The Institute of Cancer Research in Britain and the London School of Hygiene and Tropical Medicine conducted an overview of the major causes of cancer discovered during the past 50 years. As tobacco is such a major risk factor, the overview divided people into smokers and non-smokers to determine what causes the major types of the disease, and to answer if obesity causes cancer.
Tobacco is the leading single cause of cancer and accounts for more than half of all cancer deaths in smokers. In non-smokers, 10 per cent of cancer deaths in America and 7 per cent in Europe are linked to being overweight.
It is noted that about 60 per cent of all cancer deaths in smokers are caused by smoking and smoking causes as many deaths from other diseases as it does from cancer. It is estimated that up to three-quarters of cancers in smokers can be avoided if people quit. The sooner, the better.
Smoking is the leading cause of lung cancer and also contributes to stomach, liver, cervical, pancreatic, bladder and kidney cancers. The cause of cancer is not as clear in non-smokers although it is clear that being overweight heightened the risk. Scientists however aren't sure of the mechanism which causes excessive weight to increase the risk of the disease or if it can be reduced if people lose weight.
Cancer is more common in overweight people. Or as some medical journal headlines state, obesity causes cancer. The evidence on weight is strongest for post-menopausal breast cancer and cancer of the endometrium (lining of the womb), gall bladder and kidney.
There are other known factors associated with the development of cancer.
Helicobacter pylori, a bacteria linked to ulcers and stomach cancer, and the human papilloma virus found in most cervical cancers are among infections that contribute to about 15% of cancers.
Infections and a weakened immune system are other known risk factors for cancer, along with excessive alcohol consumption, sunlight exposure and pollution. Doctors also suspect childhood leukemia to be triggered by an infection. Scientists however have not discovered the cause.
Viruses are especially important in the developing world. Hepatitis B virus, which can be prevented by vaccination, causes almost as many cancers as smoking does in China.
Information provided is courtesy of and compiled by the Academy of Anti-aging Research staffs, editors, and other reports.
The interesting finding in this overview is the consensus that overweight is a contributing factor to cancer. Over-consumption of calories leads to increased metabolic activity in the body. This in turn leads to excessive free radical formation. Free radicals damage cells and causes genetic mutation, which ultimately can lead to cancer. Plainly put obesity causes cancer, for in some cases obesity was the major contributing factor.
From an anti-aging perspective, the target weight should be 5 to 10 per cent below the ideal body weight. Most Americans are 10-20% above their ideal body weight. Eating 30 per cent less is a good way to get started for most people. Following the modified Mediterranean Diet (50 per cent fruits and vegetables, 25 per cent protein, and 25 per cent fat) should be a life-long endeavor. Stay away from sugar and trans-fat (cookies and French fries) is the key. Don't forget to drink at least 12 glasses of pure filtered water a day.
It is important to note that obesity is also connected to the body’s stress response. While traditionally, the body’s stress response has been seen as a neuroendocrine event, the more comprehensive perspective of the neuroendometabolic stress response model reveals the involvement of many metabolic processes.
When sufficient stress is experienced by the body, the stress response pathways begin to become dysregulated, upsetting the normal function of the body and giving rise to various stress related symptoms. The involvement of metabolic processes explains why some of the stress related symptoms such salt and fat cravings, hypoglycemia, and increased allergies. Notably, metabolic regulation of energy can also become dysregulated, leading to increased stockpiling of fat causing obesity.
Returning to the importance of a proper diet, the intake of nutrition is important not only to provide the optimal amount of calories and to provide adequate nutrition to “grease the gears” of the body’s metabolic function; but it also lessens the amount of stress placed on the gastrointestinal tract and the metabolic energy. The combination of adequate nutrition to improve the body’s function as well as minimization of stress placed on the gastrointestinal tract is what makes it so important to have the proper diet.