diet suited to all humans. That’s why you hear so many wonderful and woeful claims about all of them! The truth is, we’re all metabolically, biochemically, and genetically different and if you ever come across a naturopath, nutritionist or doctor that has a dogmatic, one-size-fits-all approach to diet, then run a mile! Medicine and nutrition should always be personalised and tailored to the individual.

Now while certain metabolic types can do really well on vegetarian (and vegan with B12 supplementation) diets, as a naturopath specialising in anxiety and depression, I generally DON’T recommend these diets for people suffering with mental health issues.

The science is pretty clear on this one: many studies have shown an increased risk of depression and anxiety in people who are vegan and vegetarian.

The Cold, Hard, Data

If you like to geek out on science, here’s a few of them summarised and linked below:

• In 2014, Austrian researchers published a study of 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 ate mostly fruits and veggies. The subjects were carefully matched for sex, age, and socio-economic status. The vegetarians were about twice as likely as the other groups to suffer from a mental illness such as anxiety and depression.

• A Scandinavian study published in Neuropsychobiology in 2016, showed that Finnish vegetarians were 4 times more likely to suffer from Seasonal Affective Disorder (SAD) than non-vegetarians, and in the Netherlands the figures were similar but slightly lower: Dutch vegetarians were 3 times more likely to suffer from SAD than meat-eaters.

• A large French study published in 2018 looked at 90 000 patients who had given up certain food groups and the impact it had on depression symptoms. It looked at meat-eaters, vegans, vegetarians and pescatarians (“vegetarians” who eat fish) and the incidence of depression increased with each food group that was given up. People who had given up 3-4 animal-related food groups (eg. vegans) were 2 and a half times more likely to suffer from depression.

• In an Australian longitudinal study on women’s health published in 2000, researchers looked at a cross-section of over 9000 women in their 20s and found that while the vegetarian and semi-vegetarian women were generally more active and had healthier BMI’s than non-vegetarians, they had clinically significant higher levels of both menstrual problems and mental health disorders.

• A 2012 German study found that vegetarians showed elevated prevalence rates for depressive disorders, anxiety disorders and somatoform disorders.

• In a study entitled Red Meat Consumption and Mood and Anxiety Disorders, researchers looked at a sample from a cohort of 1,046 women aged 20-93 and found that those who ate less than 3-4 servings of beef or lamb a week were TWICE as likely to be diagnosed with depression and/or anxiety.

A Balanced View 

Now, in the interest of avoiding bias, it’s important to note that there are a few much smaller studies showing vegetarianism to be linked to lower levels of anxiety and depression perhaps due to higher antioxidant levels. And nutrition is not a “settled” science, correlation does not equal causation and it’s never as simple as whether someone eats meat or not.

For example, a vegetarian who eats lots of unprocessed fruit, veggies, wholegrains, and legumes will definitely fare better than a meat-eater who lives on hot dogs and chips. (Especially seeing as the latter diet would be much more pro-inflammatory) And likewise, a vegan who regularly eats highly-processed, soy-based “franken-meats” and white bread is not going to be as healthy as someone on a clean paleo diet who eats loads of organic meat, seafood and eggs with plenty of fruit and veggies.

An Educated Guess

Scientists don’t know for sure why vegetarians and vegans are more likely to suffer from anxiety and depression, but as a nutritionist I’d like to take an educated guess.

First of all, it comes down to nutrient density. Now while vegetables, and to a lesser extent, fruit, are the most nutrient-dense foods we can eat (and everyone should make them the largest food group consumed), after them comes seafood, organ meats, eggs and red-meat. Legumes and grains (the biggest food groups in most vegetarian/vegan diets by caloric density) are the least nutritionally dense and also contain anti-nutrients that can block the absorption of important minerals as well as damage gut lining. (And gut issues are commonly an underlying factor in mental health problems).

Plus, certain key nutrients found in abundance in seafood, meat and eggs are actually REALLY important for mental health such as essential fatty acids, B vitamins (especially choline, B12 and B6), vitamins A and D, trace minerals such as iodine, iron, selenium and zinc as well as amino acids that act as precursors in the formation of neurotransmitters.

Another key factor that can’t be overlooked is blood-sugar balance. Anxiety and depression can be severely worsened if blood-sugar levels are not kept in check, and adequate protein and fat with each meal and snack is essential to maintaining balance. According to holistic psychiatrist Dr Kelly Brogan, most people who suffer from anxiety and depression are “parasympathetic dominant” in terms of metabolism and are more likely to have difficulty with blood-sugar regulation without animal food.

Please understand, my point here is NOT to vilify vegetarian or vegan diets nor get into a debate around food ethics. My goal is to help people suffering from anxiety and depression, and if you’re a vegetarian or vegan suffering from these conditions, I invite you to take an open-minded approach as you investigate what could potentially be one factor out of many contributing to your symptoms.

If you’d like a free copy of the anti-inflammatory diet I typically recommend to my patients, you can download it here.

If you’d like help uncovering the causes of YOUR anxiety & depression symptoms as well as a simple plan to overcome them naturally, check out my 1:1 service here.

And if you have any questions or comments please post them below!

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