For several years after World War II ended, the British government continued to ration certain foodstuffs, including eggs, dairy products and sugar. This not only popularized resourceful recipes such as the vinegar-based “Wacky cake”; it also kept the average diet within what we now recognize as modern guidelines for daily sugar consumption. Now a study shows this restriction conferred lifelong health benefits on people who were infants during rationing.
Scientists have long wondered how sugar affects the developing body and brain. But observational studies of families who consume less or more sugar can struggle to disentangle diet’s effects from those of related factors such as income or geographic location. “This type of experiment helps to remove some of that noise,” says Juliana Cohen, a nutrition researcher at Merrimack College and the Harvard School of Public Health, who was not involved in the work.
The study authors used the medical database U.K. BioBank to compare disease incidence in about 60,000 people born in the years before or after sugar rationing ended in September 1953. The transition sharply altered sugar intake without affecting other dietary factors—rationing of other ingredients ended on different dates—allowing the researchers to probe the effects of reduced sugar within the developmentally crucial first 1,000 days of life.
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Infants conceived in the years before sugar rationing ended had a 35 percent lower risk of diabetes and a 20 percent lower risk of hypertension in their 50s and 60s compared with those conceived after, the team reported in Science. For ration-era kids who ultimately did develop these conditions, onset was four and two years later, respectively. The longer a person lived under rationing, the greater the benefit they saw—but the strongest effects came while in utero and past the first six months of life, when babies begin eating solid foods.
Many mechanisms could explain the results, says lead author Tadeja Gračner, an economist at the University of Southern California. People who consume excessive sugar might gain an unhealthy amount of weight or develop diabetes during pregnancy, putting their children at risk for obesity and insulin resistance. High sugar intake could also prompt a growing fetus to express different genes to similar effect. And children raised on sugary diets may simply come to prefer sweeter foods; in a separate study, Gračner’s team found that people exposed to rationing consumed less daily added sugar as adults than those who weren’t.
The Centers for Disease Control and Prevention recommend that kids younger than two avoid added sugar and that everyone else keep their daily intake to less than 10 percent of their total calories. But today’s American toddlers average far more (nearly six teaspoons of added sugar a day), and many pregnant people consume triple the recommended amount for adults. Cohen notes dietary change is difficult because our nutritional environment isn’t set up to support it—yet any reduction helps, and there’s no need to avoid sugar entirely.
“It’s all about moderation,” Gračner says. “A birthday cake, candy, a cookie here and there—these are all treats we need to enjoy.”