If you could decrease your risk of dying from cancer by 13%, would you?Chances are your answer is a resounding YES! The great news is that there is a simple way to do so: just eat more fruit and vegetables.1 According to the International Agency for Research on Cancer (IARC),25 to 12 % of cancers may be linked to eating too little fruit and veggies. 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.1
Cancer Protective PropertiesFruit and vegetables are high in nutrients that are potentially cancer protective,3 such as phytochemicals (e.g. carotenoids, phenolic compounds), vitamin C, vitamin E, minerals, fibre, and other bioactive compounds.3;4 Scientists think that it is a combination of these factors working synergistically in whole fruit and vegetables that helps to reduce cancer risk. For example, some compounds may help regulate oestrogen, important in hormone-dependent cancers like breast cancer. Other compounds work as free radical destroying antioxidants, or block or slow down cancer cell division and growth. This means a whole food approach should be followed, rather than focusing on any one fruit, vegetables, or vitamin/mineral supplement.
Weight ManagementWhile fruit and vegetables can directly provide anti-cancer nutrients, these healthy foods may also have an indirect role in managing a healthy weight. Obesity is a convincing risk factor for getting several types of cancer5 (e.g. kidney, pancreas, gut, oesophagus, and breast). Low in energy (kilojoules/calories), rich in fibre, with the ability to displace high energy/nutrient poor foods from the diet, it is clearly a double whammy of weight maintenance and cancer prevention when you include more fruit and vegetables in your diet.
Low GIThe glycaemic index (GI) is a measure that ranks how quickly a carbohydrate food is digested and metabolised by the body. Foods consisting of carbohydrate that are digested, absorbed, and metabolized at a quick rate (i.e. spiking blood sugar and insulin), are considered high GI foods e.g. white bread, added sugar, and sugar-containing foods. Foods that are digested, absorbed, and metabolized at a slower rate are low GI foods, such as oats, wholegrains, and most fruit and vegetables. Diets with too many high GI foods have been linked to several types of cancer. 6 This may be because eating high GI foods mean we eat too little of the low GI foods (i.e. fruit and vegetables), displacing the cancer-protective nutrients in our diet. For this reason, the World Cancer Research Fund (WCRF) recommends that we choose unprocessed cereals (grains) and/or pulses (e.g. beans, chickpeas, lentils) with every meal, limiting refined, white starches and added sugar.
Fruit and Vegetable Eaters are Healthier OverallFruits and vegetables are naturally rich in healthy nutrients, contain gut-healthy fibre, are low in energy (kilojoules/calories), and are virtually free from less desirable nutrients from processed foods with excessive sodium, saturated fat, and added sugar. Fruit and vegetable lovers are less likely to smoke, be overweight, drink less alcohol, and are more active, according to research. Each of these factors play a role in cancer risk. It is also possible that certain dietary patterns (such as vegetarian diets and the Mediterranean diet) that include a lot of fruit and vegetables may have cancer protective properties. We know that those who follow a Mediterranean style of eating may have a lower overall cancer risk7, risk of dying from cancer, as well as risk of getting colorectal, breast, gastric, liver, head, and neck cancers. Other factors associated with the Mediterranean diet, like anti-inflammation, genetics, and a favourable gut microbiome, may also reduce colon cancer risk.
How Many Fruits and Vegetables Must I Eat?For good health, the South African dietary guidelines recommend that we eat at least 5 portions (400g) of a variety of fruit and vegetables each day. But new research shows that more is even better. According to a large global study8 on over 2 million participants, eating up to 7½ servings of fruits and veggies per day (600g) lowers the risk of dying from cancer by 13%. What does one serving of vegetables (80g) look like?
- 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.
- ½ cup of roasted veggies
The FitChef WayAt FitChef, we are fans of all fruits and vegetables. To maximise the benefits of these healthy foods you may need to include at breakfast, lunch and dinner, and even as part of your snacks. Choose a mix of fresh, whole, cooked, and raw options. Aim for a variety of colour (e.g. red tomatoes, yellow gem squash, green spinach, white cauliflower, purple berries, etc), with each colour representing different nutrients and phytochemicals known to help lower overall cancer risk.
- 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.
- International Agency for Research on Cancer. IARC handbooks on cancer prevention, vol. 8: Fruit and vegetables. Lyon: IARC; 2002
- 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.
- Hamilton KK, Grant BL. Medical nutrition therapy for cancer prevention, treatment, and survivorship. In: Mahan LK, Raymond JL, editors. Krause’s Food and the Nutrition Care Process. 14th edition. St Louis, Missouri: Elsevier; 2017. p. 729-756.
- 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.
- Word Cancer Research Fund/ American Institute for Cancer Research Continuous Update Project Export Report 2018. Other Dietary Exposures and the Risk of Cancer. Available at http://www.dietandcancerreport.org.
- Schwingshackl L, Hoffmann G. Does a Mediterranean-type diet reduce cancer risk? Curr Nutr Rep.2015. DOI: 10.1007/s13668-015-0141-7.
- 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