First up it's the Paleo diet... What is it? Essentially mimicking the diet of your pre-agricultural ancestry, so don’t dig out your family tree just yet...we’re talking further back than that.

The Good: Generally based around whole foods. Good quality sources of protein (meat and fish), carbs (mainly vegetables) and fats (nuts, seeds and oils). I doubt anyone will disagree that’s a pretty solid foundation of any healthful diet. Filling your plate with each of those in relative proportions most of the time will probably see you losing weight without doing anything else.

The Bad: The complete avoidance or exclusion of certain foods, or food groups. Foods that potentially have healthful benefits such as grains and dairy. The goalposts for this diet also seem to move regularly, with regards which foods are deemed ‘paleo approved’. The Stupid: There’s a whole market that exists on ‘paleo approved’ versions of commonly wonderful tasting foods. Some of these concoctions, will not only leave you craving the actual thing, but some actually run higher in calories (and sugar) than their ‘less healthy counterparts. We’ll also blame cavemen for propping up the ‘gluten-free’ industry.
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What is cancer?
Our bodies are made up of billions of cells organised into groups with specialised functions. e.g. heart, liver, lung, brain etc. All of our cells are born, reproduce (with some exceptions) and die. The lifespan of cells is sometimes days, other cells may live for months or even longer. The life cycle of cells is not left to chance and the birth, reproduction and death of cells is rigorously and meticulously controlled. Each time a cell reproduces, there is a very small chance that a genetic error will occur. Many of these errors are detected and reversed but some or not. The more times a cell reproduces, the more chance there is for errors to occur.

It is probably an accumulation of such errors, which is at least in part responsible for aging and the increased risk of developing cancer as we get older. Cancer is an abnormal proliferation of cells where either too many cells are being born, or they fail to die. Often, both of these factors seem to be involved. Because the cells are growing too fast or are failing to die, uncontrolled tumours (cancer) develops and these cells often spread to other sites, where they continue their abnormal growth and interfere with the function of normal tissues and organs. Any factors which increase cell growth and reproduction are therefore usually associated with an increased risk of genetic errors and cancer formation.

Within the last ten years or so, it has become apparent that obesity (too much fatty tissue) increases the risk of cancer and taking regular exercise, reduces the risk of cancer. It is now thought that obesity is second only to cigarette smoking as a preventable cause of cancer. Indeed, approximately one in five of all cancer is directly attributable to obesity and this figure rises to around one in two cancers in postmenopausal women. The types of cancer linked to obesity include colon, breast, prostate, kidney, oesophageal, endometrial, melanoma, thyroid cancer, leukaemia, certain forms of lymphoma and multiple myeloma.

​Not only does obesity increase the incidence of cancer but the outcome of cancer appears also to be worse in obese individuals. It is also likely that there is a dose effect, in that the more obese you are the higher the risk and the poorer the outcome. Furthermore, if you are of normal weight and then become obese in later life, you similarly increase your risk of cancer, implying a direct cause and effect between obesity and cancer.  For reasons that are not fully understood, excess fatty tissue in the abdominal area, seems to be particularly bad in terms of your risk of cancer.

How does obesity cause cancer?
Needless to say we don't yet have all the answers to this but there are a number of mechanisms that seem to be important. We know that obesity also causes type 11 diabetes, which is an inability to use glucose properly as a fuel, and this in turn increase the levels of certain hormones and growth factors, such as insulin. It is suggested that these factors drive abnormal cell growth and enhance cell survival. Secondly, obesity is associated with alterations in other hormone levels (particularly sex hormones such as oestrogen, progesterone and testosterone)) and these altered hormone levels also seem to drive cell growth and survival. Thirdly, the immune system does not like excess fatty tissue accumulation and cells of the immune system invade this fatty tissue and in the process produce a large variety of products which drive cell growth and retard cell death. It is also thought that one of the normal functions of the immune system is to seek out and destroy cancerous cells and in obese people this function of the immune system may also be impaired.
 
All of this may seem like bad news if you are overweight or obese. However, all is far from lost and some very achievable remedies are available. While we know that obesity causes cancer, we also know that moderate levels of exercise directly prevents cancer and furthermore, as regular exercise reduces obesity this also indirectly lowers cancer risk. The direct effects of exercise on reducing cancer risk appears to be particularly associated with breast, colon, endometrial, lung and prostate cancer, but probably has a direct effect on the risk of other cancers as well. If you add in the effects of exercise in reducing obesity, then regular exercise can have a large positive impact in reducing cancer risk.

Aside from its effect in reducing obesity, how does exercise directly affect cancer risk?
Again, the answer to this is not fully understood but mechanisms such as reduction in cell growth factors with exercise, improved hormone balance, improved immune function, improved cardiovascular function, reduced inflammation and a better capacity to deal with physical and psychological stress are all probably important.

This is all good news if you want to reduce your risks of developing cancer but what if I already have cancer?
Well there is more good news regarding the effects of exercise. There is now a widespread consensus that moderate amounts of physical activity improves quality of life following cancer diagnosis. Regular exercise is particularly good for dealing with cancer related fatigue and psychological well-being, improving cardiovascular function, and reducing the risk of additional complications such as type two diabetes and atherosclerosis. There is even some preliminary information emerging that regular moderate levels of exercise may improve survival in some cancers such as breast and colorectal cancer. If you have cancer, exercise will certainly help but talk to your doctor first and make sure you don’t have particular medical reasons for avoiding certain types of exercise.
 
Although cancer is in many ways a feared disease the outlook for many types of cancer has improved dramatically and cure is now possible in many cases. In particular, there are now some straightforward steps we can take to significantly reduce our cancer risk and help our quality of life post cancer diagnosis. Stop smoking, eat appropriately, reduce alcohol consumption, exercise well (30 minutes per day) and take steps to incorporate some form of daily relaxation and down time into your life. Although not all cancer risk is under our direct we can all take steps to significantly reduce our chances of developing cancer. 

Eating appropriately, taking regular exercise, reducing alcohol consumption and ceasing smoking is the standard advice you may be given for improving your health. However, this advice may not always achieve its aim, as it ignores a very important dimension to health. Healthy body, healthy mind is a familiar maxim, and it is stating the obvious to say that one cannot exist without the other, we are after all, complete and entire creatures.  
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Regarding your health, you may have often wondered how much of a particular symptom or illness is physical and how much is of the mind. The answer to this is not straightforward and there are a number of important dimensions to this issue. Firstly, the question is mainly based on a misconception. There is no such thing as a separate body and separate mind, we are integrated and whole. Occasionally it may be useful to artificially separate the two and act as if they are not one and the same. In particular, Western Culture (including medicine, science and religion) promotes this idea and we often go through life as if our bodies were something separate from our minds. If you are of a certain vintage, you will be familiar with the “body bad, mind good” school lesson, which compounds this idea of a separate mind and body. Eastern cultures on the other hand, tend to be much more holistic in their approach to physiology.

Secondly, every single symptom and illness has both physical and mental components, every symptom and illness is, after all, experienced in the mind.  Both the physical and mental components affect each other (through our hormonal, immune and nervous systems) and it is interesting to observe how individuals with apparently the same illness can have very different outcomes. Thirdly, as the ancient philosophers taught, everything is experienced through the mind and therefore, is of the mind. Shakespeare put it slightly differently when he said that there is nothing either good or bad in the world, but thinking about it makes it so. One final factor to consider in this context is that every illness has a documented placebo effect. In other words, if you believe a therapy is going to improve your health, then there is a good chance that it will (the likelihood varies with each illness). This is so, regardless of the nature of the “therapy”
Another related issue to be considered in terms of managing our health, is our current lifestyles, which have dramatically changed in very recent times. It is worth reminding ourselves that in the past humans have, since they began walking on two legs (and before), led quite different lifestyles. For example, electrification in Ireland happened predominantly in the 1930s to the late 1950s. Before that, our lives were governed by the seasons and especially by the amount of daylight available. When darkness came, we retired to our cabins and rested. In wintertime, there was a lot of resting. The important regulatory systems in our bodies, the nervous system, our hormones and the immune system were adapted over millennia to these natural cycles and organised our body systems appropriately. Then there was very abrupt and dramatic change which continues today at rapid pace. There are bright lights, bright screens and loud noises at all hours of the day and we are constantly on the go or being bamboozled by new information. We are continuously available and have become obsessed with our phones and social media (very unsocial !). Our regulatory systems seem always to be in drive mode and we lead our lives on an adrenaline rush, often giving ourselves further stimulation with caffeine and other drugs. In terms of health, some people may think they can get away with this, but most cannot. There is consequently, a whole new set of common ill-health’s in which “stress” plays a role. Cardiovascular disease, anxiety, depression, cancer, inflammatory diseases, skin disorders, allergy and irritable bowel syndrome are some well-known examples. The adrenaline rush is not only bad for your health but also impacts adversely on our relationships with others and the wider world around us.

For the first time also, one of our major problems in this part of the world, is not that we have insufficient availability of food, but we now have too much. We can observe too, that the quality of our food has changed and become highly processed to fit in with our “busy” lives. We also turn to food, not just to satisfy our nutritional needs but to satisfy deep seated emotional needs.  We often eat because we are bored, angry, depressed, anxious or simply because we cannot sit still. As a consequence, obesity has become a major problem and in Ireland, we may soon have the most obese population in Europe. We all know that obesity is bad for your heart and lungs, your ability to use glucose as a fuel (type 11 diabetes), your joints, your energy levels and your overall sense of wellness. What was not understood until recently, is that obesity is an important cause of cancer and contributor to inflammatory disease. Recent studies are suggesting that as many as one in five cases of cancer are now linked to obesity. With certain types of cancer (e.g. oesophageal cancer) obesity may be involved in as much as forty percent of cases. Obesity is also associated with an increased risk of inflammatory disease such as atherosclerosis (causing plaque build-up in blood vessels), arthritis, asthma and type two diabetes. It is now apparent, that obesity itself is an inflammatory process. What this means in simple terms, is that obesity activates the immune system. Cells of the immune system don’t like fat accumulation and they invade fatty tissue. This in turn produces excess factors which cause cell growth and may promote cancer (essentially an abnormality of cell growth) and other diseases.

The good news is that there are some straightforward ways in which we can rectify the situation and restore important balance to our lives. To the previously mentioned appropriate eating, exercise, smoking cessation and reducing alcohol, we need to also promote taking time out and actively relaxing. Actively relaxing may at first seem a contradiction in terms, but put simply, it means taking active steps to relax and restore balance and control to your whole being. It means also learning to be more at ease with oneself and trying to live more completely in each moment. There are many ways to do this, meditation or mindfulness are very useful, but taking time out for yourself, be it in hobbies, past times or simply sitting still are important as well. You should to do this every day and preferably be “unavailable” for at least thirty minutes every day. This requires discipline and time for it to have an effect. However, there are many reliable studies showing that meditation or mindfulness practice re-sets your nervous system, your hormones and immune system and helps to restore normal regulation and wellbeing. However, you cannot reverse the habits of a lifetime in a few weeks or even months. It takes time for balance to be restored and your regulatory pathways to be returned to what nature has designed over hundreds of thousands of years. Eat well, exercise well and relax well (but preferably not with a cup of coffee!).
John Jackson
(Prof Jackson is a Health and Fitness Consultant at Body Health and Fitness, Sandyford, Dublin.)