Sugar, Your Brain, Diabetes, and Alzheimer's
Although we never anticipate our lifestyle inflicting so many problems as we age, the truth exists that due to inactivity and poor nutrition many of us face the prospect of Type II diabetes. The diagnosis seems to come from out of the blue. Okay a family member might have had diabetes but that won’t happen to me. But then you get the word that you are pre-diabetic or diabetic and your whole world changes. If you choose not to believe the news and continue to live with old habits, then your problems get even bigger.
There has always been a belief that diabetes and Alzheimer’s disease are associated. Because of the concern surrounding escalating Alzheimer’s cases and the continued rise in type II diabetes, researchers started looking closer at the association. The first association was with the action of diabetes destroying small vessels in the brain. And then there was the brain cell destruction that occurred with resulting brain volume loss in people with diabetes that alerted researchers to the connection between the two diseases. What researchers found though was the way the brain handled sugar was more important than the other actions of diabetes. Type II diabetics are insulin resistant. That means that they don’t appropriately utilize insulin to keep blood sugar levels stable. Higher levels of insulin and blood sugar end up circulating in the body and the brain.
Insulin plays a key role in brain aging. One particular study showed that insulin and beta-amyloid (the protein that collects in the brains of people with Alzheimer’s disease) have a direct relationship with each other. The two substances regulate each other. Insulin also plays a role in synaptic health. Synapses are critical for the passage of signals from one neuron to another. They are believed to be the structure for memory. Insulin resistance also makes it difficult for insulin to pass through the brain blood barrier. Diabetes isn’t the only disease that causes insulin-resistance. Half of all people that have high blood pressure are also insulin resistant.
So let’s get to the problems with sugar and the brain. The brain needs carbohydrates for energy. It does not produce energy on its own but is dependent on the carbohydrates that are sent to the brain with each heartbeat. The brain is an energy cannibal and requires 25% of carbohydrates, oxygen, and blood from each heartbeat. If you are overeating sugar you might be having problems with poor memory formation, learning disorders, and depression. The US Department of Agriculture estimates that the average American consumes 156 pounds of added sugar annually. That amounts to five grocery store shelves loaded with 30 or so one pound bags of sugar each (Psychology Today, 2012). The Center for Disease Control puts the amount of sugar we consume at 27.5 teaspoons of sugar per day per person. The calorie total for this is approximately 440 which accounts for one-quarter of the calories of a daily 2000 calorie diet. Now you are probably thinking that these stats are way off-base. There is no way that you consume that much sugar in one day!
You might not be physically eating straight sugar to make this statistic reasonable. Even though there is sugar in fruits and vegetables, this added sugar is found in the processed foods we eat every day and we absorb it in the form of fructose. Remember I said that our brains need sugar for energy. This natural sugar is not a problem for the brain – it is all the added sugar we consume.
I have mentioned BDNF (brain-derived neurotrophic factor) in a past post. BDNF acts as a fertilizer for new cell growth, helps memory formation and assists in learning and memory. The research has indicated that diets high in added sugar have decreased amounts of BDNF. Other findings demonstrated that people with glucose metabolism problems – pre-diabetics and diabetics – have particularly low levels of BDNF and those levels decrease as sugar metabolism worsens. Consistently eating added sugar starts a cascade of events by reducing BDNF and the resulting lower levels of that brain chemical begin to contribute to insulin resistance which then leads to type II diabetes and metabolic syndrome (high blood pressure, high cholesterol, coronary artery disease)and possibly a whole host of health problems (Psychology Today, 2012). And just when you thought it couldn’t get any worse, low BDNF levels are linked to depression and dementia. Research continues on this link because it pops up in different studies.
The end result of these findings point to the catastrophic effect added sugar from processed food has on our brains. Increased levels of insulin and sugar are toxic to our brains. We must remember that there are consequences with our food choices.
DiSalvo, D. (April 27, 2012). What eating too much sugar does to your brain. Retrieved August 15, 2012 from http://www.psychologytoday.com/print/94132
Mirkin, M. (Novembeer 7, 2011).The diabetes-alzheimer's link.Dana Foundation, Brain in the news 18(10).
Reinbirg, S. Type 2 diabetes may shrink the brain, study suggests. Retrieved May 6, 2015 from http://consumer.healthday.com.