Less sugar early in life might be linked to lower dementia risk

Parents of toddlers know all too well what sugary treats can do. Children may get a burst of energy at first, then crash or have mood swings later. Now a new study adds evidence that too much sugar early in life may also be linked to health problems much later.

Consuming too much sugar in the first 1,000 days of life may be associated with a higher risk of developing dementia decades later, scientists report in the Aug. 25 issue of Neurology.

“The first 1,000 days are critical for brain development,” says epidemiologist Jiazhen Zheng of the Hong Kong University of Science and Technology in Guangzhou, China. He says the brain undergoes exceptionally rapid growth and neuronal development during that period.

Existing data suggest that high sugar intake early in life may contribute to health problems, including diabetes and high blood pressure. Zheng had previously studied sugar’s effects on the cardiovascular system and wondered whether it might also affect brain health.

He and his colleagues examined health records of nearly 65,000 people in the U.K. Biobank who were in utero, infants or toddlers between July 1942 and June 1954. During those years, they would have been subject to a British government policy that capped how much sugar a person could buy each day. The policy, a World War II austerity measure, allowed each person 41 grams of sugar a day — roughly the sugar in a 12-ounce can of Coke today.

After adjusting for lifestyle, socioeconomic status and other conditions, the team found that people who lived their first two years of life under sugar rationing had a 23 percent lower risk of developing dementia and a 28 percent lower risk of developing Alzheimer’s disease than those born after the policy ended. Risk was similarly lower among those who lived under rationing for the first year of life. Among those who did develop either condition, the disease developed almost three years later on average than in those never subject to rationing.

Other factors beyond sugar consumption may also have played a role, Zheng says, so he cannot say how much sugar is safe to consume to reduce risk.

Still, given the data, families should limit added sugars in their children’s diets, he says. The Dietary Guidelines for Americans, for instance, do not recommend any added sugars for children under 11 years old. “That’s one of the best things they can do, a sensible step for children’s overall health,” he says.