Researchers studied over 1,100 Iranian adults who were at risk for heart disease to see if eating a healthy diet called the PURE diet could help with depression and anxiety. The PURE diet focuses on eating fruits, vegetables, beans, nuts, fish, and dairy products in moderate amounts. They found that people who followed this diet more closely had lower rates of depression and anxiety, especially women. This suggests that what we eat might affect not just our physical health, but also our mental health and mood.

The Quick Take

  • What they studied: Whether eating a healthy diet (called the PURE diet) is connected to having less depression and anxiety in people at risk for heart disease
  • Who participated: 1,120 adults from Iran with an average age of 52 years who were at high risk for heart problems. They came from nine different ethnic backgrounds.
  • Key finding: People who ate more foods recommended by the PURE diet had about 45% lower chances of depression and 37% lower chances of anxiety. This connection was especially strong in women but wasn’t as clear in men.
  • What it means for you: Eating more fruits, vegetables, beans, nuts, fish, and dairy products may help improve your mood and reduce feelings of sadness or worry. However, this is just one study, so more research is needed before we can say this works for everyone.

The Research Details

This was a cross-sectional study, which means researchers looked at a large group of people at one point in time and compared their diets to their mental health. The researchers recruited 1,120 adults from Iran who had visited hospitals for heart tests. They asked participants detailed questions about what they ate using a food questionnaire, then calculated a “PURE score” based on how much fruit, vegetables, beans, nuts, fish, and dairy they consumed. To measure mental health, they used a standard questionnaire called the Hospital Anxiety and Depression Scale, which asks questions about feelings of worry and sadness. The researchers then used statistical methods to see if people with higher PURE scores had fewer signs of depression and anxiety, while accounting for other factors that might affect mental health like age, exercise, and smoking.

This study is important because it looks at a real-world group of people rather than just testing one thing in a lab. By studying people from different ethnic backgrounds in Iran, the researchers could see if the PURE diet works across different populations. The study also separated results for men and women, which helped show that diet might affect mental health differently depending on sex. Understanding these connections helps doctors and nutritionists give better advice about how food choices can improve both physical and mental health.

This study has some strengths: it included over 1,100 people, used validated questionnaires (tools that have been tested and proven to work), and adjusted for many factors that could affect the results. However, because it’s a cross-sectional study, we can’t prove that the diet causes better mental health—we can only see that they’re connected. The study was done in Iran, so results might be different in other countries with different food cultures. The researchers themselves noted that more long-term studies are needed to confirm these findings.

What the Results Show

The main finding was that people with higher PURE diet scores had significantly lower odds of both depression and anxiety. For depression, people who followed the PURE diet more closely had about 45% lower chances of having depression. For anxiety, they had about 37% lower chances. These results were statistically significant, meaning they’re unlikely to have happened by chance. When the researchers looked at men and women separately, they found that the connection was much stronger in women. Women who followed the PURE diet more closely had 44% lower chances of depression and 48% lower chances of anxiety. In men, the connection was weaker and not statistically significant, meaning we can’t be sure if the diet actually helped men with their mental health.

The study also showed that the PURE diet’s benefits appeared to work through multiple food groups. The diet emphasizes eating more fruits, vegetables, legumes (beans and lentils), nuts, fish, and moderate amounts of dairy products. All of these foods together seemed to create the protective effect against depression and anxiety. The researchers adjusted their results for many other factors that could affect mental health, including age, physical activity, smoking, and other health conditions, and the connection between diet and mental health remained strong.

Other healthy diets like the Mediterranean diet and DASH diet have been shown to help with depression and anxiety in previous studies. The PURE diet is different because it allows for more animal products and whole-fat dairy, whereas some other healthy diets limit these foods. This study suggests that you don’t need to completely avoid animal products to get mental health benefits from eating well—moderate amounts of fish and dairy can be part of a healthy diet for your mood. The findings add to growing evidence that what we eat is connected to how we feel mentally.

This study has several important limitations. First, because it only looked at people at one point in time, we can’t prove that eating the PURE diet actually causes better mental health—we can only see that they’re connected. It’s possible that people who are already feeling better mentally choose to eat healthier foods. Second, the study was done only in Iran with people at risk for heart disease, so the results might not apply to everyone in other countries or people without heart disease risk. Third, the study didn’t find the same benefits in men as in women, which we don’t fully understand. Finally, the researchers relied on people’s memories of what they ate, which can be inaccurate.

The Bottom Line

Based on this research, eating more fruits, vegetables, beans, nuts, fish, and moderate amounts of dairy products appears to be associated with better mental health, especially for women. However, this is one study, so we should view these findings as promising but not definitive. If you’re struggling with depression or anxiety, talk to a doctor or mental health professional—diet changes alone may not be enough. Diet can be a helpful addition to other treatments like therapy or medication. Start by adding more of these healthy foods to your meals rather than making drastic changes all at once.

This research is most relevant to women who are concerned about depression and anxiety and want to improve their mental health through diet. It’s also useful for people at risk for heart disease, since eating this way helps both the heart and the mind. The findings may be less relevant to men based on this study, though eating healthy is still important for everyone. People with serious depression or anxiety should work with healthcare providers rather than relying only on diet changes.

Mental health improvements from diet changes typically take several weeks to a few months to notice. You might start feeling small improvements in mood and energy within 2-4 weeks of eating more of these healthy foods, but bigger changes usually take 8-12 weeks. Everyone is different, so be patient and consistent with your eating habits.

Want to Apply This Research?

  • Track your daily servings of PURE diet foods: count how many servings of fruits, vegetables, legumes, nuts, fish, and dairy products you eat each day. Aim to gradually increase these to match the PURE diet recommendations.
  • Use the app to set a daily reminder to eat one serving from each PURE food group. Start with one meal per day that includes these foods, then gradually add more meals. For example, add berries to breakfast, beans to lunch, and fish to dinner.
  • Weekly check-in: rate your mood and anxiety levels on a scale of 1-10 each week, and compare them to your PURE diet adherence score. Over 8-12 weeks, look for patterns between eating more PURE foods and improvements in how you feel. Share this data with your doctor or therapist to track progress.

This research suggests an association between the PURE diet and lower rates of depression and anxiety, but it does not prove that diet alone can treat or prevent these conditions. If you are experiencing depression, anxiety, or other mental health concerns, please consult with a qualified healthcare provider, mental health professional, or therapist. This study was conducted in a specific population in Iran and may not apply to all people. Do not use diet changes as a substitute for professional mental health treatment. Always talk to your doctor before making significant changes to your diet, especially if you take medications or have existing health conditions.