Sugar in shape of a heart

Research suggests less sugar intake as an infant promotes lower heart disease risk as an adult. (Credit: vectorfusionart on Shutterstock)

Post-WWII rationing in the UK decades ago may be benefitting locals’ hearts to this day.

In a Nutshell

  • The Study: Researchers examined 63,433 UK adults born around 1951-1956 to see how sugar rationing during their first 1,000 days of life (from conception through age 2) affected their heart health decades later.
  • Key Finding: People exposed to sugar rationing in utero plus their first 1-2 years had 20-31% lower risks of cardiovascular disease, heart attack, heart failure, stroke, and related deaths compared to those never exposed to rationing.
  • The Protection Effect: Longer exposure to sugar restriction provided progressively greater protection, with those rationed throughout the full 1,000-day window developing cardiovascular disease about 2.5 years later than their non-rationed peers.
  • The Takeaway: Limiting sugar intake during pregnancy and early childhood to levels matching current WHO guidelines (under 40g daily for adults, essentially none for infants under 2) appears to provide lasting cardiovascular benefits well into adulthood.

Sugar restriction during pregnancy and the first two years of life was associated with lower cardiovascular disease risk six decades later, according to research published in The BMJ.

British adults who experienced limited sugar intake from conception through approximately age two showed substantially lower risk of heart attacks (25% reduction), heart failure (26%), irregular heart rhythms (24%), stroke (31%), and overall cardiovascular disease (20%) in their 60s and 70s compared to peers born roughly a year later who never experienced sugar rationing.

The study analyzed 63,433 British adults born in the early 1950s, when wartime food rationing created an unintended experiment in early nutrition. The protective effects extended across multiple cardiovascular outcomes, with disease onset delayed by roughly 2.5 years for those with the longest exposure to sugar restrictions.

The Critical 1,000-Day Window

This period spans from conception through approximately 24 months after birth. During this window, organs develop rapidly and biological systems establish patterns that can persist for decades.

Lead researcher Dr. Chuang Yang and colleagues found that the longer someone experienced restricted sugar intake during this window, the greater the protection. Exposure only during the nine months in the womb offered modest benefits. Continuing restrictions through age one strengthened the effect. Extending through age two provided the most protection.

Between 1942 and September 1953, the UK government rationed sugar as part of wartime food controls. Adults received about 40 grams daily (roughly eight teaspoons), with children under two receiving no sugar or sweets through official ration channels. After rationing ended, adult sugar consumption rose sharply from 41 grams per day in early 1953 to approximately 80 grams by mid-1954, when all food rationing fully terminated.

Birth date determined exposure in this natural experiment. The study compared those born during rationing (October 1951 through September 1953) to a “never exposed” comparison group born significantly after rationing ended (July 1954 through March 1956). Those born immediately after September 1953 experienced some in-utero exposure but fell into an intermediate group, while the cleanest comparison came from those born at least 10 months after rationing ceased.

Previous research suggests that during pregnancy, maternal sugar intake may affect fetal development through multiple pathways. High glucose levels can increase fetal insulin secretion, which may trigger changes in heart muscle growth and blood vessel formation. Excess sugar can generate oxidative stress and inflammation in the placenta, potentially impairing how nutrients reach the developing fetus.

After birth, as infants transition from breast milk to solid foods, continued sugar exposure shapes metabolic systems still under construction. The study indicates the postnatal period matters just as much as prenatal development.

Researchers examined cardiac imaging in a subset of participants. Those exposed to restricted sugar during the 1,000-day window showed measurably better heart function in their 60s. Left ventricular ejection fraction, a measure of pumping efficiency, was 0.84 percentage points higher. Stroke volume index, indicating the amount of blood pumped with each heartbeat relative to body size, was 0.73 mL/m² higher.

These differences appear small but carry clinical weight. Even modest improvements in heart function, when sustained over decades, can reduce disease risk.

A British food ration coupon book. Introduced in 1940 during the Second World War, rationing was ended in 1954.
A British food ration coupon book. Introduced in 1940 during the Second World War, rationing was ended in 1954. (Credit: David Fowler on Shutterstock)

Modern Sugar Consumption

During rationing, sugar allowances matched what many health organizations now recommend. Adults consumed less than 40 grams of added sugar daily. Infants and toddlers encountered minimal added sugars in their diets.

Background research cited by the BMJ authors shows today’s nutritional environment differs substantially. Pregnant women in developed nations consume, on average, more than 80 grams of added sugars daily, well above the recommended 50 grams. Many commercial infant and toddler foods contain substantial added sugars, sometimes exceeding amounts indicated on labels.

The World Health Organization recommends keeping free sugars below 10% of total energy intake. More recent guidelines call for avoiding all added sugars for children under two. The rationing period inadvertently enforced standards close to these recommendations.

When restrictions lifted, sweetened products became widely available and processed foods with added sugars proliferated, transforming the food landscape almost overnight.

Tracking Disease Over Seven Decades

The research team used UK Biobank data covering participants recruited between 2006 and 2010, when most were in their mid-50s. Linked health records tracked hospital admissions, disease diagnoses, and deaths through July 2023, providing long-term cardiovascular outcome data.

Statistical models adjusted for genetics, birthplace, birth month, parental health history, maternal smoking, breastfeeding status, food prices, and socioeconomic factors. The protective pattern persisted across all analyses.

To rule out coincidence, researchers examined osteoarthritis and cataracts, conditions unrelated to early sugar exposure. Rationing showed no association with either condition, supporting the specificity of cardiovascular effects.

The team validated findings using two external aging studies. The British cohort, which also experienced rationing, showed similar protective patterns. The American cohort, which didn’t experience comparable restrictions, showed no relationship between birth year and heart disease risk.

Understanding the Protection

Adult-onset diabetes and high blood pressure together explained roughly 31% of the protective effect. Both conditions damage blood vessels and strain the heart. Both show links to sugar consumption. Early nutritional programming may make some individuals more resistant to developing these conditions later.

Yet most of the benefit remained unexplained, pointing to additional pathways. Changes in gene expression, differences in how blood vessels develop, alterations in metabolic efficiency, or shifts in inflammatory responses might all contribute.

Birth weight accounted for just 2.2% of the association. Fetal growth has traditionally been considered a key link between prenatal nutrition and adult disease, but the results indicate that nutritional quality during development matters more than birth size alone.

Animal studies support biological plausibility. Rats fed high sugar diets during pregnancy produce offspring with altered cardiac gene expression, vascular stiffness, and irregular heart rhythms. The effects persist even when offspring eat normal diets after weaning.

Heart Health Protection Starts Immediately

The study examined a historical population under unique circumstances. Directly applying findings to contemporary pregnancies requires caution. Environmental exposures, medical care, and overall nutrition have changed since the 1950s.

Still, the biological principles likely remain relevant. The first 1,000 days represent a period when nutrition appears to exert outsized influence on lifelong health trajectories.

British adults exposed to less sugar before the age of two had a lower risk of heart attack, stroke, and heart failure well into their 60s and 70s.
British adults exposed to less sugar as infants had a lower risk of heart attack, stroke, and heart failure well into their 60s and 70s. (Credit: dturphoto on Shutterstock)

Current dietary guidelines already recommend limiting sugar intake during pregnancy and avoiding added sugars for infants and toddlers. The research adds long-term cardiovascular outcomes to existing concerns about tooth decay, obesity, and metabolic health.

For expecting parents, the evidence supports meeting current recommendations: consuming added sugars in moderation during pregnancy, exclusively breastfeeding when possible during the first six months, and delaying introduction of sweetened foods as infants transition to solids.

For parents of young children, choosing products without added sugars and limiting sweet treats aligns with both immediate health goals and potential long-term protection. The protective effects emerged gradually with longer exposure to restrictions, indicating that sustained dietary patterns throughout the 1,000-day window matter more than occasional treats.

Study Limitations

The research design offered advantages over typical nutrition studies. Birth date determined exposure, creating comparison groups that differed primarily in early sugar intake rather than other factors. Participants couldn’t selectively recall or report dietary habits, avoiding common biases. The large sample size and decades of follow-up provided statistical power.

Still, there were limitations. UK Biobank participants skew wealthier and healthier than the general population. Whether findings fully apply to other groups remains uncertain, though validation in a separate British aging study provides some reassurance.

Individual sugar intake data wasn’t available. Analysis relied on national consumption averages, which mask personal variation. The observational design cannot prove causation with certainty. Early life factors like birth weight, maternal smoking, and breastfeeding were self-reported years later, introducing possible recall bias.

Concurrent changes in other rationed foods and total calorie intake, though modest, could have influenced results. Researchers adjusted for fat consumption and food prices, and the patterns held. Total calorie intake changed less than 5%, with most variation stemming from sugar, supporting the specificity of sugar effects.

The 1,000-day window observed in the research represents both constraint and opportunity. For children being born today, the window opens fresh with each pregnancy. Parents, healthcare providers, and policymakers can use evidence about this period to shape nutritional environments that may offer protection extending well into the next century.

The study tracked participants through their 60s and 70s. Many remain alive. Whether protective effects persist into the 80s and beyond remains to be seen, though the delayed disease onset observed points to lasting benefits.

A wartime natural experiment offers a glimpse of how early nutritional choices ripple across decades, potentially shaping the arc of cardiovascular health from a baby’s first heartbeat through late adulthood.


Disclaimer: This article is for general informational purposes only and does not constitute medical advice. Pregnant women and parents should consult healthcare providers for personalized nutritional guidance.


Paper Notes

Limitations

The study relied on national average sugar consumption data rather than individual intake measurements, which may mask personal variation. UK Biobank participants tend to be wealthier and healthier than the general population, potentially limiting generalizability. Some early life factors (birth weight, maternal smoking, breastfeeding) were self-reported years later, introducing possible recall bias. The observational design cannot prove causation despite extensive adjustments for confounding factors. Concurrent changes in other rationed foods and overall calorie intake, though modest, could have influenced results. The findings reflect a specific historical period and population, requiring caution when extrapolating to current pregnancies and modern dietary environments.

Funding and Disclosures

The research was supported by the Guangzhou Municipal Research Fund (grant Z2023209). The funders played no role in study design, data collection, analysis, interpretation, manuscript writing, or publication decisions. All authors completed conflict of interest disclosures and reported no financial relationships with organizations that might benefit from the published findings.

Publication Information

Zheng J, Zhou Z, Huang J, Tu Q, Wu H, Yang Q, Qiu P, Huang W, Shen J, Yang C, Lip GYH. “Exposure to sugar rationing in first 1000 days after conception and long term cardiovascular outcomes: natural experiment study,” published October 22, 2025 in BMJ; 391:e083890. DOI: 10.1136/bmj-2024-083890.

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1 Comment

  1. ANGELA MOORE says:

    I’m having a trouble with the idea that 63K participants aged 20-50 years believe they can remember or have records somewhere recording their diets and sugar consumption they experienced as very young children. To me this makes the study finding somewhat suspect. If anyone can add anything to this notion then thanks for the input.