Lifestyle Health and Cancer

• Non-communicable diseases are not infectious
• Non-communicable diseases cannot be transferred between one organism and another
• Causal mechanisms have been proven for some risk factors

  • Diet, smoking and exercise have a causal relationship with cardiovascular disease
  • Obesity has a causal relationship with Type 2 Diabetes
  • Alcohol affects liver and brain function
  • Smoking can increase the risk of lung disease and cancer
  • Smoking and alcohol can affect unborn babies
  • Carcinogens are risk factors for cancer
• Risk factors and causal mechanisms
• The human papillomavirus (HPV) is a common virus that infects the skin and cells lining the inside of the body, including the mouth, throat, and genitals
• HPV infection usually causes no symptoms (asymptomatic), for most people, HPV will be cleared from the body, and they will never know they had it
• HPV usually spreads through close skin-to-skin contact, usually during sexual activity, including vaginal, anal, or oral sex
• Cervical cancer is the main type of cancer linked to HPV, nearly all cases of cervical cancer are caused by HPV, the HPV vaccine helps to prevent cancer by protecting against HPV, all children aged 11-13 in the UK can get the HPV vaccine
• The pie charts show the persistence of HPV infection, after one year the percentage of infection is 30% compared to 10% after two years, the percentage of infection decreases with time
• The bar chart shows that cervical cancer has the highest incidence attributed to HPV in the US, 11500 cases out of 12000 cases of cervical cancer were caused by HPV, this was the biggest proportion
• The line graph shows the prevalence of HPV infection by age, 20-24 year olds have the highest percentage of infection
• Epidemiology


  The study of the distribution and patterns of health and disease, in and across populations, scientists study the incidence of disease, using medical records, and use medical research to investigate causes of disease, when investigating health and disease, and risk factors are involved, scientists can't study every person on the planet, scientists must study samples, samples must be representative - they must reflect the population under study
• Health is the state of physical and mental well-being, diseases, both communicable and non-communicable, are major causes of ill health, other factors including diet, stress and life situations may have a profound effect on both physical and mental health
• Different types of disease may interact, defects in the immune system mean that an individual is more likely to suffer from infectious diseases, viruses living in cells can be the trigger for cancers, immune reactions initially caused by a pathogen can trigger allergies such as skin rashes and asthma, severe physical ill health can lead to depression and other mental illness
• Cancer


  Cells grow then divide by mitosis only when we need new ones – when we're growing or need to replace old or damaged cells, when a cell becomes cancerous, it begins to grow and divide uncontrollably, new cells are produced – even if the body does not need them, a group of cancerous cells produces a growth called a tumour, cancer cells are undifferentiated – they do not carry out their normal function
• Benign tumours


  Growths of abnormal cells which are contained in one area, usually within a membrane, they do not invade other parts of the body
• Malignant tumours


  Cancer cells, they invade neighbouring tissues and spread to different parts of the body in the blood where they form secondary tumours
• Scientists have identified lifestyle risk factors for various types of cancer, there are also genetic risk factors for some cancers
• Risk factors of cancer

  • Viruses linked with cancer, such as the human papilloma virus (HPV), being spread from person to person through sexual intercourse
  • The chemical carcinogens in cigarette smoke increasing the risk of lung cancer
  • Alcohol intake is linked with certain cancers
  • Exposure to ultraviolet radiation during sunbathing or outdoor activities can lead to the development of skin cancers
  • Diet, including fat and salt intake, increases the risk of cancer
• Carcinogens


  Chemicals and other agents that can cause cancer, they cause cancer by damaging DNA, carcinogens cause mutations to occur, a single mutation will not cause cancer – several are required, for this reason, we are more likely to develop cancer as we get older
• Health is the state of physical and mental well-being
• A causal mechanism has been proven for some risk factors, but not in others
• Benign tumours are growths of abnormal cells, malignant tumour cells are cancers