The new findings -- almost five years from men, and just over four years from women --suggest that disparities in these risk factors help explain why some ethnic and socioeconomic groups have lower life expectancies.
“Our results demonstrate that a small number of risk factors for chronic disease account for a noticeable part of the disparities in life expectancy in the U.S., with the largest contributions from smoking and high blood pressure,” say the researchers, led by Majid Ezzati, PhD, an associate professor of International Health at the Harvard School of Public Health in Boston. The findings appear in the journal PLoS Medicine.
The 8 Americas
Researchers from Harvard and the Institute for Health Metrics and Evaluation at the University of Washington in Seattle classified individuals from several 2005 national data sources into eight subgroups based on their race, geographic locale, and socioeconomic characteristics. The “Eight Americas” consisted of:
2. Low-income whites in the Northern Plains and Dakotas
3. Middle America
4. Low-income whites from Appalachia and the Mississippi Valley
5. Western Native Americans
6. African-American middle America
7. Southern low-income rural African-Americans
8. High-risk urban African-Americans
In general,your location and your ethnicity affect your life expectancy and how healthy and fit you are. These findings held among all age groups -- the young, the middle-aged, and older adults.
Asians Healthiest, Live Longest
Overall, Asians were leaner, least likely to smoke, and had the lowest blood sugar levels. Asians also had the highest life expectancies.
In 2005, men lived to 75.1, on average, and women lived to 80.3. Asians had an average life expectancy of 82.3 for men and 86.8 for women. The study authors point out that this is one and two years longer than the highest life expectancies seen across the globe.
African-Americans from the rural South had the highest blood pressure levels in the new study. They also tended to be more overweight and have higher blood sugar levels. Rural African-American males had life expectances that were seven years lower than the national average, and their female counterparts' life expectancies were reduced by 5.4 years.
Controlling risk factors, however, can improve life expectancy significantly, the study authors point out. For example, if a man got his blood pressure under control, he would add 1.5 years to his life, while a woman could add 1.6 years to hers. Quitting smoking would add 2.5 years to a man’s life and 1.8 years to a woman’s life, the study showed.