1 in 31: the number of the most common cancers that could be prevented by following a healthy diet.
This is why the World Cancer Research Fund have packaged together a few key, healthy lifestyle choices which, together, can have a great impact on our likelihood of developing cancer.
Focus on Fruit and Veg
A diet rich in colourful fruit and vegetables can decrease your risk of dying from cancer by 13%.2
In particular, there is good evidence to show that high fruit and veggie intake may help lower the risk of cancers of the mouth, pharynx, larynx, oesophagus, and stomach.2
This is because fruit and vegetables are high in cancer protective nutrients,3 like phytochemicals, vitamin C, vitamin E, various minerals, fibre, and other bioactive compounds.
It is the combined effect each of these nutritive factors that together work to reduce cancer risk.
Added to this, research suggests that fruit and vegetable lovers are less likely to smoke, be overweight, drink less alcohol, and be more active, all of which play a role in cancer risk.
How much fruit and vegetables should you have?
Aim for 400 g each day.2 Yet new research shows that more is even better! According to a large study4 on over two million participants, eating up to 7 ½ servings of fruits and veggies per day (600g) lowers the risk of dying from cancer by 13%. A serving size of 80g of fruit or veg looks like this:
- One large carrot.
- 1/2 cup cooked broccoli or 1 cup uncooked.
- 1 small banana or ½ an apple.
- 2 cups of greens like lettuce or baby spinach.
Go for Grains
There is strong evidence that eating wholegrains2 protects against colorectal cancer.5
Wholegrains like oats, brown rice, wholewheat pasta, and bran are rich in fibre.
Unfortunately, a diet low in fibre may negatively change the composition of our gut microbiota (the collection of organisms in our gut).
This change increases the activity of a variety of faecal enzymes which produce cancer-causing compounds.
This is the likely reason why more fibre means more protection against colorectal cancer.
In addition, a high fibre diet helps against weight gain, overweight and obesity6, which we know increases the risk of cancer.
How much fibre should we eat?
The ideal is to aim for at least 30g per day.
Yet studies have shown that South Africans eat only half of this7 with women and men eating as little as 16g and 18g of fibre per day, respectively.
Swap Out the Sugar
The World Cancer Research Fund1 recommends that we limit our intake of sugar-sweetened drinks, avoiding these beverages all together if possible.
The trouble is that added sugar causes a quick spike in blood glucose, triggering a host of metabolic changes in the body.
One of which is the kickstarting of the inflammatory processes that can over the long-term be linked to chronic disease like cancer (as well as heart disease and diabetes).
And of course, eating excessive amounts of sugar may also lead to weight gain.
This is because sugar does not keep us feeling full, while being high in energy (calories/kilojoules), contributing to weight.
Studies have shown that as many as 1 in 5 of all cancer deaths8 may be related to excess weight.
There is strong evidence that being overweight or obese increases the risk various cancers6 such as cancer of the mouth, pharynx, larynx, oesophagus, stomach, pancreas, gall bladder, liver, colon, breast (post-menopause), ovary, endometrium (womb), prostate and kidney.
Put Away the Processed Meat
For every 50g of processed meat eaten each day (about one hot dog or 4 slices of ham), we increase our colorectal cancer risk by 16%, according to the WCRF.1
And the evidence is similar for red meat: for every 100g of red meat eaten daily, our cancer risk increases by 17%.
For this reason, the World Cancer Research Fund recommends we eat less than 300 g of red meat each week, and very little, if any, processed meat.
While we know that cancer is a multifactorial, complex disease, we also know that there is a lot we can do to help manage our cancer risk.
Take control of your diet and you can take control of your cancer risk.
- World Cancer Research Fund/ American Institute for Cancer Research. Diet, nutrition, physical activity, and cancer: A summary of the third expert report. 2018. Available at: https://www.wcrf.org/wp-content/uploads/2021/02/Summary-of-Third-Expert-Report-2018.pdf.
- Word Cancer Research Fund/ American Institute for Cancer Research Continuous Update Project Export Report 2018. Wholegrains, vegetables and fruit and the risk of cancer. Available at http://www.dietandcancerreport.org.
- Hurtado-Borrosa S et al. Vegetable and Fruit Consumption and Prognosis Among Cancer Survivors: A Systematic Review and Meta-Analysis of Cohort Studies. Adv Nutr 2020;11:1569–1582.
- Aune D et al. Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality-A systematic review and dose-response meta-analysis of prospective studies. Int J Epidemiology. 2017;1,46(3):1029-1056. Doi: 10.1093/ije/dyw319
- Word Cancer Research Fund/ American Institute for Cancer Research Continuous Update Project Export Report 2018. Diet, nutrition, physical activity, and colorectal cancer. Available at: https://www.wcrf.org/wp-content/uploads/2021/02/Colorectal-cancer-report.pdf
- Word Cancer Research Fund/ American Institute for Cancer Research Continuous Update Project Export Report 2018. Body Fatness and Weight Gain and the Risk of Cancer. Available at http://www.dietandcancerreport.org
- Mchiza ZJ et al. A Review of Dietary Surveys in the Adult South African Population from 2000 to 2015. Nutrients. 2015;7:8227-50.
- Font-Burgada J, Sun B, Karin M. Obesity and cancer: the oil that feeds the flame. Cell Met Rev. 2016; http://dx.doi.org/10.1016/j.cmet.2015.12.015.
- Word Cancer Research Fund/ American Institute for Cancer Research Continuous Update Project Export Report 2018. Limit red and processed meal. Available at: https://www.wcrf.org/dietandcancer/limit-red-and-processed-meat/.