Controversy Surrounds the Impact of the Mediterranean Diet on Cognitive Health
Key Takeaways:
- The Mediterranean diet, predominantly composed of vegetables, fruits, fish and healthy fats with minimal dairy or meat, has been lauded for its potential benefits to brain health. However, a recent Swedish study did not find a significant difference in dementia risk between those adhering to the Mediterranean diet and those on conventional diets.
- Experts emphasize that these findings should be interpreted within the wider context of ongoing research. Observational studies show association but not causation, and a comprehensive understanding of the relationship between diet and dementia risk requires diverse, interventional studies across different demographics.
- The Alzheimer’s Association is conducting the U.S. POINTER Study, a two-year experimental trial investigating if multi-faceted lifestyle adjustments can protect the cognitive abilities of at-risk older adults.
- Samantha Heller, a senior clinical nutritionist, underscores the influence of overall dietary patterns on disease risk and quality of life. She mentions healthy eating patterns like MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay) or DASH (Dietary Approaches to Stop Hypertension).
- Ultimately, a balanced approach that includes factors like diet, regular exercise, management of heart risk factors, abstinence from tobacco and moderate alcohol consumption will likely have a cumulative effect on cognitive function.
The Mediterranean diet—characterized largely by the consumption of vegetables, fruits, fish, and healthy fats, and minimal dairy or meat—has been praised for being beneficial to brain health. On the contrary, a recent Swedish study suggests otherwise. Nonetheless, some are advising to take these fresh findings—with a more cautionary approach.
Critical Evaluation Required
According to Heather Snyder, VP of medical and scientific relations at the Alzheimer’s Association, the results of the study, released online Oct. 12 are far from definitive. “It’s highly important to unravel the links between diet and nutrition and the risk of dementia,” stressed Snyder.
She proposes that these recent findings be viewed within the framework of ongoing research. Snyder had no involvement in the study she critiques.
Living Studies
“This is an observational study that acknowledges an association between variables but does not confirm causation. To establish this, we need an interventional study; thankfully, many present-day studies are testing diet and nutrition-related interventions,” Snyder noted. She suggests a holistic approach, pointing out that strategies to lower dementia risk should not be viewed independently, but combined.
In line with this, the Alzheimer’s Association is leading the U.S. POINTER Study, an experimental trial lasting two years, aiming to discover whether lifestyle adjustments targeting multiple risk factors can safeguard the mental functioning of older adults who are at risk.
“The relationships between diet and dementia risk need to be studied across several studies, different populations and even various countries—which could yield diverse outcomes,” Snyder remarked.
New Study Sparks Debate
In the current study, Dr. Isabelle Glans and her team from Lund University, looked at data from 28,000 Swedes free of dementia. The average age of the participants was 58. Over a span of two decades, 7% developed dementia, including Alzheimer’s disease.
On examining participants’ diets, the researchers observed no significant difference in dementia risk for those following a Mediterranean diet or a conventional diet. Isabelle Glans, in a prepared statement, said, “Although our study does not exclude a potential correlation between diet and dementia, we did not discover a link in our study.”
The Bigger Picture
Samantha Heller, a senior clinical nutritionist at NYU Langone Health in NYC, argues that the impact of diet on the risk of various forms of dementia is inconsistent. But she cautions that we need to look at the overall effect of dietary patterns on disease risk and quality of life. She emphasizes the wealth of evidence suggesting that a healthy diet significantly cuts down the risk of—or helps manage—several chronic diseases that can often be prevented.
She mentions eating patterns such as MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay); [DASH (Dietary Approaches to Stop Hypertension); Mediterranean; or other plant-focused diets.
“By eating a variety of whole grains, legumes, vegetables, fruits, nuts and other high-fibre foods, we ensure that our bodies and minds get the nutrients they need to stay healthy and combat diseases,” Heller added.
The study and a parallel editorial were published online on Oct. 12 in the journal Neurology.
A Final Word
Dr. Nils Peters of University Hospital Basel in Switzerland, the co-author of the editorial, asserts that diet alone may not have a robust effect on cognition, but instead should be considered as one of many factors having a cumulative effect on brain function.
He lists diet, regular exercise, managing heart risk factors, abstaining from tobacco, and moderate alcohol consumption among these factors.
More Information
The U.S. National Institute on Aging provides more data regarding diet and dementia.
