Can Diet Plus Exercise Boost Brain Function? What a New Review Found

Researchers asked whether doing both a diet program and an exercise program together helps thinking and memory more than either one alone. This matters because lifestyle changes are often suggested to protect the aging brain. The study looked at people, not animals.

🔍 What the study did

The authors searched four research databases for randomized controlled trials — studies where people are assigned by chance to different groups — that tested combined diet and exercise against either one alone. They found 11 trials with 3,428 participants. They pooled the results and rated the quality of the evidence.

📊 What it found

• Combined diet and exercise improved overall thinking scores (effect size 0.32, 95% confidence interval 0.15 to 0.49).
• Memory function improved (effect size 0.29, 95% confidence interval 0.16 to 0.41).
• Executive function — planning and self-control — improved (effect size 0.52, 95% confidence interval 0.31 to 0.72).
• Compared with diet or exercise alone, the combined approach showed no significant improvement in overall thinking.
• People at risk for cognitive decline improved more (effect size 0.76) than cognitively healthy people (effect size 0.10).
• The DASH diet and supervised diet programs showed positive effects on overall thinking.

🧠 What it means

Doing both diet and exercise together was linked to better thinking, memory, and planning skills. But adding one on top of the other did not clearly beat doing just one. The benefit looked larger in people already at risk for decline than in those who were cognitively healthy.

🚫 What it does NOT show

• It cannot show whether combined diet and exercise prevents dementia or Alzheimer's disease.
• It cannot show how long any thinking benefits last.
• It cannot show which specific diet or exercise plan works best.
• It cannot show results for people not included in the 11 trials.

📐 Evidence level

A systematic review and meta-analysis of randomized controlled trials in people.

🎯 How much to trust it

The trust tier is Strong. A meta-analysis combines results from many randomized trials, which gives a more reliable picture than any single study.

⚠️ Limitations

• Only 11 trials were included, which limits how much can be concluded.
• Some analyses showed high inconsistency between studies (I2 up to 76%).
• The evidence quality was rated moderate, not high.
• Diet and exercise programs varied across trials, making comparisons difficult.

❓ Open questions

• How long do the thinking benefits last after the programs end?
• Which specific diet and exercise combinations work best?
• Do these results apply to people with different health conditions?

✅ Your action plan

• ✅ The study's approach combined a structured diet program with regular exercise sessions.
• ✅ Diet plans studied included the DASH eating pattern and supervised diet programs.
• ✅ If you are curious about diet and exercise for brain health, discuss it with a professional.
• ✅ No proven human plan from this study exists yet for you to copy exactly.

🏁 Takeaway

Combining diet and exercise may support thinking and memory, especially in people already at risk for decline, but it did not clearly outperform either alone.

This summary is for general information only and is not medical advice. Talk to a qualified professional before changing anything about your health.

📚 Source

Does a combined intervention of diet and exercise lead to a more positive impact on neurocognitive function? A systematic review and meta-analysis.. European journal of nutrition. 2025 PubMed