Study Ties Lower Sugar Intake in Early Life to 23% Lower Dementia Risk Decades Later

A new study published in the journal Neurology found that people who consumed less sugar in the womb and during their first two years of life had a meaningfully lower risk of developing dementia decades later.

Researchers examined health records of more than 64,000 people in the United Kingdom, using a real-world dividing line: sugar rationing in Britain, which ended in September 1953. That policy shift gave scientists a natural experiment. People born before rationing ended grew up with strict limits on sugar. People born after had much freer access to it.

The results, according to the study: people whose mothers had lower sugar intake during pregnancy and through their first year of life had a 21% lower risk of dementia. Those whose own sugar intake stayed limited through age two had a 23% lower risk. People in the low-sugar group also developed dementia an average of 2.6 years later than those exposed to more sugar early on.

"Our findings suggest that limiting sugar during the earliest stages of life may have lasting benefits for brain health," said Jiazhen Zheng, the study's author and a researcher at The Hong Kong University of Science and Technology, in a press release accompanying the study.

An Outside Expert Pumps the Brakes

Not everyone is sold. Dariush Mozaffarian, director of the Food is Medicine Institute at Tufts University, who had no role in the research, told Fox News Digital he's impressed by the method but not convinced by the conclusion.

"I'm impressed with the researchers' creativity, pulling together information across decades to look at this question, but the findings are not convincing," Mozaffarian said.

His concern is a legitimate one. Wartime and postwar Britain didn't just differ in sugar availability. Overall nutrition, calorie intake, food scarcity, rationing of meat and fats, stress levels, and general living conditions were all different between the two eras. Any of those factors, alone or combined, could be driving the dementia gap researchers found, not sugar specifically.

That's the core limitation of using a historical event like rationing as a stand-in for a controlled experiment. Researchers can't isolate sugar as the single variable when an entire country's diet and economy shifted at once. The study's authors are working with population health records, not a clinical trial where one group's sugar intake was deliberately controlled while everything else stayed constant.

Still, the size of the effect and the consistency between the two comparisons, pregnancy-through-year-one and pregnancy-through-year-two, suggests the researchers have something more than a coincidence to point to. A 21-23% risk reduction is not a trivial number in dementia research, where most interventions studied so far produce far smaller effects.

What This Doesn't Change

Mozaffarian was clear that the study shouldn't change the standard advice already given to pregnant women.

"Ultimately, we know from other research that women who are pregnant should consume the healthiest foods possible for both their own health and that of their baby," he told Fox News Digital.

This isn't a new diet mandate. It's a data point suggesting that sugar exposure in the earliest window of human development, from conception through roughly age two, might matter more for long-term brain health than previously appreciated. It doesn't mean adults who ate sugar as toddlers in the 1970s or 1990s are doomed to dementia, and it doesn't establish sugar as a cause the way a randomized trial would.

A Separate but Related Warning

Fox News medical analyst Dr. Marc Siegel, discussing the study, also flagged a related trend: rising daily caffeine consumption among children and teenagers, often from sources parents don't think of as caffeinated, like sweetened baked goods and soda. That's a separate issue from the dementia study but points in the same direction, that early-life exposure to sugar and stimulants is getting less scrutiny than it probably deserves.

What's Next

The Neurology study is observational, meaning it shows an association, not proof that sugar restriction alone causes lower dementia risk. Confirming the finding would likely require additional studies that can better separate sugar intake from the dozens of other variables that shifted in postwar Britain. No U.S. or UK health agency has issued new pregnancy nutrition guidance based on this study as of this writing.