The link between type 2 diabetes, impaired brain health and cognitive decline is so well established that some doctors call Alzheimer’s disease “type 3 diabetes.”

But don’t be too sure the risk of dementia only goes up once you’ve been diagnosed with full-blown diabetes, which typically happens when you’re middle-aged or a senior. In our sugar-saturated society, waning brain function may start at a much earlier age.

A group of researchers from Australia attempted to find out. . .

When Normal Blood Sugar isn’t Really Normal

The damage to the brain from chronically high blood sugar is well known when it reaches an advanced stage, but high blood sugar starts much earlier, and we know less about its effects on the brain at that stage.

A strong clue came from a major study published in the New England Journal of Medicine in 2013. The researchers found that even among adults without diabetes, every higher increment in glucose levels let to an increased risk of dementia.

In a more recent article, a team from the Australian National University reviewed the research results of over 200 international studies. They also included findings from 7,484 Australians taking part in the PATH study, which investigates aging, health and cognition across the lifespan.

From the findings of all this research they concluded that higher blood glucose levels, even those considered to be in the normal range, contribute to brain degeneration. And the higher the blood sugar level, the greater the damage.

The Australian scientists also found that disease processes kick off in mid-adulthood or before and what’s more, some studies have identified specific mechanisms “supporting a causal link between glucose metabolism dysregulation and neurodegeneration.. . ”

Translation: High blood sugar causes brain cells to degenerate.

Their research found that cellular damage and impaired functioning in the brain are caused by an abundance of free radicals and chronic inflammation. These processes also contribute to blood vessel disease and have been linked to lower levels of BDNF, an important protein that promotes the survival of brain cells.

They point the finger at poor diets, the consumption of too many calories, obesity and lack of exercise as major risk factors.

Dementia Prevention Needs to Start Early

Professor Nicolas Cherbuin, who led the research, said, “The link between type 2 diabetes and the rapid deterioration of brain function is already well established.

“But our work shows that neurodegeneration, or the loss and function of neurons, sets in much, much earlier — we’ve found a clear association between this brain deterioration and unhealthy lifestyle choices. People are eating away at their brain with a really bad fast-food diet and little-to-no exercise.

“The damage done is pretty much irreversible once a person reaches midlife, so we urge everyone to eat healthy and get in shape as early as possible — preferably in childhood but certainly by early adulthood.”

He admits that although the message is simple, bringing about this change will be a major challenge. The tragic consequences of the obesity and metabolic syndrome epidemics are likely to be with us for decades to come.

The Problem is All Too Obvious

To see why he’s concerned, you only have to look at a few disturbing statistics regarding US adults.

The average person consumes more than 3,600 calories daily. Even an active adult over age 36 needs no more than 2,800 calories.

58% of the calorie intake comes from highly processed foods.

Three quarters of men and three out of five women are either overweight or obese.

Fewer than one in four adults achieve the recommended levels of exercise.

Prof. Cherbuin added, “As a society we need to stop asking, ‘do you want fries with that?’, and the mindset that comes with it. If we don’t, then expect to see more overweight and obese people suffering from serious diseases.”