New Study: High Glucose Levels Can Fry Your Brain

Those who know me well also know that I have been harping about the adverse affects of high glucose levels on brain function for years. It’s nice to see that the researchers are finally getting around to studying this important issue. In early August the New England Journal of Medicine published a landmark observational study showing a strong correlation between high glucose levels and dementia. This was true for both people with and without diabetes. They tracked glucose levels and glycated hemoglobin levels over time. Glycated hemoglobin (HbA1c) levels give you an average glucose reading over a period of time.

As You Age, Bring Along Your Brain!
The study involved over 2,000 patients with an average age of 75 years and they were followed for almost seven years.  524 of the participants subsequently developed dementia. They found that in both those with diabetes and those without diabetes, the average blood glucose level was strongly correlated with the risk of developing dementia. It’s important to remember that this was an observational study so it does not prove cause and effect, but it does suggest that if you want to bring your brain with you as you age, it’s a good idea to keep your glucose levels steady. Other studies have shown that diabetes is associated with cognitive dysfunction—a fancy term suggesting that your brain isn’t working as intended.

So what’s the deal with glucose and the brain? Doesn’t the brain rely on glucose for most of its energy? Indeed, under most circumstances your noggin does rely on glucose to function, but humans evolved in an environment free of dangerous glucose spikes and fluctuations. When primitive humans consumed real whole food, glucose levels were held steady by the intricate interplay of hormones like insulin, glucagon and leptin. Most cells in your body require insulin for glucose to enter into the cell. Because the brain uses a lot of glucose, Mother Nature decided to leave out this insulin gate when it comes to neurons. Your body has a complex system to make sure that glucose levels don’t drop too low where neurons would be deprived of their primary energy source because neurons start to malfunction quickly when deprived of energy. If you don’t eat for a period of time, your body has stored glucose in the form of glucogen. When you run out of glycogen your body will produce glucose through the process of gluconeogenesis.

When this system is working as intended your brain hums along nicely because it has plenty of energy. Even though your brain makes up only 2% of your body weight, it consumes 20% of your bodies’ energy. Because primitive man never developed insulin resistance from consuming massive amounts of excess fructose in the form of sugar and HFCS that are found in our modern diet and because he never consumed high glycemic carbohydrates, he never developed dangerous glucose spikes. Primitive man learned to monitor food intake partly by measuring blood glucose levels in the brain. When glucose levels started to drop his brain would send out “feed me” hunger signals. If our primitive dude failed to find anything to eat, these hunger signals would intensify and the brain would throw in the big gun—carbohydrate cravings. With dangerously low glucose levels his brain would push him to eat a carbohydrate rather than a mastodon steak because that’s the quickest way to restore glucose levels.

A Modern Invention—Glucose Spikes
This system worked fine until it was introduced to Twinkies and similar fare in our modern diet loaded with added sugars and processed carbohydrates. Most people consuming a modern diet already have some degree of insulin resistance where it takes more insulin to push glucose into cells after they eat. When you have insulin resistance and eat that Twinkie, you end up with a massive glucose spike followed by a crash below normal. Because your brain didn’t evolve to read glucose spikes, it doesn’t respond to them. When your glucose then crashes below normal it does know what that means—it’s time to eat! You respond by eating another Twinkie, generating another glucose spike and crash. Your brain sees these repeated low glucose levels and assumes you haven’t been listening, so it ramps up the hunger levels and carbohydrate cravings. Thus hunger signals and carbohydrate cravings more or less get kidnapped by this vicious cycle and they lose their evolutionary function.

There’s one big problem when your brain is subjected to repeated glucose spikes. Because neurons have no insulin gate these glucose spikes also occur inside your nerve cells and high levels of glucose can damage cells. The energy factories called mitochondria can be damaged by too much glucose leading to mitochondrial dysfunction. Glucose spikes can also cause excessive dumping of neurotransmitters like dopamine, serotonin and norepinephrine. You experience this as a “donut high” as the neurotransmitters flood your brain followed by a crash when the cells run out of neurotransmitters.

A Form of Reversible Brain Dysfunction
Eventually these cells cannot function properly, leading to brain dysfunction symptoms. Dementia and the cognitive dysfunction experienced by diabetics involve major permanent changes in brain structure and function. It’s obvious that you don’t go from normal brain function to dementia without something in between. We call that in between state Carbohydrate Associated Reversible Brain syndrome or CARB syndrome. CARB syndrome is a reversible form of brain dysfunction that can interfere with your ability to function optimally. You aren’t demented but your brain isn’t running on all cylinders. If you wait until you have dementia, much of the damage has already been done. If you intervene when you have CARB syndrome, it’s possible to restore healthy brain function.

This study in the NEJM is important because it shows a strong correlation between elevated glucose levels and brain damage. Because of ethical considerations we will never do randomized controlled trials in humans to prove this is true, so we need to rely on empirical observations, evolutionary biology and observational studies to show us what is likely the healthiest way to eat. As best we can tell, excessive fructose mainly from sugar and HFCS, high glycemic carbohydrates mainly from grains and excessive omega 6 fatty acids from vegetable oils are the primary triggers of CARB syndrome. That’s one reason I often recommend following a Paleo diet because it eliminates these dietary elements. If you are interested in learning more about this approach, I suggest visiting Loren Cordain’s or Robb Wolf’s web sites.

Even Fido’s Brain Gets Fried
Today we took our two Jack Russell terriers to our Vet. We were discussing dog diets and he agreed that dogs should not eat grains, but he then admitted that he has never heard of the Paleo diet. We certainly have our work cut out for us! Dogs are now getting obese and developing brain dysfunction from eating commercial dog food loaded with grains and bad fats. If you want to destroy your own health, living in a free society you have the right to do so, but please don’t subject your innocent pet to this type of toxic diet.

Protect Your Brain From Dangerous Glucose Spikes
If you want to protect your brain, what should you be doing? As I mentioned above, eat a whole foods diet and stay away from processed foods. If you already have strong cravings for sweet and starchy foods—the hallmark symptom of CARB syndrome, consider taking the amino acid L-glutamine 1,000 mg 3x daily on an empty stomach. The dose can be increased as needed. I also recommend taking Cinsulin, a concentrated form of cinnamon, before meals that contain any carbohydrates. Chromium picolinate is another useful supplement. If you already have many of the 22 symptoms of CARB syndrome, you might consider taking CARB-22, a supplement that restores healthy levels of neurotransmitters. You also should take a look at the toxic nature of sugar. I recommend reading “The Fat Switch” by Richard Johnson as a good starting point. I also recommend paying attention to Robert Lustig’s work when it comes to the toxic nature of sugar. He has been leading the charge against sugar.

So far we have been talking about the brain’s dependence on glucose for energy. Let’s not forget that the brain can also use ketones for energy. Once a person is adapted to a low carbohydrate, moderate protein, high fat ketogenic diet, their neurons do quite nicely using ketones for energy. This type of diet was first developed at the Mayo Clinic to treat seizures. Once they developed drugs for seizures, the diet was largely forgotten. Now it has now been resurrected by people like Jimmy Moore for weight loss and to treat an array of brain disorders. If you are interested in learning more, check out Jimmy’s blog posts on this topic. When it comes to carbohydrates, Gary Taubes is the master. I highly recommend reading his book “Why We Get Fat—And What to do About it.”

You don’t want to develop dementia and you certainly don’t want to develop CARB syndrome. To protect your precious brain you need to start eating a healthy diet today. You have the power to live a healthy and long life but you want to take your brain along for the ride. Grab the bull by the horns and go for it.