Less sugar as a baby, fewer heart attacks as an adult

The strongest protective effect, along with the greatest delay in the onset of heart disease -- was observed among individuals whose sugar intake was restricted from conception ("in utero") through about age 2.

Health experts have long suggested that the first 1000 days of life (from conception to around 2 years of age) represent a critical window when nutrition can influence long term health. Current guidelines recommend avoiding sugary drinks and ultra-processed foods (which often contain high amounts of sugar) as infants and toddlers begin eating solid foods.

A Natural Experiment Using UK Sugar Rationing

To explore whether limiting sugar during this early window affects future heart health, researchers took advantage of a unique historical event. Sugar rationing in the UK ended in September 1953, creating a natural comparison between children born before and after that policy change.

The analysis included 63,433 participants from the UK Biobank, with an average age of 55, who were born between October 1951 and March 1956 and had no prior history of heart disease. Of these, 40,063 were exposed to sugar rationing early in life, while 23,370 were not.

Researchers linked participants' health records to monitor rates of cardiovascular disease (CVD), heart attack, heart failure, irregular heart rhythm (atrial fibrillation), stroke, and death from cardiovascular causes. The analysis accounted for genetic, environmental, and lifestyle factors that could influence heart health. An additional comparison group of adults born outside the UK, who did not experience sugar rationing or similar policy shifts around 1953, was also included to strengthen the findings.

Lower Cardiovascular Risk and Delayed Onset

The study found that longer exposure to sugar rationing corresponded with steadily lower risks of cardiovascular disease in adulthood. Part of this benefit appeared to stem from lower rates of diabetes and high blood pressure among those exposed to rationing early in life.

Compared with people who were never exposed to rationing, individuals exposed in utero plus 1-2 years had a 20% lower risk of CVD overall. They also had reduced risks of heart attack (25%), heart failure (26%), atrial fibrillation (24%), stroke (31%), and cardiovascular death (27%).

In addition to lower risk, heart problems tended to develop later. Those exposed to sugar rationing before birth and in early childhood experienced delays in the onset of cardiovascular conditions of up to two and a half years compared with those who were not exposed.

Researchers also observed modest but meaningful improvements in measures of healthy heart function among individuals who experienced rationing.

Sugar Limits and Modern Dietary Guidance

During the rationing period, sugar allowances for the entire population, including pregnant women and children, were capped at less than 40 g per day -- and infants under age 2 were not allowed any added sugars. These limits align closely with today's dietary recommendations for young children.

Because this was an observational study, it cannot prove that lower sugar intake directly caused better heart outcomes. The researchers note several limitations, including the lack of detailed individual dietary records and the possibility of recall bias.

Even so, they emphasize that the large scale and careful design of the study allowed them to compare different periods of exposure and examine potential pathways connecting early sugar intake with later cardiovascular health.

"Our results underscore the cardiac benefit of early life policies focused on sugar rationing. Further studies should investigate individual level dietary exposures and consider the interplay between genetic, environmental, and lifestyle factors to develop more personalized prevention strategies."