ByMaria Azzurra Volpe
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People who consumed less sugar during the first 1,000 days after conception may be significantly less likely to develop Alzheimer’s disease later in life, according to a new study published in the journal npj Aging
Researchers found that individuals exposed to sugar restriction from pregnancy through roughly age 2 had a 46 percent lower risk of developing Alzheimer’s disease compared with those who were not exposed to those restrictions. They also showed lower risks of dementia, anxiety and depression in later life
The findings come from an analysis of more than 60,000 people enrolled in the UK Biobank and suggest that nutrition during the earliest stages of life may have lasting effects on brain health decades later
How Wartime Sugar Rationing Created a Natural Experiment
Scientists were able to investigate the question using a unique historical circumstance. During World War II and for several years afterward, sugar was heavily rationed in the United Kingdom. Children younger than 2 did not receive a sugar ration. When rationing ended in September 1953, adult sugar consumption nearly doubled
Because it would be unethical to deliberately restrict a baby’s diet for research purposes, the period of rationing created a natural experiment that allowed researchers to compare people exposed to lower sugar levels early in life with those who were not
A team of researchers in China examined the health records of 60,394 people born between 1951 and 1956. Participants were divided into groups based on whether sugar rationing covered their time in the womb only, their time in the womb and early childhood, or neither period, which served as the control group
The researchers then analyzed medical records and self-reported health conditions recorded in the UK Biobank to determine how participants’ health changed as they aged
…
Compared with the non-rationed control group, people who experienced sugar restriction during the first 1,000 days after conception had a 27 percent lower risk of developing dementia from any cause. Their risk of anxiety was 20 percent lower, while their risk of depression was reduced by 11 percent
The study found no association between early-life sugar restriction and the risk of Parkinson’s disease
To understand whether the differences extended to the brain itself, the researchers also examined MRI scans from a subset of 9,053 participants
After accounting for other factors that could influence brain health, including genetics and family history, they found that people who were exposed to sugar rationing had brains that appeared younger than expected for their age. On average, the difference was about 0.39 years
The scans also revealed larger volumes in certain brain regions, including the hippocampus and thalamus, areas involved in memory and other cognitive functions
Summarizing their findings, the researchers wrote: “These quasi-experimental findings suggest that early-life sugar restriction is associated with attenuated neurobiological aging and lower risks of dementia and psychiatric disorders.”
What the Findings Mean—and Their Limits
Professor Fahad Hanna, associate professor of public health at Torrens University Australia, told Newsweekthat the findings are broadly consistent with current understanding of how early-life conditions can influence long-term health
“The first 1,000 days represent a critical period of brain development during which nutrition can influence metabolism, immune function, the gut microbiome, and even epigenetic pathways that may have lifelong consequences,” Hanna said. “Excessive sugar intake early in life could contribute to metabolic dysregulation and chronic inflammation, and these are recognized as risk factors for cognitive decline and dementia.”
However, he cautioned that Alzheimer’s disease has many contributing factors and that early-life nutrition should not be viewed as the sole determinant of future brain health
“Alzheimer’s disease is a complex condition influenced by genetics, cardiovascular health, education, lifestyle, and many environmental factors accumulated across the lifespan. Early-life nutrition is likely to represent one piece of a much larger puzzle,” Hanna said
The study authors also urged caution in interpreting the findings. While the researchers adjusted their analyses for a range of factors that could influence brain health, they emphasized that the results do not prove that lower sugar consumption directly prevents Alzheimer’s disease or other neurological conditions
Hanna echoed that limitation
“The study provides an important association but does not establish direct causation,” Hanna said. He noted that people exposed to lower sugar intake early in life “may also have differed in many other ways that influence dementia risk decades later, including socioeconomic circumstances, health consciousness in general (including physical activity) healthcare access, education, and broader dietary patterns throughout childhood and adulthood.”
He also noted that the findings were based on a unique period of sugar rationing that may not reflect modern dietary environments, highlighting the need for further research in other populations and settings
The authors made a similar point in their paper, writing: “These findings require replication in contemporary cohorts with detailed early-life dietary assessments before informing clinical or public health recommendations.”
While Hanna said the findings support existing public health guidance to limit excessive added sugar during pregnancy and early childhood, he warned against drawing conclusions about Alzheimer’s prevention at this stage
“Parents should not interpret these findings as suggesting that occasional sugar exposure determines a child’s future cognitive health,” Hanna said
“Rather than viewing this as a story solely about sugar, I see it as further evidence that the first 1,000 days may be one of the most important windows for lifelong health. We have long recognized this for cardiovascular disease, obesity, and diabetes. Studies like this raise the intriguing possibility that brain health and dementia risk may also begin much earlier in life than we once thought.”
Reference:
Xingji Lian et al, Early-life sugar rationing, brain aging, and long-term neurodegenerative and psychiatric health outcomes: a population-based natural experiment study, npj Aging (2026). DOI: 10.1038/s41514-026-00452-z
Contact Newsweek editors on this story: Kara Dolman and Emma Lee-Sang
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