Our bodies are designed to maintain the stability of our internal environment through interdependent mechanisms that maintain equilibrium regardless of external influences. We are a “harmonious ensemble” of 15 to 20 trillion cells designed to survive in highly diverse conditions through constant adjustment of the myriad components necessary for life. Our biological systems are dynamic and exquisitely tuned. Anything that disturbs the balance in any system will induce immediate responses that work to return us to stability.
One of our supremely regulated mechanisms is the availability of fuel (fatty acids and glucose) in our bloodstream. A stable fuel supply is necessary for survival of each cell and its contribution to the life of the organism. Crucial to our equilibrium is a blood-sugar level that does not fluctuate outside a narrow, healthy range. Glucose is a particularly reactive molecule––it is a metabolic toxin in high levels. Our bodies need only a scant teaspoon of glucose in the blood at any precise moment for those few critical tissues that depend on it. Any excess must be burned for fuel or safely stored away for future use. Enter the hormone insulin: its most critical job is to keep blood sugar under control.
Throughout our ancestral history, there were few carbohydrates in the diet, so we had little excess glucose or fructose to deal with. These days, carbohydrates are ubiquitous. Insulin, produced by our pancreas, now is forced to work overtime to prevent blood-sugar from remaining too high. It lowers blood glucose by “locking” fatty acids in the fat cells so they cannot be metabolized until glucose is back in the safe range. It shuttles what glucose cannot be burned into the fat cells for storage as triglycerides. It tells the muscles to burn glucose instead of fatty acids and to store glucose as glycogen.
When we eat carbohydrates every few hours, we will also have chronically high insulin levels because, again, a high level of glucose is toxic. Carbohydrates are singularly responsible for stimulating the release of insulin. Dietary fat has no effect on insulin. The impact of protein is effectively nil as well. The more carbohydrates we eat, the sweeter they are, and the easier they are to digest, the more insulin is ultimately secreted. Insulin is the one hormone that coordinates and regulates the storage and use of nutrients––the homeostasis of our bodies and of life itself. However, insulin in high levels is toxic, too.
A healthy hormonal system is able to maintain blood sugars within a narrow range of 70-85 mg/dL. The insulin produced by our pancreas works to maintain this glucose homeostasis. However, when blood sugar is chronically high, as it is when we consume a diet high in carbohydrate-rich foods (like our Western diet),the resulting chronically high insulin levels lead to insulin resistance and Metabolic Syndrome––a cascade of deterioration of cells, tissues, and organs throughout our bodies.
Concomitant with high blood glucose and high insulin come the Western degenerative diseases––diabetes, high blood pressure, heart disease, and obesity––just a few of the metabolic diseases of civilization. Alzheimer dementia is now called Type 3 diabetes. Diabetes complications result from high blood glucose and high insulin.
Most cancers feed exclusively on glucose. The risk of cancer is greatly reduced when blood glucose is kept within the healthy range. In a recent paper (Seyfried and Shelton: Cancer as a metabolic disease. Nutrition & Metabolism 2010 7:7. ) we read:
…cancer is primarily a metabolic disease… A transition from carbohydrate to ketones for energy is a simple way to target energy metabolism in glycolysis-dependent tumor cells while enhancing the metabolic efficiency of normal cells.
This study highlights the inability of cancer cells to run on fatty acids or ketone bodies. Meaning that that very low carbohydrate ketogenic diets, which are very high in fat, can be used successfully to treat cancers that depend on glucose. Ketogenic diets have been used for decades to treat epilepsy in both children and adults.
Insulin is a master hormone that performs countless tasks. It prompts the liver to make triglycerides from carbohydrates. It drives up blood pressure by stimulating the kidneys to reabsorb sodium. It damages arteries by altering the mechanics of the blood vessels. The production of small, dense LDL particles, the most atherogenic form, is activated by insulin. It is the only hormone that controls glucose metabolism, thus it is the only hormone that drives fat accumulation. At least eight hormones release fatty acids––our dominant fuel source––from the adipose tissue for their use as fuel, but these hormones are suppressed by even a minuscule amount of insulin.
Our cells are able to metabolize both glucose and fatty acids, but they cannot burn fructose. Fructose, the sugar in fruits, honey, table sugar, and high-fructose corn syrup, is also several times more reactive than glucose. The body has mechanisms to keep its cells from being exposed to too much fructose, so it goes straight to the liver and gets stored as fat (de novo lipogenesis). It is a particularly potent hepatotoxin and, in combination with glucose, it amplifies the magnitude of metabolic devastation.
We evolved over the millennia on fats and proteins. There are absolutely no essential carbohydrates. Most of our cells prefer to “burn” fatty acids. In fact, the heart and brain function 25% more efficiently on free fatty acids. For the few cells that depend entirely upon glucose, our metabolism will convert from protein the scant teaspoon it needs each day through a process called gluconeogenesis.
What We Can Do :
Diet is a very effective way to control blood glucose, thereby reducing insulin secretion and enhancing insulin sensitivity. From Gary Taubes’ Good Calories, Bad Calories, “The current thinking is that a lifelong reduction in blood sugar, insulin, and IGF [insulin-like growth factor] bestows a longer and healthier life. The reduction in blood sugar also leads to reduced oxidative stress and to a decrease in glycation, the haphazard binding of sugars to proteins, and glycation end-products and all the toxic sequelae that follow.” A carbohydrate-restricted, high- fat regimen predictably raises HDL, the “good” cholesterol, and lowers serum triglycerides below 100 mg/dL.
Our bodies have not evolved to thrive on industrial seed oils, sugars and refined grains. However, we can adapt modern foods to the proper mix of ancestral nutrition by eating a diet that is low in carbohydrates, and high in natural fats and cholesterol. Animal foods provide all the essential vitamins, minerals, essential fatty acids (natural fats and cholesterol), and essential amino acids (proteins). Our body needs these fuels and nutrients to maintain its processes, protect itself, build new cells, and repair damage. An evolutionarily appropriate diet that is aligned with our DNA allows an optimal expression of insulin and a healthy body.
When you adopt this optimal way of feeding your fifteen trillion cells, you will experience a new vitality, increased strength and wellness. A welcome side effect may be loss of weight as your body normalizes. Of great benefit is the wonderfully satisfying and delicious food you will be eating for the rest of your life!
Clark & Nina