Early-Life Sugar Limits May Be Linked to Lower Dementia Risk

By: Oluwasola Samuel, Freelance health writer. Medically reviewed by: A. Odutola, MBBS, PhD, FRCSEd.

August 10, 2026

An AI-generated image of a young African mother carrying her baby in a cradle position while seated in a room. She’s spoon feeding the baby. Click on image to enlarge. 

Introduction

Every parent wants to give their baby the best possible start in life. But what if some of the choices we make for our babies today could affect their health many decades from now, even into old age?

A new study has found something surprising. Babies who had access to less sugar before birth and in their diet during their first two years of life may have a lower risk of developing dementia much later in life as older adults. The research comes from a rare natural experiment involving sugar rationing in the United Kingdom after the Second World War, and it offers a fresh perspective to think carefully about on early feeding habits.

For expectant mothers, nursing mothers, and anyone caring for a young child, this is worth paying attention to. Let's break down what the study found, and what it may mean for families in the sub-Sahara Africa region.

About the Study

The research was published in the journal Neurology on 29 July 2026, and carried out by a team at the Hong Kong University of Science and Technology.

The researchers used a rare moment in history when sugar was rationed in the United Kingdom during and after World War II. Families could only buy and consume small quantities. This rationing ended suddenly in September 1953, and sugar became freely available again. This sudden change gave scientists a natural way to compare babies who grew up with strict sugar limits to those who did not, without having to run a controlled experiment themselves.

The study followed 64,737 people who were part of the UK Biobank, a large health database. All of them were born around the time rationing ended, which meant some had sugar rationed while their mothers were pregnant with them and into their early childhood, while others had no rationing at all.

The participants were placed into three groups, based on how much early-life sugar rationing they experienced:

• 15,025 people had rationing while their mother was pregnant with them, and through their first year of life.

• 15,256 people had rationing while their mother was pregnant with them, and through their first two years of life.

• 23,774 people had no sugar rationing at all, since they were born after it ended.

The average age of participants when the study began was about 55 years old. From that point, researchers tracked their medical records for up to 15 years to see who went on to develop dementia, including Alzheimer's disease and vascular dementia. They also adjusted for other factors that could affect the results, such as sex and existing health conditions like high blood pressure and diabetes, so the sugar exposure itself could be studied more clearly.

A smaller group of participants also had brain scans done, which allowed researchers to look directly at brain structure and not just dementia diagnoses.

What the study found

The researchers found something striking. Those who had rationing before birth and through their first year of life had a 21% lower risk of developing dementia later in life, compared to babies who had no sugar rationing. Those who had rationing before birth and through their first two years had an even lower risk, 23% lower, compared to the unrationed group.

To put this in real numbers:

• Out of 15,025 people who had rationing through their first year, 388 later developed dementia. 

• Out of 15,256 people who had rationing through their first two years, 456 developed dementia. 

• And out of 23,774 people with no rationing at all, 504 developed dementia.

The benefits did not stop at lower risk. For those who did go on to develop dementia, having less sugar early in life was linked to a delay in when it appeared. On average, dementia showed up about 2.6 years later in this group. This delay was seen across different types of dementia, including Alzheimer's disease and vascular dementia.

The brain scans also revealed that people who had less sugar early in life had a higher total volume of grey matter, the part of the brain responsible for processing information, memory, and decision-making. They also had lower levels of white matter hyperintensities, which are small areas of damage in the brain often linked to poorer brain health as people age. On top of this, In addition, they performed better on tests of processing speed and reasoning, meaning their brains were working faster and more efficiently.

Researchers also checked whether these results could simply be explained by other conditions like type 2 diabetes or high blood pressure, since both are known to affect brain health and are also linked to sugar intake. They found that these two conditions together only explained about a quarter of the link, 25.5% to be exact. This means most of the connection between early sugar exposure and dementia risk cannot be explained by diabetes or blood pressure alone, and something else about sugar exposure itself in early life may be at play.

Taken together, these findings suggest that the first two years of life, alongside the time spent in the womb, may be a critical window where sugar intake has a lasting effect on how the brain ages, decades down the line.

What the Study Means for Africans

This study was carried out in the United Kingdom, using people born in the early 1950s. The study did not include Africans and the study findings cannot be generalsed to Africans. But people in sub-Sahara Africa can learn important lessons from the findings.

For many African families, sugar often finds its way into a baby's diet earlier than expected, and not always on purpose. A spoon of sugar is often added to pap, tea, or custard. Fizzy drinks or juice are given to babies as a treat, sometimes even before the child's first birthday. In many homes, sweet food is a way of showing love, comfort, and generosity, especially from grandmothers and aunties who grew up believing that a sweet treat makes a baby happy and well fed.

This is where the study's findings become useful and serve as a gentle nudge. If early sugar exposure can affect a baby's brain health decades later, then small changes made today, like cutting back on sugary drinks, choosing plain cereal over sweetened ones, or offering fruit instead of sweets, could matter far more than we realise.

Talking to family members about this does not have to cause conflict.  It can be framed as new information, rather than criticism of how older generations fed their own children. This will often make these conversations easier and more welcome.

For expectant and nursing mothers, the takeaway is just as relevant. Choosing lower sugar options during pregnancy and when introducing solid foods is a small, practical step that lines up with what this research suggests, even though the study itself measured the baby's own sugar exposure rather than the mother's diet during breastfeeding specifically.

Limitations of the Study

Even with such striking results, it's important to understand what this study does and does not prove.

First, this research shows an association, not direct proof of cause and effect. In simple terms, the study found a clear pattern that babies with less sugar exposure early in life tended to have lower dementia risk later. But it cannot be said for certain that sugar alone is the reason for this. Other factors that were not fully measured in the study could also play a role.

Second, the study was observational and looked backwards at events that had already happened, rather than following babies forward in real time from birth. Researchers could not control exactly how much sugar each baby consumed. Instead, they relied on whether a baby was born during a period when sugar rationing was in place. This is a reasonable way to estimate exposure, but it is not as precise as tracking each child's actual diet day by day.

Third, the study was carried out using UK Biobank data, made up largely of people born in the early 1950s in the United Kingdom. This means the findings, while important, have not been specifically tested in African populations. Diets, food availability, and other health conditions can differ significantly between regions, so more research would be needed to confirm whether the same pattern holds true for African children.

Finally, while the researchers accounted for factors like diabetes and high blood pressure, no study can account for every single variable that might influence dementia risk over a person's lifetime. This means some of the link between early sugar exposure and dementia could still be explained by factors the study did not measure.

None of this takes away from the value of the findings. It simply means the results should be seen as a strong signal worth acting on, not as absolute proof. As the researchers themselves noted, further research is still needed to fully understand how early sugar exposure influences dementia risk over time.

Wrap Up

This study offers a hopeful message rather than a worrying one. It suggests that some of the small, everyday choices we make for our babies today, like cutting back on added sugar, could have benefits that last a lifetime, all the way into old age.

No parent or caregiver needs to feel guilty about the past. What matters most is what happens from here. Reducing added sugar in weaning foods, choosing water or milk over sweetened drinks, and gently having conversations with family members about early feeding habits are all simple steps that align with what this research suggests.

If you are an expectant or nursing mother, or you care for a young child, this is a good moment to look closely at what sugar might be hiding in their daily meals and drinks. It may also help to speak with a doctor or a nutritionist about the best feeding choices for your baby, especially during pregnancy and the first two years of life.

Small steps taken now, while your baby's brain is still developing, may be one of the simplest ways to protect their brain health, decades before a condition like dementia becomes a concern.

Source: Zheng J, Lip GYH, Zhang Z, Lee SWR. Association of Sugar Restriction in Utero Through Age 2 Years on Dementia Risk Later in Life. Journal Neurology 2026, 107 (4) e218313. Doi: 10.1212/WNL.0000000000218313. Available from here. 

Related:

Dementia: What Africans need to know

Alzheimer's disease: What Africans need to know

Vascular Dementia Explained for Africans: Causes, Types and Stages

Published: August 10, 2026.

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