Risk of dementia may be increased by this common drink

Your daily drink of choice may do more than quench your thirst: it could also influence your brain health in unexpected ways. Sugary drinks, including soda, sweetened tea, sweetened fruit juices, and energy drinks, may contribute to health problems associated with a higher risk of dementia when consumed regularly.

“Sugary drinks may not cause dementia on their own, but if consumed in excess over the long term, they can worsen known risk factors for dementia such as high blood pressure, diabetes, and heart disease,” says Maggie Moon, MS, RDN, brain health nutrition specialist. But what exactly is their link to dementia? We explain how these drinks may impact dementia risk and share expert tips for supporting brain health as you age.

They can increase insulin resistance

Regularly drinking sugary drinks can contribute to blood sugar fluctuations that can influence your brain health over time. “These drinks are liquid sugar without protein, fiber, or fat to slow absorption, so blood sugar can rise quickly,” says Diana Dibblee, RD, MEd, YTT. An occasional sugary drink is unlikely to be harmful, but Dibblee warns that the more you drink, the more the effects can add up.

When blood sugar spikes occur repeatedly, as is the case with frequent consumption of sugary drinks, they can contribute to insulin resistance. “Insulin resistance occurs when your cells stop responding well to insulin, the hormone that removes sugar from your blood, and, over time, it can contribute to type 2 diabetes,” says Dibblee.

But what does this have to do with brain health? Dibblee explains that the brain depends on insulin signaling for energy and memory. Disruptions in these processes can affect brain function, while diabetes-related complications can further contribute to dementia risks. In fact, Dibblee notes that the 2024 Lancet Commission on Dementia Prevention, Intervention, and Care identifies diabetes as a risk factor for dementia. She also points to a large study conducted in 2023 that suggests drinking more than two sugary drinks per day, rather than none, is associated with a higher risk of dementia.

They can damage blood vessels

Your brain depends on a constant supply of oxygen and nutrients to function properly, and healthy blood vessels make this possible. But frequent consumption of sugary drinks can contribute to conditions that damage these vital vessels and, therefore, affect brain health.

“Drinking lots of sugary drinks over time is linked to weight gain and obesity, as well as higher blood pressure,” says Dibblee. These conditions can narrow and stiffen blood vessels, including those that supply blood to the brain. As a result, damage to the brain’s blood vessels can impair circulation and contribute to cognitive decline. Dibblee shares that obesity and high blood pressure are both recognized risk factors for dementia. Although studies have shown a link between sugary drinks and dementia risk, more research is needed to confirm whether these drinks directly contribute to this disease. Still, limiting sugary drinks can help support both vascular health and brain function.

They can replace brain-protecting drinks and foods

When it comes to protecting your brain from cognitive decline, the overall quality of your diet is important. “When sugary drinks (including 100% fruit juice) absorb more than their fair share of the day’s calories, there is less room for neuroprotective foods and drinks that support brain function,” says Moon.

Research shows that people with high consumption of added sugar, especially from sugary drinks, tend to have poorer overall diet quality and consume fewer nutrient-dense foods. This can crowd out brain-protecting foods that are rich in antioxidants, polyphenols and omega-3 fatty acids, such as berries, leafy greens, nuts and fish.

Of course, enjoying a sugary beverage occasionally doesn’t mean you’re lacking in these nutrients. The biggest problem is that these drinks regularly replace more nutrient-dense options. Although more research is needed to determine a direct link, giving more space to brain-beneficial foods may help protect your brain health as you age.

Expert advice to reduce dementia risk

• Try the MIND Diet. The MIND diet, which emphasizes leafy greens, vegetables, fruits, whole grains, beans, nuts, fish, and healthy fats like olive oil, is associated with a lower risk of dementia and Alzheimer’s disease, says Dibblee.
• Exercise regularly. “Physical inactivity is one of the 14 major modifiable risk factors identified by the 2024 Lancet Commission on Dementia,” says Dibblee. She points out that regular physical activity helps with blood circulation, blood pressure and blood sugar, all of which impact brain health.
• Never stop learning. Moon shares that the brain gains a lot through games, hobbies, and learning new skills. “Novelty keeps the brain busy and flexible, which is why I recommend people never stop learning and playing,” says Moon.

Our expert opinion

Although sugary drinks alone don’t determine your risk of dementia, drinking them regularly may have implications for long-term brain health. Over time, the excess sugar in these drinks can contribute to conditions such as type 2 diabetes, high blood pressure and obesity, which can affect blood vessels in the brain and increase the risk of dementia. Sugary drinks can also replace nutrient-dense foods and drinks that can support healthy brain function. However, your overall diet matters much more than any single food or drink. That’s why a balanced diet rich in leafy greens, berries, whole grains, beans, nuts and fish, along with regular exercise and activities that stimulate your brain, are part of a comprehensive approach to reducing your risk of dementia.