World War II Sugar Rationing Data Hints That Limiting Intake of the Sweet Stuff Early in Life Lowers the Risk of Dementia and Cancer

Toddlers often whine to get their hands on sweet treats, while parents step in so the kids don’t gorge themselves on cake and candy. Doing so might have more benefits than avoiding a child who’s bouncing off the walls. Limiting sugar intake during their earliest developmental windows might affect cognitive function and cancer risk up to 70 years later.

According to two studies published in July the journals Neurology and npj Aging, people who lived during a national sugar ration during their first 1,000 days—starting at conception—experienced lower rates of Alzheimer’s disease, dementia, depression and anxiety as adults than those who consumed more of the sweetener. Additionally, a study published in August in the Proceedings of the National Academy of Sciences suggests that the early life sugar rationing reduced the incidence of five major adult cancers. Researchers had a rare historical event to thank for these insights: sugar rationing in the United Kingdom during World War II that ended in September 1953.

For about a decade, government policy capped individual intake at roughly 40 grams a day—a stack of ten standard sugar cubes. Once rationing ended, national sugar consumption nearly doubled almost overnight. Because children born just months apart experienced vastly different diets, the policy shift created a unique natural experiment with two sets of populations whose long-term outcomes could be studied.

Scientists examined medical records of tens of thousands of individuals while minimizing differences in factors that could affect health outcomes, like socioeconomic status, that typically complicate nutrition research. Zhang and his colleagues analyzed health records from more than 60,000 participants in the U.K. Biobank born between October 1951 and March 1956.

Adults whose first 1,000 days fell under rationing had a 46 percent lower risk of Alzheimer’s disease and a 27 percent lower risk of all-cause dementia compared to those born after restrictions ended. Early sugar limits were also linked to an 11 percent reduction in depression risk and a 20 percent drop in anxiety risk. Brain scans provided visual clues for these outcomes.

Participants who consumed little sugar early in life had brains that appeared 0.39 years younger than their chronological age, along with larger volumes in memory-critical structures like the hippocampus and thalamus, the team found. The findings were backed by the Neurology study conducted by a different team of researchers. They examined nearly 65,000 U.K.