Written by: Kevin Cann
Most people reading this have heard of the term insulin resistance. For those of you that are new to the paleo diet and the site, insulin resistance is when our muscle, liver, and fat cells become desensitized to the hormone insulin. This leads the pancreas to have to produce more insulin and shovel the majority of glucose into our fat cells for storage.
Type 2 diabetes is a result of prolonged insulin resistance. The pancreas becomes tired from being overworked trying to produce extra insulin and eventually we cannot manage our blood sugar levels. Type 2 diabetes is an epidemic that the world is currently facing. It is estimated by the Center for Disease Control (CDC) that nearly 30 million Americans suffer from diabetes.
What if I said that type 3 diabetes is likely to be the next major epidemic that we face? You might be thinking “Type 3 diabetes? Is that such a thing?” You may know type 3 diabetes by another name, Alzheimer’s disease (AD). Yes, AD is a form of diabetes.
I am not just making this up. Research published in the Journal of Diabetes Science and Technology concluded by stating:
“ We conclude that the term “type 3 diabetes” accurately reflects the fact that AD represents a form of diabetes that selectively involves the brain and has molecular and biochemical features that overlap with both type 1 diabetes mellitus and T2DM” (1). This same research also showed that AD was treatable with insulin sensitizing agents.
Instead of having insulin resistance in the muscle, liver, and fat cells, we can develop insulin resistance in the brain. This is not hard to see once we realize that the brain uses about 25% of the body’s glucose supply. Type 3 diabetes does differ from type 2 in one scary way. We do not have to have dysfunctional blood sugar to develop it.
Some fascinating research is being conducted out of the University of Penn. For the first time they were able to prove that insulin resistance actually occurs in the brain. They also showed that this change can occur in the brain in non-diabetics and without any presence of hyperglycemia (2). This makes sense as insulin plays a critical role to glucose uptake and the health of brain cells. If something in this system becomes dysfunctional, cognitive decline would be a logical outcome. Glucose oxidizes easily in the blood and that oxidation can lead to DNA damage in the cells. Also, if we have insulin resistance in the brain our cells cannot get the glucose that they need to function.
According to the researchers at the University of Penn, people with diabetes are 50% more likely to develop AD. With this type of increase seen in this population it makes sense that insulin resistance plays a role in the development of AD. The theory is that the insulin resistance in the brain causes the formation of plaques and tangles in the neurons associated with cognitive impairment.
Insulin resistance in the brain also alters dopamine function. Dopamine is our neurotransmitter responsible for memory, focus, and energy (3). Dysfunctional dopamine levels have been linked to depression, ADD, ADHD, gambling addiction, drug addiction, and schizophrenia. Ironically sugar addiction has been linked to low dopamine levels as well.
This insulin resistance link to dopamine may explain why ketogenic diets are a useful therapeutic tool when treating diseases of cognitive decline and schizophrenia (4,5). Theoretically speaking, maybe the ketogenic diet reverses insulin resistance in the brain and brings the system back to normal.
Now that we know what causes AD how do we avoid it? Do we need to run as far away from carbohydrates as possible? In my opinion, no. There are a number of things that may lead to one developing AD such as food, stress, environmental toxins, gut health, and genetics.
In order to decrease our risk of developing AD we need to maximize each of those specified areas. Eating a healthy diet rich in nutrient dense foods is a start. I would not get so hung up on carbohydrate quantity as much as I would on quality. Most people that develop insulin resistance develop it from overeating highly refined and processed carbohydrates. I think we can still minimize our risk of developing AD eating a high carbohydrate diet that consists of fruits and sweet potatoes. If it was just the high carbohydrate intake leading to insulin resistance we would see more type 2 diabetes and AD in groups such as the Kitavans that consume a diet consisting of roughly 70% carbohydrates.
We need to manage our stress. If you are not doing something to actively manage your stress, you need to. Try adding in some daily meditation to your routine. Exercise is important to preventing AD, but it is not a stress management activity. Exercise increases insulin sensitivity and helps us recover from the stress response, but is a stressor in and of itself. Lift some weights 2-4 days per week and remain physically active throughout the week by walking more and standing up at your desk.
Limit the amount of environmental toxins in your home. Use cleaning products that are made from natural sources. Filtering your tap water is also a way to limit environmental toxins in your life. Some of us cannot control our work environment and may be surrounded by toxins there. Do the best you can to limit exposure and make sure you’re eating a nutrient dense diet. In a lot of cases nutrients in our food help protect us from environmental toxins.
We need to attempt to maximize our gut health. Our gut bugs are the gatekeepers of our immune system. They keep all unwanted things out. If they get out of balance things begin to slip through the cracks leading to a chronic inflammatory response. When this happens inflammatory cytokines are released and these cytokines cause DNA damage and inhibit cellular DNA repair (6).
Genetics may be a piece that is out of our control. However, our genes are not just locked into place. They respond to internal and external stimuli and express themselves accordingly (epigenetics). If we take more of the steps listed above I truly believe we can alter our genome for a favorable outcome.
AD, or type 3 diabetes, does not need to be the world’s next epidemic. We can take a proactive stance and eat a healthier diet consisting of nutrient dense real foods, manage our stress, optimize gut health, and limit environmental toxin exposure. If we do this we can age gracefully and enjoy a full life