Courtesy of THIS Quarterly magazine  
 
 
Diet and Colorectal Cancer  
 
   
     
 

IT IS DIFFICULT TO TALK ABOUT DIET AND COLORECTAL CANCER SENSIBLY AND SCIENTIFICALLY BECAUSE OF prevailing folklores, hearsays, advertisements and media claims. Everyone from relatives to friends and coffeeshop buddies appear to be an expert on this subject. We are constantly bombarded by information on special diets, health foods and expensive supplements which could prevent or cure cancer. If they were all true, there would be nobody suffering from colorectal cancer: but the irony is that this cancer is most commonly found in modern societies.

To understand the relationship between diet and colorectal cancer, we need first to look at the overall picture. Colorectal cancer is an inordinately complex disease caused by the interactions of genetic, aging, inflammatory and a wide variety of lifestyle factors: of which diet is only a component. As such it is not conceivable that a particular food - like dragon fruit, bird’s nest or duck meat - is capable of preventing or causing colorectal cancer.

That said, colorectal cancer is a cancer of developed countries where food, especially rich and processed food, are over-consumed. Analysis of worldwide cancer trends for the last 20 years shows the greatest increase occur in economically transitioning populations like the Czech Republic, Slovakia, Shanghai, Miyagi Prefecture (Japan) and Singapore. As these populations do not share a common diet, it implies that the quantity of food consumed could be important. Experiments on worms, insects and laboratory animals have also consistently demonstrated that creatures both big and small, when allowed free consumption of food (compared to those whose food intake are restricted to 70%) develop more cancer, age faster and die faster.

Human metabolism, cell growth and cell death within the human body are kept in perfect balance. Inadequate nutrition can cause ill health, but excess nutrition does not necessarily create super-normal health; on the contrary, it might cause more harm as suggested by Dr James Watson, the Nobel Laureate who co-discovered the Double-Helix of DNA.

 

Excessive consumption of vitamins and other antioxidants may actually cause and perpetuate colorectal cancer.

Except for the hereditary variety, colorectal cancer takes decades to form. It means that cultivating a healthy dietary habit should start from the very young. After 30 years of careful research, it is well accepted that regular consumption of unprocessed dietary fibre (especially from whole grain), fruits and vegetables protect against colorectal cancer while the consumption of red meat, processed meat, cigarettes and alcohol increase the risk. Fifty grams of red and processed meat per day is safe, but 100 grams or more increases the risk by 20%; smoking adds another 8% and drinking more than three glasses of alcohol each day adds a further 11%

While diet is important, it is only part of a healthy lifestyle that should also include physical activity, prevention of obesity, diabetes and an over-exposure to radiation. Dietary supplements are not recommended in healthy individuals but are important in those with deficiencies, such as patients who have not been eating before or after abdominal surgery, individuals with osteoporosis and expectant mothers.

If there is a magic pill that has been known to reduce the chances of developing colorectal cancer, it has to be aspirin, the common over-the-counter painkiller. Taking 100mg of aspirin a day has been known to reduce the risk of developing colorectal cancer by 30%.

However, even if a person adopts a perfect lifestyle, eats a healthy diet and takes aspirin regularly, he can only prevent 45% of colorectal cancer; screening for colorectal cancer is just as, if not more, important. America is the epitome of over-consumption with its obsession with fast foods, unhealthy diet and obesity. However, thanks to the sheer number of Americans who undergo regular screening by colonoscopy, it is also the only developed country in the world that has a decreasing incidence of colorectal cancer.

 
 
 
DR GOH HAK SU | Colorectal Surgeon
MBBS, FRCS, FAMS

Address
 
Goh Hak-Su Colon & Rectal Centre
6 Napier Road #04-08
Gleneagles Medical Centre
Tel : (65) 6473 0408
Website : www.gohhaksu.sg