Is nature's most helpful diet whole-food plant-based? Bpositive speaks to Dr. Shireen Kassam, a consultant haematologist from London's King's College hospital, who offers her personal view on one particular type of nutritional dietary approach.
As a Consultant Haematologist at King’s College Hospital, London, specialising in the care of patients with lymphoma and haematological cancers, including leukaemia, I have spent the last three years educating myself in the field of nutrition. It’s been a personal journey, arising from an ethical choice to live a vegan lifestyle, as well as a practical one; discovering the nutritional benefits of a whole-food plant-based diet.
What many patients find surprising and difficult to accept is that, once treatment is completed, or at least the most intensive part, haematologists give very little advice on how to maintain good physical and mental health. In other countries, patients with cancer are provided with information on how to maintain a healthy lifestyle, an ‘after cancer care’ programme if you like. They focus on maintaining physical health through diet and exercise and mental wellbeing with techniques such as mindfulness, yoga and meditation. In the UK, it is sadly something that can be lacking. If you are going through treatment, or you are on the road to recovery, here are some tips on how to take back some healthy control.
What is a healthful diet?
One of the most common questions I get asked by patients diagnosed with cancer is ‘what should I eat? It will perhaps surprise you to know that most doctors have very little knowledge of nutrition. Most medical schools provide minimal if any education in nutrition science. The focus of undergraduate and postgraduate medical education is the treatment of disease, not the maintenance of good health. For most of us, what we consider a healthful diet is influenced by our cultural background, our upbringing and our exposure to mainstream media. So, depending which doctor or haematologist you ask, you will likely get a different answer. If a patient asks me, I tell them that a whole-food plant-based diet is the most healthful. This statement is backed up by numerous scientific studies.
"Once treatment is completed, or at least the most intensive part, haematologists give very little advice on how to maintain good physical and mental health" Dr. Shireen Kassam
For those of you that have completed treatment with chemotherapy and/or radiotherapy, you may be aware that heart disease has been cited as one of the medium to long term side effects of these treatments. It is not the subcutaneous (under the skin) fat that is directly related to disease, but the visceral (organ) fat in places such as the liver and heart, that increases our risk. Those affected are sometimes called ‘thin on the outside, fat on the inside’. This abnormal deposition of fat in the organs is directly related to our diet. Most of us know that our chances of getting various diseases can be reduced by diet choice, but it’s also been proven that diseases can be reversed through changes in diet too. Therefore it is never too late to have a positive impact on your health.
What do we know about the impact of nutrition on health?
Scientific literature can at times be confusing, partly because many nutritional studies have been conducted by those that have a vested interest in the results. When interpreting scientific data in the field of nutrition you need to make be aware of who is funding or sponsoring the study before taking on board the findings. The largest epidemiological study (study of causes and effects of disease in populations) to investigate the impact of diet on health and disease was the China-Cornell-Oxford project, otherwise known as the China study. It was a collaboration between the Chinese Academy of Preventative Medicine, Cornell University in New York, and Oxford University, and took place in 65 counties in China. It was able to show that a diet high in animal foods (meat, dairy and eggs) was associated with a higher incidence and risk of death from diseases such as heart disease, diabetes and certain cancers. In contrast, a diet high in whole plant foods was associated with a reduced incidence and risk of death from the same diseases.
Aren’t some diseases genetic?
Of course there is some influence of your genes. However, the impact of your genes on disease is at most around 10-20%.
What about haematological cancers?
Although blood cancers are not specifically related to lifestyle, studies have shown the incidence of blood cancers is lower in populations that consume a predominantly plant-based diet.
Why are animal foods so bad for our health?
There are a multitude of reasons. Take dairy products made from cow’s milk as an example. In nature, cow’s milk is a growth fluid for baby cows, enabling them to grow from a 65Ib calf to a 700lb cow as fast as possible. Therefore, this milk contains growth hormones, including bovine growth hormone and something called insulin-like growth factor. In addition, the dairy industry keeps cows pregnant at the same time as milking them and so cow’s milk will also be high in female hormones such as oestrogen. In humans, exposure to these bovine hormones can result in abnormal growth of cells and increase the risk of cancer, especially those cancers that are hormone driven like prostate and breast cancer. These cancers have the highest incidence in populations that consume the most dairy. Alarmingly, bovine leukaemia virus, a cancer-causing virus in cattle, has been found in a large proportion of human breast cancers.
With regards to meat, one reason for its adverse effect on health is that when muscle tissue is heated to high temperatures it forms a group of carcinogens known as heterocyclic amines that have been implicated in cancer development. In addition, meat is said to be devoid of dietary fibre and have little in the way of vitamins or minerals, except iron. The World Health Organisation has classified processed meat as a class 1 (definite) carcinogen (causes cancer) and red meat as a possible carcinogen. Why these foods don’t come with a health warning is somewhat surprising. All animal foods are high in saturated fat and cholesterol, with animal foods being the only source of dietary cholesterol, whereas plant foods do not contain cholesterol
"Although blood cancers are not specifically related to lifestyle, studies have shown the incidence of blood cancers is lower in populations that consume a predominantly plant-based diet."
Dr. Shireen Kassam
What is a whole-food plant-based?
It’s a diet that is made up of vegetables, fruits, whole grains, nuts, seeds, and beans and lentils. It should also be low in fat and salt. Such a diet will be made up of around 80% carbohydrates, 10% fat and 10% protein, a combination that is perfect for optimal health. It is a diet that is naturally high in dietary fibre and micronutrients, including vitamins and minerals. By definition it is a diet that excludes animal foods, and avoids processed foods so will be low in processed and added sugars, as well as saturated fats. On a WFPB diet you will be able to maintain a healthy body weight without counting calories. Spices and herbs should be liberally included in cooking as they have natural healthful properties including anticancer, anti-inflammatory and antibacterial.
At the very least, I hope this article has stimulated your interest in finding out what a healthful diet is and how your diet can impact positively on your health. If this is the first time you are reading about a WFPB diet then you will have many questions. I refer you to some excellent sources of information. These sources act as references for all the statements I have made in this article. Happy eating! "
By Dr. Shireen Kassam
Consultant Haematologist, King's College hospital, London
*All views expressed in this article are from Dr. Shireen Kassam, Consultant Haematologist at King's College Hospital, London*