A recent study has found that Britons born during the period of sugar rationing in the Second World War had a significantly lower risk of developing dementia later in life compared to those born after rationing ended. The research, which analysed health data from 65,000 participants in the UK Biobank, suggests that limited sugar intake in early life—including prenatal exposure—may have lasting benefits for brain health.

Sugar was rationed in the United Kingdom from 1940 until 1953 as a result of wartime shortages and disrupted imports. During this period, adults were allowed about eight ounces (227 grams) of sugar per week, with further restrictions on sweets imposed from 1942. The study examined individuals born during this 13-year period and compared them with those born after rationing ceased.

The researchers found that those exposed to sugar rationing before birth and up to age one had a 21 percent lower risk of developing dementia between the ages of 55 and 70. This protective effect increased to a 23 percent reduction in risk for those whose exposure to restricted sugar lasted until the age of two. Additionally, among individuals who did develop dementia, symptoms appeared an average of 2.6 years later than in those born after rationing.

Brain imaging conducted on a subset of participants revealed that lower early-life sugar consumption was associated with higher grey matter volume and fewer white matter hyperintensities—markers linked to brain tissue damage. The study’s lead author, Dr. Jiazhen Zheng of the Hong Kong University of Science and Technology, suggested that limiting added sugars during pregnancy and infancy could be a beneficial strategy to reduce dementia risk. Zheng noted, however, that further investigation is necessary to fully understand how early sugar intake influences metabolic processes and brain development.

The findings build on earlier research indicating that those born during the rationing era also had lower incidences of cardiovascular conditions such as heart failure and stroke. Dietitians have historically regarded the wartime rationing period as one of the healthiest nutritional eras in the UK, characterised by increased consumption of eggs, milk, fruits, vegetables, and fish.

Experts caution, however, that the study is observational and does not establish a direct causal link between sugar intake and dementia prevention. Dr. Sara Rodrigues, a senior research manager at Alzheimer’s Research UK, highlighted the importance of further research to clarify these associations and noted that the organisation does not currently recommend specific sugar reduction in pregnancy or infancy solely to prevent dementia. She emphasised that maintaining a healthy, balanced diet remains the best supported approach for long-term brain health.

Currently, major dementia risk assessments such as those by the Lancet Commission do not list sugar intake as an independent risk factor. Nonetheless, the study contributes to growing interest in how early-life nutrition may influence cognitive health in later years.