Why is there a controversy over salt?
1) Dear Food Industry: Lower the Salt, Save Lives
Henry R. Black, MD, Graham MacGregor, MB BChir
Medscape Cardiology
Black on Cardiology
http://www.medscape.com/viewarticle/815133_1Dr. Black: I want to talk about something that you have been interested in, possibly for your whole career: the so-called "salt controversy." Why is there a controversy?
Dr. MacGregor: That is a good question. I am not sure, but my guess is that it is mainly due to pressure from the salt and food industry.
The evidence for salt is overwhelming. Look at the wealth of the epidemiologic migration; all the animal evidence studies in chimpanzees; the treatment, genetic, and outcome studies that we have now. The evidence is overwhelming that salt raises blood pressure and is responsible for a very large number of strokes, heart attacks, and heart failure. In countries where it is high, such as China and Japan -- even higher than in the United States -- cancer of the stomach is very clearly related to a high salt intake.
2) His research ...
Salt reduction in England from 2003 to 2011: its relationship to blood pressure, stroke and ischaemic heart disease mortality.
BMJ Open. 2014 Apr 14;4(4):e004549. doi: 10.1136/bmjopen-2013-004549.
http://bmjopen.bmj.com/content/4/4/e004 ... l.pdf+htmlAbstract
OBJECTIVES: To determine the relationship between the reduction in salt intake that occurred in England, and blood pressure (BP), as well as mortality from stroke and ischaemic heart disease (IHD).
DESIGN: Analysis of the data from the Health Survey for England.
SETTING AND PARTICIPANTS: England, 2003 N=9183, 2006 N=8762, 2008 N=8974 and 2011 N=4753, aged ≥16 years.
OUTCOMES: BP, stroke and IHD mortality.
RESULTS: From 2003 to 2011, there was a decrease in mortality from stroke by 42% (p<0.001) and IHD by 40% (p<0.001). In parallel, there was a fall in BP of 3.0±0.33/1.4±0.20 mm Hg (p<0.001/p<0.001), a decrease of 0.4±0.02 mmol/L (p<0.001) in cholesterol, a reduction in smoking prevalence from 19% to 14% (p<0.001), an increase in fruit and vegetable consumption (0.2±0.05 portion/day, p<0.001) and an increase in body mass index (BMI; 0.5±0.09 kg/m(2), p<0.001). Salt intake, as measured by 24 h urinary sodium, decreased by 1.4 g/day (p<0.01). It is likely that all of these factors (with the exception of BMI), along with improvements in the treatments of BP, cholesterol and cardiovascular disease, contributed to the falls in stroke and IHD mortality. In individuals who were not on antihypertensive medication, there was a fall in BP of 2.7±0.34/1.1±0.23 mm Hg (p<0.001/p<0.001) after adjusting for age, sex, ethnic group, education, household income, alcohol consumption, fruit and vegetable intake and BMI. Although salt intake was not measured in these participants, the fact that the average salt intake in a random sample of the population fell by 15% during the same period suggests that the falls in BP would be largely attributable to the reduction in salt intake rather than antihypertensive medications.
CONCLUSIONS: The reduction in salt intake is likely to be an important contributor to the falls in BP from 2003 to 2011 in England. As a result, it would have contributed substantially to the decreases in stroke and IHD mortality. 24732242
In Health
Jeff