Healthy Diet Slows Aging and Lowers Dementia Risk

Healthy Diet Slows Aging and Lowers Dementia Risk

Summary: Researchers linked healthier diets to a reduced risk of dementia and a slower pace of biological aging, unveiling the partial mechanism behind this protective effect. Researchers applied the DunedinPACE epigenetic clock to data from the Framingham Heart Study’s Offspring Cohort, revealing that adherence to the MIND diet significantly slowed aging and lowered dementia risks.

This relationship between diet, aging speed, and dementia risk highlights the potential of dietary interventions in dementia prevention. Although the study sheds light on the importance of monitoring biological aging, it also calls for further research to fully understand the diet-dementia connection.

Key Facts:

  1. The study connects healthier eating habits with slower biological aging and a decreased likelihood of developing dementia.
  2. Slower biological aging, as measured by the DunedinPACE clock, accounts for a significant part of the diet’s protective effect against dementia.
  3. Despite these findings, researchers emphasize the need for further exploration into the specific brain mechanisms involved and the replication of results in diverse populations.

Source: Columbia University

A healthier diet is associated with a reduced dementia risk and slower pace of aging, according to a new study at Columbia University Mailman School of Public Health and The Robert Butler Columbia Aging Center.

The findings show that a diet-dementia association was at least partially facilitated by multi-system processes of aging. While literature had suggested that people who followed a healthy diet experienced a slowdown in the processes of biological aging and were less likely to develop dementia, until now the biological mechanism of this protection was not well understood.

The findings are published in the Annals of Neurology.

This shows an older lady making a salad.
Past research linked both diet and dementia risk to an accelerated pace of biological aging. Credit: Neuroscience News

“Much attention to nutrition in dementia research focuses on the way specific nutrients affect the brain” said Daniel Belsky, PhD, associate professor of Epidemiology at Columbia School of Public Health and the Columbia Aging Center, and a senior author of the study.

“We tested the hypothesis that healthy diet protects against dementia by slowing down the body’s overall pace of biological aging.”

The researchers used data from the second generation of the Framingham Heart Study, the Offspring Cohort. Originating in 1971, participants in the latter were 60 years of age or older, were free of dementia, and also had available dietary, epigenetic, and follow-up data.

The Offspring Cohort were followed-up at nine examinations, approximately every 4 to 7 years. At each follow-up visit, data collection included a physical examination, lifestyle-related questionnaires, blood sampling, and, starting in 1991, neurocognitive testing. 

Of 1,644 participants included in the analyses, 140 of the participants developed dementia. To measure the pace of aging, the researchers used an epigenetic clock called DunedinPACE developed by Belsky and colleagues at Duke University and the University of Otago. The clock measures how fast a person’s body is deteriorating as they grow older, “like a speedometer for the biological processes of aging”, explained Belsky. 

“We have some strong evidence that a healthy diet can protect against dementia,” said Yian Gu, PhD, associate professor of Neurological Sciences at Columbia University Irving Medical Center and the other senior author of the study,

“But the mechanism of this protection is not well understood.” Past research linked both diet and dementia risk to an accelerated pace of biological aging. 

“Testing the hypothesis that multi-system biological aging is a mechanism of underlying diet-dementia associations was the logical next step,” explained Belsky.

The research determined that higher adherence to the Mediterranean-Dash Intervention for Neurodegenerative Delay diet (MIND) slowed the pace of aging as measured by DunedinPACE and reduced risks for dementia and mortality. Furthermore, slower DunedinPACE accounted for 27 percent of the diet-dementia association and 57 percent of the diet-mortality association.

“Our findings suggest that slower pace of aging mediates part of the relationship of healthy diet with reduced dementia risk, and therefore, monitoring pace of aging may inform dementia prevention,” said first author Aline Thomas, PhD, a Postdoc at the Columbia Department of Neurology and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain.

“However, a portion of the diet-dementia association remains unexplained, therefore we believe that continued investigation of brain-specific mechanisms in well-designed mediation studies is warranted.”

“We suggest that additional observational studies be conducted to investigate direct associations of nutrients with brain aging, and if our observations are also confirmed in more diverse populations, monitoring biological aging, may indeed, inform dementia prevention,” noted Belsky. 

Co-authors are Calen Ryan and Jiayi Zhou, Columbia Aging Center; and Avshalom Caspi, Terrie Moffitt, and Karen Sugden, Duke University.

Funding: The study was supported by the National Institute on Aging grants R01AG061378, R01AG073402, R01AG059013, R01AG061008, R01AG073207 and R01AG049789. 

About this diet, aging, and dementia research news

Author: Stephanie Berger
Source: Columbia University
Contact: Stephanie Berger – Columbia University
Image: The image is credited to Neuroscience News

Original Research: Closed access.
Diet, Pace of Biological Aging, and Risk of Dementia in the Framingham Heart Study” by Daniel Belsky et al. Annals of Neurology


Abstract

Diet, Pace of Biological Aging, and Risk of Dementia in the Framingham Heart Study

Objective

People who eat healthier diets are less likely to develop dementia, but the biological mechanism of this protection is not well understood. We tested the hypothesis that healthy diet protects against dementia because it slows the pace of biological aging.

Methods

We analyzed Framingham Offspring Cohort data. We included participants ≥60 years-old, free of dementia and having dietary, epigenetic, and follow-up data. We assessed healthy diet as long-term adherence to the Mediterranean-Dash Intervention for Neurodegenerative Delay diet (MIND, over 4 visits spanning 1991–2008). We measured the pace of aging from blood DNA methylation data collected in 2005–2008 using the DunedinPACE epigenetic clock. Incident dementia and mortality were defined using study records compiled from 2005 to 2008 visit through 2018.

Results

Of n = 1,644 included participants (mean age 69.6, 54% female), n = 140 developed dementia and n = 471 died over 14 years of follow-up. Greater MIND score was associated with slower DunedinPACE and reduced risks for dementia and mortality. Slower DunedinPACE was associated with reduced risks for dementia and mortality. In mediation analysis, slower DunedinPACE accounted for 27% of the diet-dementia association and 57% of the diet-mortality association.

Interpretation

Findings suggest that slower pace of aging mediates part of the relationship of healthy diet with reduced dementia risk. Monitoring pace of aging may inform dementia prevention. However, a large fraction of the diet-dementia association remains unexplained and may reflect direct connections between diet and brain aging that do not overlap other organ systems. Investigation of brain-specific mechanisms in well-designed mediation studies is warranted.