Less Sugar in Childhood Boosts Brain Health

Research suggests that limiting sugar early in life may have lasting brain benefits, with people exposed to less sugar before birth and during their first one to two years of life being less likely to develop dementia more than six decades later. A new study found that less exposure to sugar in utero and early childhood was linked to delaying the onset of dementia by about two and a half years.

Study Design and Methodology

The study analyzed nearly 65,000 UK Biobank participants and grouped them by whether sugar rationing was in effect while they were in the womb, during their first one or two years of life, or not at all. The researchers used the abrupt end of UK sugar rationing in 1953 as a natural experiment to compare people born just before and after sugar became widely available again.

The termination of this World War II–related austerity measure created a rare opportunity to study the effects of sugar exposure on brain health. During and after World War II, the United Kingdom rationed sugar and sweets, keeping sugar intake below 40 grams a day for adults and below 15 grams for young children.

Findings and Implications

The study revealed that those whose time in the womb and first year of life occurred during the rationing period had a 21 percent lower risk of all-cause dementia and a 23 percent lower risk of Alzheimer’s disease. Those whose time in the womb and first two years of life occurred during the rationing period had a 23 percent lower risk of all-cause dementia and a 28 percent lower risk of Alzheimer’s disease.

They estimated that rationing through age 2 delayed the onset of all-cause dementia by 2.55 years, Alzheimer’s disease by 2.87 years, and vascular dementia by 2.49 years. The findings have important public health relevance, given that the average American consumes 1.5 to 2 times the recommended daily allowance of sugar.

Limiting sugar intake is essential for maintaining good health. The study’s results suggest that limiting sugar early in life may be a key factor in reducing the risk of dementia.

Possible Mechanisms and Limitations

Previous studies have linked higher sugar exposure during pregnancy or infancy with childhood cognition, newborn brain organization, and memory changes in animals.

However, the study has limitations, including the fact that researchers didn’t know how much sugar any individual mother or child ate. The groups also differed in age, education, and some health conditions, and other parts of postwar life may have changed in ways the analysis couldn’t capture.

Despite these limitations, the study’s findings are significant and warrant further research. Kaitlin Seibert, MD, a behavioral neurologist at the Cleveland Clinic Center for Brain Health, notes that this study raises the possibility that nutrition during the first 1,000 days of life — a critical period for brain development — may influence brain health much earlier than previously appreciated.

The study’s results should encourage more research into how nutrition can affect brain health decades later. While the findings alone aren’t enough to make recommendations on sugar intake for expectant mothers or infants to reduce dementia risk, they do suggest that limiting sugar early in life may be an important factor in maintaining good brain health.

Experts agree that there are many environmental and lifestyle factors that impact dementia risk, including regular movement, a balanced diet, management of high blood pressure and diabetes, adequate sleep, and social and mental engagement. By understanding the relationship between sugar exposure and brain health, researchers can work towards developing effective strategies for reducing the risk of dementia.