It’s rewarding to have good dietary habits. However, contrary to prior studies, reducing dementia risk isn’t one of its many benefits. New research published in the journal Neurology found that following two diets, including the Mediterranean diet right from early adulthood is not linked to reduced risk of developing dementia, including Alzheimer’s disease and vascular dementia.

The number of dementia cases worldwide in 2015 has been estimated to be over 47 million. Yet, it’s been predicted to triple in the next 30 years. Possibilities of dietary patterns as a potentially modifiable risk factor have been a controversial topic among scientists. Although, prior studies on the link between good diet patterns and the incidence of dementia have shown inconsistent results.

Lead study author, Isabelle Glans, MD, of Lund University in Sweden together with her team, then worked to investigate whether adhering to conventional dietary recommendations including a Mediterranean diet can be linked to reduced dementia risk.

Importantly, the Mediterranean diet comprises an increased consumption of vegetables, legumes, fruits, and fish as well as healthy fats (e.g. olive oil) and reduced consumption of meats, dairy products, and saturated fatty acids (e.g. nuts, seeds, and butter). 

Survey Methodology

In the study, the researchers looked at data from a total of 28,025 participants residing in Sweden. All participants were free from dementia at the start of the study and had an average age of 58 years. To gather extensive dietary data of the participants, they were to fill out a self-administered food frequency questionnaire along with a 7-day diet diary and undergo an hour interview. The interview enabled the team to ensure accuracy in the information filled in both the questionnaire and diet diary. 

During a long follow-up period of 20 years, the team found that of the 28,025 dementia-free participants, about 6.9 percent (1,943) were diagnosed with dementia. In addition to that, the participants that eventually developed dementia were found to be older and had a lower schooling level. 

Meanwhile, after adjusting for age, sex and education, the researchers found no indication of a significantly reduced risk of developing dementia, including vascular dementia and Alzheimer’s disease among those following conventional and Mediterranean diets.

“While our study does not rule out a possible association between diet and dementia, we did not find a link in our study, which had a long follow-up period, included younger participants than some other studies, and did not require people to remember what foods they had eaten regularly years before,” says Glans.

Previous studies may have shown favorable effects on the aspect of diet slowing cognitive decline and reducing the risk of dementia, but the team recognizes several limitations in their analysis. This study, therefore, adds to the growing body of evidence that diet on its own does not have a powerful effect on cognitive performance. But it most certainly is one factor capable of influencing the progression of brain health

Above all, the researchers concluded that more research is necessary to further validate their findings. 

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