Boost Your Brain With Nuts

This is a brief summary of the research study: Haskell-Ramsay CF, Dodd FL, Smith D, Cuthbertson L, Nelson A, Lodge JK, Jackson PA, Mixed Tree Nuts, Cognition, and Gut Microbiota: A 4-Week, Placebo-Controlled, Randomized Crossover Trial in Healthy Nonelderly Adults, The Journal of Nutrition, Volume 152, Issue 12, 2022, 2778-2788.

The Yolk

What is healthy about nuts?

• Healthy fats
• Low in carbohydrates
• Protein
• Fiber
• Vitamins & minerals – magnesium, B6, iron, zinc
• Decrease inflammation
• Lower cholesterol
• Lower blood pressure

Mixed tree nuts, cognition and the gut

• Research design
  • 79 adults aged 18-49 consumed nuts or placebo every day for 4 weeks
    • Nut group – 30 grams of mixed tree nuts (walnuts, almonds, hazelnuts)
    • Placebo – cellulose compound instead of nuts
  • Assessed relationship between gut changes and cognition
• Results
  • Metabolic responses
    • No changes in either group
  • Bacteria changes in the gut
    • Increase in Lachnospiraceae microbial species in nut group
      • These produce short chain fatty acids – good for inflammation and brain health
    • No changes in placebo group
  • Cognition
    • Nut group had faster reaction time for picture recognition
    • Nut group had fewer errors on a peg and ball task
    • Nut group had better accuracy for visual info processing
  • Mood
    • No changes in either group
• Nut consumption had a positive effect on cognition and microbial species associated with gut health, but no correlation between gut and cognition changes

Perspective

• Regardless of results, nuts have been a nutritious food and should be included in a healthy diet
  • For those with nut allergies, seeds may be a good option
• A handful each day appears to be a sufficient amount
  • If you don’t prefer nuts alone, mix them into other foods
• Choose from walnuts, almonds, pistachios, cashews, Brazil nuts, pecans, hazelnuts, macadamia nuts

Research & Resources

• Systematic review shows nuts reduce blood pressure, improve glucose response, and inflammation
• Walnuts improve cognition function
• Nut intake may improve cognition in older ages
• Lack of consistency across studies on nuts and cognition, and more improvement shown in participants with a high risk of decline
• Alzheimer’s associated with gut alterations
• Diets including nuts did not cause weight gain