Study details

For the study, researchers analyzed data from 64,761 people born in Britain between 1951 and 1956. During this time, sugar and other common foods were rationed in order to prevent food shortages following World War II. After rationing ended, average daily sugar consumption across the United Kingdom almost doubled from around 41 grams to 80 grams, while consumption of other major foods remained stable.

Using data from the UK Biobank study, the researchers then compared health outcomes among adults who spent the first 1,000 days of their life (or the period from conception to a child's second birthday) under sugar restrictions to those who were born after the restrictions were lifted.

The researchers found that adults who spent their first 1,000 days under sugar rations were less likely to develop a number of different cancers. Overall, they had a:

• 69% reduced risk of liver cancer
• 52% reduced risk of prostate cancer
• 41% reduced risk of lung cancer
• 40% reduced risk of rectal cancer
• 36% reduced risk of breast cancer

The researchers also found that the participants exposed to sugar rationing early in life ate less sugar, ate smaller portions, and maintained healthier, more diverse diets over 50 years later.

Discussion

Other studies have also linked sugar rationing during early life to improved health outcomes.

For example, another recent study found that people exposed to sugar rationing in their first 1,000 days of life were significantly less likely to develop depression and anxiety in adulthood. Other studies using the same UK Biobank data also found that those exposed to sugar rationing early in life had lower risks of chronic disease, Alzheimer's disease, and better cardiovascular health.

However, Slomovitz noted that natural experiments from decades ago come with some limitations.

"We're talking about the 1950s, so clearly there are some biases in data collection," he said. "Secondly, the numbers are very, very, very low. Of all the cancers, most of them had [fewer] than 100 cases ... to show a 70% decrease, I think is probably an ambitious conclusion."

Slomovitz also pointed out that while cancers driven by obesity align with metabolic pathways, other findings in the study, like a reduced risk of lung cancer, are typically tied to external factors like smoking instead of dietary sugar.

According to Zhang, the study's results don't mean "that children should not eat sugar at all, and it certainly does not mean that postwar sugar rationing is a desirable policy."

"What this historical evidence shows is that, during a critical period of development, even relatively small differences in sugar exposure over a short period may leave effects that are still observable half a century later," Zhang wrote. "Children may not remember what they ate before age two. But their later health, their bodies and even their taste preferences may still carry the imprint of those very early-life experiences."