By Liz Butler BSc (Hons) MSc Nutr Med Dip ION
Senior Nutritional Therapist, Penny Brohn Cancer Care
In mainstream medicine it is now well established that dietary intervention can play an important role in the management of conditions such as obesity, type II diabetes, heart disease and osteoporosis. Unfortunately the idea that dietary support may have a part to play in the management of cancer is still not very well accepted. While, thankfully, it seems less common for a cancer patient enquiring about the importance of diet to be told “diet makes no difference”, still too many are being sent away with the advice to “eat a balanced diet” but without any further information or guidance. That might be ok if people understand what a balanced diet consists of but most people don’t, medical professionals included.
Recently, two documents have been published which, hopefully, will begin to change the perception medical professionals have of the role of diet in the cancer recovery process.
The first of these is the NHS Cancer Reform Strategy1 published by the government following the biggest review of UK cancer services since the Cancer Plan in 2000. This five-year cancer plan emphasises the need for more effective prevention of the disease plus earlier diagnosis and treatment. In addition it makes recommendations for improving the experience of those living with cancer, one of these being that cancer survivors are given nutritional advice.
According to Mike Richards, National Cancer Director, this latter recommendation was included in view of the findings of the second document to be highlighted here: the 2007 report published by the World Cancer Research Fund (WCRF) and American Institute of Cancer Research (AICR), ‘Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective’2. This is the eagerly awaited second report by the WCRF and AICR following their original report published in 1997. It is the largest ever review of the research on diet and cancer with a rigorous methodology based on a series of systematic literature reviews for each cancer type.
Unlike the original WCRF/AICR report, the most recent document includes a systematic literature review on diet and cancer survivorship. Unfortunately the evidence is too limited at this time to draw firm conclusions on the best diet for those with cancer. Despite this the report makes the suggestion that people with cancer follow the report’s dietary guidelines for cancer prevention and this recommendation is based on the general knowledge, backed by research, that a balanced diet is beneficial to health rather than evidence specific to cancer survivors.
With two high profile documents suggesting that nutrition is an issue of importance for those with cancer, more health professionals may be persuaded to discuss this subject with their cancer patients. The difficulty they may face however would be to know what advice to offer due to their limited nutritional training. A solution for doctors and nurses wishing to impart dietary advice would be to refer to information produced by organisations with expertise in this area. No organisation would be better placed to meet such needs than Penny Brohn Cancer Care.
Nutritional support at Penny Brohn Cancer Care
Penny Brohn Cancer Care is widely regarded as the leading UK holistic cancer charity and since its inception, almost 28 years ago, has gained a large amount of experience in supporting those with cancer. During that time the organisation has built a worldwide reputation for its ‘Bristol Approach’ - a unique combination of physical, emotional and spiritual support using complementary therapies and self-help techniques designed to enhance the health of people with cancer and those close to them.
Nutrition has always played a prominent role in the therapeutic approach at Penny Brohn Cancer Care. One of the key aims of the organisation is to stay up-to-date with the research that relates to all areas of complementary health and cancer, including nutrition, and the work of the dedicated research and information team mean that this is possible. Whilst keeping abreast of the latest scientific findings is incredibly important the limitations of many studies in measuring the impact of nutrition on health is recognised and acknowledged. For this reason the nutrition work of Penny Brohn Cancer Care is also informed by the practical experience of staff and experts in the field.
Many people visiting Penny Brohn Cancer Care will come once or twice rather than on a regular basis and therefore for these people the nutritional information they receive is relatively general and more educational rather than prescriptive in its intent. The nutritional therapists role in these cases is to set that person on a path of healthy eating giving them a comprehensive set of guidelines that are to some extent tailored to their needs but with the recommendation that they seek out a local nutritional therapist if they would like in depth nutritional support. For those people who are close enough to Bristol to visit regularly in-depth nutritional support is available through the Cancerpoint service.
In the early days of the Charity the nutritional advice offered to those with cancer was more restrictive than it is today and was along similar lines to the diet developed by Max Gerson. The nutritional programme is still very much based on the principles of naturopathy; however research and experience have told us that a more gentle dietary approach can be just as effective in supporting people and is much more acceptable to most. Above all the nutritional advice and practical information given by the organisation, as well as the experience of the food in the Charity’s award-winning restaurant, serves to motivate and inspire people. The emphasis is on introducing new and exciting foods and ensuring people realise that pleasure and enjoyment of food is still very much on the menu.
The Bristol Approach to nutrition
A person who develops cancer needs to gather their nutritional resources as much as possible in an effort to normalise the biochemical disorder that progresses as part of the disease. Equally important is the elimination from the diet of elements that may further promote biochemical imbalance. In simple terms this means encouraging the use of foods in their most natural, unadulterated state.
The Bristol Approach to nutrition focuses on a plant-based diet with small amounts of good quality animal products. A range of evidence strongly supports the idea that a diet composed mainly of vegetables, fruit, wholegrains, pulses, nuts and seeds protect against cancer. The benefits of these foods come from a range of nutrients including vitamins, minerals, fibre and a whole host of powerful phytonutrients, many with direct anti-tumour activity.
While small to moderate amounts of animal products appear to be beneficial for most people, the WCRF/AICR report found that a high intake of red meat, and in particular processed meat, can increase the risk of certain cancers. At Penny Brohn Cancer Care it is recognised that some people with cancer may require a greater intake of animal products, however the general advice is to keep levels relatively low at around 4 small portions per week. We would suggest that people stick mainly to white meat, fish and eggs and consume smaller amounts of red meat and dairy products.
With regard to the dairy issue, there is evidence that milk and milk products increase the risk of certain cancers such as prostate. The factors within milk that may be responsible for their negative effect include saturated fats, calcium (which in excessive amounts can inhibit the formation of active vitamin D, a cancer protective nutrient), hormones such as oestrogen, and growth factors such as insulin-like growth factor-I (IGF-I). As of yet no studies have been conducted to assess whether the presence of dairy in the diet has any influence on cancer progression or recovery from the disease and until such research is available it is not possible to say that dairy products should be avoided by all people with cancer. However, given the fact that many people experience digestive problems when consuming dairy, particularly following chemotherapy, our general advice is to keep dietary intake of milk products to a minimum.
For those people removing dairy products from the diet the most obvious replacement food is soya in its various forms. The use of soya in cancer is an area where the scientific research conflicts to a degree with some papers suggesting the soya isoflavones inhibit various cancer processes and others suggesting they promote them. However, the negative studies tend to be based on laboratory research whereas generally speaking the dietary studies indicate that soya foods are protective against cancer. At Penny Brohn Cancer Care we avoid recommending large amounts of any one food and instead emphasise balance and variety in the diet. In relation to soya we suggest people include a moderate amount as part of a balanced diet focusing on the traditional soya foods such as tofu, miso and tempeh, rather than the heavily processed variety.
A key Penny Brohn Cancer Care dietary recommendation is the removal of sugars and refined carbohydrates from the diet. The biochemical changes that occur within a cancer cell allowing it to create energy without oxygen (anaerobic respiration) more readily mean that in order to produce the energy it requires for survival more glucose is required than for a normal cell. The cancer cell’s greater need for this simple sugar has led to speculation that a high sugar diet may encourage cancer cell growth and there is some evidence to support this idea. For this reason it seems wise to limit sugars and refined carbohydrates.
High insulin levels (hyperinsulinaemia) are closely associated with high blood glucose levels. Insulin is a tissue building (anabolic) hormone and is known to encourage cell proliferation and inhibit apoptosis directly and through its potent stimulation of growth hormones such as IGF-1, discussed earlier. Insulin also encourages the production of pro-inflammatory compounds (eicosanoids) by influencing fatty acid metabolism.
This leads to one of the most fundamental facts on which the Penny Brohn Cancer Care dietary recommendations are based - that cancer is a disease characterized by chronic, low-level inflammation, a sign of immune disorder. The association between inflammation and cancer is not a new concept, as it was in 1863 that Rudolf Virchow discovered leucocytes in neoplastic tissues and first made the connection. However it is only recently that scientific interest has really grown in this area. One of the results of this deeper understanding of the link between inflammation and cancer is the trial of anti-inflammatory agents such as fish oils as part of the treatment process.
Fish oils are one of the supplements often recommended at Penny Brohn Cancer Care, along with a multivitamin and mineral, a multiantioxidant and vitamin C. Other supplements may be included for those requiring extra support such as probiotics for those with digestive problems.
To summarise, the Bristol Approach aims to rebalance the body’s biochemistry and regulate the inflammatory response. The diet is plant-based containing 8 to 10 portions of fresh vegetables and fruit per day plus plenty of wholegrains and pulses. It contains small amounts of animal products but limited red meat and dairy products. The avoidance of sugars and refined carbohydrates is strongly encouraged along with processed and refined foods, excess salt and caffeine and alcohol. Plenty of pure water along with herbal teas and fresh vegetable juices are recommended. Good quality nutritional supplements are advised to compliment the diet.
Even though the WCRF/AICR found the research on diet and survivorship too limited to draw conclusions at this time, the studies already published have generally produced positive results. As the evidence grows it is likely that a stronger picture of the benefits of nutritional support will emerge. In the mean time, the WCRF/AICR has chosen to recommend a healthy diet for those with cancer. This is a great step forward and it is hoped that medical professionals will be motivated to act on this recommendation. Whether it is medical professionals or cancer survivors themselves, the nutritional guidelines produced by Penny Brohn Cancer Care, based on research and experience, are the perfect resource for encouraging sensible dietary changes and promoting wellbeing for those living cancer.
1. Department of Health. Cancer Reform Strategy, 2007.
2. World Cancer Research Fund and American Institute for Cancer Research. Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective. 2007.