Bowel Cancer: Reducing risk after Mel Schilling diagnosis

Bowel Cancer: How to reduce your risk of developing disease following Mel Schilling's diagnosis

Following Mel Schilling's bowel cancer diagnosis, Professor Robert Thomas looks at what people can do to prevent getting the deadly disease

Professor Robert Thomas

5th January 2024 

Mel Schilling, the dating expert from Married at First Sight, was diagnosed with bowel cancer and had to spend her days before Christmas in Kingston Hospital. Mel is certainly not alone in the celebrity World, sharing this condition with the likes of Morgan Freeman, Audrey Hepburn, Michael Douglas, and Sharon Stone.

Internationally, it’s the third most common cancer (about 2 million cases a year) and the second most common cause of death by cancer. The good news is that the chances of beating bowel cancer have more than doubled since the 80s, so now over 85% of people with early stages, usually picked up by screening, are expected to be cured.

Overall, however, taking all stages into account, the long-term cure rate is still sadly only around 50%, and to achieve this, many men and women have to endure major surgery, chemotherapy, and biological therapies, all of which have troublesome side effects. Clearly, prevention and early detection are the keys to improved outcomes.

Why do people get bowel cancer?

Some people have a genetic susceptibility to bowel cancer via conditions called familial adenomatous polyposis (FAP) or Lynch syndrome. These individuals often have a family history and develop cancer at a younger age.

Having inflammatory bowel disease, such as ulcerative colitis increases the risk as well as being male and tall. Despite these inherited factors, official figures from Cancer Research UK report that over half of bowel cancers can be prevented through lifestyle choices. I believe this figure could be even higher if considering the latest data for gut health, nuts, vitamin D and diet.

The 10 most important lifestyle factors to reduce our risk of bowel cancer 

•    ·  Regular exercise and avoiding long periods of sedentary behaviour have been linked to, at least, a 30% lower risk of bowel cancer in several large robust studies. The mechanisms underlying the protective effect of exercise include:
•         Promoting bowel motility, which reduces the time that harmful waste products such as carcinogens spend in the colon.
•        Helping to reduce chronic inflammation, which causes cells to divide faster, increasing the risk of spontaneous genetic mutations.
•        Enhances the formation of antioxidant enzymes that protect our DNA from oxidative damage such as radiation and environmental chemicals.
•        Improving the muscle-to-fat ratio, reducing the risk of diabetes and insulin-like growth factor, which promotes abnormal cell growth and cancer formation.
•        Strengthens the immune system so it can identify early cancer cells and kill them.

The American Cancer Society recommends 150 minutes of moderate-intensity exercise or 75 minutes of vigorous-intensity exercise per week for a preventative benefit. It is also never too late to start, studies have also shown that regular exercise, after recovery from cancer treatments, can reduce the risk of relapse by up to a third.

Whole grains such as wheat, whole rice, corn, barley, oats, and rye are rich in fibre, vitamins, minerals, and other cancer-protective micronutrients. Unfortunately, refining grains to make white flour and rice removes the germ and outer fibre, reducing the health benefits. So try to eat foods that use the whole grain such as bulgur (cracked wheat), oatmeal, and brown rice.

The drawback is gluten intolerance, which is becoming more commonplace, especially as we get older. Switching to sourdough bread and soaking grains overnight can help reduce gluten in wheat and other similar proteins in oats.

Pulses (legumes) and seeds such as beans, lentils, peas, pumpkin seeds, and peanuts are particularly concentrated sources of dietary fibre and essential cancer-protective nutrients. They also help the growth of healthy bacteria in the gut by acting as prebiotics. The same applies to mushrooms, artichokes, garlic, and other allium vegetables such as leeks and onions.

Non-starchy vegetables are particularly good for bowel health, and these include carrots, beets, leafy green vegetables such as spinach and lettuce; cruciferous vegetables such as broccoli, asparagus, and watercress.

Fruit, including virtually all edible berries and citrus varieties, are excellent sources of vitamin C, fibre, and minerals. Much of the fibre and cancer-protective chemicals are found in the pulp and white core that runs through the whole fruit, so squeezing and drinking the juice will only give half the nutrients. Juicing also significantly increases the sugar content, which negates some of the benefits. So, as they say in California, ‘eat your fruit and juice your vegetables’.

Herbs and spices are rich in natural chemicals called phytochemicals which provide the colour, aroma and taste but also have enormous health benefits including the prevention of cancer. Phytochemicals, especially the biggest group called polyphenols, are also abundant in vegetables, salads, herbs, teas, nuts, fruits, mushrooms, seeds and legumes more often used in Asian and Mediterranean diets.The typical western diet, on the other hand, are dreadfully deficient in polyphenols, meaning we need to eat a lot more of them. Ongoing studies are investigating whether boosting these foods in supplement form could enhance their health properties. Ideally we should aim to have one or more vegetable, fruit or other phytochemical rich food with every meal of the day.

Some of the multiple mechanisms responsible for their anti-cancer benefits of phytochemicals include:

•        Reducing excess inflammation in the gut
•        Encouraging the production of anti-oxidant enzymes
•        Blocking the formation of carcinogens from meat
•        Acting as prebiotics which improves gut flora
•        Slowing the transport of sugar across the gut wall reducing diabetes risk
•        Reducing joint pains making exercise more comfortable
•        Improving mood putting us in a better frame of mind to live healthily

Nuts are a high-quality vegetable protein, have unsaturated fatty acids, fibre, vitamins, and essential minerals such as zinc, potassium, calcium, magnesium, phytochemicals such as flavonoid and cholesterol-reducing phytosterols. Not a surprise then that well-conducted studies have shown that eating a handful of nuts such as almonds, walnuts, hazelnuts, and brazils more than three times a week reduces the risk of heart disease, diabetes, and bowel cancer by up to 25%.

Excess meat intake is a major contributor to human disease and it is a well-established fact that cancer rates are lower among vegetarians. There are, of course, some benefits to eating some meat, as it is an easily absorbable source of protein, a good source of vitamin B12 and if it comes from an animal that has been reared on grass and is free-range, is a good source of omega 3.

Young women with periods who are at a higher risk of iron deficiency would benefit from some meat in their diets. On the bright side, meat eaters in these studies who also had a high intake of vegetables, fruit, whole grains and spices only had a moderately increased risk, whereas it was the salad-dodging carnivores who had a particularly high risk.

It’s not just the quantity of meat that matters, but also the quality, and how it is preserved and cooked. Processed meats such as many sausages, bacon, sliced ham and all tinned meats are the main culprits.

The European Prospective Investigation into Cancer (EPIC) study reported a strong link between red meat intake and colon cancer. A combined analysis of over 140 prospective studies concluded that people processed meat most days were 30% more likely to die prematurely and 22% more likely to die of bowel cancer. Processed meats are often high in nitrates, other preservatives, and even sugar.

In 2018, one of the largest and well conducted studies in the UK called the UK biobank study found that processed-meat intake (equivalent to two sausages a week) was linked to an increased risk of bowel as well as breast cancer. The World Health Organisation (WHO) have now issued warnings that processed meats definitely increase the cancer risk via their nitrate content.

It is worth noting that nitrates in plants are not harmful; in fact, they are healthy because they combine with vitamin C and phytochemicals in the plants to be converted to nitric oxide (NO), which has numerous health benefits. For example, NO relaxes muscles around arteries, improving blood flow to organs such as the heart and muscles and reducing blood pressure.

On the other hand, nitrites in meat combine with the protein in the meat to form substances called nitrosamines, and these are the real bad guys which damage our DNA, causing cancerous mutations.

The harm from nitrates can be somewhat counterbalanced by eating plenty of phytochemical-rich herbs, spices, and vegetables with them as this converts them to NO rather than nitrosamines.

This was eloquently demonstrated by a barbecue-loving researcher from the University of Arkansas in the US. His study showed that the level of nitrosamines in the bloodstream of consumers was significantly lower if meat had been marinated in rosemary, oregano, or parsley before cooking. So, make sure to include some tomatoes and spinach with your cooked breakfast.

Other factors that affect nitrosamine formation are the amount of healthy bacteria present in the gut as they block the formation of nitrosamines. Conversely, harmful bacteria such as Helicobacter pylori can create an environment conducive to nitrosamine formation, which may explain why chronic overgrowth of this bacteria increases the risk of cancer.

The other culprits in meat are Heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) are toxins created when meat is grilled, fried, or chargrilled over an open flame. Specifically, HCAs are formed when amino acids, sugars, and creatinine (found in the meat’s muscle) react at high temperatures, while PAHs are formed when fat and juices from the meat drip onto the fire and then rise up in the smoke that is generated, sticking to the surface of the meat.

There is no debate from numerous studies that eating fried, well-done, charred, smoked or barbecued meats is associated with an increased risk of cancer, particularly colorectal, pancreatic and prostate cancers. It is known that harm from these chemicals can differ from one person to another, so some people are lucky enough to be inherently more resistant to these carcinogens, while others are more sensitive.

Considering all these factors, eating less meat would have considerable health and also help the environment. That said, many people like the taste of meat and feel their lives are less fulfilled without it and evidence suggests that eating meat up to three times a week is safe.

If you are a carnivore, it may be worth considering the following tips to keep meat intake at a safe level:

•        Go for quality not quantity and try to limit consumption to 2-3 times a week
•        Use meat for its taste, but not as the main content of the meal
•        Red meat shouldn’t be your main protein, include fish, quinoa and pulses like lentils
•        Eat plenty of herbs, spices and vegetables with every meal
•        Avoid processed sausages, hot dogs, bacon, pies, tinned and smoked meats
•        Try to go for free-range, organic or at least grass-fed animals
•        Avoid barbecued or blackened meats and reduce the heat when grilling
•        Remove charred portions of meat
•        Avoid direct exposure of meat to flame or a hot metal surface
•        Continuously turn or flip meat over when it is frying
•        Consider making a casserole rather than frying or burning meat on the barbecue

Several studies including a recent analysis of over 650 Canadians published in 2022 linked gum disease with at least a one and a half times increased risk of bowel cancer. Gum disease increases the whole body inflammation, which promotes cancer and trials have found the same inflammation promoting bacteria from the gums imbedded in the cancers in the colon indicating a direct mechanism for cancer formation.

Moderate to heavy alcohol consumption (more than 2 drinks a day) increases the risk of bowel cancer but people with a genetic susceptibility to alcohol common in Asian countries, may be more vulnerable to lower amounts. Regular alcohol intake contributes to weight gain and lower mood and motivation to exercise.

Ethanol metabolism generates acetaldehyde and acetate which have carcinogenic properties. More recently it has been discovered that alcohol can disrupt the balance of healthy to unhealthy bacteria. The effect is less with low quantities of red wine as it contains a healthy polyphenol called resveratrol which in a study from Kings College London was shown to actually help the growth of anti-cancer gut bacteria.

Many studies have linked poor gut flora with a higher risk of bowel cancer. There are several reasons for this. As mentioned above, unhealthy bacteria encourages the formation of damaging nitrosamines from nitrates in meat.

Having poor gut health also creates inflammation in the gut lining cells which then divide faster. More rapidly dividing cells are more likely to develop spontaneous mutations of DNA and have less time for them to repair themselves.

On top of this, the areas in the gut which generate the immune cells, called Payers patches, shrink so there is a lower chance that the local immune system will recognise the early cancer cells and kill them. It has also recently been discovered that biological treatments for cancer are less effective in the presents of unfriendly gut bacteria.

Lots of factors affect the health of the gut from exercise, smoking diet, weight gain and stress.

People associate smoking with lung cancer but smokers have a 10% increased risk of bowel cancer and this increases with the number of cigarettes smoked per day. Smokers are also more likely to develop polyps which could turn into cancer if not discovered. If you smoke, try to explore strategies to help you quit and make sure you participate in regular bowel screening.

Smoke can also be ingested by food. This can explain why Hungary and Slovenian, which have a tradition of home smoking meat, have the highest rate of bowel and also stomach cancer.

A number of studies including a trial involving over 12,000 participants has firmly established that higher blood vitamin D levels are linked to a lower risk of bowel cancer. Interestingly the best protection was from levels over 75-100 nmol/L. The majority of people in Northern climates have levels significantly lower than this, especially in the Winter.

Regular, sun exposure (without burning) is the best way to maintain vitamin D levels but this is impractical for most people throughout the year. Vitamin D supplementation especially if combined with a probiotic which enhances its effect does seem a sensible approach to maintaining these levels.

Milk has received a bad reputation over the years, but several studies consistently show that people who consume milk have a lower risk of bowel cancer. The challenge is that milk, cream, and cheese can be fattening, increasing the risks, so use them in moderation.

Additionally, many of us are lactose intolerant, especially as we age, which can cause digestive problems. Mature cheeses like parmesan and live yogurts have most of the lactose fermented, making them usually safer to consume.

Other plant-based milks, such as soy and almond milk, are also rich in calcium, considered the main protective element.

Being overweight or obese and carrying excess weight around your waist can increase your risk of bowel cancer by about 10%. The reasons why obesity contributes to the risk of bowel cancer are multifactorial, including associations with reduced exercise levels, poorer diets, and suboptimal gut health.

In conclusion, it is inevitable that most foods and lifestyle habits will contain some harmful elements, but you have to consider the overall picture. The concentration of toxins and the accumulation of bad habits over time are what matter.

Your body can certainly cope with the occasional unhealthy meal, but consuming foods containing toxins without the healthy antidotes every day will strain it, especially when combined with a sedentary lifestyle or other factors such as smoking.

Without becoming paranoid or developing food phobia, it is worth being aware of the most common lifestyle and dietary factors that empower us to avoid this malicious disease.