Is your brain safe from sugar?

sugar glucose levels diabetes dementia Alzheimer's disease

Did you quit sugar yet?

I haven’t…

I try to limit refined, processed junk, and follow a Mediterranean diet, but sadly, I’m quite partial to a piece of chocolate with my afternoon post-nap coffee.

Quitting sugar, or at the very least, paying attention to regulating your blood glucose levels and reducing your risk diabetes is a wise move because:

Diabetes is linked to poor brain health

Diabetes, especially type 2 diabetes, is a risk factor for dementia.

People with diabetes have a 47% increased risk of any dementia, a 39% increased risk of Alzheimer’s disease, and a 138% increased risk of vascular dementia.

And if you have diabetes you’re also at greater risk for general cognitive decline as you age.

Scientists are still unravelling the exact molecular pathways and mechanisms that link diabetes and dementia, but it’s most likely a combination of the effects of insulin resistance, vascular pathology, oxidative stress, glucocorticoid excess and inflammation.

Not too worried because you don’t have diabetes?  Well, hold back on that chocolate…

You don’t need to have diabetes to get be at higher risk of dementia.

Higher blood sugar levels are associated with higher dementia risk, even among people who do not have diabetes

A recent report in the New England Journal of Medicine followed 2000 over-65 year olds for five years in the Adult Changes in Thought (ACT) study.  The participants blood sugar levels were taken 17 times and averaged out of the course of the study.

The finding was clear: high blood sugar levels were associated with an increased risk for developing dementia.

In people WITH diabetes, dementia risk was 40% higher for people with an average glucose level of 190 mg/dl compared to those with an average glucose level of 160 mg/dl.

For people WITHOUT diabetes, those with an average glucose level of 115 mg/dl were compared to people with an average glucose level of 100 mg/dl (normal is 70-100 mg/dl).  The higher blood sugar group had an 18% higher risk of going developing dementia.

Associate Professor Paul K. Crane, one of the authors from the University Washington School of Medicine, said,

“What we found was that people with higher levels of glucose had a higher risk of dementia, on average, than did people with lower levels of glucose,”

“There was no threshold value for lower glucose values where risk leveled off.”

Rather depressingly, the authors reported that they have not yet found evidence that dementia risk could be lowered even if people ate less sugar. 

 “Your body turns your food into glucose, so your blood sugar levels depend not only on what you eat but also on your individual metabolism: how your body handles your food.”

“While that is interesting and important, we have no data to suggest that people who make changes to lower their glucose improve their dementia risk.”

It’s not all bad news though.

Professor Crane and the ACT study group have previously found that exercise lowers the risk of dementia developing (as have numerous other studies).  EXERCISE.  There you have it again!  Exercise is one of the best ways to regulate your blood sugar levels and prevent the development of diabetes.

Time to quit sugar perhaps?


Tell me in the comments below if you’ve tried to quit sugar.  Or are you like me and can’t kick the chocolate?



Crane et al Glucose Levels and Risk of DementiaNew England Journal of Medicine, 2013; 369 (6): 540 Group Health Research Institute. “Dementia risk tied to blood sugar level, even with no diabetes.”ScienceDaily, 7 Aug. 2013. Web. 4 Nov. 2013.  Strachan MWJ, et al. The relationship between type 2 diabetes and dementia. British Medical Bulletin, 2008, 88:131-146.  Lu F-P, et al. Diabetes and the risk of multi-system aging phenotypes: a systematic review and meta-analysis. PLoS ONE, 2009, 4(1): e4144. Alzheimer’s Australia.Dementia Risk Reduction: A Practical Guide for Health and Lifestyle Professionals. March 2010.
Strachan MWJ, Reynolds RM, Frier BM, Mitchell RJ, & Price JF (2008). The relationship between type 2 diabetes and dementia. Br Med Bull DOI: 10.1093/bmb/ldn042

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  1. Babs Philbin on March 7, 2014 at 7:57 pm

    I might well be addicted to sugar, certainly have a sweet tooth, so no, I have never tried to quit as it seems impossible. Even when I try to make healthier food choices like fresh, often green juices, there is a lot of sugar in them, although a healthier kind I am led to believe. I am trying to find alternatives to the sweet things I like, creating similar things, like chocolate spread, on a more plant based level, but obviously it’s not quite the same. I do use Stevia as a sweetener as well. And when I do have refined sugar I often have cinnamon with it in order to keep my blood sugar levels low.

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  3. Peter on April 22, 2016 at 12:15 pm

    A bit like you Sarah, I have minimised the refined and processed stuff, and upped the Mediterranean goodies. Haven’t cooked with sugar (or honey, * syrup, stevia, etc.) for ages. If I want sweetness, I use fruit, either fresh or dried. I figure that way at least I get some other nutrients at the same time – could be some fibre, vitamins, minerals. Sugar has nothing. For my chocolate fix, it’s a couple of squares of dark chocolate each night. I seem to have settled on 85% cocoa – that way it can’t have any more than 15% sugar. I was surprised how quickly (couple of weeks) after reducing my sugar intake that previously ‘normal’ treats tasted too sweet for me. Bonus!

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About Dr Sarah

I’m an Oxford University-educated neuroscientist, presenter of ABC Catalyst, director of The Neuroscience Academy, and author of The Women's Brain Book. The neuroscience of health, hormones and happiness.

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