Like many other medical terms, metabolism comes from an ancient Greek word that means change or evolution. It is an umbrella term for numerous processes and mechanisms that take place inside the human body, converting nutrients such as food into the energy that fuels the daily activity of cells. It is a key function of the body, required for every single task like muscle movement, toxin elimination or damage repair. Metabolism problems are very serious and a malfunctioning one can even be lethal.
Scientists classify metabolism into two main types. First, the food is separated into the molecules used as fuel by our body, a process named catabolism. The second stage is anabolism, when other required compounds are produced.
Since the processes of metabolism mainly concern the flow of nutrients, they are closely linked with nutrition and digestion. The entire chemical and metabolic processes that allow a cell to use energy are named bioenergetics. This is one of the ultimate goals of metabolism, to supply energy to cells.
It all starts with nutrition, which provides the raw materials required. Metabolism then breaks down nutrients into smaller particles that can be used as energy at cell level. Energy is required for all of the daily operations, as well as the production of genetic material and proteins.
Metabolism is a very complex system, with a delicate balance. There are many compounds needed by the body at specific times and in precise amounts, any variation can have serious health consequences.
Some of these nutrients are considered to be essential. These include calories, needed for the generation of energy, as well as various chemicals that can't be produced by the body and only come from exterior sources. The food we eat supplies many different useful compounds, required for the operation, build-up and repair of tissues.
At a molecular level, the body needs a number of essential inorganic elements such as oxygen, hydrogen, carbon, nitrogen, phosphorus, sulfur and approximately 20 others. These are part of the carbohydrates, lipids and proteins found in the food we consume. Water is also key for living organisms, as well as other vitamins and minerals.
Researchers have identified many metabolic pathways, which are chains of chemical reactions. A metabolic pathway is the entire process that uses enzymes to transform a nutrient into other compounds, needed by our body. This makes enzymes a critical element of metabolism, since they trigger and modulate the chemical reactions that ultimately generate energy. All energy-related processes are controlled by enzymes, including those that use it. Enzymes are actually catalysts, they do not start reactions but rather accelerate them. Enzymes also respond to signals from nearby cells or environment factors and help optimize metabolic pathways.
Since metabolism is involved in the absorption of nutrients, it works closely with the digestive function. Many factors can have an influence on metabolism, such as hydration, nutrition or physical effort. A proper balance between them is required for a healthy metabolism and any changes will decrease its efficiency. As a result, body weight is directly linked with the metabolism, as well as the process that leads to weight loss.
In weight loss diets, we usually reduce the supply of fats and calories in our food. While this can reduce weight, it also hampers our metabolism. This is why it's important to compensate through physical exercises and other measures. Some people try to lose weight very fast by not eating at all or radically slashing their intake of calories. This can have unwanted effects, since the reduced metabolism actually lowers the burn rate of calories and fats and can actually make the body store more fats as reserves.
Other chemicals, for example drugs, are also processed by our metabolism. This is part of the catabolic metabolism, when drugs and any other intakes are separated into smaller and more manageable molecules. The second step of metabolism is named anabolic metabolism and represents the reverse process. In this phase, enzymes are used to reconstruct larger compounds needed by the body from the small ones generated in the first step.
There are a number of compounds, such as nicotine, which have a direct influence on our metabolism. One of the reasons why some people increase in weight after they stop smoking is that nicotine boosts the rate of metabolism and the burning of fats. A counter for this is to stimulate metabolism through exercise, so that no weight is gained. It is always a good idea to quit smoking and the concern for weight gain should not be an issue.
Metabolism is made up of numerous very complicated processes that are essential for life support. Without it, healing, growth and even the daily operations of cells would be impossible.
Researchers have discovered that the metabolic rate decreases with age. Adults have a rate lower by 5% when compared to younger people. Scientists suspect this is caused by a reduced metabolic rate of muscles or the loss of metabolically active organ tissues, but the exact cause is still unknown. The metabolic rate starts to drop after the age of 40 in men and over the age of 50 in women.
A healthy metabolism allows the cells in the skin to send signals to one another and maintain a proper channel of reaction and communication. This means in practice that skin maintenance remains at optimal levels. The skin produces the needed collagen, damage caused by sunlight is repaired and cells exfoliate when needed.
Aging has a direct effect on metabolism and causes its rate to slow down. A slow metabolism has many effects, although most people are only concerned by their weight. It does indeed cause weight gain and you can no longer eat as much as you want without any consequences.
The effects at skin level have been measured in studies. After the age of 20, the body's collagen production decreases by about 1.5% every year. At the age of 30, collagen production is already severely limited. Many external factors, like sugar consumption, sun damage or smoking, can amplify the negative effects of aging. In practice, the slow metabolism and low collagen production become visible in the form of dry skin, with fine lines, wrinkles and dark spots.
All of these problems are directly caused by insufficient amounts of collagen in the skin. This key compound is required for skin maintenance and allows it to stay hydrated, without wrinkles or spots.
No matter what we do, the skin metabolism rate will drop with age. However, we can compensate for it with a healthy diet, the proper food supplements as well as a daily routine of skin maintenance.