A new study examined how different nutrients affect dementia risk in older adults. Researchers followed more than 6,200 U.S. adults aged 50 and older for seven years. They looked at 101 dietary nutrients and their connection to cognitive decline.
About the study
Participants filled out a questionnaire about how often they ate 163 foods and drinks over the past year. Scientists then analyzed each nutrient separately and created a combined score to see how groups of nutrients influenced risk. Each participant also took a cognitive test, and a close relative or friend answered questions about the person’s memory.
Five nutrients linked to lower dementia risk
The study identified five nutrients that were associated with a reduced risk of dementia. These are:
Isorhamnetin — a plant flavonol with anti-inflammatory and neuroprotective effects. Early research suggests it may help reduce the buildup of amyloid-beta, a protein linked to Alzheimer’s disease. Food sources include red onions, pears, apples with skin, berries, kale, and green tea.
Dietary fiber — a type of carbohydrate that nearly 95% of U.S. adults do not get enough of. Fiber feeds gut bacteria and supports cognitive function. Good sources are lentils, black beans, oats, chia seeds, apples, raspberries, broccoli, and whole grains.
Beta-tocopherol and beta-tocotrienol — forms of vitamin E that act as antioxidants and protect against oxidative stress. Found in sunflower seeds, hazelnuts, walnuts, wheat germ, and barley.
Manganese — a trace mineral needed for enzyme function and brain energy metabolism. It helps with neurotransmitter synthesis and may protect brain cells from oxidative damage. Food sources include pineapple, oats, pecans, brown rice, chickpeas, and spinach.
Foods that increase risk
The study found that diets high in added sugars were linked to a higher dementia risk. Some dairy-derived nutrients, including lactose, were also associated with greater risk. However, the researchers noted that dairy foods also contain vitamin D and calcium, which are tied to healthy aging. Dairy is a complex food, and its overall effect on brain health can depend on the nutrient balance.
The takeaway
While this study points to specific nutrients that may support memory and cognition, it reinforces that a whole-food diet rich in antioxidant fruits, vegetables, nuts, and seeds supports long-term brain health. The findings suggest that focusing on these five nutrients and limiting added sugars could help reduce dementia risk in older adults.
