Everyone knows you should eat less salt...right? Salt makes you retain water, it increases your blood pressure, it makes you more likely to have a heart attack or stroke...right?
The Mayo Clinic says the average American eats 3.4 grams per day, and should eat <2.3 grams (and <1.5 grams if you have high blood pressure)
Livestrong reiterates this same information, as does the CDC. The CDC goes on to states that lowering sodium could save thousands of lives annually because there are 400,000 deaths per year attributed to high blood pressure.
They can't all be wrong...right?
The problem is - they are all assuming they understand cause and effect. They assume that lower sodium decreases blood pressure, and that lowering blood pressure in that way decreases deaths.
Sadly the ACTUAL RESEARCH does not verify their claims or assumptions.
The latest research, published in July 2011 shows something quite interesting. It shows that as expected, decreasing salt intake can help the healthy American decrease their risk (a little) of dying by a cardiovascular accident.
That's not the interesting part. Guess what the data show when you look at patients who have high blood pressure or already have heart failure?
If you already have high blood pressure - decreasing salt intake will have no effect whatsoever on your chances of dying by stroke or heart attack.
If you already have heart failure - lowering salt intake will kill you faster.
SO......if this article and research are accurate that means the CDC, Mayo Clinic, Livestrong, and all cardiologists and family docs should be telling you:
Everyone out there reading this who is healthy - decrease your salt. (yeah, because that's gonna happen)
Everyone who has high blood pressure - don't change your salt intake at all.
Everyone who has heart failure - Don't you dare decrease your salt intake or you're even MORE likely to die of a heart attack or stroke!
I am getting to enjoy reviewing medical research literature more and more. Each time I go to research conferences I learn more and more about how the conventional wisdom and even medical advice is completely wrong.
If anyone is curious - the source for this information is pretty much the best source there is. It's almost universally agreed that the Cochrane Database is THE database for information.