Genetics May Affect Dietary Choices for Alzheimer's, Study Shows

Wine and cheese
Wine and cheese.

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Key Takeaways:

  • Certain dietary patterns may influence rates of decline in Alzheimer’s disease.
  • This study looks at how specific foods, including cheese, meat, and alcohol, affect fluid intelligence in adults with or without a genetic risk or family history of Alzheimer’s disease.
  • The results show that there are differences in fluid intelligence based on dietary patterns, family history of Alzheimer’s, and genetics.

 About 5.8 million Americans age 65 and older are living with Alzheimer’s, a progressive neurodegenerative disease that includes memory loss, disorientation, and changes in physical abilities, such as walking. At present, there is no cure for AD, but researchers are looking at ways to slow its progression.

Fluid intelligence (FI) is the ability to problem-solve and learn new things. In early Alzheimer’s, FI declines more rapidly than crystallized intelligence (knowledge based on past experiences).

Researchers are constantly looking for ways to protect FI and delay Alzheimer’s progression, and diet is often examined. A recent study published in the Journal of Alzheimer's Disease reported a positive association between red wine and cheese consumption and cognitive function for certain populations.

People with the APOE4+ gene have an increased risk of Alzheimer's. This study took a closer look to see how carrying the APOE4+ gene or having a family history of AD may affect dietary factors (and in turn fluid intelligence). Still, these findings require further investigation, as some information contradicts established dietary guidelines for Alzheimer's patients.

What Was Studied?

This study used data from the UK Biobank study, a prospective cohort study that began in 2006. This study included 1,787 participants and gathered genetic, cognitive, and dietary measurements. 

At three touchpoints over a 10-year period, participants aged 46-77 completed a food frequency questionnaire, which asked about their intake of 49 different foods and beverages, including alcohol.

The results suggest that whole foods could affect FI both cross-sectionally and longitudinally. However, differences are present between subgroups for APOE4+ and whether there was a family history of Alzheimer’s disease. 

These specific trends were noted:

  • Red meat did not appear to be beneficial overall.
  • Eating lamb once a week was associated with improved FI for people without a family history of AD for those who carried the APOE4+ gene.
  • Eating more cheese was associated with healthier cognition for those with or without the APOE4+ gene and in those without a family history of AD.
  • There was a significant association between red wine and higher FI in the data, but only in those with an APOE4– genotype or a family history of AD.

Overall, there did appear to be differences in FI based on food intake, family history, and whether participants carried the APOE4+ gene.

What This Means For You:

It’s too soon to say which exact foods may delay the progression of Alzheimer’s disease for any particular person. In absence of widespread genetic testing to determine which foods are right for your specific genes, experts recommend following the Mediterranean-DASH Intervention for Neurodegenerative Delay diet, or MIND diet. This means eating vegetables, berries, fish, beans, nuts, and whole grains, as well as minimizing consumption of red meat and highly processed foods.

The MIND Diet

This study builds on previous research that examined healthy eating patterns to slow the progression of Alzheimer's.

Prior to this study, there has been published research on dietary patterns for slowing the progression of AD, most notably the MIND diet. 

Kelli McGrane, MS, RD

The MIND diet is very similar to both the Mediterranean and DASH diets in that it emphasizes a diet that's rich in whole, minimally processed foods and limits the intake of heavily processed foods and red meat.

— Kelli McGrane, MS, RD

“The MIND diet is very similar to both the Mediterranean and DASH diets in that it emphasizes a diet that's rich in whole, minimally processed foods and limits the intake of heavily processed foods and red meat,” says Kelli McGrane, MS, RD, dietitian and author of "MIND Diet for Beginners". 

She explains that what makes the MIND Diet unique is the focus on foods specifically linked with benefits for brain health. 

McGrane says that an observational study found a 53% reduced risk of Alzheimer's disease over 4.5 years in those with the highest compliance to the MIND diet compared to those with the lowest MIND diet score.

“Furthermore, even those with just moderate adherence to the diet had a 35% reduced risk of Alzheimer's,” says McGrane.

Where Do Cheese and Meat Fit In?

The MIND Diet provides a list of foods to eat most often, which include vegetables, berries, nuts, olive oil, fish, beans, and wine. Interestingly, the MIND Diet also encourages limiting cheese and red meat, a recommendation that differs from the findings of the present study.

Verywell spoke with Brandon Klinedinst, a PhD Student in Neuroscience at Iowa State University and one of the researchers, to find out why. He explained that the results of his study may support or further inform the MIND diet.

“If it says to limit but not abstain from red meat, the results from our study suggested a flexitarian approach to red meat consumption,” says Klinedinst. 

Lamb was only consumed about once a week, so that’s still consistent with a MIND Diet pattern of limiting red meat in favour of poultry, beans, or fish.

Plus, the study researchers said that lamb is known to contain more than twice the amount of oleic fatty acid (the fat found in olive oil) content compared to beef, which may explain the favorable outcome.

Brandon Klinedinst, PhD candidate

It's possible that [a diet containing] only modest but regular servings [of cheese] is ideal, but we need to know a lot more before making decisions and recommendations.

— Brandon Klinedinst, PhD candidate

As for cheese, Klinedinst says they were not able to ascertain what the ideal amount of cheese to consume was, only that consuming it regularly appeared to result in better outcomes.

“It's possible that [a diet containing] only modest but regular servings [of cheese] is ideal, but we need to know a lot more before making decisions and recommendations,” says Klinedinst.

McGrane reminds us that cheese and lamb can be part of a healthy diet, but moderation is still important.

“When we see headlines like cheese and lamb are protective of brain health, it's really easy for us to think that eating more cheese and more lamb will also be beneficial, but that’s not the case,” says McGrane.

She explains that there could be other reasons why cheese and lamb were found to be protective, such as those who eat moderate amounts tend to also eat an overall higher quality, nutritious diet.

What’s Next?

Klinedinst reminds readers to remember that this observational study does not show causality.

“This study definitely helps identify the need to explore how food choices and an individual's genetics interact with important outcomes,” says Klinedinst.

“However, we consider this research to be hypothesis-generating rather than confirming anything.”

Ultimately, it’s the ability to individualize diets based on one’s genetics that may be the answer one day.

“My guess is that in the future, all decisions about medicine, supplements, and food-choices can be informed by individual genetics,” says Klinedinst. “For now I think we still have a lot of research to complete.”

Ultimately, this study drilled down further by looking at individual food categories within the MIND diet. Hopefully it can lead to further improved and personalized diets in the future.

5 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. McDonough IM, Bischof GN, Kennedy KM, Rodrigue KM, Farrell ME, Park DC. Discrepancies between fluid and crystallized ability in healthy adults: a behavioral marker of preclinical Alzheimer’s diseaseNeurobiol Aging. 2016;46:68-75. doi:10.1016/j.neurobiolaging.2016.06.011

  3. Klinedinst BS, Le ST, Larsen B, et al. Genetic factors of Alzheimer’s disease modulate how diet is associated with long-term cognitive trajectories: a UK Biobank studyJ Alzheimers Dis. 2020;78(3):1245-1257. doi:10.3233/JAD-201058

  4. Morris MC, Tangney CC, Wang Y, et al. MIND diet slows cognitive decline with agingAlzheimers Dement. 2015;11(9):1015-1022. doi:10.1016/j.jalz.2015.04.011

  5. Morris MC, Tangney CC, Wang Y, Sacks FM, Bennett DA, Aggarwal NT. MIND diet associated with reduced incidence of Alzheimer’s diseaseAlzheimers Dement. 2015;11(9):1007-1014. doi:10.1016/j.jalz.2014.11.009

By Cara Rosenbloom, RD
 Cara Rosenbloom RD is a dietitian, journalist, book author, and the founder of Words to Eat By, a nutrition communications company in Toronto, ON.