Researchers studied 312 people who have been vegetarian or vegan their whole lives from Western and Indian communities to understand how their food choices and friendships affect their mental health. They found that people eating higher-quality plant-based diets had fewer signs of depression. However, the study revealed something surprising: having strong social connections and friendships was just as important—or even more important—than diet quality, especially for people in Indian communities. This suggests that when choosing a plant-based lifestyle, both what you eat and who you spend time with matter for your mental wellbeing.

The Quick Take

  • What they studied: How the quality of plant-based diets, social friendships, and depression symptoms are connected in people who have been vegetarian or vegan for their entire lives
  • Who participated: 312 adults (about half men, half women) who have been lifelong vegetarians or vegans, split between Western countries and India. About 51% were vegan and 49% were vegetarian
  • Key finding: People eating higher-quality plant-based diets showed fewer depression symptoms. Those eating the lowest quality plant-based foods had depression scores of 18.7, while those eating medium quality had 12.3, and highest quality had 10.38. However, having strong friendships and social connections was equally or more important than diet quality
  • What it means for you: If you’re vegetarian or vegan, focus on eating nutritious plant foods, but don’t overlook the importance of spending time with friends and family. Both matter for your mental health. Results may vary based on your cultural background and community

The Research Details

This was a cross-sectional study, meaning researchers collected information from 312 people at one point in time rather than following them over months or years. Participants answered questions about their diet quality, how connected they felt to friends and family, and whether they experienced depression symptoms. The researchers used a statistical method called hierarchical linear regression, which is like building a puzzle piece by piece to see which factors matter most for depression symptoms.

The study included lifelong vegetarians and vegans from two different regions—Western countries and India—to see if cultural background made a difference. This is important because food choices and social connections have different meanings in different cultures. Participants filled out questionnaires measuring diet quality (how nutritious their plant-based eating was), social connectedness (how close they felt to others), and depressive symptoms (signs of depression like sadness or loss of interest in activities).

Understanding why some vegetarians and vegans experience depression while others don’t is important because plant-based diets are often promoted for health benefits, but some research shows vegetarians report higher depression rates. This study helps explain why—it’s not just about the food itself, but also about the social and cultural context. By looking at both diet quality and friendships together, researchers can give better advice to people choosing plant-based lifestyles

This study has some strengths: it included a decent-sized group of 312 people, it looked at two different cultural populations, and it measured multiple factors (diet, social connection, and depression). However, because it’s a snapshot in time rather than following people over years, we can’t say for certain that diet quality causes lower depression—only that they’re connected. The study also relied on people’s self-reported answers, which can sometimes be less accurate than objective measurements

What the Results Show

The main finding was that people eating higher-quality plant-based diets had fewer depression symptoms. The difference was clear: people in the lowest diet quality group had an average depression score of 18.7 (out of what appears to be a higher scale), while those eating medium quality had 12.3, and those eating the highest quality had 10.38. This shows a steady improvement as diet quality increased.

However, the story became more complex when researchers looked at social connections. When they included how connected people felt to friends and family in their analysis, diet quality stopped being a significant factor for the Indian population. This suggests that for people in Indian communities, having strong social bonds might be more important for mental health than the specific quality of their plant-based diet.

For the Western population, diet quality remained important even when social connection was considered, suggesting cultural differences in how these factors influence mental health. This finding highlights that the same dietary pattern can have different effects depending on someone’s cultural background and social environment.

The study revealed important cultural differences. In Western populations, diet quality continued to predict depression symptoms even after accounting for social connections. This suggests Western participants may benefit more directly from eating nutritious plant-based foods. In contrast, Indian participants showed that social connectedness was the stronger factor, suggesting that in Indian culture, community and family relationships may play a larger role in mental health than specific dietary choices

Previous research has shown that plant-based diets rich in vegetables, fruits, and whole grains are associated with lower depression risk because these foods contain nutrients that support brain health. However, other studies have found that vegetarians and vegans sometimes report higher depression symptoms, which seemed contradictory. This study helps explain that contradiction by showing it’s not just about what you eat—it’s also about your social environment and cultural context. The finding that social connection matters as much as or more than diet quality aligns with growing research showing that loneliness and isolation are major risk factors for depression

This study has several important limitations to consider. First, it’s a snapshot in time, so we can’t prove that better diet quality causes lower depression—only that they’re connected. Second, the study relied on people’s self-reported answers about their diet, social connections, and depression symptoms, which can be less accurate than objective measurements. Third, the sample included only lifelong vegetarians and vegans, so results may not apply to people who recently switched to plant-based eating. Fourth, we don’t know the exact size of the Western versus Indian groups or other demographic details that might affect results. Finally, the study didn’t measure other important factors like exercise, sleep, or access to mental health care that could influence depression

The Bottom Line

If you follow a vegetarian or vegan diet, focus on eating a variety of nutritious plant foods including whole grains, legumes, vegetables, fruits, nuts, and seeds (moderate confidence). Equally important: invest time in building and maintaining strong friendships and community connections (moderate to high confidence). If you’re experiencing depression symptoms, talk to a healthcare provider—diet and social connection are helpful but not replacements for professional mental health care (high confidence)

This research is most relevant for people who are vegetarian or vegan and concerned about their mental health. It’s especially valuable for people in Indian communities where cultural factors may influence how diet and social connection affect mood. People considering becoming vegetarian or vegan may also find this helpful for understanding the importance of both nutrition and community. This doesn’t apply to people eating meat-based diets, though the general principle that social connection matters for mental health is universal

Improvements in mood from better diet quality may take several weeks to a few months to become noticeable, as the brain adjusts to improved nutrition. Benefits from strengthening social connections may appear more quickly—even a few weeks of increased social activity can improve mood. However, if depression symptoms are severe, professional help should be sought immediately rather than waiting for dietary changes to take effect

Want to Apply This Research?

  • Track daily plant-based food variety (aim to eat at least 5 different plant foods daily) and weekly social connection time (number of meaningful interactions with friends/family). Rate mood on a 1-10 scale each evening to see patterns
  • Set a weekly goal to have one social meal with friends or family while eating a nutritious plant-based meal. This combines both protective factors—good nutrition and social connection—in one activity
  • Create a simple weekly dashboard showing: (1) diet quality score based on variety and nutrition of plant foods eaten, (2) hours spent in social activities, and (3) mood/depression symptom rating. Look for patterns over 4-8 weeks to see which changes correlate with better mood

This research suggests associations between diet quality, social connection, and depression symptoms in vegetarians and vegans, but does not prove cause-and-effect relationships. If you are experiencing depression or mental health concerns, please consult with a qualified healthcare provider or mental health professional. This information is not a substitute for professional medical or psychological advice, diagnosis, or treatment. Always discuss dietary changes with your healthcare provider, especially if you take medications or have existing health conditions. Individual results may vary based on genetics, lifestyle, and other factors not measured in this study.