Less sugar can reduce the risk of Alzheimer’s disease

History has provided a unique opportunity to study the long-term effects of nutrition on brain aging: During the Second World War and for several years after it, the UK had a strict sugar norm. Children under the age of two did not receive any sugar allowance at all, and after the restrictions were lifted in September 1953, sugar consumption among adults almost doubled. For scientists, this has become a kind of natural experiment. It is ethically impossible to intentionally limit the nutrition of infants for the sake of research, but historical data allow us to trace the effects of different conditions without direct intervention.

Researchers from China analyzed the medical data of 60,394 people born between 1951 and 1956 and included in the UK Biobank database. The participants were divided into three groups based on whether their prenatal and early childhood periods were affected by the norm: some experienced the restriction only during their prenatal period, others experienced it both during their prenatal period and in their early years, and the third group (the control group) did not experience the norm at all. The scientists then examined the medical records and self-reported health data of the participants, as well as analyzing MRI scans of a subgroup of 9,053 people.

After statistically adjusting for other factors, including genetics and family history, the researchers found that those who had normal blood sugar levels had an average brain that appeared about 0.39 years younger than expected for their age. In addition, they had larger brain regions, particularly the hippocampus and thalamus, which play an important role in memory and other cognitive functions.

The authors emphasize that this is an association that has been identified, rather than a proven causal relationship. According to them, these results need to be replicated in modern cohorts, where more detailed information about early-life nutrition can be collected, before any clinical or public recommendations can be made.

If the link is confirmed, early nutrition may be one of the significant factors that determine the trajectory of brain aging and the risk of neurodegenerative diseases.