Most of us know that eating too much added sugar isn't good for our waistlines, teeth or metabolic health. But increasingly, people are asking a much bigger question:
Does sugar affect our brain health too, and could it even increase our risk of Alzheimer’s or dementia?
Let's look at what Alzheimer's actually is, what the latest research tells us about sugar and the brain, and some of the small everyday habits that can help us look after our brains for the long term.
What Is Alzheimer’s Disease?
Alzheimer's is a progressive disease of the brain and the most common cause of dementia. It gradually damages brain cells, affecting memory and thinking and, eventually, a person's ability to carry out everyday activities.
Age remains the biggest risk factor, and genetics also play an important role. But scientists now know that our risk isn't determined entirely by things outside our control. Research has identified a number of potentially modifiable factors associated with dementia, including physical inactivity, high blood pressure, high cholesterol, obesity and type 2 diabetes.
Which brings us to sugar.
Does Sugar Cause Alzheimer’s or Dementia?
So, does eating too much sugar cause Alzheimer's? We can't say that directly. But the evidence increasingly points in the same direction: diets high in sugar can damage our metabolic health, type 2 diabetes is an established risk factor for dementia, and large recent studies have linked higher sugar consumption itself with increased dementia risk. Put simply, there is good reason to believe that consistently eating too much added sugar is not good for our long-term brain health.
One of the most striking recent studies came from the UK Biobank. Researchers followed more than 172,000 people and found that those with higher intakes of total sugar had a 29% higher risk of developing dementia, while higher free-sugar intake was associated with a 25% higher risk. Interestingly, the associations were particularly evident among women.
That study cannot prove that sugar itself caused dementia. It was observational, meaning other differences in diet, health and lifestyle could have contributed. And not every study has reached the same conclusion. A 2026 Swedish study following nearly 28,000 people for around 25 years found no significant association between free-sugar intake and Alzheimer's disease or overall dementia.
But sugar isn't the only reason scientists are interested in the relationship. Type 2 diabetes is already a confirmed risk factor for dementia, and the risk appears to increase with the duration and severity of diabetes. Researchers are also investigating how insulin resistance may affect the brain, alongside the roles of blood vessels, inflammation and impaired glucose metabolism.
There are even similarities between some of the changes seen in diabetes and Alzheimer's disease. Alzheimer's Society notes that nerve cells in the brain may become resistant to insulin and that this may contribute to the build-up of amyloid and tau proteins associated with Alzheimer's. It's this fascinating area of research that has led Alzheimer's to sometimes be unofficially called "type 3 diabetes", although it isn't an official medical diagnosis.
So where does this leave us? We can't yet say that sugar directly causes Alzheimer's, but the direction of the evidence is increasingly difficult to ignore. High sugar intake can damage metabolic health, type 2 diabetes is an established risk factor for dementia, and large recent studies have linked higher sugar consumption with increased dementia risk. While scientists continue to unravel exactly how these factors interact in the brain, the practical message is much clearer: reducing excessive added sugar is an important part of protecting our metabolic health and giving our brains the best chance of staying healthy as we age.
Is Loss of Smell an Early Sign of Alzheimer’s?
Now this is where things get very interesting for us at Killa Vanilla.
Your sense of smell has an incredibly close relationship with your brain, and researchers have been investigating whether changes in our ability to smell could provide clues about neurodegenerative diseases.
Research from the US National Institute on Aging has found associations between declining ability to identify smells, cognitive decline and Alzheimer's-related changes in the brain. Other research has found that poorer smell function is associated with faster cognitive decline and loss of brain volume in older adults.
That doesn't mean losing your sense of smell means you have Alzheimer's. Our sense of smell can change for many reasons, including ageing, infections and other health conditions, and researchers are still investigating exactly how useful olfactory changes could become in detecting neurodegenerative disease.
As olfactory enthusiasts, we find the relationship between smell and the brain absolutely fascinating. The important takeaway is that a declining sense of smell is recognised as a potential early indicator of neurodegeneration, sometimes appearing before more obvious cognitive symptoms develop.
So, How Can We Look After Our Brain Health?
There is no single food, supplement or daily ritual that can guarantee Alzheimer's prevention. What the evidence increasingly suggests is that brain health is influenced by the collection of things we do over many years.
The good news is that many of them are surprisingly ordinary.
Keep moving.
Regular physical activity is one of the best-supported lifestyle changes for reducing dementia risk, as well as supporting our heart, circulation, weight and metabolic health.
Look after your metabolic health.
Managing blood pressure, cholesterol, weight and blood glucose matters to the brain as well as the rest of the body.
Eat well most of the time.
Rather than searching for one magical "brain food", aim for a varied, balanced diet with plenty of fruit and vegetables, wholegrains and other nutritious foods. Alzheimer's Society also recommends keeping sugary foods such as sweets, biscuits, cakes and chocolate as occasional treats only.
Stay mentally and socially active.
Learning, hobbies, conversation and maintaining relationships are all part of looking after our brains as we age.
Protect your sleep.
Good-quality sleep supports memory, learning and healthy brain function. Making sleep a priority is another simple way to support our brains as well as our wider health.
Where Does Reducing Added Sugar Fit?
This is where we come back to something we've talked about at Killa Vanilla for years.
Knowing that we would like to eat less cake, chocolate, biscuits and other foods high in added sugar is one thing. Actually doing it when the craving arrives is another.
That's because eating isn't driven purely by hunger or nutritional need. Our brains learn associations between situations, foods and reward. Finish dinner, want chocolate. Make a cup of tea, reach for a biscuit. Difficult afternoon, fancy something sweet.
Over time, these patterns can become remarkably automatic.
And that's precisely the problem Killa Vanilla was created to help with.
Rather than suppressing hunger, Killa Vanilla is designed for those cue-driven craving moments. By smelling the specific vanilla scent on and off for two minutes when a sugar craving appears, we're using olfaction and the Cross-Modal Sensory Compensation Effect to help satisfy the brain's craving for a sweet sensory reward without actually eating the sugary food.
Used consistently, the bigger goal is habit change: same familiar cue, different response.
Looking after our health isn't usually about one dramatic intervention. It's about the small decisions and habits we repeat day after day, whether that's moving more, eating better, looking after our blood pressure and metabolic health, staying connected with other people or finally tackling that sugar habit we've been meaning to change.
Our brains, it turns out, deserve looking after just as much as the rest of us.
