The unhealthy consumption of high-calorie food threatens to reverse declines in smoking-related cancers in developed countries, while cancer death rates are expected to increase in developing countries, a new report suggests.
Researchers estimated the burden of cancer in terms of death and disability in different parts of the world. They called it the first such global attempt for 27 types of cancer.
Overall, average premature mortality was higher in lower-income countries, while disability and impairment attributed to cancer were higher in wealthier countries.
Worldwide, an estimated 169.3 million healthy life-years were lost to cancer in 2008, Dr. Isabelle Soerjomataram of the International Agency for Research on Cancer (IARC) in Lyon, France, and her co-authors concluded in Tuesday's issue of The Lancet.
North America, Australia and northern Europe reported cancer mortality declines that were attributed to a reduction in lung and other smoking-related cancers in men and breast cancer in women. But in most countries, cancer mortality is still rising, the researchers said.
"Our findings emphasize the need for increased efforts in cancer control in low-resource settings," the authors wrote.
"The inadequate prevention, early detection and treatment programs in low-income to middle-income countries should be reassessed in view of the predicted long-term increased in the future burden of cancer."
It is difficult to build a model from sparse cancer registry data, but the findings emphasize the growing burden that cancer poses in developing countries, Dr. Ahmedin Jemal of the American Cancer Society in Atlanta said in a journal commentary linked to the study.
Obesity and physical inactivity have been associated with an increased risk of cancers including colorectal, post-menopausal breast, kidney and pancreatic, Jemal said.
"Incidence rates for most of these cancers are on the rise in several countries partly because of the obesity pandemic in recent decades," he wrote. "If no action is taken to halt or reverse these trends, they might wipe out the gains from the reduction in smoking-related cancers, especially in developed countries."
Jemal supported the researchers' call for better cancer control tailored to the needs of developing countries.
The study's authors estimated disability rates for women were highest in eastern African countries such as Uganda and Zimbabwe. For men, the rates were highest in Hungary and Uruguay.
The cancer burden of the developing world partly reflects aging and growth of the population as well as marketing that is driving increased use of tobacco and consumption of high-calorie foods, Jemal said.
He added that there are opportunities to reduce risk factors through:
- Tobacco control.
- Improving opportunity for physical activity and healthier diet patterns.
- Vaccinating against the hepatitis B virus, which causes liver cancer, and human papillomavirus (HPV), which causes some cervical, other genital and oropharyngeal cancers.
- Promoting safe sex and increasing availability of antiretroviral therapy for those who face HIV-infection related cancers in sub-Saharan Africa.
Bacteria and viruses account for about 22 per cent of cancer cases in developing countries, such as stomach cancer caused by H. pylori.
The study was funded by the Dutch Scientific Society, Erasmus University Rotterdam and IARC.
RELATED: 6 common myths and facts about breast cancer:
One of the possible risk factors that is the most controversial in the world of breast cancer are the findings about soy's source of estrogen — which some say can even cause cancer. One thing is certain, the soybean and its derivatives — tofu, soymilk, tempeh (fermented soybeans) — are all interesting alternatives to meat because of their protein content and unsaturated fat levels. But other studies indicate that soybeans are rich in antioxidants known to prevent several cancers, including breast cancer itself. That being said, some studies indicate that it would be safer to consume soy before menopause and women with breast cancer or in remission should reduce soybean consumption or eat in moderation.
A scientific journal published in Advances in Nutrition in 2011, noted the importance of having zinc in your diet to boost the immune system and our DNA make-up. Until more scientific evidence is found, it would still be a good idea to add zinc-related foods to your dish like oysters, clams, butter sesame seeds, pumpkin seeds and legumes.
Well known for its role in calcium absorption, vitamin D has also been the subject of studies for cancer prevention. In the case of breast cancer, some studies have shown that vitamin D can even prevent it. On the contrary, other studies have not achieved the same results. That said, we also know that the treatment of breast cancer chemotherapy causes a loss of bone density in women pre-menopause. This is more of a reason to ensure an adequate intake of vitamin D, especially from October to March, when sunlight is rare. Try foods like fish, — especially canned with bones, milk, yogurt, vegetable drinks fortified with vitamin D, eggs and shiitake mushrooms.
Several studies have confirmed that women who consume alcohol on a regular basis increase their risk of being diagnosed with breast cancer. Even one drink a day raises the risk by four per cent. Those who have the habit of drinking three or more drinks a day saw their risk rise to over 40 per cent. That being said, moderation is key for cancer prevention.
Obesity significantly increases the risk of developing breast cancer, particularly in post-menopausal women. Being diagnosed with obesity at the time of breast cancer was associated with poorer survival, the study added.
Nursing can possibly help prevent breast cancer and lower it's risks, according to a report by About.com. On top of this, one 2002 study found that an estimated 25,000 breast cancers would be prevented in developed countries if women had the same number of children but breastfed each child for six months longer, the CBC reports.