• Diet alone is unable to treat or cure cancer. However, there are diet and lifestyle strategies you can use to help reduce your risk of developing cancer.
• To help reduce cancer risk, you should eat a healthy diet, maintain a healthy body weight and exercise regularly.
• An Accredited Practising Dietitian (APD) can help you improve your diet, reduce potential health risks and tailor recommendations to your personal needs.

15 minute read

Nutrition and cancer

Diet can play a role in preventing some cancers and can also reduce the risk of cancer recurrence and other long-term health issues. 

Following a strict diet or eliminating food groups to try to prevent cancers can cause more harm than good. Restricting or cutting out key food groups could lead to nutritional deficiencies and therefore negatively affect your health. Instead, you should focus on healthy lifestyle changes including the healthy eating recommendations outlined below. These are backed by evidence available from the world’s leading cancer nutrition research organisations.

Key preventative measures

Maintain a healthy weight

Research has found staying at a healthy weight throughout your life is one of the best ways to protect yourself against cancer. 

The most effective way to stay within a healthy weight range include:

• eating a diet rich in whole foods such as fruits, vegetables, wholegrains, legumes, nuts and seeds
• limiting your intake of low nutrient and highly processed foods
• avoiding alcohol and sugary drinks       
• staying active.

Eat more fruit and vegetables

Many Australians don’t get enough fruit and vegetables in their diet. Data has found that around only 6% of Australian adults meet the recommended five serves of vegetables per day. 

Evidence suggests that fruit and vegetables have a protective effect against some cancers, as well as weight gain and obesity. Aim to eat 2 serves of fruit and 5 serves of vegetables each day. 

Easy ways to add more fruit and vegetables each day:

• add a serve of fresh, frozen or dried fruit to your breakfast cereal like sultanas, cranberries, berries, kiwi fruit, passionfruit, pineapple, pomegranate, grated apple or banana
• make up a bowl of fruit salad or stew up some pears or apples. Serve with some cinnamon and a dollop of Greek yoghurt
• if making egg dishes, add in or serve them with a side of spinach leaves, chopped capsicum, tomatoes, avocado or mushrooms
• incorporate fermented vegetables such as sauerkraut or kimchi into your sandwiches and salads or on snacks
• keep some of the pre-washed bags of spinach leaves, coleslaw or stir-fry medleys in your fridge. Add a good handful or two into your dinner meals, sandwiches or snacks. Vegetable or salad mixes are also an easy way to top up the vegetable content in any takeaway or ready-made meals
• at the start of the week, roast a tray of mixed- root vegetables. Store in the fridge and use as a side to lunch and dinner meals. Options can include sweet potato, pumpkin, eggplant, zucchini, fennel, corn or beetroot
• moisten your homemade or packet mix desserts, puddings, slices or cakes with extra fruit or grated vegetables such as pear, apple, carrot, beetroot or zucchini
• if making soups, curries, mince-based dishes, stews or pasta, add in extra grated or chopped vegetables such as carrots, zucchini, celery, broccoli, kale or cauliflower. You could also try mixing in a can of legumes such as lentils, chickpeas, cannellini or kidney beans
• boost the umami taste of minced meals and replace around one-third of the meat portion with a punnet of finely chopped or blended mushrooms
• put out a plate of chopped vegetables with hummus to snack on when cooking dinner or for the kids to pick at.

Remember, fruit and vegetables are best brought when they are in season. Otherwise, try frozen or canned vegetables as they are just as nutritious and budget-friendly as well. 

If you are someone who doesn’t look forward to eating fruit or vegetables, start slowly with those you do like. Try serving them, flavouring, or cooking them in different ways. You can also disguise them in sauces, minced meals, or curries. 

Eat more whole grains, legumes and high-fibre foods

Whole grains and legumes should be a part of your daily diet. These foods are high in fibre, as are fruits and vegetables. High-fibre foods can reduce your risk of gastric and colorectal cancers. 

Whole grains, in particular, protect against colorectal cancer. They also help you maintain a healthy weight, support digestion and gut health.

Aim to include some high-fibre foods in each of your main meals and snacks. This will help you to reach the recommended target of 30g in your diet each day. Higher- fibre food options include:

• whole-grain cereals, brown rice, oats, barley and quinoa
• legumes including lentils, chickpeas, baked beans and kidney beans
• fruits and vegetables (keep the skin on where possible)
• psyllium husk
• nuts and seeds.

Easy ways to eat more whole grains, legumes and high-fibre foods:

• start by choosing a fibre-rich or whole-grain cereal, whole oats or whole-grain toast option for breakfast. Aim for at least 3-5g of dietary fibre content per serve
• add a mix of seeds such as linseed, pumpkin or chia seeds into any breakfast bowls, salads or as a toast or snack topper
• choose whole-grain bread varieties (with seeds in the bread) over white or refined whole meal types. Enjoy a mix of grain-rich breads, rolls, wraps, bagels, pasta, crackers and rice. If you don’t like grainy cereal foods, try working them in slowly by mixing half and half. For example, try cooking half brown and half white rice
• mix in tinned lentils, kidney beans or chickpeas into meat or chicken meals such as bolognese, chilli con carne or curries. This is a cost-effective way to extend the protein rich foods in the meal and also reduce your intake of red meat     
• to add protein into your salads, mix in some drained canned lentils or other bean mixes. They go well with roasted vegetables, some goats cheese, spinach/rocket leaves and a splash of balsamic vinegar
• experiment with other grains such as quinoa, buckwheat, couscous, freekeh, barley or rye
• popcorn is another tasty whole-grain snack. You can either air-cook corn kernels in a covered pot in the microwave or with a dash of oil in a saucepan. Try it with fresh flavours such as chili powder and a squeeze of lime, cinnamon and a sprinkle of sugar, or grated parmesan cheese with oregano. 

Eat more plant-based foods

Plant-based foods include fruits, vegetables and whole grains. These foods protect against a host of cancers as they provide many important phyto-nutrients, which reduce inflammation in the body. There is a strong link between an increase in their consumption and reduced cancer risk.

Increasing your intake of non-starchy vegetables and fruit protects against various cancers. This includes breast cancer and cancers of the respiratory and digestive tracts such as throat, oesophagus and stomach cancers. 

If your aim is to prevent cancer and you are not experiencing any eating or digestive difficulties, fill your plate with ½ vegetables, ¼ grain foods and ¼ protein- rich foods. 

Protein- rich foods include lean meat, poultry, fish, other seafood, eggs, legumes, tofu, nuts, seeds and dairy foods or fortified dairy alternatives. 

 

Limit intake of low nutrient and energy dense, fast foods or highly processed foods

Highly processed foods are generally:

• low in essential nutrients
• high in energy or kilojoules
• high in unhealthy fats, such as trans and saturated fats
• high in refined starches or sugars.

Eating a lot of these foods is linked to obesity and higher risks of cancer. 

There is also evidence that the increase in blood sugar and insulin after eating an energy-dense or high glycaemic index meal is linked to some cancers. 

These foods are often high in energy (kilojoules), sugars, unhealthy fats and salt. They may also be highly processed, leaving them high in energy and low in nutritional value.

Reducing these foods can help you manage your energy intake and maintain a healthy weight. 

There is no need to avoid all foods high in fat. It is important to include foods rich in healthy fats, such as oily fish, avocado, nuts, seeds and extra virgin olive oil. 

Watch your salt intake

Eating too much salt from salty or processed foods increases the risk of stomach cancer. Because processed and fast foods tend to be high in salt, you should limit your intake of these. You should also limit the salt that you add to meals, during cooking and at the table. 

Try to reduce your salt intake by using herbs and spices in cooking to add flavour instead of salt. Choose products that are reduced salt and have less than 400mg sodium per 100g product. 

Avoid sugary drinks and alcohol

Swap sugary drinks for water or unsweetened drinks. Sugary drinks can cause weight gain and obesity, increasing the risk of many cancers. 

Try to reduce added sugar in coffee and tea. Limit your intake of fruit juices, soft drinks and other sweetened drinks to prevent excess calorie energy intake. 

When it comes to preventing cancer, it’s also best to avoid alcohol because it is a known risk factor in the development of many cancers. This applies to all types of alcohol, whether it is beer, wine or spirits.  

The key factor is the 'amount' of alcohol you drink. There is no ‘‘safe’‘ level of alcohol consumption. Any reduction is a positive move for your health. 

Tips to reduce your alcohol intake:

• reduce the number of days you drink by having some alcohol-free days
• try the no or low alcohol drink varieties
• substitute or alternate alcoholic drinks with a sugar-free flavoured soda or sparkling mineral water
• if you are concerned about how much alcohol you drink, or if you feel you may be alcohol dependent, talk to your GP or seek the help of a qualified counsellor.

 

Limit red and processed meats

Evidence suggests red meats and processed meats increase your risk of developing colorectal and some other cancers.

This doesn’t mean you have to give up red meat completely. It’s a good source of protein, iron, zinc and vitamin B12. 

Instead, eat smaller serves, aiming for no more than 350-450g of cooked lean red meat each week. You can also bulk-up meat-based meals by adding dairy, or plant-based sources of protein such as legumes, nuts or tofu.

 Enjoy these red meat alternatives: 

• shaved turkey breast
• shredded chicken breast
• falafel
• legumes such as lentils, chickpeas and kidney beans
• marinated tofu, tempeh or seitan
• grilled mushrooms
• fish, including tinned tuna or salmon
• cheese, such as haloumi or cottage cheese.

Also try to avoid or reduce your processed meat intake. Processed meats also contain chemicals called nitrates. Nitrates are added to keep processed meat fresher for longer. These chemicals can be converted into cancer causing agents. Processed meats include bacon, ham, salami and some sausages. These meats are also high in sodium and calories. They can contribute to heart disease, diabetes and obesity.

Choose whole foods over supplements

High-dose supplements are not recommended. They are far less effective in preventing cancer than a healthy, nutritious diet. It’s better to get the nutrients you need from whole food sources than to look to vitamins and supplements to fill nutrient deficiencies. If you are concerned about any specific nutritional deficiencies, discuss this with your doctor who may be able to request a blood test.

Promote breastfeeding

Breastfeeding is beneficial for both mother and baby. It can protect against breast cancer. It also lowers the mother’s risk of type 2 diabetes and obesity. 

For the baby, breastfeeding promotes healthy growth and immune system development. It also reduces the child’s risk of obesity later in life and therefore reduces the child's risk of cancer in the long term. 

Cancer prevention dietary strategies: a summary

 

 

This material has been reproduced from the World Cancer Research Fund/American Institute for Cancer Research. Diet, Nutrition, Physical Activity and Cancer: A Global Perspective. Continuous Update Project Expert Report 2018. Available at dietandcancerreport.org.

Learn more about how to reduce your cancer risk with your diet on the World Cancer Research Fund website.