- Previous studies have identified specific genetic variants that may increase a person’s risk for Alzheimer’s disease, such as the APOE4 variant.
- A new study found that following a Mediterranean diet may help lower a person’s risk of developing dementia and decelerate cognitive decline.
- Scientists discovered that this protective effect was strongest in high risk participants with two copies of the APOE4 gene variant.
Researchers estimate there are more than 55 million people around the world living with dementia.
While doctors still don’t know exactly what causes Alzheimer’s disease, the most common form of dementia, past research has identified certain factors that play a role, such as
Previous studies have identified specific genetic variants that may increase a person’s risk for Alzheimer’s disease, such as a variant of the apolipoprotein E (APOE) gene known as
Now. a new study recently published in the journal
Scientists said this protective effect was most powerful in high-risk participants with two copies of the APOE4 gene variant.
For this study, researchers analyzed medical data from more than 4,000 adult women who had participated in the Nurses’ Health Study. The study followed participants from 1989 — when they had an average age of 57 — to 2023.
Scientists also examined similar health data from nearly 1,500 men who had participated in the Health Professionals Follow-Up Study and were followed from 1993 to 2023.
Researchers focused on study participants’ long-term dietary patterns and genetic data.
“Alzheimer’s disease and related dementias are influenced by both genetics and lifestyle,” Dong D. Wang, MD, ScD, assistant professor of medicine at Brigham and Women’s Hospital and Harvard Medical School, assistant professor in the Department of Nutrition at Harvard T.H. Chan School of Public Health, and lead author of this study, told Medical News Today.
Genetics are not destiny“Genetics set the baseline risk, but they are not destiny. Understanding how diet and other modifiable factors work together with our genes is important, because their influence may depend on a person’s genetic makeup. Unlike inherited genes, which we cannot change, lifestyle factors such as diet are modifiable, and that means they offer a way to lower risk and possibly delay disease onset, even for those at higher genetic risk.”
— Dong D. Wang, MD, ScD
At the study’s conclusion, researchers found that study participants who followed a more Mediterranean-style diet had a lower risk of developing dementia. Additionally, these participants had a slower rate of cognitive decline.
“This suggests that diet can play an important role in maintaining cognitive health over time,” Wang explained. “Even modest differences in dietary patterns were associated with differences in dementia risk and cognitive decline, which is encouraging because it means that relatively achievable lifestyle changes could make a meaningful impact.”
Additionally, Wang and his team discovered that the protective effect of the Mediterranean-style diet was strongest in study participants carrying two copies of the APOE4 gene variant.
“This is important because APOE4 homozygotes are the highest-risk genetic group for sporadic Alzheimer’s disease,” he said. “Our results suggest that they may also benefit the most from adherence to the Mediterranean diet, highlighting the potential of precision nutrition tailored to an individual’s genetic background.”
“A healthy diet matters for everyone, but it may be especially critical for APOE4 homozygotes, who face the highest genetic risk of Alzheimer’s disease. Genetics are not destiny, and following a Mediterranean diet can still make a big difference.”
— Dong D. Wang, MD, ScD
MNT spoke with Megan Glenn, PsyD, clinical neuropsychologist at the Center for Memory and Healthy Aging in the Hackensack Meridian Neuroscience Institute at Jersey Shore University Medical Center in New Jersey, about this study’s results, which she commented left her feeling hopeful.
“For so long, genes like APOE4 have been viewed as a non-modifiable risk factor for developing dementia,” Glenn explained. “However, this study contributes to the growing literature base on how modifiable lifestyle factors, in this case diet, can help mitigate that risk. This is empowering because, even for people at high genetic risk, diet becomes a tool — something they can do to actively fight back against developing Alzheimer’s disease.”
“Prevention is our best tool right now. We don’t have a cure for Alzheimer’s disease or other forms of dementia, and current medications offer only modest benefits. By the time someone is showing Alzheimer’s-related symptoms, like memory loss, the disease has already been present and progressing in the brain for decades. If we can identify protective factors, like diet, and implement them early, we have a better chance of slowing or even preventing the disease before it takes hold.”
— Megan Glenn, PsyD
For readers who may be interested in starting to eat a more Mediterranean-style dietary plan, we asked Monique Richard, MS, RDN, LDN, a registered dietitian nutritionist and owner of Nutrition-In-Sight, for her top tips on how to do that.
Richard said it’s all about keeping it simple and focusing on what you can add, not just what you take away.
“From olives to oregano, small swaps can bring big benefits for brain health. Meals don’t need to be complicated — something as simple as a chickpea salad drizzled with olive oil and lemon, or 4 ounces of herbed grilled salmon with roasted vegetables, checks all the boxes.”
— Monique Richard, MS, RDN, LDN
Additional tips Richard offered for creating more Mediterranean-forward meals include:
- Swapping out butter for cold-pressed extra virgin olive oil.
- Grabbing a handful of nuts instead of chips.
- Adding an extra serving of vegetables like leafy greens, tomatoes, or cruciferous vegetables to your lunch or dinner plate.
- Trying a different fatty fish twice a week (such as mackerel, sardines, salmon, or anchovies).
- Enjoying beans and lentils as the star of a few meals, snacks, or, yes, even desserts.
- Herbs and spices bring both flavor and brain-supportive compounds, so play with seasonings like rosemary, oregano, and turmeric, or roasting seeds like sesame, sunflower, or pumpkin.
“It’s about building consistency with small, enjoyable steps,” Richard added. “The Mediterranean diet is not just a way of eating — it’s a way of nourishing the body and mind for decades to come.”
