Blood sugar shrinks your brain

If you want to stay healthy, it is becoming clearer and clearer that you have to keep your blood sugar under control. In fact, a new study shows that even blood glucose levels in the high end of the normal range appear to cause some significant problems.

In a sample of randomly selected older middle-aged people, high normal levels of fasting plasma glucose were significantly associated with hippocampal and amygdala atrophy over 4 years. In plain English, even if you’re not officially diabetic, elevated blood sugar can literally shrink your brain.

These results definitely confirm my opinion that the current “normal” range for blood glucose should be changed. Again. That range has already dropped once since I was in medical school. But it appears that it needs to drop even more.

The problem is, most people don’t take a rise in their fasting blood sugar seriously enough. And even most physicians don’t think it’s important to mention until the person becomes diabetic. However, we are increasingly finding that elevated blood sugar causes much more than diabetes. In this instance, brain atrophy. And I would bet that it is the main culprit behind heart disease too, given that blood sugar swings cause arterial cell wall damage. But I doubt that study will ever be done, since it would eliminate the need for statin drugs. (And wouldn’t THAT be the proverbial “shot heard round the world”?)

The American Diabetes Association uses a stringent threshold of 100 as the upper end of what is considered “normal” fasting blood sugar. In this study, atrophy was seen in participants with blood glucose levels less than 100. And the compelling case here is that none of the participants in this study had any neurological disorder, were taking anti-depressants or had diabetes. They were your basic, everyday people who thought they were in great shape. And by every measure we have and use, they were. That’s the shocker.

The rate of brain atrophy was 2% per year. Plasma glucose effects accounted for 6% to 10% of that atrophy. This is an incredible finding. And one that I hope will make you think twice before you say OK to that slice of pie “just this once.”

High blood glucose levels can affect the brain through various mechanisms. Inflammation is one likely culprit that I harp on all the time. But another possible mechanism is abnormal blood clotting brought on by high glucose levels. This increases your risk of thrombosis, embolism, and stroke–which are all risk factors for brain aging. (And adds more evidence to my long-held assessment that sugar contributes to heart disease as well.)

Regardless of how it happens, there’s no denying that blood sugar negatively impacts the brain. And I don’t know about you, but I need all my wits about me. So consider this yet another reason to banish sugar from your diet once and for all. Your brain will thank you.

“Higher normal fasting plasma glucose in associated with hippocampal atrophy” Neurology 2012; 79: 1019-1026.