The researchers analyzed 247 surveys of adult sodium intake, stratified by age, gender, region and country between 1990 and 2010 as part of the 2010 Global Burden of Diseases Study, an international collaborative study by 488 scientists from 303 institutions in 50 countries around the world.

Next, they determined how the amount of sodium people were consuming was affecting their risk of cardiovascular disease, by performing a meta-analysis of 107 randomized, prospective trials that measured how sodium affects blood pressure, and a meta-analysis of how these differences in blood pressure relate to the risk of developing cardiovascular disease compared with consuming no more than 1,000 mg per day of sodium, which the researchers defined as an optimal amount of sodium for adults. Cardiovascular disease includes all diseases of the heart and blood vessels, including stroke.

Nearly 1 million of these deaths -- 40 percent of the total -- were premature, occurring in people 69 years of age and younger. Sixty percent of the deaths occurred in men and 40 percent were in women. Heart attacks caused 42 percent of the deaths and strokes 41 percent. The remainder resulted from other types of cardiovascular disease. Eighty-four percent of these deaths due to eating too much sodium were in low and middle-income countries, rather than high-income countries.

"National and global public health measures, such as comprehensive sodium reduction programs, could potentially save millions of lives," said Dariush Mozaffarian, M.D., Dr.P.H., lead author of the study and co-director of the Program in Cardiovascular Epidemiology and associate professor of medicine and epidemiology at Brigham and Women's Hospital, Harvard Medical School and the Harvard School of Public Health.

Among the 30 largest countries in the world, those with the highest death rates (per million adults) due to over consuming sodium were:

• Ukraine -- 2,109
• Russia -- 1,803
• Egypt -- 836

Among all countries, the three countries with the lowest death rates (per million adults) due to over consuming sodium were:

• Qatar -- 73
• Kenya -- 78
• United Arab Emirates -- 134

The U.S. ranked 19th out of the 30 largest countries, with 429 deaths per million adults due to eating too much sodium (representing 1 in 10 US deaths due to these causes).

The American Heart Association recommends limiting sodium in your diet to no more than 1,500 mg a day, and has tips on how to reduce the amount of sodium in your diet, as well as information on six commonly consumed foods that are high in sodium.

Note: If no author is given, the source is cited instead.

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