Sugars a sweet poison for brain and body

Did you know that the average American now consumes more sugar in a week than they once did in a whole year?

Two hundred years ago, the estimated intake was 0.9kg a year. Now it is 1.36kg a week!

Though this may seem irrelevant to us in Australia, we are equally guilty of excessive sugar consumption and there is no doubt that many of us eat more than is healthy for us.

This is not surprising – sugar is addictive and is everywhere. It is part of the modern curse of ubiquity. Having such easy access to this sweet poison means we are fighting an uphill battle when it comes to moderating our intake.

We are hard-wired to seek out sugar. As with many of these things, they have their origins in our evolutionary past.

Our physiology is geared up to prioritise immediate survival over long-term health.

It cares far more about the ability to deal with here-and-now threats – attacks by others and starvation chief among them – than whether our brain and body are going to be in good shape decades down the track.

Sugar is a ready source of quick energy and is ideal for these short-term goals. It is no surprise then, that we have developed a hankering for it; the same dopamine-based neurocircuitry that creates addiction to illicit drugs is fired up when we consume sugar.

If it were something that we could access only from time to time – as was the case when we roamed the savannah – there would not be a major problem, but this is not the case.

So, what does chronic excessive intake of sugar do to our body and brain? Well, the most obvious thing is to cause us to put on weight.

Sugar is converted into fat when we eat more than we can use. Being overweight puts stress on our heart and vascular health and this in turns negatively affects the brain. Sugar also induces chronic inflammation which again may predispose us to dementia.

Then there are alterations in insulin levels. Insulin is a hormone that pushes sugar into our cells where it is used to produce energy. Chronically high sugar levels push up insulin levels.

With time, cells adapt to this high insulin by becoming less sensitive (they become insulin resistant).

Insulin resistance is associated with Alzheimer’s disease – the brain cells of those with this condition cannot use sugar effectively.

This may lead to the brain’s capacity to function becoming impaired.

Insulin also affects the formation and/or clearance of amyloid and tau in the brain. These proteins are intimately associated with Alzheimer’s disease.

Worryingly, it seems that you don’t even have to be diabetic for negative brain processes to occur. Studies have shown that even high-normal blood sugar levels cause structural changes that are of concern.

The message here is very clear: be aware of how much sugar you eat (check the labels on food products when you can) and try to keep it at a minimum.

The occasional treat is not a problem, but too much too frequently undoubtedly is. Remember also that something doesn’t have to be sweet to contain sugars – refined carbs such as white pasta and white bread as well as starchy vegetables such as potatoes are also broken down into sugars in the gut.

See your doctor to have your blood sugar checked regularly.

Though it may seem daunting to cut down on sugar, bear in mind that doing so not only helps the long-term health of your brain, but, once your body has adjusted, will make you feel better day to day.

Kailas Roberts is a psychogeriatrician and author of Mind your brain The Essential Australian Guide to Dementia. Visit yourbraininmind.com
Dr Roberts has created a new app for the iPhone called BrainScan which helps users identify their own modifiable risk factors for dementia. It also provides advice on how to address them. Find it at the App Store now.