Metabolic health is determined by various changing enzymatic processes. An important factor in maintaining metabolic health will be adaptability to changing conditions, which is what we call ‘metabolic flexibility’.
This is currently one of the topics most intensively researched by endocrinologists, diabetologists, cardiologists, oncologists, nutritionists and exercise physiologists. The topic is additionally important because it is presumed to play a significant role in the ageing process, so expanding our knowledge on the subject may provide answers on how to stay young and healthy for longer.
So, what is metabolic flexibility and in which processes is it involved?
Metabolic flexibility is the ability to efficiently adapt to changing energy sources and the changing needs of the body. In the simplest terms, the primary sources of energy are fatty acids and glucose.
The utilisation of one or the other source is determined by whether the body is immediately after a meal (causing a significant increase in glucose concentration and preferential use of glucose) or in a fasting state, when mainly fatty acids are consumed. Two hormones, insulin and glucagon, are essentially responsible for regulating the availability of both substrates.
The smooth interaction of both hormones is key to ensuring ‘metabolic flexibility’ . Their proper functioning is essentially diagnosed by diabetologists and endocrinologists. Intensive research into these issues in recent years has led to a considerably expanded list of hormones that determine ‘metabolic flexibility’ .
Among these, hormones produced in the gastrointestinal tract play a very important role. Currently, the glucagon-like peptide 1 GLP-1 is widely known, mainly due to the sought-after and hard-won drugs for the treatment of obesity and t.2 diabetes, unfortunately in part by people without indications for their use.
Another topic directly related to the gastrointestinal tract, concerning ‘metabolic flexibility’, is metabolic steatohepatitis MAFLD, the definition of which was established by modifying the previously functioning definition of non-alcoholic fatty liver disease NAFLD. It is far more common in people who are obese and/or treated for type 2 diabetes.
Undoubtedly, its direct cause is the disruption of ‘metabolic flexibility’, i.e. the smooth interaction of many hormones, enzymes and organs in response to changing environmental conditions. How quickly the consequences of these abnormalities affect a person is determined by environmental factors, which depend on the person’s lifestyle, and his or her genetic predisposition.
Particularly in recent years, it has been shown that a genetic predisposition can be modified to a considerable extent through the individual application of an appropriate diet (its quality, but also the rhythm of meals, e.g. in the form of intermittent fasting), selected physical activity in the field of endurance, resistance and functional training, and thanks to new generation drugs currently in preclinical trials.
Modification of genetic predisposition involves the appropriate activation or inactivation of specific genes. These issues are dealt with by epigenetics, a discipline whose basic principles were defined just over 20 years ago.
The topic of ‘metabolic flexibility’, in addition to the aforementioned clinical specialists and geneticists, is also an area of intense exploration for molecular biologists. It has been known for years that a key to metabolism, in terms of energy production, is the efficient functioning of mitochondria in cells. Further progress is therefore only possible by understanding phenomena at the molecular level.
“Metabolic flexibility” is therefore a common theme for most of the specialists in the life sciences, whose cooperation in many centres around the world is already producing the first results, and spectacular discoveries are a matter of the next few years. Author: Dr Sławomir Powierża, cardiologist