During the last decade cancer has received a great amount of media attention, either in terms of prevention options, possible cures or potential causes that we should be aware of. It is the second most common cause of death after cardiovascular disease with more than 200 different types and 12.7 million new cases worldwide in 2008, and 156,090 deaths in 2009, in the UK alone; according to the UK cancer research.
But what exactly is this disease? How much do scientists know about it so far? Is there any truth in all the health claims about foods with anti-cancer properties? In this week’s article learn about the main characteristics of this disease and its connection with a healthy nutrition.
How does cancer occur?
Our cells are programmed to divide in a controlled and regulated way to reproduce or repair. However, in the case of cancer this function is permanently altered. Due to reasons not yet clearly understood, a formation of an abnormal cell mass (tumour) occurs which leads to a permanent damage to the cells’ DNA. The tumour, which keeps growing uncontrollably, infects and destroys its healthy surrounding tissues, and continues spreading to other parts of the body (metastasis). This procedure is called carcinogenesis and usually takes years to develop. The four main types of cancer that account for 50% of cases in the UK are breast (most common type in women), lung (most common type in men), prostate and colorectal cancer.
Although initially without symptoms (asymptomatic), as a tumour develops non-specific symptoms such as tiredness, fever, weight loss and night sweats usually appear. As the disease progresses patients experience loss of appetite, further weight loss and especially loss of muscle mass (wasting), anorexia, nutrient deficiencies, pain and mental stress. Their energy needs increase dramatically and the body is in a state of breakdown (catabolic state), unable to function. Their nutritional status is severely impaired with consequences on their immune function and life quality.
The only treatment for cancer is a combination of radiotherapy, chemotherapy and surgical removal of the tumour. Of course, early detection and intervention means higher chances of this treatment being successful. Apart from surgery, Medical Nutrition Therapy (MNT) is necessary in order to minimise weight loss and muscle wasting, correct nutrient deficiencies and prevent faster progression of the disease. Malnutrition is very common among cancer patients due to physiologic and psychological factors and the treatment therapy often adds to the pain and stress they experience.
What is the link with nutrition?
According to recent statistics 40% of cancers today can be prevented through nutrition and other lifestyle changes. For example, lung cancer is caused almost entirely by smoking and more than 1/3 of cancers are caused by an unhealthy diet.
There has been a great amount of research into nutrition and cancer risk and scientists argue that there are many modifiable risk factors to be aware of. For example, high-fat/calorie diets, high saturated fat consumption, high-calcium diets, coffee consumption, and obesity can increase the risk of colorectal, stomach and prostate cancer. Food preparation is also something to keep in mind as recent evidence suggests that cooking at high temperature (barbeques and grilling) can lead to cancer promoting substances (carcinogen) formation due to the smoke and the burned surfaces of the food. In addition, alcohol overconsumption has been linked to breast and colorectal cancer. Other substances that may increase cancer risk include nitrate, which is used in cured meat products, iodine deficiencies or excess, arsenic, cadmium, chromium, nickel, and agricultural residues like DDT.
So how exactly can our diet protect us? According to numerous studies a diet high in fruit and vegetable consumption along with regular physical exercise and maintaining a healthy weight are the key to prevent cancers. Specific nutrients such as vitamins are considered extremely beneficial for cancer protection due to their antioxidant properties. For example, vitamin C and carotenoids found mostly in fruit and vegetables are proven to protect against cell DNA damage. Furthermore, folate (vitamin B9) plays a very important role in DNA synthesis and repair, fibre rich diets can be beneficial for prevention of colorectal cancer, and phytochemicals, found mostly in vegetables and pulses, are thought to protect against breast cancer.
In conclusion, cancer has emerged as one of the most serious non communicable diseases of our time. However, there are numerous ways we can protect ourselves though our diet and lifestyle. Scientists urge us to make small changes in our everyday routine to lower our risk of serious health problems such as cancer. And of course, keep in mind that we need to take care of our bodies not only to lower the risk of disease but also to improve our quality of life.
By Kleio Bathrellou
Associate Nutritionist & Certified Sports Nutritionist