There is a lot to fight over in the vagaries of dietary science, but possibly nothing has been as contentious or as longstanding as the salt wars. For decades, public-health officials have pushed people to eat less salt, which is linked to lower blood pressure, which in turn is linked to less heart disease. And for the same decades, a vocal opposition has challenged the guidelines as unscientific: No solid evidence directly links salt intake to heart disease over the long term.
The vitriol of the salt wars was on display in Science. The journal noted that one side took an article as “compelling evidence of the value of reducing sodium intake,” while another said the same article “reads like a New Yorker comedy piece” and was the “worst example of a meta-analysis in print by a long shot.” That was 1998. The evidence hasn’t gotten much better since then.
What would settle the debate once and for all is a randomized controlled trial: Take thousands of people, randomly assign them a low-salt or regular diet, and follow them for years—recording not just short-term changes in blood pressure but also long-term changes in heart attacks and death from heart disease. This is what the Institute of Medicine—a body of expert scientists that has since changed its name to the National Academy of Medicine—suggested at the end of a 2013 review on salt intake research.
In May 2017, Daniel Jones, an obesity researcher at the University of Mississippi Medical Center, convened a group on both sides of the salt debate to explore the feasibility of a randomized controlled trial. “Over the last few years in the medical literature,” he said, “there has been…” He paused to look for the right words. “I’ll say, a more contentious spirit. It was bothersome to me to see people disagreeing in a disagreeable way.” Jones himself believes salt can lead to heart disease, but he thinks stronger evidence in the form a randomized controlled trial could provide the push for policies that limit salt in processed foods.
The groups ran through their research options. The best evidence linking salt intake and high-blood pressure comes from short-term feeding studies, where researchers prepare the meals for participants over several weeks. But it is far too expensive to feed participants for the years it takes for heart disease to show up. And frankly, how many …read more
Source:: The Atlantic – Health