Cancer is the second most important cause of morbidity and mortality worldwide. It is estimated by numerous epidemiological studies and statistical surveys of data from most countries that between 40-50% of all cancer cases are preventable by changing into a healthier lifestyle, with special emphasis on smoking cessation, healthier diet, reduced obesity/overweight, decreased alcohol consumption and avoid sedentary life with daily exercise. Prevention offers the most cost-effective long-term strategy for the control of cancer and  national policies should aiming to raise awareness, to reduce exposure to cancer risk factors and adopt healthy lifestyle. This review collected and analysed data from various studies on the quantitative reduction of risk for certain cancers associated with five modifiable lifestyle factors:

  1. Cessation of smoking is an alternative to an unhealthy lifestyle habit. Quitting smoking showed spectacular reduction in lung cancer mortality and other types of human malignancies. Quitting smoking for more than 10 years decreased half of the risk for lung cancer, while more than 20 years of smoking cessation decreased drastically adult morbidity and mortality from cancer and other diseases. B. Reducing alcohol consumption is another lifestyle factor that decreases cancer risk. In particular 6 alcohol-related cancers: colorectal, post-menopausal breast, oral cavity and pharynx, liver, larynx and oesophageal squamous cell carcinoma. Heavy drinkers can have as much as a 10-15 times higher risk of developing these cancers than those who do not drink. Light alcohol consumption can be slightly beneficial to health.  C. Reduction of overweight/obesity can be beneficial to health and decreases the risk of related cancers. Obese people have even higher risk for certain cancers compared to normal-weight people. Overweight/obesity is associated with increased risk for colorectal, breast (in postmenopausal women), endometrium, oesophagus, kidney, liver, multiple myeloma, gastric cardia, ovarian and thyroid. D. Following daily physical exercise and an active life can be beneficial to health and reduce the risk for a number of cancers. E. Healthy eating is another important factor in the fight against cancer. Increased consumption of fruit and vegetables, whole grains, fat-free dairy products, lean meats, poultry, fish, beans, nuts, seeds, legumes and olive oil is beneficial to health, Avoiding processed meats, saturated and trans fats, sodium, salty and smoked foods, and added sugars control cancer risk. This review contains some very important reviews and epidemiological studies from the international scientific literature.