Cancer fighting foods
- After a cancer diagnosis, overall diet quality and choosing particular foods can be very helpful for supporting health and resilience. These choices can also contribute to other aspects of your health and wellbeing.
- Better quality diet is associated with longer survival in people affected by cancer according to studies.
- Plant foods are healthful choices, providing an array of vitamins and minerals, and particularly phytonutrients, botanical compounds in certain foods are especially valuable.
- Particularly beneficial foods include green cruciferous (brassica) vegetables, red and orange vegetables such as tomatoes and sweet potatoes, and dark berries such as blueberries. Compounds in these foods help several functions in the immune system and in cell regulation.
- Garlic and mushrooms both support immunity.
- Flaxseeds provide fiber that supports the elimination of cancer causing compounds, and natural compounds that can help support healthy hormonal balance.
After a cancer diagnosis, people often have questions about diet. You may wonder if there are foods that you should avoid, or particular foods that may help. We are all individuals, what’s best for one person may not be right for someone else.
Unfortunately there is still uncertainty in many areas of diet and nutrition, and the advice can be contradictory even amongst the ‘experts’. Studies on diet and cancer prevention have provided some persuasive evidence on some of the best ways to avoid cancer, but very few studies have examined how diet may affect people after they have developed cancer. There are many reasons why it’s difficult for research to prove how diet may affect people after a cancer diagnosis. Unlike studies of drug treatments which can be carefully controlled, diets are complex. Individual foods can vary between different varieties and even when cooked in different ways. Against this background of uncertainty, some cancer specialists feel unable to give definitive advice on nutrition for people with cancer, and may even dismiss diet as a factor worth considering. However, balanced against this apparent confusion and uncertainty, is the simple fact that we all need to eat. Importantly, some very recent results from a study with people after a cancer diagnosis showed that a better quality diet was linked to longer survival1. In the US National Health and Nutrition Examination Survey, a high intake of vegetables and fruits was strongly linked to longer survival in people who had been diagnosed with cancer1.
Your food choices can also impact on other disease risks, like heart disease, and can help with energy levels and mood. So this article, and other Curve resources, are intended to inform you about nutritional choices that may be helpful, even if there is no cast-iron proof.
The strongest evidence we have is that collected by the World Cancer Research Fund (WCRF), which along with the American Cancer Society (ACS) advises that people with a diagnosis of cancer should follow the advice for cancer prevention. One of the reasons for this is that prevention guidelines identify dietary elements, such as processed meats, that may trigger cancer growth. Once cancer has developed, it is sensible to take away known triggers, and to increase known protective factors in the diet. So leading world cancer bodies acknowledge that food probably plays a role in treatment and preventing recurrence, at least for many people. Let’s take a look at the different ways that nutrition may have an influence on cancer growth.
How foods may impact on cancer
There are known elements in diet that are linked to more cancer growth. The strongest evidence is on processed red meat, especially smoked, cured and charred meats. They contain cancer causing compounds (carcinogens) that cause damage to the DNA in cells that are exposed to them, firstly in the digestive system. However, breast cancer is also more likely with a high intake of processed meats, as the carcinogens travel through the body. Other known carcinogens include acrylamides from burned starchy foods and also fungal toxins from mouldy foods. So reducing intakes of these may reduce the overall carcinogen burden in your body.
So we can avoid foods that may trigger cancer growth, but what about foods that can even help reduce cancer growth? Despite what you may see in the papers or on some websites, there is, unfortunately, no single ‘superfood’ that can turnaround a cancer diagnosis. There are many foods that may help people affected, in various ways, and research suggests that it’s the overall pattern of food that provides the most benefit to fight cancer. This may be because foods may work together to have a beneficial effect, but also the principle of ‘diet displacement’ may also help. For example, people who eat more vegetables are probably reducing their intake of other less helpful foods, because the fiber in the vegetables fills you up for longer. So less healthy foods are being displaced by more beneficial ones. There are also some particular beneficial effects of some foods that can be helpful for people after a cancer diagnosis.
Let’s take a look at some of these. Firstly there are foods that contain nutrients that help to protect your DNA against damage, this is important as a cancer prevention strategy and also when living with and beyond cancer. Damage to DNA happens all of the time, even in the healthiest body, but cells have tools to repair this damage. Cancers progress when the amount of damage outweighs the repair mechanisms. Providing nutrients that help protect DNA can help support your cell defences. There are also foods that help the body to eliminate cancer-causing compounds, for example by supporting the liver to process and excrete carcinogens. As an example, onions provide sulphur that helps the liver to carry out this important role. Also studies suggest that a high fiber diet is linked to less bowel cancer in part because the fiber helps speed up the removal of carcinogens from the intestines, so the cells are exposed to them for less time.
There are also many foods that help to fight cancer by providing your immune system with nutrients that support effective defences against abnormal cells and against infection. As well as boosting your immune system during and after cancer treatment, some food choices can help reduce inflammation in the body and aid healing. Some nutrients may also slow down the ability of tumours to make new blood vessels. None of these food properties are a substitute for proper cancer treatment, but adding some beneficial foods into your daily routine can help support your defences and resilience.
Most cancer-fighting foods are plant foods. This is partly due to known vitamins, like vitamin C in fruits, but also plants contain a wide variety of compounds termed phytonutrients. These are often part of the plant defense system. For example, bitter compounds in arugula leaves and rosemary herb may have evolved to deter plant-nibbling insects! Some of the most potent phytonutrients are the bright colored pigments such as purple resveratrol in grapes. So they may have been selected by humans for their visual appeal, but at the same time they have unique nutritional benefits. The mechanisms of these phytonutrients are still not fully understood, but a good rule of thumb is to aim for the brightest array of plant foods on your plate, to maximise your intake and make the best use of nature’s powerhouse of phytonutrients.
Eating well can help your body at all stages of the cancer journey from diagnosis, through treatment and recovery, and for people living with and beyond cancer. At Curve we consider food to be a key element in your armoury against cancer following diagnosis, whatever your stage. We say this not to replace treatment, but to support you to get the most out of your treatment and to boost your resilience. There’s no single study proving it will help, and there’s no single food that’s a miracle, but there is enough evidence to suggest that some food choices can be of real benefit. This is not just in how patients feel, but also maximising your health while living with disease, preventing recurrence, or living well in a palliative situation.
Let’s take a look in more detail at some of the best foods to include regularly in your diet that can help you fight cancer. This is not an exhaustive list, but rather a highlight of some of the best cancer fighting foods. Our Introductory Course to Cancer Self Help also contains more information on nutrition and cancer.
Broccoli and the brassica (cruciferous) family of vegetables
The humble cabbage is a veritable power-house of cancer-fighting compounds. Foods like broccoli, cabbage, watercress and arugula (rocket) contain compounds that help your body to remove cancer-containing compounds produced in cigarette smoke and in burned meat. Glucosinolates are a group of compounds that directly or indirectly help in the fight against cancer1. Sulphoraphane is perhaps the most potent compound in this group of cancer-fighting diet treasures. It appears to help counteract abnormalities in the pattern of markers that control how DNA behaves. This effect at the ‘epigenetic’ level may help to prevent abnormal cell division that is the hallmark of cancer2.
The brassica group of foods also helps with the healthy metabolism of estrogen, as it supports the conversion of highly active forms of estrogen to less active estrogen metabolites3. To obtain the most benefit from these foods, don’t overcook, in fact eat some raw in salads, or just lightly steam cabbage and broccoli, or gently stir-fry. As well as these uniquely powerful cancer-fighting phytonutrients, these green veggies in your diet also contain folate and vitamin C, which also help with healthy cell turnover and immunity.
Versatile, tasty and colorful, tomatoes are more than just a visual treat to include in your cancer-fighting meals. Tomatoes contain a powerful phytonutrient, lycopene, that helps to support normal cell activity. As a carotenoid, it acts as an antioxidant, which helps to fight cellular damage and protect DNA. Studies have also suggested that specifically lycopene may help reduce proliferation of prostate cells4. This can be particularly helpful for men at risk of, or living with, prostate cancer. Like all carotenoids, it’s a fat-soluble phytonutrient, so it is absorbed better when mixed with a healthy fat, and cooked tomatoes have more availably lycopene than raw, so cooking with olive oil would be a great combination to boost your intake.
Also rich in carotenoids, orange sweet potatoes are nutritionally powerful, providing antioxidants that help protect DNA against damage, and the purple sweet potato has additional benefits5 that are linked to a compound in the skin and just below6. So a great way to use these bright foods that fight cancer is to bake them, split and drizzle with olive oil, which helps with the absorption of the fat-soluble carotenoids.
Blueberries and other dark red and purple berries pack a powerful punch of cancer-fighting nutrients, acting in several ways. These purple powerhouses contain anthocyanin, a potent antioxidant that is also anti-inflammatory. Studies suggest it can suppress cancer cell proliferation and may reduce DNA damage7,8. Blueberries, along with red grapes, also contain resveratrol, which has been studied in the lab with prostate cancer cells which are subjected to radiation, to mimic radiation therapy. These early studies suggest the resveratrol may make the cancer cells more susceptible to the cancer killing effects if the radiation treatment9. These early lab studies don’t prove the same action would work in a human having radiation therapy for cancer, but there are other good reasons for including blueberries in a cancer-fighting diet. They add a colorful touch to breakfast oatmeal, or yoghurt.
Exotic mushrooms such as Shiitake and Oyster varieties and the humble white button mushroom all provide useful nutrients in a diet to help fight cancer. As well as providing protein, fiber and several vitamins, all mushrooms contain beta-glucans and lectins, compounds that help stimulate a healthy immune response10. Some exotic varieties have specific nutrients that may offer further immune enhancements, so try Shiitake mushrooms in a stir-fry with colorful veggies. It’s best to buy your mushrooms from a reputable store, as mis-identification or contamination are risks for these high value cancer-fighting foods. In some cuisines around the world, especially in the east, mushrooms are traditionally used to help protect against cancer. A medicine made from one particular mushroom, the turkey tail or Coriolus mushroom, is used to help the immune system recover after chemotherapy in Japan11.
These small seeds are a great addition to your cancer-fighting diet. Firstly as a source of plant protein and several vitamins and minerals such as selenium, they are easy to add to breakfasts and yoghurt. Flaxseeds and the oil produced from them provide omega-3 fats that help to reduce inflammation. Try baking flaxseeds in healthful breakfast muffins, the fiber content helps to support healthy intestinal transit and helps support the growth of beneficial bacteria in the intestine. Lignans in flaxseeds are, a group of phytonutrients that have a structure that has some similarities to estrogen and testosterone. Lignans and other ‘phytoestrogens’ may compete with these hormones in the body and reduce their impact. Studies suggest including flaxseed and other dietary phytoestrogens such as soy foods, may be particularly beneficial for women diagnosed with breast cancers12.
A flavourful addition to many foods, garlic has a number of natural compounds to boost your health and help you fight cancer 13,14. Lab studies point to the sulphur-containing compounds that are found in all Allium vegetables like onion, scallion and leek. These compounds such as allicin may help with DNA repair and helping the body to break down cancer-causing compounds. They may also be able to turn on cancer-suppressor genes. The fiber content helps to support healthful balance of microbes in the intestine, which are now recognised as important for immunity.
Spices and herbs
There are many hidden treasures in spices and herbs. Turmeric and ginger can help reduce inflammation and help digestive function. More detail can be found in the ‘Spice up your life’ feature.
After a cancer diagnosis, overall diet quality and choosing particular foods can be very helpful for supporting health and resilience. Research suggests that better quality diet is associated with longer survival in people affected by cancer. Plant foods are healthful choices, they provide an array of vitamins and minerals, but they also provide phytonutrients. These botanical compounds in certain foods are especially valuable. These include green cruciferous (brassica) vegetables, red and orange vegetables such as tomatoes and sweet potatoes, and dark berries such as blueberries. The colored pigments in these foods help several functions in the immune system and in cell regulation. Garlic and mushrooms (which are delicious together!) both support immunity. Flaxseeds provide fiber that supports the elimination of cancer causing compounds, and natural compounds that can help support healthy hormonal balance. Making these choices can also contribute to other aspects of your health and wellbeing.