Simply defined, ketosis as the metabolic state which causes the production of ketone bodies due to the large breakdown of fat. This metabolic state occurs if someone has been fasting for a few days or is following a low-carbohydrate high-fat diet also known as a ketogenic diet. In reality it is actually a complex system of chemical reactions that occur in various organs and cells of the body. Because of its complex interconnections, a state of ketosis can actually have a variety of health benefits.
Why Ketosis Happens
When there is limited glucose in the body (less than 50 g of carbohydrates eaten per day) the pancreas releases a hormone called glucagon. Glucagon is essentially the antagonist to insulin. Glucagon causes the breakdown of glucose in the muscles and liver. This is in order to raise blood glucose levels, so that all the cells of the body can take up glucose for their energy needs. After a few more days without glucose from the diet, the body has to rely on other sources. This is when it switches to breaking down fats. Fats are absorbed and stored as molecules called triglycerides. When a triglyceride is broken down it, releases a glycerol molecule and a free fatty acid. The glycerol molecule is converted to glucose by a process called gluconeogenesis. The free fatty acid is broken down in a process called beta-oxidation, which releases large amounts of energy and produces molecules that can be used in energy-producing chemical reactions without the need for glucose. By entering these chemical reactions, these molecules cause the formation of ketones. The brain is able to use ketones as a source of energy.
Misconceptions About Ketosis
A lot of people consider ketosis to be an unhealthy state because it is essentially removing the body’s favorite source of energy. But, as explained above, there are a variety of ways the body compensates for this. One of the theories as to why the human body favors glucose as its source of energy is that ancestors adapted to needing a quick source of energy from carbohydrates that they ate, but also needing a long-term source of energy to keep them going when there were few carbohydrates available. This makes logical sense as human ancestors were nomads and did not farm grains for carbohydrates.
Ketosis And Health
With the understanding that ketosis is a normal biological process, you can begin to see that there are many health benefits that stem from it. The breakdown of stored fat helps a person to lose weight. Causing the brain to use ketones as a source of energy increases levels of mitochondria (part of the cell that produces its energy) in brain cells which improves neuron (brain cell) stability. This reduces the chance of developing seizures. A variety of scientific studies have found that ketosis also reduces the risk of developing heart disease, metabolic syndrome, Alzheimer’s disease, cancer or Parkinson’s disease.
There is a concern that because ketones cause the blood to become slightly acidic, ketosis may eventually cause ketoacidosis – a dangerous condition where the blood becomes too acidic to sustain life in the body. Ketoacidosis commonly occurs in diabetics but it is different from ketosis because in ketoacidosis there are also high levels of sugar which enhance the blood acidity. In ketosis, the normal mechanisms to reduce acidity in the blood are able to keep the body healthy because there aren’t high levels of sugar in the blood.