It is in your hands

In the United Kingdom, the National Bowel Cancer Screening Programme, which involves 2 yearly faecal occult blood screening, is predicted to reduce the colorectal cancer mortality in those screened by 13-15% over the next 20 years (J Med Screen 2008; 15: 163 – 174). The same researchers from London have now published their analysis predicting that realistic lifestyle modifications involving diet and exercise could prevent more colon cancers than screening. The lifestyle modifications are

·         Consuming < 90 g/day of red and processed meat

·         Consuming ≥ 5 portions /day of fruit and vegetables

·         Exercising ≥ 30 minutes / day on ≥ 5 days / week, at least at moderate intensity (equivalent to brisk walking)

·         Alcohol consumption not exceeding 3 units / day for men and 2 units / day for women (half a pint of beer, a single measure of spirits, a glass of wine or a small glass of sherry or port is equivalent to a unit).

They have estimated that adhering to these lifestyle modifications could lead to a 26% reduction in the number of cases of colorectal cancer in the British population (Eur J Cancer Prev epub, February 20, 2009).

Since this is an estimation based on projection, you might not be convinced that lifestyle changes can have such major impact on your lifetime cancer risks. Consider this then. Researchers from Tokyo University of Science examined the effects of consuming broccoli sprouts on Helicobacter Pylori colonization in the stomach. [The WHO has classified H Pylori as a carcinogen. H. Pylori infection gives rise to gastritis, stomach ulcer and stomach cancer. Eradication of H. Pylori infection with triple therapy leads to resolution of gastritis, stomach ulcers and the prevention of stomach cancer.] The researchers studied 48 people with H. Pylori infection. They were randomized to consume either 70 g / day of broccoli sprouts (containing 420 µmol sulforaphane precursor) for 8 weeks or an equal amount of alfalfa sprouts (Cancer Prev Res 2009; 2: 353 – 360). Alfalfa sprouts are rich in phytochemicals but do not contain sulforaphane. 

All the participants had blood, stool and urine samples taken on days 0, 28, 56 and 112. H. Pylori stool antigen (HpSA), a biomarker of H. Pylori colonization, and serum pepsinogens PGI and II, biomarkers of gastric inflammation, were measured. Urea breath test was used to assess severity of H.Pylori colonization. The HpSA level in the broccoli sprout group was reduced by > 40% while it remained unchanged in the alfalfa group. The serum pepsinogens levels were significantly reduced only in the broccoli sprout group. Two months after stopping broccoli sprouts in the diet, the HpSA and pepsinogens levels returned to baseline.

The study showed that broccoli sprout consumption successfully reduced H. Pylori colonization but does not completely eradicate the pathogen. It is unrealistic to expect any form of dietary chemoprevention to completely eradicate the risk of developing a particular disease or cancer. Just like eating broccoli sprouts, the lifestyle changes suggested above will only help to reduce the risk of developing colon cancer but will not eradicate the risk completely. In order to benefit from them, we have to persevere with these lifestyle changes and maintain the changes or habits over the long term.

The ball is now in your court. You decide.