As the leading cause of death in Aotearoa, cancer is responsible for tearing apart many families. But while some cases may be harder to prevent due to environmental factors or genetic predisposition, others are more likely to be averted.
No cancer is 100 percent preventable, but managing certain controllable factors such as your diet, physical activity and other lifestyle choices can reduce your risk of developing the disease. This is particularly true for several specific cancers which are considered to be more preventable than others.
AIA Insurance chief medical officer Dr John Mayhew, an Auckland-based general practitioner who served as a doctor for the All Blacks for 15 years, says skin, cervical, lung, bowel and stomach cancer are among the more avoidable with a healthy lifestyle and managing specific risk factors.
As a disclaimer, this is general information only: you should always obtain professional advice from a medical or health practitioner in relation to your own personal circumstances.
With that being said, Dr Mayhew has shared his advice for lowering your risk of developing each of these five cancers.
Skin
The most common cancer in New Zealand, over 90 percent of skin cancer is caused by over-exposure to the sun and its UV rays, which damage skin cells. There are two types of skin cancer - melanoma and non-melanoma. New Zealand has one of the highest rates of melanoma in the world, with 6000 diagnoses every year.
While the survival rate is high, the focus should be on prevention rather than treatment. Cancer Society NZ has several guidelines to help Kiwis avoid developing skin cancer:
- Wear clothing that covers as much of your skin as possible, or keep to the shady areas where possible during the key sunshine hours of 10am to 4pm
- Apply plenty of sunscreen that is water-resistant with at least SPF30 before you head outdoors (at least 20 mins prior). Reapply every two hours, especially after being in the water or sweating
- Wear a hat that will protect your head, neck, face and ears. A broad-brimmed hat is recommended over a cap
- Wear sunglasses that can protect your eyes from UV radiation.
While experts advise taking precautionary measures all-year-round, it's important to remember that UV levels are at their highest between 10am and 4pm from September to April. If you're out on the water or in the mountains, the sun can also reflect off the snow, sand, or concrete - so make sure to regularly reapply your sunscreen, even in winter.
Cervical
Cervical cancer is caused when the cells in the cervix (the lower part of the uterus) grow abnormally. Most cervical cancer is caused by the human papilloma virus, otherwise known as HPV.
Cervical screening, also known as a smear test, is one of the most important things you can do to prevent cervical cancer. The test can detect abnormal cells early, which means they can be removed before becoming cancerous. Aotearoa has a National Cervical Screening Programme in which women aged 25 to 69 can undergo a smear at a local GP, health clinic or other healthcare provider.
Oral and lung
Lung cancer is the leading cause of cancer-related death in New Zealand as it is often detected too late: according to the Lung Foundation, every year more New Zealanders die of lung cancer than of breast cancer, prostate cancer and melanoma combined.
For lung cancer and oral cancers of the lip, cheeks, tongue or mouth, smoking and alcohol are both major contributing factors. Research indicates that alcohol and cigarettes, both known carcinogens, work in tandem to increase the risk of cancer in your upper digestive tract.
Your best bet at reducing your risk of lung and oral cancer is to avoid or reduce your consumption of alcohol and quit smoking. However, one in five people diagnosed with lung cancer have never smoked, so other healthy lifestyle habits are also important.
Bowel
While bowel cancer is the second most common cancer in Aotearoa, a healthy diet and regular exercise routine can lower your risk. According to Bowel Cancer NZ, a number of studies have indicated that a diet high in red meat and processed foods can heighten the risk.
Our digestive system has the highest exposure to carcinogens and for that reason, a healthy diet low in red and processed meat and high in fruits, vegetables, wholegrains and legumes can help prevent this type of cancer. Again, quitting smoking is advised for a lowered risk.
Stomach
More than 400 people are diagnosed with stomach cancer every year in New Zealand, with a five-year survival rate of about 29 percent.
While the exact causes are unknown, strong links are emerging to lifestyle choices such as smoking, a poor diet and alcohol consumption. One of the main risk factors involved is obesity: a 2019 study found a lower percentage of excess body fat not only lowered the risk of gastrointestinal cancers, but reduced the risk of cancer in general.
Eating a diet rich in fresh fruit and raw vegetables may lower the risk of stomach cancer, as well as avoiding processed and charcoaled meats. Meanwhile, alcohol consumption may increase your risk: as per New Zealand's Gut Cancer Foundation, the evidence for this link is strongest in those who consume three or more drinks a day.
According to the Gut Cancer Foundation, some risk factors for cancer are controllable while others aren't: examples of the latter include age, ethnicity, and gender. The risk is higher for those in their 60s, 70s and 80s, and it's more common in men than women.
