Part 2 – Sugar
In this section, we look at the effect sugar has on the brain. Sugar is obtained from the breakdown of carbohydrates, which are essentially chains of sugar. There are many types of sugar in the average American’s diet. There are healthy types of sugar we obtain from the metabolic breakdown of fruits, vegetables, grains (e.g. rice), and starchy foods (e.g. potatoes); these are simple and complex carbohydrates, respectively. Another type of sugar is sucrose, also known as table sugar, which is a disaccharide that provides essentially empty calories from foods such as sodas, candy, cookies, and cakes. As a matter of fact, one can of Coca-Cola contains ten teaspoons of sugar. Also, there is high fructose corn syrup, a man-made sugar introduced in 1978 to save money on table sugar. It consists of 55% fructose (fruit sugar), 42% glucose, and 3% other carbohydrates. It’s also an empty source of calories but one that is more dangerous as it contains mercury, a metal that’s toxic to the brain.
Diets high in sugar cause multiple problems.
First, upon digestion, high carbohydrate meals of starchy foods such as potatoes, rice, or beans and empty calories from soda and beer flood the bloodstream with sugar. This causes insulin levels to spike as the pancreas attempts to establish normal blood sugar levels, and excess calories are stored as fat. When the pancreas is continually assaulted with a surge of sugar, eventually it stops working as efficiently as it should. This is known as insulin resistance. If this continues, it will lead to type 2 diabetes in which the pancreas is no longer able to properly restore normal blood sugar levels. A study by the Archives of Neurology (June, 2012) concluded that chronically elevated blood sugar negatively affects cognitive performance and also contributes toward mental decline. It has also been linked to Alzheimer’s disease and results in an increased production of advanced glycation end products (AGEs).
Glycation is a process in which sugar binds to protein, amino acids, or fat. Those of you with type 2 diabetes are likely familiar with the hemoglobin A1C test. This is a test that measures the glycation of hemoglobin and sugar during the average life of red blood cells, about three months. In other words, this test measures the amount of sugar that is attached to the proteins of red blood cells. There is some controversy regarding the accuracy of this test. The argument being that the red blood cells of a person with diabetes often don’t survive as long as a non-diabetic; this causes the result to be falsely decreased. Chris Kresser, an integrative medicine practitioner makes a valid argument for the accuracy of this test so performing a glucose level approximately two hours postprandial (after a meal) is recommended for a more accurate measure of blood sugar.
Advanced glycation end products (AGEs) are formed when sugar binds to protein, amino acids or fat. Although glycation is a normal metabolic process like inflammation and free radical production, an over production of AGEs contributes toward a decline in brain function. AGEs are also associated with kidney disease, diabetes, vascular disease and premature aging, hence they are appropriately named, AGEs. The explanation for this is that AGE’s cause protein fibers to become inflexible and malformed, and this leads to the destruction of tissues, proteins, and even DNA. It also has a damaging effect on fat. Diseases in which deformed proteins cause damage to healthy cells that lead to brain damage and dementia are referred to as Prion diseases. Remarkably, Alzheimer’s disease is thought to share Prion-like characteristics. This is where sugar comes into play, a high carbohydrate diet speeds up the glycation process. Since sugar is a rapid stimulator of glycation, which leads to AGE’s, the goal is to reduce the amount of sugar in the diet. It is particularly important to avoid high fructose corn syrup as this unnatural sugar is reputed to increase glycation ten-fold.
Interestingly enough, the Cayce readings on diet recommend certain combinations of food to avoid. One of which is protein and starch, such as chicken and rice. In contrast to vegetables, starchy foods such as rice and pasta, provide higher amounts of carbohydrate (15 grams versus 5 grams) thus providing more sugar after digested. This excess sugar would then be available to bind with protein to form an advanced glycation end product. Perhaps this is the rationale behind some of Cayce’s food combinations. Another recommendation regarding vegetables is to have three above-the-ground vegetables to each below-the-ground vegetable. Since root vegetables contain a more concentrated amount of carbohydrate, this 3:1 ratio keeps the carbohydrate, or sugar, low and the number of healthy phytochemicals high. Cayce also recommended eating citrus fruits alone; feel free to dine with a friend, but I expect the reasoning for this is so they would not be able to participate in the glycation process. When proteins are glycated, free radical production is increased exponentially; this can lead to apoptosis, also known as cell death.
In part 3, we will look at the effect of fat and cholesterol on brain health.