How sugar intake in first two years of life may affect dementia risk

In an article published July 29, 2026, in Neurology®, researchers studied more than 64,000 people in the United Kingdom who were born before and after World War II sugar rationing.

During rationing, sugar was limited, and children younger than age two received little or no added sugar. After rationing ended in 1953, sugar became more available to all ages.

By comparing people born before and after rationing ended, researchers examined whether consuming sugar early in life was linked to dementia risk later in life. They found that people who had a lower sugar intake before birth and during their first one to two years of life were less likely to develop dementia than those born after sugar rationing ended.

After factoring in age, sex, high blood pressure, and diabetes, participants who experienced sugar rationing before birth and through age one had a 21% lower risk of dementia. Those who experienced sugar rationing through age two had a 23% lower risk.

The study also found that dementia developed later in people who had less sugar early in life. On average, dementia onset was delayed by about two and a half years.

In a smaller group of participants who underwent brain scans, those with lower sugar exposure early in life had more gray matter, which contains many of the brain’s nerve cells, and fewer signs of damage in the brain’s white matter. They also performed better on some tests of thinking speed and reasoning.

Researchers believe some of the benefits may be related to lower rates of conditions such as type 2 diabetes and high blood pressure, both of which are linked to dementia risk.

The study suggests that sugar consumption during pregnancy and the first two years of life may be important for long-term brain health. However, the study was observational, meaning it cannot prove that reducing sugar directly prevents dementia. More research is needed to understand exactly how early-life nutrition influences the aging brain.