Your Risk of Dementia May Increase If You Eat the Wrong Carbs

 

Carbohydrates have long been a staple of the human diet, but not all carbs are created equal. Emerging research suggests that the type of carbohydrates you eat may play a significant role in long-term brain health — and eating the wrong ones could increase your risk of developing dementia later in life.

Dementia, a condition marked by declining memory, thinking, and reasoning skills, affects millions of people worldwide. While age and genetics are major risk factors, lifestyle choices — especially diet — are increasingly being linked to cognitive decline. Scientists now believe that diets high in refined and ultra-processed carbohydrates may negatively impact brain function over time.

So-called “bad carbs” include refined sugars, white bread, pastries, sugary cereals, and processed snacks. These foods are quickly digested, causing rapid spikes in blood sugar levels. Repeated blood sugar surges can lead to insulin resistance, inflammation, and damage to blood vessels — all of which are factors associated with cognitive decline and dementia.

One of the key concerns is chronic inflammation. Diets heavy in refined carbohydrates can trigger systemic inflammation in the body, including the brain. Inflammation has been linked to the buildup of amyloid plaques and tau tangles, two hallmarks commonly associated with Alzheimer’s disease. Over time, this inflammatory environment may accelerate damage to brain cells and impair communication between neurons.

Another issue is the impact of poor-quality carbohydrates on metabolic health. Studies have shown that conditions such as type 2 diabetes and obesity — both strongly influenced by diet — are associated with a higher risk of dementia. High-carb diets dominated by refined grains and added sugars can worsen blood glucose control, increasing the likelihood of these metabolic disorders.

In contrast complex carbohydrates appear to support better brain health. Foods such as whole grains, oats, brown rice, legumes, vegetables, and fruits contain fibre, vitamins, and antioxidants that help regulate blood sugar and reduce inflammation. Fibre also supports a healthy gut microbiome, which researchers increasingly believe plays a role in brain function through the gut–brain axis.

Whole-food carbs are digested more slowly providing steady energy to the brain — an organ that relies heavily on glucose to function. Unlike refined carbs, these foods help prevent sharp blood sugar spikes and crashes that can affect concentration, mood, and long-term cognitive health.

Experts emphasise that carbohydrates themselves are not the enemy. The problem lies in overconsumption of low-quality, processed sources that lack nutritional value. A balanced diet that prioritises whole foods, healthy fats, and lean proteins — such as the Mediterranean-style diet — has repeatedly been linked to lower dementia risk and improved cognitive ageing.

While no single food determines your future brain health dietary patterns over decades matter. Choosing the right carbohydrates today may not only support your energy levels and metabolic health but also help protect your brain as you age. As research continues to evolve, one message is becoming clear: when it comes to carbs, quality matters just as much as quantity.