Restricting sugar before birth and in early childhood greatly reduces risk of chronic disease later in life
A low-sugar diet during pregnancy and in the first two years of life can meaningfully reduce the risk of chronic diseases in adulthood, a new study has found, providing compelling new evidence of the lifelong health effects of exposure to sugar restrictions early in life.
Published in Science, the study finds that children who were in the womb or born during times of sugar restrictions during their first 1,000 days after conception had up to 35% lower risk of developing Type 2 diabetes and as much as 20% less risk of high blood pressure (hypertension) as adults. Exposure to limited sugar before birth was enough to lower risks, but continued sugar restriction after birth increased the benefits.
World War II sugar rationing poses a natural experiment
Taking advantage of an unintended “natural experiment” from World War II, researchers at the USC Dornsife College of Letters, Arts and Sciences, in collaboration with McGill University in Montreal, and the University of California, Berkeley, examined how sugar rationing during the war influenced long-term health outcomes.
The United Kingdom introduced limits on sugar distribution in 1942 as part of its wartime food rationing program. Rationing ended in September 1953.
The researchers used contemporary data from the U.K. Biobank, a database of medical histories and genetic, lifestyle and other disease risk factors, to study the effect of those early-life sugar restrictions on health outcomes of adults conceived in the U.K. just before and after the end of wartime sugar rationing.
“Studying the long-term effects of added sugar on health is challenging,” says study lead author Tadeja Gracner, senior economist at the USC Dornsife Center for Economic and Social Research. “It is hard to find situations where people are randomly exposed to different nutritional environments early in life and follow them for 50 to 60 years. The end of rationing provided us with a novel natural experiment to overcome these problems.”
Sugar rationing ends, consumption spikes
Sugar intake during rationing was about 8 teaspoons (40 grams) per day on average. When rationing ended, sugar and sweets consumption nearly doubled to about 16 teaspoons (80 grams) per day.
Notably, rationing did not involve extreme food deprivation overall. In fact, diets generally appeared to have been within today’s guidelines set by the U.S. Department of Agriculture and the World Health Organization, which recommend no added sugars for children under 2 and not more than 12 teaspoons (50g) of added sugar daily for adults.
The immediate and large increase in consumption of sugar – but no other foods – after the end of rationing created an interesting natural experiment: Individuals were likely exposed to different levels of sugar early in life, depending on whether they were conceived or born before or after September 1953. Those conceived or born just before the end of rationing experienced sugar-scarce conditions compared to those born into a more sugar-rich environment just after rationing ended.
50 years of post-rationing data offers long-term health insights
The researchers examined 50 years of U.K. Biobank data on individuals born around that period. By focusing on a narrow birth window near the end of sugar rationing, they could compare midlife health outcomes of birth cohorts that were otherwise similar.
Living through the period of sugar restriction during the first 1,000 days of life substantially lowered the risk of developing diabetes and hypertension. For those who were later diagnosed with either of those conditions, the onset of disease was delayed by four years and two years, respectively.
Notably, experiencing sugar restrictions solely in the womb was enough to lower risks, and disease protection increased once a low-sugar diet continued after birth, likely when solids were introduced.
Early-life low-sugar diet offers extensive long-term benefits
The magnitude of this effect is significant, as it can reduce health care costs, extend life expectancy and, perhaps more important, improve quality of life, say the researchers.
In the United States, people with diabetes incur annual medical expenditures averaging about $12,000. Furthermore, developing diabetes at an earlier age significantly reduces life expectancy — every decade that diabetes develops earlier cuts three to four years off life expectancy.
These numbers underscore the importance of early interventions to delay or prevent the disease, the researchers note.
Experts are increasingly concerned about children’s long-term health as they consume excessive amounts of added sugars during their early development, a critical period for lifelong health. Adjusting children’s sugar consumption, however, is not easy — added sugar is everywhere, even in baby and toddler foods, and children are bombarded with TV ads for sugary snacks, say the researchers.
“Parents need information about what works, and this study provides some of the first causal evidence that reducing added sugar early in life is a powerful step towards improving children’s health over their lifetimes,” says study co-author Claire Boone of McGill University and the University of Chicago.
Co-author Paul Gertler of UC Berkeley and the National Bureau of Economics Research adds: “Sugar early in life is the new tobacco, and we should treat it as such by holding food companies accountable to reformulate baby foods with healthier options and regulate the marketing and tax sugary foods targeted at kids.”
This study is the first of a larger research effort exploring how early-life sugar restrictions affected a broader set of economic and health outcomes in later adulthood, including education, wealth, and chronic inflammation, cognitive function and dementia.
About the study
The study, “Exposure to Sugar Rationing in the First 1000 Days of Life Protected Against Chronic Disease,” was supported by National Institute on Aging grants R01AG065482, P30AG012815 and T32 AG000243.