- A UK Biobank study found people exposed to sugar rationing in early life had lower later-life risk of dementia and Alzheimer’s disease.
- The strongest association was seen when sugar restriction covered both pregnancy and the first years after birth.
- The findings are interesting, but they do not prove that cutting sugar in early childhood directly prevents Alzheimer’s.
Sugar exposure early in life may leave a longer mark on brain health than we once thought.
A new study used a rare historical event to examine this: sugar rationing in the UK during and after the Second World War.
During rationing, sugar intake was tightly limited, and children under two did not receive a sugar ration.
When the policy ended in September 1953, adult sugar consumption rose sharply.
That created a natural comparison between people exposed to lower sugar early in life and those born after restrictions ended.
Researchers studied 60,394 people born between 1951 and 1956 using UK Biobank data.
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They grouped people by whether sugar rationing covered their time in the womb, their early childhood, both or neither.
The first 1,000 days after conception are a critical period for brain and metabolic development.
In this study, people exposed to sugar restriction during that period had a 27% lower risk of dementia from any cause.
They also had a 46% lower risk of Alzheimer’s disease.
The same group had a 20% lower risk of anxiety and an 11% lower risk of depression.
No clear association was found for Parkinson’s disease.
The researchers also looked at MRI brain scans from more than 9,000 people.
Those exposed to early sugar rationing had brains that appeared around 0.39 years younger than expected.
Some brain regions were also larger, including the hippocampus and thalamus.
That matters because the hippocampus is strongly involved in memory, and is one of the key regions affected in Alzheimer’s disease.
For a diabetes audience, the findings are worth paying attention to.
They fit with a broader pattern linking early nutrition, metabolic health and long-term brain ageing.
But this is not proof that sugar alone determines dementia risk.
People born during rationing may have differed in other ways too, including wider diet, family circumstances, healthcare access and post-war living conditions.
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The authors are cautious, and rightly so.
They describe the findings as a natural experiment, not a definitive cause-and-effect trial.
Still, the study adds weight to a sensible public health message.
Lower added sugar in pregnancy, infancy and childhood may matter for more than weight and teeth.
It may also be part of building better lifelong brain health.
