Children waiting for a sweetshop to open in Britain.
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Sugar Rationing Lowered Diabetes and Hypertension in British Children

British data shows that children conceived and born during a period of sugar rationing were less likely to develop diabetes or high blood pressure later in life.

by · NY Times

People who were restricted to limited amounts of sugar in the first few years of life were less likely to develop diabetes and high blood pressure decades later, a new study has found.

The study, published Thursday in the journal Science, took advantage of a unique situation in the United Kingdom. The country was under strict rationing during World War II and its aftermath. When the rationing ended, in September 1953, the average sugar intake by people in Britain doubled. That provided a natural experiment and allowed the researchers to ask: What happened to the health of people who were conceived and born when sugar was rationed compared with people conceived and born just after sugar rationing ended?

To find out, the researchers, Tadeja Gracner, an economist at the University of Southern California, and her colleagues, Claire Boone of McGill University and Paul J. Gertler of the University of California, Berkeley, turned to the UK Biobank. It contains genetic and medical information on half a million people, and steps have been taken to preserve contributors’ privacy. Using the data, the investigators analyzed the health of 60,183 people who were born from October 1951 through March 1956, and were age 51 to 60 when they were surveyed.

The investigators reported that those exposed to sugar rationing early in life had a 35 percent lower risk of diabetes and a 20 percent lower risk of high blood pressure in middle age. The onset of those chronic diseases was also delayed by four years for diabetes and two years for high blood pressure. They also found that disease protection was greatest for those who had been conceived during sugar rationing and were babies while rationing continued. Those who were exposed to sugar rationing only before birth and then grew up with higher sugar intake had higher disease rates.

The results contribute to a body of evidence suggesting that nutrition very early in life can affect health much later. But because of the unique circumstances of British sugar rationing, the new study provides additional rigor, experts said.

For example, a study of military records of men whose mothers were in the first half of pregnancy during the Dutch famine, or Hunger Winter, during World War II found that the men were more likely to be obese at age 19 than men born after that event. Another study found that women whose mothers were pregnant during the famine were heavier at age 50 than women born later.

Chemical changes in DNA might explain the different health outcomes, noted Aryeh Stein, a professor of global health at Emory University who has conducted studies of the Dutch famine.

But famine studies cannot pinpoint any particular nutrients that might have caused the effect.

The new study had that ability, with its focus on sugar. And its results are unexpected, Dr. Stein said. Although the absolute amount of sugar the population consumed doubled, from 41 to 80 grams a day, that is only an additional 155 calories. Yet, he said, the researchers’ methodology is sound and the result appears “really interesting.”

Dr. Gracner noted that other foods in addition to sugar were rationed in the United Kingdom during and after World War II. When butter was rationed, people substituted margarine. Cereals were rationed, too, but the amount people ate did not change much when rationing ended.

Sugar consumption was the exception, as it doubled when rationing ended.

“There was a huge demand for sugar,” Dr. Gracner said.

The early 1950s was generally not a time of starvation or food shortages, minimizing the possibility that the health effects were a result of a general lack of calories early in life.

Researchers not involved with the study said it was entirely credible.

“I believe it,” said Dr. Anupam Jena, a health economist and physician at Harvard Medical School. “The study design is really quite good.”

And, he added, it is an important contribution to the field of nutritional epidemiology that, he noted, has been plagued by studies that draw conclusions almost exclusively from correlations. There are claims that excess sugar consumption leads to poor health, for example, based on observational studies of people eating more sugar, or less. But there generally are many differences between groups that are studied, leaving open the possibility that other factors are affecting health.

The new study is different, he said. With the sharp cutoff of sugar rationing, and with the Biobank data, “this study introduces a different kind of thinking,” Dr. Jena said.

Of course, Dr. Jeffrey Flier, an obesity and diabetes researcher at Harvard Medical School, noted, it is still possible that factors other than sugar consumption affected the people in the Biobank. But, he said, “the authors have done a lot of analysis to support the conclusion.”

One thing the new study cannot answer, though, is why sugar rationing early in life had such profound effects later.

“It is very weird,” said Kriti Jain, a program officer at the National Institute on Aging, which funded the study. But, she added, “this kind of study is not designed to tell us why — it is designed to tell us what.”

One idea, Dr. Gracner said, is that early exposure to sugar leads to a lifelong craving for it. People who were conceived and born during sugar rationing ate less sugar later in life, according to the British government’s National Diet and Nutrition Survey.

She sees the disease risk as “a cumulative response” to a lifetime of sugar consumption.

“Chronic diseases do take time to develop,” she said.

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