April is a bowel cancer awareness month in the UK.
Bowel, colon, or colorectal cancer as it’s known is a very personal topic for me as my paternal grandmother had 5 bowel cancer surgeries and lived with a colostomy bag for many years before succumbing to this disease. My father also had colon cancer and very narrowly escaped colostomy. This family history puts my brother and I at an increased risk of colon cancer and makes me more focused on reducing this risk.
I am also very aware of the stigma surrounding this particular type of cancer and the difficulties in getting tested/diagnosed if a person is under the age of 40. Getting regular screening tests for colon cancer is a good way to protect yourself from the disease as it can catch cancer early, but the best way to prevent getting the cancer in the first place is having a healthier lifestyle. Scientist believe by having a healthier lifestyle around half (54% to be precise) of all bowel cancers could be prevented.
A numerous studies have shown that diet modulates inflammation and inflammation plays an important role in cancer development. Chronic inflammation has been implicated as a key predisposing factor to colorectal cancer.
I would like to therefore highlight the importance of going beyond what constitutes a generally healthy diet by adopting an anti-inflammatory diet in preventing colon cancer. But before taking a deeper dive into the chronic inflammation, healthy gut microbiome, anti-inflammatory food compounds and other factors that also play a role, let’s remind ourselves of the basics.
What is bowel cancer
Bowel cancer is the fourth most common cancer in the UK and the second biggest cancer killer. However, it is treatable and curable, especially if diagnosed early.
The bowel is part of the digestive system. It is made up of the small bowel (small intestine) and the large bowel (colon and rectum). Cancer is more likely to develop in the large bowel. Small bowel cancer is much less common.
Normally, body cells follow an orderly process of growth, division, and death. Cancer happens when cells grow and divide uncontrollably, without dying.
Most colon cancer originates from noncancerous, or benign, tumors called adenomatous polyps that form on the inner walls of the large intestine.
There are often no symptoms in the earliest stages, but symptoms may develop as the cancer advances. They include:
- diarrhoea or constipation
- changes in stool consistency
- loose and narrow stools
- rectal bleeding or blood in the stool (look for dark red or black blood)
- abdominal pain, cramps, bloating, or gas
- pain during bowel movements
- continual urges to defecate
- tiredness and weakness (Bowel cancer may lead to a lack of iron in the body, which can cause anaemia - lack of red blood cells. If you have anaemia, you are likely to feel very tired and your skin may look pale.)
- unexplained weight loss
- irritable bowel syndrome (IBS)
Can you be at risk?
You are more at risk of getting bowel cancer if you have one or more of the following risk factors:
- A strong family history of bowel cancer
- A history of non-cancerous growths (polyps) in your bowel
- Longstanding inflammatory bowel disease such as Crohn’s disease or ulcerative colitis
- Type 2 diabetes
- An unhealthy lifestyle – your diet, drinking alcohol, smoking and not being physically active can all increase your risk
- Inherited syndromes such as familial adenomatous polyposis (FAP) and Lynch syndrome
- Radiation therapy for cancer. Radiation therapy directed at the abdomen to treat previous cancers increases the risk of colon cancer.
Prevention: What to avoid & what to embrace
Numerous studies have indicated that a diet too rich in red meat is associated with a heightened risk of colon cancer. "Red meat" is defined by the World Health Organization (WHO) as "all mammalian muscle meat, including beef, veal, pork, lamb, mutton, horse, and goat.
A study of North Italian populations showed that individuals who eat red meat alongside eggs, cheese, and other fatty foods — as well as refined starches — on a frequent basis had an almost twice higher risk of developing rectal or colon cancer than their peers who favoured a plant-based diet.
In 2015, a report published by the International Agency for Research on Cancer made the news by pointing out that every 50-gram portion of processed meat, such as bacon or salami, eaten every day increases a person's risk of developing colorectal cancer by 18%.
This evidence led the WHO to classify processed meats as "carcinogenic to humans.
This highlights the dietary factors can be related to bowel cancer through mechanisms other than inflammation. For example, consumption of red and processed meat increases the risk of bowel cancer through increased levels of the haem iron content, N-nitroso compounds formed during the processing of meat, of polycyclic aromatic hydrocarbons and heterocyclic aromatic amines from cooking meat at high temperatures (sorry to get a bit scientific).
A study from the Loma Linda University in California found that vegetarian-style diets are linked to a decreased risk of colorectal cancer.
The protective compounds found in plants such as antioxidants and polyphenols have been proven to reduce inflammation which in turn reduces the risk of chronic diseases and also improves mood and overall quality of life.
What does an anti-inflammatory diet do?
Your immune system becomes activated when your body recognizes anything that is foreign, such as an invading microbe, plant pollen, or chemical. This often triggers a process called inflammation. Intermittent bouts of inflammation directed at truly threatening invaders protect your health.
However, sometimes inflammation persists, day in and day out, even when you are not threatened by a foreign invader. That's when inflammation can become your enemy. Many major diseases including cancer, heart disease, diabetes, arthritis, depression, and Alzheimer's have been linked to chronic inflammation.
Choose the right anti-inflammatory foods, and you may be able to reduce your risk of illness. Consistently pick the wrong ones, and you could accelerate the inflammatory disease process.
If you're looking for an eating plan that closely follows the rules of anti-inflammatory eating, consider the Mediterranean diet, which is high in fruits, vegetables, nuts, whole grains, fish, and healthy oils or consult a nutritionist that can work out specific anti-inflammatory meal plans. You can also get your levels of inflammatory markers tested, such as C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF).
Let’s look at just a handful of anti-inflammatory foods you should have in your diet:
- Berries (blueberries, blackberries, raspberries, strawberries) contain antioxidants called anthocyanins that have anti-inflammatory effects.
- Broccoli (and other cruciferous vegetables such as cauliflower, Brussels sprouts, kale) is rich in sulforaphane, an antioxidant that fights inflammation by reducing your levels of cytokines and NF-kB which drive inflammation.
- Chili peppers and bell peppers are rich in quercetin, sinapic acid, ferulic acid and other antioxidants with strong anti-inflammatory effects.
- Grapes contain anthocyanins and resveratrol - compounds that reduce inflammation.
- Cherries are rich in antioxidants, such as anthocyanins and catechins, which fight inflammation.
- Tomatoes are high in vitamin C, potassium and lycopene, an antioxidant with impressive anti-inflammatory properties. Lycopene may be particularly beneficial for reducing pro-inflammatory compounds related to several types of cancer.
- Dark Chocolate and Cocoacontains flavanols that have anti-inflammatory effects.
- Extra Virgin Olive Oilcontains oleocanthal, an antioxidant that has been compared to anti-inflammatory drugs like ibuprofen.
- Turmeric boasts a powerful anti-inflammatory compound called curcumin. Eating black pepper with turmeric can significantly enhance the absorption of curcumin.
- Mushrooms contain phenols and other antioxidants that provide anti-inflammatory protection (best to eat them raw or lightly cooked).
- Green tea’s high EGCG (epigallocatechin-3-gallate) content reduces inflammation by reducing pro-inflammatory cytokine production and damage to the fatty acids in your cells.
- Fatty fish (salmon, sardines, herring, mackerel, anchovies) are a great source of protein and the long-chain omega-3 fatty acids EPA and DHA. Your body metabolizes these fatty acids into compounds called resolvins and protectins, which have anti-inflammatory effects. In clinical studies, people consuming salmon or EPA and DHA supplements had decreases in the inflammatory marker C-reactive protein (CRP).
- Avocados are packed with potassium, magnesium, fiber and heart-healthy monounsaturated fats. They also contain carotenoids and tocopherols, which are linked to reduced cancer risk.
An anti-inflammatory diet isn’t just about what you eat, but what you don’t eat. Foods high in salt, saturated fat, sugar, and refined carbohydrates should be limited or avoided.
Chronic inflammation throughout the body can also contribute to increased intestinal permeability (the so-called leaky gut syndrome). When the gut is "leaky" and bacteria and toxins enter the bloodstream, it can cause widespread inflammation and possibly trigger a reaction from the immune system.
Chronic stress is another factor contributing to multiple gastrointestinal disorders as is poor gut health. There are millions of bacteria in the gut, some beneficial and some harmful. When the balance between the two is disrupted, it can affect the barrier function of the intestinal wall.
Recently, scientists have identified a molecular mechanism through which an oral bacterium called Fusobacterium nucleatum present in tooth decay, accelerates colorectal cancer growth. F. nucleatum produces the molecule FadA adhesin, which sets off a series of molecular events in colon cells that scientists have linked to a number of cancers. It is therefore important to stick to your regular dental and dental hygienist check ups.
We could discuss the leaky gut syndrome and healthy gut microbiome at length, but essentially improving your gut health comes down to diet again.
"Let food be thy medicine and medicine be thy food" Hippocrates