The Big Picture

What determines how long someone lives? Is there anything I can do to ensure a longer life span? Several factors — heredity, behavior, and the environment — can determine one's life span. There is no way to control what genes you inherit. Some life-shortening illnesses, such as hemophilia, sickle-cell disease, muscular dystrophy, and cystic fibrosis, are strictly genetic and generally rare. Other conditions, such as cancer, heart disease, and diabetes, have genetic components but can be modified through proper behavior. For example, if several of your relatives have diabetes, exercise, a healthy diet, and a healthy weight can reduce your chances of developing this condition.

Aside from genetics, many behaviors can shorten your life span. Smoking is one of the most dangerous. One in 10 smokers will develop lung cancer; a smoker has 24 times the risk of developing lung cancer than does a nonsmoker. But that's not all: Smoking also is associated with heart disease, chronic lung disease, and non-lung-related cancers. Failing to wear your seatbelt also can affect your life span. Studies have shown that more than 60 percent of the victims of motor vehicle fatalities were not wearing seatbelts.

Age-appropriate preventive health care and telling your doctor about any medical concerns also can affect your longevity. Early detection and medical intervention can be key to a good prognosis. For example, if breast or prostate cancer is caught early enough, the patient has a significantly better chance at survival. For women, monthly breast self-exams and regular mammograms can help. For men, physical exams and prostate specific antigen testing are useful.

Always be honest with your doctor — even if the truth is embarrassing. Your doctor needs accurate information to provide you with the best medical care. Don't be afraid to ask questions. Make sure you understand the doctor's instructions, and then follow them to the letter. This is especially important when taking any medication. If you're on multiple medications, it can be difficult to keep track of instructions and doses. Use weekly or monthly pillboxes, or develop another system to assure complete compliance.

Finally, your immediate environment can affect your longevity. Environmental factors include emotionally stressful situations, exposure to secondhand smoke, and chemical contaminants. Managing stress, avoiding smoking areas, and properly handling chemicals such as fertilizers and benzene-containing fuels can help eliminate these factors.