If you were to sum up the overall health of a nation in one single number, what would that be? At the top of the list, you would likely find average life expectancy — the total number of years, on average, that a person in a country can expect to live. Wars, famine, and economic crises are expected to lower life expectancy. Breakthroughs in science, strong economies, and behaviors like eating a healthy diet, exercising, and avoiding tobacco typically raise average life expectancy.
An amazing rise, a surprising fall
Between 1959 and 2014, the United States experienced an unprecedented increase in life expectancy, which rose from 69.9 years to 78.9 years. The simple thought of adding almost 10 years, on average, to the lifespan of each individual in the country in that short amount of time is amazing and astounding, a true testament to our rapidly increasing understanding of health, medicine, and the environment.
Unfortunately, that’s where the good news ends. Between 2010 and 2014, life expectancy in the US plateaued. And then in 2014, something worse happened: life expectancy began decreasing. The US experienced three years in a row of declining life expectancy. As an article in the Washington Post observes, this is the first time the US has seen such prolonged declines since 1915 to 1918, when Americans experienced both World War I and a flu pandemic. The US is also the only developed country in the world whose average life expectancy stopped increasing after 2010. We now rank 35th in the world. The average American can expect to live 3.5 years less than the average Canadian. So now, in this decade, without large-scale war causalities or a severe pandemic, without economic crisis or famine, why is US life expectancy decreasing?
Diving into details on life expectancy
A recent report in JAMA provides a comprehensive, detailed look at this phenomenon. The authors focused attention on midlife, defined as adults ages 25 to 64. Midlife is the time when adults are typically the most productive, raising families and making up the majority of the workforce. Tragically, mortality rates in this age group are bringing down the national average. Key findings below help explain why.
(First, a quick note about percentages: A 100% increase in deaths from an illness means the death rate doubled since the last time it was measured. A 400% increase means deaths are five times as high as they were previously.)
Certain health problems are driving higher death rates. Since 1999, the US has seen drastic decreases in deaths due to heart disease, cancer, HIV, and motor vehicle injuries. But since 1999, drug overdose deaths in midlife increased almost 400%, while deaths from alcoholic liver disease and suicide increased by about 40% each. Likewise, deaths caused by illnesses related to high blood pressure increased by nearly 80%, while those from obesity-related illness rose 114%.
Gender matters. Overall,