Get access to everything we publish when you sign up for Outside+ Join today!.
When most people hear the phrase, “You are what you eat,” they think about it in terms of body size or physical medical issues — such as being overweight or underweight or having Type 2 diabetes. But research shows your food choices also affect your mental health, mood, and temperament.
“Eating a healthy diet containing fruits, vegetables, whole grains, legumes, nuts, and seeds —with the addition of fortified foods and supplements when indicated — can support mental well-being,” says Reshma Shah, M.D., a plant-based pediatrician and coauthor of Nourish: The Definitive Plant-Based Nutrition Guide for Families. “Phytonutrients, which have a protective effect, and fiber, which is responsible for the health of our gut microbiome, are exclusive to plants and have been associated with improved mental health outcomes.”
Mental Health Benefits of a Plant-Based Diet
There’s no shortage of research being done on the mood-boosting and mental health effects associated with the consumption of fruits, vegetables, and other plant-based fuel. These include:
- Anxiety and stress. “The arachidonic acid, found only in animal products like eggs and chicken, sets off multiple chemical reactions in the body that eventually lead to an increase in inflammation,” says Dr. Kasey Nichols, NMD, licensed physician and member of the Arizona Naturopathic Medical Association (AzNMA). “When this inflammation reaches the brain, it subsequently can cause feelings of anxiety and stress, as well as depression. People who avoid foods with arachidonic acid typically report a more positive mood and improved mental health.” One survey-based study found decreased rates of stress and anxiety in those eating a vegan vs. omnivorous diet, and that vegetarians had reported better mood than non-vegetarians.
- Depression. Research suggests eating more plant-based foods can improve quality of life, mood and reduce symptoms of depression. A study published in the British Journal of Psychiatry analyzed the dietary patterns and risk of depression in 3,486 participants over a five-year period. Individuals eating whole foods reported fewer symptoms of depression compared to those who ate mostly processed foods.
- ADHD. Although diet isn’t the driving cause or cure for ADHD, Dr. Nichols says some research has shown that switching to a plant-based diet could help with its symptoms. One study showed that preschoolers who chose “processed” dietary patterns were significantly and positively correlated with ADHD symptoms, while those who chose “vegetarian” dietary patterns were negatively correlated with ADHD symptoms.
Cognition. “Some research has shown that eating more plant foods can prevent a cognitive decline later in life,” says Dr. Nichols. One study found that those who consistently ate more plant-based foods were 18–33% less likely to develop cognitive impairment than those who didn’t.
- Focus. Looking to improve productivity in the workplace? One study showed that employees who ate plant-based foods reported improved job performance and missed fewer workdays.
2 Things to Watch on a Plant-Based Diet
While eschewing animal products is a healthy lifestyle choice, it requires a thorough understanding of how to create balanced and complete meals. There are a couple areas you’ll need to pay special attention to, to ensure you’re reaping all of the healthy benefits:
- Nutrient deficiency. If done improperly, a plant-based diet could lack important nutritional needs that can negatively affect mental health. A deficiency in nutrients found in animal products — like choline, vitamin B-12, folate, omega-3 fatty acids and amino acids — have been linked to depression, poor mood regulation, poor metabolism, low energy, as well as memory and attention span difficulties. “Plant-based eaters in developed countries need to be the most concerned about lacking brain-healthy nutrients like DHA, vitamin B12, vitamin K2, zinc, iron, riboflavin, and vitamin D3,” says Dr. Nichols. “It is usually common knowledge that vegan diets need to be supplemented with B12, but many people are under the impression that colorful fruits and vegetables are excellent sources of most other vital nutrients. Dietary supplements are a great way counter any deficiency.”
- Caloric deficiency. Switching to a plant-based diet may end up resulting in a significant reduction in calories. “Many find that they lose a few pounds, but if the reduction becomes too extreme and lacks key nutrients and carbohydrates, you may become more irritable, or hangry, and easily distracted,” says Dr. Nichols. If you’re losing too much weight, add some more healthy fats (such as coconut oil and avocados) into your diet.
Related: Plant-Powered Brain Health
Boost Your Mood with These Plant-Based Must-Haves
It’s easy to fall into a rut during meal prep and planning — many people are creatures of habit who gravitate toward the same menu week after week. But if your go-to meals aren’t well-rounded, this could leave you lacking in essential nutrients. In order to ensure you’re getting the full spectrum of nutrition your body and mind need to thrive, make sure you’re including the following:
- Omega 3s. “Omega 3 fatty acids have been implicated in improved mental health outcomes,” says Dr. Shah. “Plant-based diets generally limit or exclude fish, which is a major source of omega 3 fatty acids, so they may be low in this key nutrient.” Instead, you’ll find your omega 3s in foods such as chia seeds, hemp seeds, flax seed, and walnuts.
- Tryptophan. The brain uses the amino acid tryptophan to produce serotonin, the feel-good neurotransmitter. It’s found in chicken, eggs, cheese and fish, but plant-based sources of tryptophan include leafy greens, sunflower seeds, watercress, soybeans, pumpkin seeds, mushrooms, broccoli and peas.
- B vitamins. Known to boost mood by increasing such neurotransmitters as serotonin, dopamine, and gamma aminobutyric acid (GABA), B vitamins may be the key to boosting your spirits, too. Choose from beans, legumes and lentils, fortified cereals and sunflower seeds.
“The effects of going plant-based vary from person to person, so it’s best to consult your doctor first to make sure it’s the right move for you,” says Dr. Nichols.