Why keeping healthy is all about guy instinct: Cut your risk of cancer with our unmissable series


We cannot alter the genes we are born with — but that definitely doesn’t mean we are irrevocably set on a path we can’t change when it comes to whether or not we go on to develop cancer.

As a consultant oncologist, I have studied the causes and consequences of cancer for most of my professional life — and I am now convinced that the way we choose to live our lives, day in, day out, can make a much bigger difference to our health and wellbeing than the genes we inherited.

The more research I undertake and the more patients I see whose health has been immeasurably improved by changing their diet and lifestyle, the stronger my conviction becomes.


We cannot alter the genes we are born with — but that definitely doesn’t mean we are irrevocably set on a path we can’t change when it comes to whether or not we go on to develop cancer

That’s why I wrote my new book, How To Live, in the hope of sharing the experiences and advice based on my lifetime’s work.

And it’s not just one individual factor that counts, as I explained in Saturday’s paper, but the sum of all the little choices that we make every day over the years. The food we eat (and how we prepare it) plays a very significant part in our health.

More and more studies are now linking poor gut bacteria with the risk of several cancers — both in and outside the gut — which is why, as we continue our exclusive series this week, today I’ve chosen to focus on our digestive systems.

What’s more, poor gut health doesn’t just cause problems in your digestive organs — it’s the cornerstone for many other serious diseases in the rest of the body, including diabetes, obesity, Parkinson’s disease and arthritis.

(And that’s not to mention bloating and indigestion, problems with bowel movements, low mood, sleep disorder and even depression, which can also be rooted in poor gut health)

Based on the latest research, I’ll explain just why your gut health matters and show you practical ways to build a thriving community of good gut bacteria that can help you reduce your risk of cancer and other serious diseases.

Don’t forget to brush your teeth

The process of digestion starts in the mouth, home to hundreds of species of bacteria.

The bacteria in and on our bodies — and particularly in our digestive systems (or microbiome) — can roughly be divided into ‘bad’ (those that cause infections such as food poisoning or cholera and typhoid) and ‘good’ (bacteria which prevent the growth and spread of disease, improve overall immunity and help to reduce chronic inflammation, which occurs when our bodies mistakenly react as if they are permanently under threat from disease).

Good bacteria are generally referred to as probiotic bacteria and include the lactobacillus and Bacteroidetes groups, linked with numerous health benefits. (I’ll look later at ways you can boost your good bacteria.)

However, poor dental hygiene — caused by not brushing your teeth or not flossing correctly — can upset the balance between the two, leading to a build-up of harmful bacteria, causing gum disease and tooth decay.

Chronic inflammation of the gums (or gingivitis) is linked to a higher risk of chronic diseases elsewhere in the body, particularly dementia, diabetes, heart disease and emphysema.

In terms of cancer, we saw on Saturday how two studies analysing more than 100 samples of healthy and cancerous bowel tissue found that DNA from bacteria commonly found in dental cavities was also present in bowel cancer tissue — but not in normal, healthy cells.

This led researchers to conclude that bacterial DNA from the mouth had travelled through the body, interacting with and being absorbed into gut cells, causing them to become cancerous and leading to bowel cancer.

Boost your ‘good’ bacteria

These days we read a lot about why we need strong, healthy colonies of good bacteria.

And rightly so — I cannot stress enough how important it is to cherish and feed your good bacteria because they have a vital role to play in keeping your immune system in mint condition.

This is key to helping our bodies detect and destroy early cancer cells more efficiently as well as any carcinogens in our food and environment, as I explained in Saturday’s paper.

It’s also well established that poor gut health contributes to numerous digestive problems including bloating, irritable bowel syndrome (IBS), diarrhoea, food allergies and intolerances.

Research now shows that a depleted colony of good bacteria leads to damage or thinning in your gut walls, weakening the barriers that normally prevent toxins (including carcinogens) from getting into the blood stream.

As a result, these toxins and bacteria can cause inflammation all over your body. This is commonly known as ‘leaky gut syndrome’. But it doesn’t end there.

An inflamed gut wall also makes the body less efficient at absorbing the vital nutrients it needs from food — so over the long term, this can cause deficiencies in vitamins A, D and zinc, all of which have important roles to play in our immune system’s defence against disease and cell damage.

Dining out? Then don’t overeat


Eating out and staying away from home can play havoc with your microbiome, as you are more likely to consume more alcohol and dine out on rich or unaccustomed foods.

To look after your gut when dining out or going away, try not to overeat and try to have alcohol-free days when you are on holiday.

Eating lots of fruit and vegetables and drinking plenty of water should keep your bowels regular, but if you are constipated you could try taking some extra flaxseed (also known as linseed).

In addition, many people, including me, swear by the protective benefits of a good-quality probiotic supplement, starting a couple of days before travelling.

This is why a wide range of serious diseases in other parts of the body — including dementia diabetes, arthritis and obesity — can either be caused or aggravated by poor gut health and chronic inflammation.

There is also emerging data to suggest it is a ‘trigger’ for type 1 diabetes — because the body gets confused by toxins in the blood stream and starts inadvertently attacking its own pancreas.

This chronic inflammation also helps to explain why the tumours associated with poor gut health are not just restricted to several types of bowel cancer.

In addition, scientists now know that healthy colonies of good gut bacteria use phytochemicals to produce a fatty acid called butyrate that helps protect the cells lining the colon from genetic damage.

Not only this, but butyrate also kills established colon cancer cells before they get a foothold — yet another reason why eating a diet high in phytochemical-rich vegetables, fruit, herbs and spices is a key way to look after your gut health and cut your cancer risk.

The cancer-fighting results of feeding your good gut bacteria with phytochemical-rich foods was recently illustrated by an exciting academic study that I was involved with at the Primrose Oncology Research Unit at Bedford Hospital.

Known as the Pomi-T study (after the extracts we tested: pomegranate, broccoli, turmeric and green tea), it is to date the world’s largest and probably most respected trial evaluating the impact of phytochemical-rich foods.

It was clear from our trial, which involved 203 men with diagnosed prostate cancer, that taking a gut-friendly probiotic supplement rich in phytochemicals not only reduced inflammation in the gut but also slowed the progression of the prostate cancer in those who took it, compared with those in the control group who did not.

This is one of the many reasons I am so excited at how many ways there are, based on the latest science, to take control of our own health — starting with looking after our guts. It really does help to look at your diet again and think about ways to eat for your gut.

I’ll look in more detail at which supplements are helpful to take in tomorrow’s pullout.

Going organic really can be better for you

Pesticides and other chemicals make it into our food chain without us realising it — and some can be very damaging.

They are used to control insects, weeds, fungi and bacteria and help to ensure we can produce enough food to meet demand.

But inevitably they also make it into the food chain — and some (organochlorines and organosulfates) can cause cells to mutate, while DDT, chlordane and lindane are tumour promoters.

The pesticide MXC was developed after the ban of DDT but tests have also shown that this stimulates the proliferation of breast cancer cells. Its use is falling, but others with potential risks are replacing it.

Pesticides and other chemicals make it into our food chain without us realising it — and some can be very damaging

Some insecticides also contain arsenic compounds still in common use which have been classified as carcinogens by the International Agency for Research on Cancer (IARC).

Meanwhile, chlorothalonil, a fungicide used on trees, vegetables and agricultural crops, has been classified as ‘likely’ to be a human carcinogen.

Non-Hodgkin’s lymphoma, a cancer of the lymphatic system, has previously been associated with exposure to glysophate, a herbicide commonly used as weedkiller.

Although the evidence of risk is small outside farm workers, it’s certainly worth trying to reduce your intake of pesticides over time by buying organic, growing your own fruit and veg and making sure you wash any shop-bought produce thoroughly before you eat it.

Organic food cannot be completely free of synthetic chemical residues, due to product and environmental pollution, but organic agriculture avoids synthetic fertilisers and pesticides, and instead uses holistic methods of weed and pest control such as long crop rotations, natural predator insects and insect traps.

Organic meat also has lower levels of other potentially harmful contaminants, as livestock is not given growth hormones or antibiotics, so it is worth buying organic whenever you can.

8 ways to improve digestive health

Protecting your ‘good’ bacteria should be top of your to-do list when it comes to focusing on how you can cut your cancer risk by improving your gut health.

You can either do this by ‘topping them up’ with other living microbes called probiotics or by ‘feeding’ them with compounds that strengthen them.

Here are my eight top ways to protect your core asset — and reduce your risk of a number of cancers.