New research from Northeastern University suggests that diet may have a greater impact than genetics on the risk of developing Alzheimer’s disease. The study, published in BMC Neuroscience, found that a high-fat, high-sugar diet led to significant cognitive decline in some test subjects—especially male rats without genetic risk for the disease.
Surprising Results: Diet’s Impact on Brain Health
The study, led by psychology and bioengineering professor Craig Ferris, aimed to understand how diet and geneticsinteract in Alzheimer’s risk. Researchers studied male and female rats, some of which carried a gene linked to higher Alzheimer’s risk (similar to the APOE4 gene in humans).
All the rats were fed a high-fat, high-sugar diet for four months, consisting of:
- Nearly 50% carbohydrates, with 34% of those from sugar (sucrose).
- 21% fat.
- 17% protein.
The researchers expected that female rats with the genetic risk factor would show the most cognitive decline, mirroring the human trend where women carrying the APOE4 gene have a higher risk of early-onset Alzheimer’s.
However, the biggest surprise came when the data showed that:
- Male rats without genetic risk for Alzheimer’s had the most cognitive problems.
- These rats performed poorly in maze tests, suggesting learning and memory deficits.
- Their brain scans revealed enhanced neural connectivity in areas linked to food consumption and metabolism.
Ferris summarized the surprising results, saying:
“It was the normal guys eating McDonald’s that had all the problems.”
Brain Imaging Reveals Unexpected Changes
Using 3D MRI brain scans, researchers analyzed 173 different brain areas to see how the high-fat, high-sugar diet affected the rats’ neural circuits. The male rats without the Alzheimer’s gene showed:
- Hyperconnectivity across the brain, particularly in the hippocampus (a region crucial for memory).
- Significant changes in cerebellum connectivity, an area of the brain linked to feeding behavior.
- Disrupted dopamine pathways, which may play a role in cognitive decline.
These findings support the idea that diet affects brain structure and function, potentially increasing Alzheimer’s risk—even without genetic predisposition.
The Link Between Diet, Blood Flow, and Alzheimer’s
The study adds to growing evidence that Alzheimer’s disease is closely linked to vascular health. The traditional “amyloid beta hypothesis” (which suggested that protein buildup in the brain causes Alzheimer’s) has been widely rejected in recent years. Instead, researchers now believe that poor blood flow to the brain is a major driver of neurodegeneration.
Ferris explains:
“Years ago, they said it was all about amyloid beta accumulating in the brain, but that theory has been discarded. The science is now moving toward cardiovascular disease as a key factor.”
This means that lifestyle factors such as diet and exercise may be more important than genetics in preventing Alzheimer’s.
What This Means for Alzheimer’s Prevention
This study suggests that:
- A poor diet can negatively affect brain function, even in individuals without genetic risk.
- Diet-related changes in brain connectivity could contribute to cognitive decline.
- Vascular health, rather than just genetics, plays a key role in Alzheimer’s risk.
For humans, this reinforces the importance of:
- Eating a balanced diet low in processed sugars and unhealthy fats.
- Maintaining good cardiovascular health through exercise and healthy lifestyle choices.
- Recognizing that Alzheimer’s risk is not solely genetic—lifestyle choices matter.
Future research will explore whether dietary changes can reverse or slow down brain changes seen in this study. However, for now, the message is clear: a healthy diet is crucial for protecting long-term brain health.
If you care about Alzheimer’s, please read studies about Vitamin D deficiency linked to Alzheimer’s, vascular dementia, and Oral cannabis extract may help reduce Alzheimer’s symptoms.
For more information about brain health, please see recent studies about Vitamin B9 deficiency linked to higher dementia risk, and results showing flavonoid-rich foods could improve survival in Parkinson’s disease.
The research findings can be found in BMC Neuroscience.
Copyright © 2025 Knowridge Science Report. All rights reserved.
