Press release-immediate release
December 10, 2017

Survey of the Hong Kong Anti-Cancer Society

67% of Hongkongers cannot meet the 'cancer-prevention' standard of physical activities.

Physical activity reduces risk of 13 types of cancer. Just one year of regular exercise can reduce the risk

'Daily exercise keeps us fit'. However, physical activities not only keep us fit, but also help to prevent the top killer of Hong Kong - Cancer! Nevertheless, according to the latest survey of the Hong Kong Anti-Cancer Society (HKACS), 67% of Hongkongers do not perform physical activities of moderate/high intensity regularly, while over 40% of interviewees do not know performing physical activities of moderate/high intensity regularly can reduce the risk of cancer. HKACS pointed out that, a study indicates regular physical activities of moderate intensity for as short as one year can reduce the risk of cancer. It is estimated that, if all Hongkongers can stay physically active, over 3,700 new cases of cancer could be reduced annually!

Cancer has been the No. 1 killer in Hong Kong for years. In 2015, the new cases of cancer hit the historical high and surpassed the 30,000 mark for the first time in history. To encourage Hongkongers to prevent cancer, HKACS held the 'Hong Kong Cancer Day 2017' at the Piazza of Kowloon Park on 10 December (Sunday). The theme of the day is 'Be Active. Stay Healthy'. Various game booths and activities were available to encourage participants to perform regular physical activities so as to prevent cancer. To understand the knowledge of Hongkongers on how physical activities reduce risk of cancer, HKACS carried out the 'Survey on the weight and physical activities of Hongkongers in relation to cancer prevention' which interviewed 1,006 Hong Kong residents through online questionnaires from 29 October to 10 November.

23% Hongkongers do not know physical activities are contributive to cancer prevention

Obesity is one of the risk factors of cancer. 45% of the interviewed Hongkongers are overweight or obese. It is recommended that one should start increasing the activity level to reduce cancer risk. However, while over 90% of the interviewed Hongkongers know physical activities are beneficial to relieve pressure and reduce the risk of '3H', only 70% of them aware of physical activities can reduce the risk of cancer. Even though most people aware of the fact that physical activities are beneficial to health, it seems difficult to put into action. According to the survey, 65% of Hongkongers performed physical activities occasionally or rarely, or even none in the past 6 months.

So what means 'physical activities' to Hongkongers? 19% of Hongkongers claimed 'shopping' is one of their most frequent physical activities. Only 33% of Hongkongers have a habit of doing physical activities of moderate/high intensity frequently. There were loads of excuses for not doing physical activities: 84% of the respondents who do not exercise regularly claimed that they are too occupied and cannot squeeze out time for that, more than half of them thought that physical activities are too harsh/they do not want to move/do not want to sweat.

On the other hand, over 40% of Hongkongers do not know doing physical activities of moderate/high intensity is effective for cancer risk reduction. Moreover, 83% of Hongkongers do not realize that doing physical activities (to certain intensity) for a year continuously can reduce the risk of cancer - 20% of them think that it requires a continuous effort of 20 years!

Dr. LIU King Yin, Rico, Chairman of Cancer Education Subcommittee of HKACS pointed out that, studies indicate prolonged sedentary behavior (i.e., activities that are carried out while sitting or in a reclining position, without whole body movement) was independently associated with an increased risk of developing endometrial, colorectal, breast and lung cancers.

Physical activities can reduce cancer risk by 10 - 42%

In contrast, physical activities are associated with reduced risk of 13 cancers (Appendix 1) including the top 3 cancer types in HK: colorectal cancer, lung cancer and breast cancer. 'According to a recent study which analyzed the data of 1.44 million participants, physical activities can reduce cancer risk by 10-42%. Taking the No. 2 cancer killer of Hong Kong, lung cancer, as an example, the risk can be reduced by 27% through physical activities.' Dr Liu said.

He further elaborated how physical activities can effectively reduce the risk of cancer:

• Reduce hormone level
  Certain hormones such as estrogen, are important to the development of breast and womb cancer. Regular physical exercises can lower the levels of these hormone, thus reduce the risk of cancer.

• Reduce insulin level
  Insulin can turn on signals that tell cells to multiple. Physical activities can lower insulin level which can help to reduce the chance that cells multiple out of control (which is the start of cancer), thus reduce the risk of developing certain types of cancer.

• Reduce inflammation
  When inflammation keep happening at the same part of body, cells may multiply more frequently than usual to replace dead and damaged cells, thus would increase the chance of mistakes and may lead to cancer. Continuous exercises can control inflammation of the bowel, thus reduce the risk of cancer.

• Speed up the bowel movement
  Physical activities can reduce the time that food stay in the bowel. This reduces the bowel's exposure to harmful substances, and thus reduces the chance of cancer development.

Regular activities of moderate intensity throughout one year can reduce cancer risk

Doing physical activities with the purpose of cancer risk reduction requires continuous effort, but it is never too late to start. In a randomized study, 173 overweight, sedentary post-menopausal women were assigned to two groups: one group performed moderate intensity aerobic exercise for 45 mins each day, 5 days a week, for 12 months; while the other group was control group. After 3 months, the serum sex hormone level of the 'moderate intensity exercise' group demonstrates a significant decrease from baseline, and attenuation of the event in 12 months. The result suggests that increase in physical activity and reduced body fat can reduce sex hormone level and produce protection against breast cancer.

'According to the study, doing 45 mins of physical activities of moderate intensity a day, 5 days a week, can reduce the risk of cancer. It is not difficult - any activity that makes you warm and slightly out of breath is a moderate intensity one, such as speed walking or doing housework (like vacuuming), it is easy to achieve. Shopping is an activity of low intensity, but if you walk home in a fast pace with your "rewards", then it is an activity of moderate intensity.' said Dr Liu.

All Hongkongers stay active can reduce 3,713 new cases of cancer per year

Dr. Liu pointed out that, though cancer is the No. 1 killer in Hong Kong, it can be prevented from lifestyle modification. 'From the survey we discovered that only 33% of Hongkongers performed activities of moderate/high intensity frequently. If everybody starts to do 45 minutes of activities of moderate intensity each day, 5 days a week, it is estimated that new cases of cancer can be reduced by 12% each year, that means 3,713 lives can be saved from cancer every year. It is really beneficial for oneself, for one's family, and the entire society.'

Appendix I : Type of cancer in relates to the impact of physical activities

Appendix II: How to start exercising?

• Take the stairs instead of elevator
• Walk more, ride less
• When you watch TV, do stretching exercises at the TV commercial break, such as bend your waist kick legs
• Get your family or friends involved in regular exercise, such as playing badminton and table tennis etc., and make it enjoyable to you and subsequently, establish the habit of regular exercise
• Go for a short walk at lunch time