More than 6 million Americans live with dementia. With an aging population and rising cases of conditions linked to dementia, like obesity, that number is expected to double by 2060.
We can’t avoid getting older — dementia’s single greatest risk factor is increasing age — but that doesn’t mean we’re powerless to stop it. We do have control over a number of factors that can lower or risk or delay dementia. Namely, our diet.
While eating an overall healthy and balanced diet is key, studies show that there are several specific foods that, when eaten too frequently, can up our odds of developing dementia.
1. Processed meat like bacon, sausage, hot dogs and deli meat
As little as 25 grams of processed meat a day — think two slices of deli meat — is associated with a whopping 44% increased risk of all-cause dementia and 52% higher risk of Alzheimer’s disease, a 2021 study found. Alzheimer’s is the most common cause of dementia.
You don’t need to give up all red meat, though: Researchers found that eating unprocessed varieties (whole cuts, cooked from raw) was associated with lower risks.
Authors believe it could be because unprocessed meats have more protein and iron, while processed meats increase sodium, saturated fats, and inflammatory signals in the brain.
2. Sugar-sweetened beverages like soda, sweet tea and sugary fruit drinks
The more sugar-sweetened beverages (SSBs) you drink, the higher your risk of developing Alzheimer’s. A 2025 review found that people who drank more had a 49% higher risk of Alzheimer’s.
SSBs encompass sodas like cola and ginger ale, fruit juices with added sugar, sports drinks, energy drinks and prepared coffee or tea with sugar.
Artificially sweetened beverages — like zero calorie or sugar-free drinks sweetened with substitutes like aspartame — also heightened risk of Alzheimer’s, by 42%.
Another study suggests that sugar may be affecting the way brain cells use energy and function.
3. Fried fish
The second most common cause of dementia is vascular dementia: When the flow of blood, oxygen, and nutrients to the brain get blocked or reduced.
Researchers in a 2024 review analyzed a number of specific foods to get clear answers on which raised risk of this type of dementia. Fried fish in particular — only .25 to 2 servings a week — raised risk.
They also found that people who ate more ultra-processed foods (think industrially manufactured, packaged foods with additives — especially SSBs and processed meat (more than 2 servings a week) — were at a higher risk of vascular dementia.
Those who ate more fruits and vegetables, drank more coffee, tea, and moderate alcohol (1-3 drinks a day), or had a plant-based diet, were at a lower risk of vascular dementia.
4. Refined carbs like white bread, pastries and pasta
Carbs make up more than half of most of our diets. Which ones we choose to eat make a difference.
Refined carbs like white bread, rice, pasta and breakfast cereals are processed, removing fiber and nutrients. The body digests them quickly, causing spikes in blood sugar.
Eating a lot of these processed carbs often is associated with a higher risk of dementia, a 2025 study showed. Another study in animals showed that refined carbs were shown to raise risk for dementia and Alzheimer’s.
Foods slower to absorb, like whole grains, fruits, beans, are lower on the glycemic index, and may even protect against dementia, according to the 2025 research.
5. Saturated fat
The more saturated fat you eat — from fatty red meat, dairy, pastries, and fried foods — the higher your risk of Alzheimer’s and dementia.
Every little bit counts. Every 4 grams of saturated fat a day — less than a teaspoon of butter — was associated with a 15% increased risk of Alzheimer’s, a 2018 study found. The group eating the most saturated fats had about twice the risk of the group eating the least saturated fats.
Research suggests more saturated fats can increase the amount of harmful proteins circulating in the brain and cause inflammation.
