If you heard that there was a health technique that would dramatically reduce your risk of cancer, would you want to know what it is? If not using that technique increased your risk of cancer by 300%, would you want to start using it?
In the West, 50% of the population will be diagnosed with cancer during their lifetimes. Leading experts in the causes of cancer believe that around 90% of cancers are behaviourally caused. That is, most of us cause our own cancers. Of course, no one is saying that we cause our own cancers deliberately; we are saying that our cancers are the consequences of our choices and behaviours.
For example, alcohol consumption accounts for around 9% of all cancers. One in four cancer deaths is caused by smoking. 40% of cancers are linked to or directly caused by being overweight or obese. Simply by avoiding alcohol and any form of smoking and maintaining a healthy weight, we can all reduce our risk of cancer massively.
In countries where there is less alcohol consumed, all other things being equal, there are few cancer cases.
People in many countries engage in fasting for various reasons; tradition, health, religion, and poverty…it seems to matter little the reasons for intermittent fasting; what matters is that people do it.
Fasting, at its simplest, means, not eating. It can also mean not eating or taking drinks with energy (e.g. drinking only water or black tea or black coffee), or not eating and drinking at all.
Everyone fasts for short periods of time between meals or snacks. We fast for the longest time when we sleep. Intermittent fasting means choosing not to ingest any source of energy for a period above and beyond sleep. That might mean skipping breakfast, lunch or dinner or not eating for a set number of hours.
If someone chooses not to eat after, say, 18:00 hours and then misses breakfast and has lunch at 12:00 hours, they will have fasted for 18 hours.
Skipping dinner and not eating until breakfast could mean fasting from lunch at 12:00 hours through to breakfast the next morning at 08:00 hours, making a total of 20 hours.
Missing lunch typically means fasting from 08:00 hours through to 18:00 hours, which is only 10 hours.
Is intermittent fasting beneficial to health? This fact may illustrate better than any other: where people do not engage in intermittent fasting their cancer rates are 300% higher.
To understand why intermittent fasting is so good for health it is useful to better understand what happens when we fast. No-one fully understands the biochemistry involved, there is just too much complexity among too many variables. Here is an overview of what we think we know.
The body first uses the sources of energy is has readily available in the digestive system. When those are depleted, it seems the body starts to use energy sources in the blood, glucose. Previously unused glucose is stored in the muscles and liver as glycogen. As we continue to fast, the reserves of glycogen are depleted, and the body starts to burn triglycerides, more usually known as fat. When the fat reserves are no longer available, the body starts to consume its own muscle. That, of course, is taking fasting, far too far, and is harmful to our health.
Reasonable intermittent fasting seems to work like this. When the reserves of energy in the digestive system and blood are used up, there is no longer any need for our bodies to have raised insulin levels. As insulin levels drop, as part of the natural self-regulation process, and the body still needs a source of energy, it starts using its stores of energy, otherwise known as fat.
Let’s explicitly link some apparently connected factors. People who are overweight or obese are hugely more likely to develop cancer. It is reasonable to assume, given their food consumption, that they spend fewer hours each day with low insulin levels and they have higher blood glucose (hyperglycemia), and more body fat. Prolonged periods of elevated blood glucose are known to be a health hazard causing all sorts of diseases (e.g., heart disease, vision loss, and kidney disease…).
In parts of the world where intermittent fasting is practised, for whatever reason, the levels of cancer are hugely lower. In the affluent West, where fewer people fast, the cancer rate is 300% higher.
It seems that not fasting is harmful to our health, and regular intermittent fasting is great for our health.
Hmmm… let’s reflect on that statement: “regular intermittent fasting is great for our health.” Why could that be the case?
Having evolved, most scientists in the field believe, as hunter-gatherers, it seems reasonable to assume that our hunting-gathering ancestors had many times when they failed to hunt or gather, and went hungry. They, we, seem to have evolved as intermittent fasters.
Only in recent times have people been able to keep their blood glucose levels high with three meals a day (or more in some cases).
It appears to be more than a coincidence that cancer rates are highest in the affluent West, and those rates seem to increase with more and more affluence.
Could it be that because we are not engaging in the intermittent fasting that shaped our bodies, we are harming our bodies?
Could we be causing many, if not most, of our cancers, simply by eating three square meals a day? Are we spending vast amounts of money treating cancers that could be avoided simply by missing a few meals a few times each week?
For most healthy people, perhaps this question would help: if never being hungry meant increasing your cancer risk by 300%, would you choose never to be hungry?
Maybe expressed like this might be more inspirational: if you knew that feeling hungry for a few hours a week massively reduced your risk of cancer, would you come to love the feeling of hunger?
Professor Nigel MacLennan runs the performance coaching practice PsyPerform.