Healthy diet may improve memory, says study

Story highlights

  • Those with the healthiest diets were 24% less likely to experience cognitive decline
  • A healthy diet contains lots of fruits, vegetables, nuts, fish, moderate alcohol use and minimal red meat

(CNN)We've all heard the age old adage, "You are what you eat." But could what we eat also affect how we think?

New research sheds additional light supporting the long standing notion that eating a healthy diet could potentially be linked to a lower risk of memory and thinking decline, researchers say.
    The study, published this week in the journal Neurology, further helps our understanding of the correlation a higher diet quality could have on reducing the risk of memory loss.
    "This study strengthens the support for the overall idea that eating a balanced diet may be beneficial to reduce your risk of cognitive decline," said Dr. Heather Snyder, Director of Medical and Scientific Operations at the Alzheimer's Association, who was not involved in this new study. "However, there are many aspects of diet in combination with engaging in a healthy lifestyle that may influence cognitive decline."
    Unlike previous findings relating specific diets to improvements in cognitive function, this new study suggests that improving overall diet quality is an important factor for lowering the risk of memory and thinking loss. Researchers defined a "healthy diet" as one containing lots of fruits and vegetables, nuts, fish, moderate alcohol use and minimal red meat.
    "The difference in our study is we didn't prescribe a particular diet or explore for a particular diet pattern," said Dr. Andrew Smyth, lead author of the study and a nephrologist at McMaster University in Hamilton, Ontario Canada.
    "We just wanted to look at a diverse cohort of people from all around the world and analyze what their risk for cognitive decline would be if they consumed what most organizations would consider a 'healthy diet'," Smyth said.
    For nearly five years, researchers monitored the eating habits of 27,860 men and women across 40 countries. Accounting for regional differences (but not country-specific variation), participants in the study were asked about the overall servings they consumed of different types of foods in both the healthy and unhealthy categories for which they received a corresponding point score.
    "For example, if participants consumed the standard dietary recommendations for fruits and vegetables per day, they would get a high score in that category. The reverse happens for unhealthy food choices," said Smyth.
    Participants were tested for their thinking and memory skills, at the start of the study, then again after two and five years. The results indicate that participants with the healthiest diets were 24% less likely to experience cognitive decline compared to those with the least healthy diets. These individuals were slightly older in age, more active, less likely to smoke and had a lower BMI.
    "We were interested in looking at this particular group who have a high risk for cardiovascular disease because they are also going to have a high risk of cognitive decline," said Smyth.
    "Previous research has suggested that a Mediterranean diet -- rich in fruits, vegetables, whole grains, fish, and healthy fats -- is associated with reduced risk of cognitive impairment. We've also seen preliminary research suggesting that eating vitamin C and folate-rich vegetables like spinach and broccoli may slow cognitive decline. Other research has suggested that blueberries may boost memory, and that a high intake of saturated and trans fats can have negative effects. So it's no surprise that to me that the healthiest eaters in this study fared the best in terms of their cognitive health," said Lisa Drayer, a New York-based nutritionist.
    As the body of evidence continues to grow in support of how our food choices can influence our long term ability to think clearly, researchers say the specific correlation between diet and quality of cognitive impairment still remains uncertain. For now it seems that eating those peas and carrots could pay off in the long run.