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 / Updated  / Source: NBC News
By Maggie Fox

Americans may worry about pollution and chemicals, but a new study of the major causes of death confirms what most doctors know: we are our own worst enemies.

The leading causes of death have to do with bad habits, including smoking, poor diet and a lack of exercise, the report from the Institute for Health Metrics and Evaluation at the University of Washington finds.

“Many of the leading causes of death in the U.S. are preventable,” said Dr. Ali Mokdad, a professor of global health who helped lead the study.

“It is important to remember that we need to focus on preventing these risk factors such as smoking, obesity, poor diet.”

Smoking was the number one individual risk factor for dying in America in 2013. It was involved in 443,824 deaths. Smoking causes heart disease, strokes and many forms of cancer, as well as chronic obstructive pulmonary disease and a range of other ills.

Outside the U.S., the No. 1 risk factor for death in 2013 was high blood pressure, Mokdad’s team found. High blood pressure lay behind 10.4 million deaths, a 49 percent rise from 1990.

Smoking, poor diet and a lack of exercise can all raise blood pressure, which in turn damages arteries and organs such as the heart and kidneys.

The team of dozens of researchers from around the world studies 79 different risk factors, from handwashing to malnutrition, infectious diseases and eating habits.

Their findings are in part a good news story.

In 2000, the leading cause of death and disability was malnutrition. It’s now fourth. Unsafe water and sanitation fell from the top causes.

Excesses in richer countries now outweigh the effects of poverty in underdeveloped countries, they found.

The team put together a list of 14 dietary bad habits that can kill people and found they lay behind 21 percent of all deaths globally. They include consuming too much red meat and sugary drinks, and not eating enough fruits, vegetables and whole grains, the team reports in the Lancet medical journal.

The top 10 global causes of death are:

  1. High blood pressure
  2. Smoking
  3. High body mass index
  4. High fasting plasma glucose
  5. Diet high in sodium
  6. Diet low in fruits
  7. Ambient pollution
  8. Household air pollution from solid fuels
  9. High total cholesterol
  10. Alcohol use