A research team did the first global study of the potential increase in life expectancy if 20 well-known risk factors could be eliminated or reduced to safer levels. These factors include overnourishment and undernourishment, unsafe sex, high blood pressure, elevated cholesterol, tobacco, alcohol and other drugs, polluted water, poor sanitation, and certain on-the-job risks. “We wanted to give a picture of what the whole world would look like without these major causes of death and disease,” notes Majid Ezzati, an assistant professor at the Harvard School of Public Health. “Approximately half of deaths and 40 percent of the total health loss worldwide resulted from the joint effects of these risk factors in the year 2000. It was surprising to find out how large the effects of eliminating them were. The increase in healthy life expectancy ranges from 4.4 years in Japan, Australia, and New Zealand to more than 16 years in Botswana, Congo, Kenya, and other parts of sub-Saharan Africa. Think of it, excluding these factors could result in an average gain of more than nine years of perfect health for every person in the world.”