Why our muscles are the most powerful anti-aging treatment we have.
“I want to build muscle and lose fat” is a common goal that BIOV8 customers tell us at the start of their Total Human Optimisation journey. This series of articles will discuss the physiology and practical aspects of this goal with reference to muscle, fat, metabolism and exercise – and how certain peptides may assist in achieving this goal.
Skeletal muscle makes up 40% of the total muscle mass in the average human. The rest is smooth muscle in the gut and blood vessels and cardiac muscle in the heart. There are obvious skeletal muscle groups that are easily visible and can be “bulked up” for example in the arms, back, chest and legs such as biceps, deltoid, pectoralis major etc. There are less obvious skeletal muscle groups such as muscles supporting the back and spine and between the ribs to assist with breathing.
Skeletal muscle is generally under voluntary control. It helps us stand upright, walk, run and move our limbs, breathe and generally lead active lives. It is essential to healthy ageing to have sufficient muscle mass to be able to get out of a chair and move independently – which is pretty important if you want to lead an active life!
After age 40, skeletal muscle mass and strength decreases by about 3 % per year! This has profound implications not just for moving around and lifting things as we age, it is becoming well recognized that skeletal muscle is an endocrine organ in its own right (more on this later). This is an exciting new concept, and this is why:
Age related muscle loss leads to insulin resistance, Type 2 diabetes, abnormal blood lipids, hypertension and weight gain. This collection of diseases is collectively called “metabolic syndrome”. These “illnesses” are often seen as an accepted part of normal ageing. And here’s the proof - Medications for blood pressure, diabetes, oesophageal reflux and high cholesterol make up the top ten most commonly prescribed drugs in Australia. But they don’t have to be! The traditional teaching that muscle is a mechanical device to move the limbs and enable us to breathe is too simplistic. Muscle is an extremely complex piece of biology that actively helps maintain a healthy blood glucose level and is pivotal in maintaining our metabolism and weight. It is interesting that there are medical specialists for most other body systems, but none specialising purely in muscle. It is often overlooked by the traditional medical community.
Instead of simply being a mechanical winch to move our bones, skeletal muscle has been shown to secrete cytokines and over a hundred different small peptides termed “myokines”. These myokines may be used as a signalling process within the body. When our muscles are used for example in resistance / weight training at the gym, they release myokines into the bloodstream. Exercising muscle requires a lot of blood flow to provide energy to the muscle and also to take away byproducts from the energy consumed by the muscle. The myokines are thus transported around the body via the blood, and act at a distant site to the muscle that produced them. In this way muscle can be regarded as an endocrine organ. It is thought that release of these substances may be responsible for the beneficial effects of exercise on mood, hormone levels and general health.
Exercising muscle requires lots of energy to allow the individual muscle fibres to contract. Most of this energy comes from glucose. This energy is made inside the powerplants of the cells – the mitochondria. Mitochondria are a fascinating organelle (like a battery pack) located inside most human cells – they are worthy of a whole article themselves! They are the energy factories in our cells, converting glucose to energy in the form of ATP molecules. But they are also responsible for many other chemical processes within cells and contain many enzymes to assist in chemical reactions within the cell. When a meal is eaten, the complex carbohydrates are broken down into glucose and other simple sugars – most of this is used by skeletal muscle. This explains the other beneficial role of muscle – glucose regulation. As we age and lose muscle mass, we reduce our ability to use glucose in muscle. This results in glucose accumulation, fatty liver, insulin resistance and other symptoms of the “metabolic syndrome”. This means that maintaining a large mass of healthy skeletal muscle will regulate our metabolism as we age. It will also allow us to use more glucose and avoid storage as fat.
However if skeletal muscle is not maintained correctly, inflammation and damage to mitochondria can occur. Mitochondrial damage can occur from specific diseases or due to age or inflammation within the body (referred to as “inflammaging” by Francheschi in 2000). Inflammaging is a state of low grade, chronic inflammation characterized by the presence of increased levels of inflammatory proteins such as Tumour Necrosis Factor (TNF) and Interleukins (IL-6 and IL-8). These molecules can reduce the number and size of skeletal muscle fibres and increase fat mass. This can create a vicious cycle of inflammation and muscle damage and loss. This may be part of the reason for age-related muscle loss. Ageing, inactivity or Diabetes (type 2) have similar negative effects on myokines.
The “frailty” associated with aging is partly due to the loss of muscle mass. This is termed “sarcopaenia”. This impacts balance, walking, exercising and even getting out of a chair. A fall in an elderly person often results in an injury such as a hip fracture from which they may never recover their independence. The concept of “frailty” in a medical sense has become increasingly linked to poor outcomes in patients admitted for surgery or to Intensive Care. Frail people have reduced reserves, less resistance to stressors such as infections and a much higher incidence of disability and immobility and inability to perform their required Activities of Daily Living without assistance.
On a positive note, any form of exercise that uses muscle, either resistance training or running/cardio improves mitochondrial function. Studies have shown that any form of exercise reduces the risk of Type 2 Diabetes and metabolic syndrome (hypertension/dyslipidaemia/obesity).
It is becoming increasingly obvious that it is important to maintain a good amount of healthy skeletal muscle as we get older. This not only helps us look good, be fully functional and healthy in the activities we can do – skeletal muscle uses a lot of our dietary glucose and reduces fat stores, avoiding the dreaded “metabolic syndrome”. The myokines secreted by exercising muscle also make us feel good, help mood and sleep and seem to have many other health benefits.
So back to the original goal of “build muscle and lose fat” – by following a healthy eating programme, undertaking resistance /weight training, the correct peptide protocol and supplements we can build our skeletal muscle mass – the weight loss will then follow! Keeping our Muscle healthy really is one of the most powerful anti-ageing treatments we have!
Dr. A McGirr
Senior Medical Partner