silhouette photography of jump shot of two persons

Battling Cancer through exercise


The basic concept in this blog is that ‘fitness is the absence of disease’. It is widely recognised that the fitter you are the less disease you are likely to have now, or in future. The ongoing question I have is whether fitness itself could actively promote health over disease?

This is a complex debate with too much to cover in one article. Instead it is the overall focus of this blog. The focus today is on cancer and a theory I have that fitness itself gets the body to actively fight diseases like cancer. I feel the lack of evidence simply reflects a lack of research and a lack of appreciation of the importance of activity in daily human life.

There is growing evidence that exercise helps cut cancer risk. The exact reasons are not yet clear. For example recent research shows that exercise may suppress cancer by producing a chemical called SPARC. There is also evidence that high insulin levels encourage cancer because the insulin receptors on cancer cells use a high insulin environment to absorb blood sugar and grow.

What we know is that exercise forces our bodies to be at their best. The rigours of exercise trigger processes in the body that remove weak cells. There are many ways we know this but the most simple is that exercise is used to make us stronger in many ways. We use it to go further, lift more and go faster. To do this we need to move in some way and the movement itself challenges the body. The bodies response is to improve the body so it can overcome the challenge. This is what evolution has given all species including us.

We are in a different era of history. No longer is activity and starvation common, it is the opposite. Activity and starvation are rare because we are wealthy, atleast in the west. We move less now than ever and so we are physically weaker than ever and we constantly have spare energy and cell building nutrients. Numerous studies have borne this out. Surely there is a link between this weakness, plentiful nutrients and diseases that are common in the west.

What is cancer?

I find it helpful to see cancer as an organism or parasite living inside us and using our resources. From this view I see that exercise helps fight cancer because it redirects the resources to our body instead of cancer. The current western lifestyle on the other hand feeds cancer, both by a never ending supply of energy rich food and by the lack of anything else for the body to do. No challenge on the body means there is no need to ensure vital resources go where they should so they go where they shouldn’t.

Reading Introduction to cancer biology I saw in the 6 hallmarks of cancer and cancer cells just how this could occur. If you have not read these before here is the list from wikipedia

  1. Self-sufficiency in growth signals Cancer cells are immortal, they just keep on living
  2. Insensitivity to anti-growth signals They keep growing
  3. Evading apoptosis Normal cells die over time. Cancer does not.
  4. Limitless reproductive potential They keep on dividing getting bigger taking the space of vital organs
  5. Sustained angiogenesis Create their own blood vessels for a regular supply of food
  6. Tissue invasion and metastasis Spread themselves throughout the body and into other cells

Hallmarks of Cancer: The Next Generation builds on the initial 6 hallmarks of cancer with 2 more:

  1. reprogramming of energy metabolism
  2. evading immune destruction

The overall summary of this is that cancer cells can’t be controlled like normal cells. They literally ignore the normal signals of the cell community within the body and do exactly what they want. That is why they are so dangerous. I am wondering whether this is simply easy to do in a body that has no strong regulatory control and plenty of spare resource. I am finding evidence from all angles that exercise promotes very strong regulatory control within the body and encourages proper use of resources preventing their use by cancer.

The idea that cancer works within an ecosystem is also a powerful tool for combating cancer when combined with activity.

Encouraging healthy regulation

Whether it gets cells to tow the line as it does when sugar control is out of hand in Diabetes type II. It gets cells to take up sugar and store it. In fact exercise alters metabolism in minutes. This response demonstrates how cells are in effect upgraded by exercise and become more able to tolerate the daily challenges of life. This impact on sugar control affects 2/3 of the body and explains how exercise could tackle the hallmark of cancer reprogramming of energy metabolism.

So the question for me is, ‘what other system wide effects do we see that might be going unnoticed?’ Exercise could get cells to listen to growth signals and grow only when the body needs it. By making blood a scarce and controlled resource it could deter the growth of new blood vessels in cancer cells, again because they don’t need them, the body does. It could stop cancer cells reproducing because the resources for creating new cells are earmarked for use elsewhere to make a stronger body.

Firstly because fat helps tumours to grow exercise can use up spare fat before a tumour gets to use it. So using exercise simply to keep your weight down can help prevent it. A more specific study showed that fat cells in the abdomen fuel the spread of ovarian cancer. This raises the question of cancer using us as a host. People with greater energy stores fuel cancer growth and provide a good environment for cancer to grow. So thriving for humans means preventing a poor environment for diseases to flourish. That can mean developing more muscle. Not necessarily becoming much bigger. Just being more active which natural strengthens your muscles. This is because muscle is surprisingly resistance to cancer. No one yet knows why but the logic is that by reducing your fat to muscle ratio you automatically reduce your cancer risk. Presumably by leaving less spare energy for cancer to grow. An active lifestyle ensures energy is not wasted but used for the good of the body and protected from use by cancer.

Exercise could also promote normal cell death. The challenge that exercise produces forces the body to get stronger. To do so it must regenerate better quality cells and repair existing ones to a higher standard. This requires energy and raw materials. There are mechanisms within the body to do this. One is to take cells marked as faulty and recycle them. Literally break them apart and use their raw materials. It stands to reason that in a fit, active individual this process will be highly trained and thus good at what it does.

The natural killer cells ability to destroy cancer is the kind of protection we have. Good recovery including sleep is crucial for these cells to do their jobs. While directly promoting good recovery and a balanced system exercise also helps us sleep better and promoting the activity of natural killer cells.

Cancer cells will find it much harder to avoid these ‘police’ cells and the police cells themselves will be much better equipped to tackle cancers defences. I feel a natural situation develops in an unfit person where their body systems get lazy and ineffective, thus opportunistic diseases like cancer can take hold. The body isn’t strong enough to fight off cancer in the first place. My question is whether cancer finds it so easy to take hold in an active person?

Taking this idea further cancer is known to change the DNA of cells to make them work for the cancer instead of the body. Exercise requires our DNA to be protected like any other part of our body and it also prevents the damage caused by disrupting the molecular balance of a cell.

The idea is that exercise enforces better regulation of the body. As a consequence the immune system is better at detecting and dealing with disease and faulty cells. Thus tackling the cancer hallmarks
evading immune destruction and evading apoptosis.

In summary the following lectures from Harvard on Cancer metabolism outline the latest research and understanding of metabolism in relation to cancer and how we can use that knowledge to inhibit or reduce cancer.

Strong enough to survive

Exercise might help prevent some cancers but it won’t prevent all. Could it instead make it easier to live with and survive through cancer? Again we have no answers but we do have evidence that exercise helps us survive Alzheimers. This research demonstrates how a person can suffer from a disease without it actually affecting their ability to live. A big part of being diagnosed with a disease is noticing symptoms and getting them checked out. If exercise prevents the symptoms then a diagnosis is unlikely. It would also be likely that cancer develops within the body but given the demands of exercise it is never allowed to take hold in an area associated with movement. The correct cells are instead promoted so the cancer is limited to those places that do not face those demands and your ability to move is preserved. For me this just sounds like a natural explanation that would fit evolution. Our bodies would have the ability to tolerate cancer and similar diseases because it doesn’t let them stop the body do what it needs to live. Until the last century this meant movement. Only now do we not need to move to live and cancer may simply have taken advantage.

This is concept is not just restricted to cancer. The same factors are common to many diseases and just reflect a path in which we either get busy living or get busy dying. I just wish there was a lot more high quality research in this area to help. I feel the evidence is very strong now to justify a strong inquiry into exercise as a natural way for promoting health and reducing such severe diseases.

Exposure to the sun

The obvious problem with skin cancer is exposure to the sun. It’s generally presented as a problem we can’t do anything about other than apply sunscreen or stay out of the sun. Instead I asked the question can you train your skin to resist melanoma? and found out the answer is yes. Obviously this isn’t directly related to exercise but most forms of activity will take you outside. I play a lot of tennis and have a bald head. Putting sunscreen on every time I play becomes a burden and to be honest I don’t see anyone else doing it. The evidence seems pretty clear. It’s just like anything else in your body. Don’t push any cell too far. Always build up strength and resistance first. Ever since I asked the question I have simply been building up my exposure to the sun. Ensuring I don’t burn and definitely don’t burn severely. I link it back to the concept of protecting our DNA I mentioned earlier.

Exercising outdoors is likely to increase vitamin D which may reduce risk of cancer. Just an interesting indirect way in which getting out and enjoying life can provide its own benefits.

Oxidants, antioxidants and the current incurability of metastatic cancers

Another seminal article. This time by Jim watson. of Crick and Watson fame. My take is that high levels of antioxidants could prevent normal oxidant therapies for cancer. I can’t help but feel this highlights the need for balance and buffers. The bodies ability to buffer oxidants and anti-oxidants is impaired. In this case anti oxidant foods and treatments may not help. Exercise is a natural way to restore balance. Activity itself presents a natural challenge to your body. If antioxidants or oxidants are required it encourages your body to make enough of them and make better use of what it has. Essentially building up your bodies ability to absorb damage.

As you have probably noticed I have not tried to be thorough in this article. I just wanted to introduce the theory so I can build on it. Today I felt I could put into words the varied ways in which activity could help prevent or treat such an aggressive and dangerous disease as cancer. The fact that the mechanisms I am talking about are very complex and not yet fully understood is why I think any link with activity is both hard to prove and hard for most to even see.

Hopefully by sharing this view I help others understand the concept, take it further and debate it. I could be wrong, that is part of conjecture and helps me move on and develop a better theory. However the evidence I am finding seems particularly strong that activity itself promotes health within the body in ways we are still exploring. Health is the absence of disease and thus a mechanism that promotes health must be linked with preventing disease. We just need more research and data to explain why.

The lack of pharmaceutical intervention is what particularly interests me with exercise. Exercise is just a natural part of living. Combined with good recovery it is the most natural style of life. Since no one has yet figured out how to make this into a viable business model I feel there is little incentive to research and explore it. I see much more incentive for pharmaceutical research. Hence the problem we have in finding out the answer to the question. If there is little money to be made through exercise and rest then who will fund the research to show its value?

Finally if you want a number to help you understand the impact of exercise on cancer risk I’ve just found one. The report the effect of physical inactivity on disease states that physical inactivity causes 10%  of breast cancer, and 10% of colon cancer worldwide. Inactivity itself causes 9% of premature death, or more than 5.3 million of the 57 million deaths that occurred worldwide in 2008. Whichever way you look at it that’s a big impact that simply moving and running around can have on your health and cancer risk.

I hope this has been an interesting and informative read. As usual please let me know what you think in a comment below.

Useful Reading