Everything Links

There is a gradual shift in consciousness worldwide and this is very evident in the work of many forward thinking and humble minds in science. As the veil of hubris has been dropped, it is allowing us to discover, or rather re-discover, the knowledge, understanding and wisdom of past great minds such as Leonardo da Vinci, whose visionary understanding we are only just beginning to appreciate. One such idea is summed up in his statement ‘Realise that everything connects to everything else.’ With the advent of Quantum theory we can see that on a micro- and macro-scale this inter-connection certainly appears to be the case. Yet, in regards to our bodies, the hubris of separation remains, both on a macro- and micro-level. But times they are a-changing.

Less than a couple of decades ago, most scientists wouldn’t have thought of body-fat as anything more than a place where the body stores excess energy. Subsequent research has found that it is much more than that; Body-fat is now known to be a metabolically active 'endocrine' organ, capable of secreting many molecular signals that communicate and influence the body systems in their entirety, which when balanced support the functioning of a healthy high performance body, but when out of balance lead to dysfunction and disease.

Currently evidence is growing to suggest that skeletal muscle also acts as an 'endocrine' organ and, especially when exercised, could act as a mediator to many of the signals originating from fat.

Within the last decade scientists have discovered that, like fat, muscles also secrete signaling molecules called ‘myokines.’

The discovery of myokines as protein messengers produced and secreted by contracting muscle fibers is a paradigm shift, and like all good science (which despite the common perception of it being a collection of facts, is in fact a method to constantly challenge the status quo) drastically alters the worldview in regards to metabolism and physiology. This finding has provided a foundation to explain how physical activity and muscle improve health and protect against chronic disease.

Myokines are sent out by exercising muscle to relay messages both locally within the muscle itself, as well as to other organs throughout the body such as the brain, pancreas, liver, bone, and adipose tissue. In some ways they mimic hormones, much like the earlier discovered adipokines such as Leptin secreted from adipocytes (body fat cells).

For the signals to have an effect, it is not sufficient enough to simply produce them; the amplitude and the frequency also have to be considered. Think of it in this way, from 1936 to 1955 the only television channel that you could view in the UK was BBC One. They had the monopoly on the information broadcast (signals) via a tele-visual medium. Beginning in 1955 ITV entered the foray, so you now had two competing broadcasts each with their own specific remit. Up until 1982 these two monoliths were the entirety for your tele-visual (essentially) one-way communication. They would have shaped and help form the world view of the viewers via their programming. Skip to 2013, and the whole game has changed, no longer are these two broadcasters the only players in the game, thus decreasing their relative impact, despite having hugely increased absolute presence (number of channels and extended viewing hours). And because of this, the BBC is no longer the major (although still hugely influential) provider of communiqué. This very same situation is reflected in the body; it’s all about relatively dominant signals whether provided by amplitude, frequency or a combination of the two.

When skeletal muscle is a dominant organ over body fat – as found in lean adults, where muscle can make up about 40 percent of body weight, the myokines have a greater relative influence compared to the adipokines on many different systems and metabolic processes in the body. Although the area of myokine research is still in its birthing stages, the number of myokines that have been identified and their roles are growing rapidly. So far, studies have found that myokines influence muscle growth, fat breakdown, insulin sensitivity, pancreas function, energy utilisation, and risk of certain chronic diseases.

Two of the best studied myokines to date are interleukin-6 (IL-6) and irisin, which the human body makes a lot more of, when it moves more, such as in the performance of physical activity, whether structured or not.

IL-6 was first identified in 2000, and it was found that levels of it increased 100-fold after exercise (1). It was initially believed that this myokine was an inflammatory mediator produced in response to muscle damage (1). However, further studies revealed that although IL-6 does produce inflammation when it is secreted by tissues such as immune cells, when produced by skeletal muscle it acted conversely as an anti-inflammatory agent.

Irisin is another myokine which has received much attention within the last few years due to its ability to increase energy expenditure. It does this through the development of a type of body-fat called ‘brown fat’(2). I’ve previously written about this in a number of articles, this HPC-UK Bitesize piece provides a link to the core of them:

http://humanperformanceconsulting-uk.blogspot.co.uk/2013/02/get-hard.html

Physical activity has generally been viewed as a tool to balance energy intake with expenditure and bring about weight loss, especially in the latter half of the last century. However, we’ve known for quite a while now, that thinking of physical activity in these terms is extremely myopic. The influence of physical activity on energy expenditure is obvious, the more you move, the more energy is used, but it is WAY overstated. The real value of physical activity is not the increased energy use during the sessions, nor is it really the slightly elevated energy usage following exercise (EPOC – Excess Post-Exercise Oxygen Consumption) which in the grander scheme of things are both relatively minor, but something a lot more influential.

Physical activity is one of the key stimuli that initiate a cascade that influences the Human genome to express itself in support of a healthy and high performance body and mind. Without that primary stimulus, your body, at best, expresses itself as a merely sufficient version of your DNA to exist, barely limping along. At worst it declines into disease and death.

Far from the shallow view of muscles being simply a veneer of vanity, science is proving that they are an integral part of the whole, a part that you can choose to ignore; but do so at your peril.


References:

1. Pedersen BK. Muscles and their myokines. J Exp Biol. 2011 Jan 15;214(Pt 2):337-46. doi: 10.1242/jeb.048074.

2. Boström P et al. A PGC1-α-dependent myokine that drives brown-fat-like development of white fat and thermogenesis. Nature. 2012 Jan 11;481(7382):463-8. doi: 10.1038/nature10777.