When Cheese Gets Interesting for Brain Health

You're standing in the dairy aisle, squinting at labels. Low-fat mozzarella promises virtue. The aged cheddar whispers temptation. For decades, the choice seemed obvious: fat is the villain, and cheese is a guilty pleasure at best.

A new study just complicated that story.

After tracking 27,670 Swedish adults for up to 25 years, researchers found that people who ate at least 50 grams of high-fat cheese daily had a 13% lower risk of developing dementia. The findings, published December 17, 2025, in Neurology, challenge the low-fat orthodoxy that's shaped dietary advice for generations.

"For decades, the debate over high-fat versus low-fat diets has shaped health advice, sometimes even categorizing cheese as an unhealthy food to limit," says lead author Emily Sonestedt of Lund University. "Our study found that some high-fat dairy products may actually lower the risk of dementia, challenging some long-held assumptions about fat and brain health."

This isn't a small pilot study. Researchers used the Malmö Diet and Cancer cohort, capturing baseline diets through food diaries, questionnaires, and hour-long interviews with nearly 28,000 people averaging age 58. Then they waited, tracking who developed dementia over the next quarter-century. Out of the group, 3,208 people did.

When they analyzed the data, focusing on high-fat cheese like cheddar, Brie, and Gouda, a pattern emerged.

Participants eating 50 grams or more of high-fat cheese daily showed a 13% lower risk of all-cause dementia compared to those eating less than 15 grams. That's after adjusting for age, sex, education, diet quality, physical activity, smoking, and alcohol.

What does 50 grams actually look like? Two slices of cheddar. A small wedge of Brie. Less than you might pile on crackers during a Netflix session. The comparison group, eating under 15 grams, barely gets a sprinkle on their salad.

The signal got stronger when researchers examined vascular dementia, the type caused by impaired blood flow to the brain. High-fat cheese eaters showed a 29% lower risk. While the exact mechanism remains unclear, scientists have plausible hunches: fermentation creates unique bioactive compounds, the dairy matrix might interact differently with metabolism than isolated saturated fat, or cheese might displace less healthy foods.

"These findings suggest that when it comes to brain health not all dairy is equal," Sonestedt notes.

Here's where diet culture takes a hit: low-fat cheese, low-fat cream, milk of any fat level, yogurt, kefir, and butter showed no protective association. Zero. All those virtuous swaps didn't move the needle on dementia risk in this study. It's a satisfying challenge to decades of fat-phobic messaging that turned cheese into a nutritional outlaw.

But hold off on that celebratory cheese board.

This is an observational study, not a randomized trial. It shows association, not causation. People who eat more high-fat cheese might have other protective habits. Dietary data was self-reported and captured mainly at baseline. The Swedish context matters too—cheese there is often eaten uncooked with whole-grain bread, while American cheese frequently arrives melted on pizza or burgers.

"People in Sweden and the U.S. eat roughly the same amount of cheese per person, but the type is different," Sonestedt explains. "We would like to see our findings replicated in more countries."

The Alzheimer's association was weaker and limited to people without the APOE ε4 genetic risk variant. Dr. Richard Isaacson, a dementia prevention specialist, points out that "people who carry the APOE ε4 gene are more sensitive to saturated fat." Harvard's Dr. Walter Willett adds caution: "Their finding for cheese was at the margin of statistical significance and they looked at multiple foods, so this might be just due to chance."

Sonestedt herself warns: "This is not a green light to dramatically increase intake."

If you already enjoy cheese, you can relax. A modest, consistent intake—two slices rather than two blocks—fits comfortably within a balanced diet, especially paired with fiber-rich foods like whole grains or vegetables. If you've been buying low-fat cheddar out of obligation, this study suggests you can stop. For those at high cardiovascular risk or carrying the APOE ε4 gene, discuss saturated fat tolerance with your doctor.

This research cracks open a bigger question: what else have we oversimplified? The "fat bad, low-fat good" mantra has dominated for decades, but real foods are complex packages. Fermentation, food matrix effects, and eating patterns all matter.

The study elevates curiosity over certainty. The next time you're debating between virtue and pleasure at the cheese counter, remember the science is getting more nuanced. At the very least, guilt is off the menu.