IT IS a big global effort involving an army of medical experts, but the search to pinpoint why and when cancer might strike boils down to researchers like Associate Professor Koh Woon Puay taking thousands of tiny, meticulous steps every day.

The painstaking journey to greater knowledge for Prof Koh of the National University of Singapore’s Yong Loo Lin School of Medicine is measured sample by sample, test by test.

She carefully retrieves straws of blood from special -80 deg C freezers and places them in a container that keeps them cold while being moved to a lab.

The 2,000 blood samples, which include 650 from colorectal cancer patients, will be used for yet another study that Prof Koh and her team of researchers from the NUS and several American universities are undertaking to find the link between certain food that Chinese Singaporeans eat and the incidence of cancer.

The Singapore Chinese Health Study draws on the information on the diet and lifestyle of 60,000 males and females who were first interviewed between 1993 and 1998. Around 30,000 had also donated small amounts of blood and urine for the research, which was established with funds from the National Institutes of Health in the United States.

For the latest sub-study, participants’ blood samples will be analysed to check for 25 different kinds of fatty acids, including the omega-3 kind from fish, omega-6, which is found in corn oil, and saturated fats contained in meat.

Prof Koh, 41, hopes the study will be able to bolster other research findings that have linked eating fish to lower rates of colorectal cancer.

It could also show if eating red meat increases the risk of contracting the cancer.

She says much has been gleaned from the study which started in the mid-1990s to look at how diet, genes and other environmental factors in Chinese people here contribute to cancer. The study has since
been extended to cover other diseases such as diabetes, but cancer remains the main focus.

“So far we have made several findings which are useful to Singaporeans and people around the world on the protective roles of certain types of food common in the Asian diet,” she adds. “We found for example that eating tofu could protect you from breast cancer. The amount needed is not high. Just a serving a day is enough to achieve a protective effect after 10 years.”


Yet another study found that eating fish may reduce the risk of breast cancer.

“This is probably due to the protective effect of omega-3 fatty acids, which are high in fish,” explains Prof Koh.

“Eating orange fruits such as papayas and oranges may reduce the risk of lung cancer and green tea may help reduce the risk of breast cancer in some women.”

 
Prof Koh stresses that such studies are useful in the light of the growing incidence of cancer. In the 2002 to 2006 period, there were 43,000 reported cases in Singapore, with 237 males out of 100,000 hit by the disease while 248 women out of every 100,000 were struck.

Those rates are far above those of the late 1960s: 135 per 100,000 males and 103 per 100,000 females. Chinese are 1.5 to two times more likely to be hit by cancer than Indians or Malays.

Prof Koh makes the case that lifestyle factors account for the rising number of cases among Chinese as well as across the board. “It can’t be genetic, because our genes don’t evolve so quickly,” she says.

“All the research evidence points to the fact that although genes play a part, they account for a very small percentage – less than 10 per cent.”

Environmental or lifestyle factors are more important, she says. Some of these causes are well established – such as smoking, heavy alcohol consumption, radiation and viruses. “It is clear that the rising incidence of common cancers... is driven by various potentially controllable external factors. This is surely the most comforting fact to come out of cancer research, for it means that most cancers are potentially preventable,” she stresses.

To back up her case, she pulls out the latest 500-page report on cancer prevention released three years ago by the American Institute for Cancer Research and the World Cancer Research Fund. A team of international researchers concluded that a third of cancers could be avoided by adopting a healthy lifestyle – mainly eating right and being physically active.This proportion does not include smoking, which by itself accounts for another one-third of cancers.

Overall, one causal factor stood out, she says. “The evidence scientists around the world have gathered is pretty convincing – carrying excess body fat increases risk for several cancers including that of the colon, the oesophagus and the uterus as well as post-menopausal breast cancer.”

Little wonder then that the report leads off with a recommendationto stay as lean as possible.

She highlights another key recommendation that food-loving Singaporeans should take note of – to eat healthily. That means a diet that consists of mostly plant-based foods.

“Research has shown that fruits and non-starchy vegetables are low in calories and contain micronutrients that can protect one against many types of cancer,” she explains.

Prof Koh practises what she preaches. She plays squash to keep fit,

drinks green tea and tries to eat fish at least once a day. She has these final words of advice: “Cancer does not develop suddenly. It’s a long process that happens over many years. That means it’s never too late to start making healthy lifestyle changes.

“So, if you are a smoker, stop the habit. If you’re inactive, start exercising.

“If you’re overweight, diet and exercise to bring your weight down.

“And if your diet is low in vegetables, fruits and grains, start adding them to your meals.”