The researchers analyzed 247 surveys of adult nutritional habits including processed foods and specifically 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 processed 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.
Scientists have recently found that a modern diet of processed foods, takeaways and microwave meals could be to blame for a sharp increase in autoimmune diseases such as multiple sclerosis, including alopecia, asthma and eczema.
Dariush Mozaffarian, M.D., Dr.P.H., from Harvard Medical School in Boston, and colleagues used data from the same surveys to examine the global impact of excess sodium intake on blood pressure-related cardiovascular disease. The researchers found that the mean global sodium intake was 4.0 g/day in 2010, with regional variation from 2.2 to 5.6 g/day. In 2010, nearly 2.3 million deaths were attributable to excess sodium intake, including 42 percent due to heart attacks and 41 percent to stroke. More than 80 percent of these deaths were seen in low- and mid-income countries.
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.
The overwhelming nutrition policy in all countries studied for the last 30 years has been educational programmes directed at consumers. That strategy has failed. Globally, people have higher rates of disease and obesity.
The evolution of high processed salt consumption from childhood to adulthood is a serious problem aggravated by the high intake of processed foods starting from an early age. Nearly 75 percent of commercial pre-packaged meals and savory snacks for toddlers are high in sodium, according to research presented at the American Heart Association’s Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism 2013 Scientific Sessions.
“Over 80 percent of people believe that the food industry should reduce sodium in prepared and packaged food,” stated Mary R. L’Abbe, professor and chair of the nutrition department at the University of Toronto, and her co-authors from Toronto and Guelph wrote.
“This is relevant because most of the dietary sodium is derived from packaged and prepared foods. Data has shown that it is practically impossible to consume sodium intakes of less than 2,300 milligrams per day following National Food Guide programs, because of the high amounts of sodium in the food supply.” The maximum suggested sodium intake is 2,300 milligrams per day.
“Our concern is the possible long-term health risks of introducing high levels of sodium in a child’s diet, because high blood pressure, as well as a preference for salty foods may develop early in life. The less sodium in an infant’s or toddler’s diet, the less he or she may want it when older,” said Joyce Maalouf, M.S., M.P.H., ORISE, lead author and Fellow at the National Center for Chronic Disease Prevention and Health Promotion at the Centers for Disease Control.
“National and global public health measures, such as comprehensive sodium reduction programs, could potentially save millions of lives,” said Mozaffarian, 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).