I've written several posts on sodium intake (table salt, of course, is sodium chloride, but I tend to think in terms of the sodium itself). I printed our most of the sodium, potassium and water section in the new Dietary Guidelines Advisory Committee's (DGAC) 2010 draft which I had barely touched on in my last post. The entire DGAC report is huge; there was a nine-page Executive Summary and the section on salt and water is more than thirty pages in length. I also went to another section, one on high potassium foods.
The bottom line isn't new at all, probably little changed from the 2005 Guidelines. But the data behind the recommendation is more and more solid. So here's the short version and some background.
We get way too much sodium in our American diet and way too little potassium.
Most of the sodium comes from processed foods: yeast breads, chicken, pizza, pasta, cold cuts, condiments, cheese, grain-based desserts, soups and beef. The natural sodium content of foods gives us about 10% of our total intake and table and cooking salt another 5 to 10%. So roughly 75% comes from salt added in the manufacture of foods. It's associated with high blood pressure (AKA hypertension), strongly felt to be a highly significant contributor to that disease. More than 90% of us will develop hypertension in our lifetime.
Eating a diet lower in sodium makes great sense, especially for anyone with pre-existing hypertension, middle-aged and older adults, Blacks (who have a higher risk of hypertension-related complications, e.g., stroke and kidney failure) and diabetics. We ingest more than twice the 1,500 milligrams per day the DGAC thinks we should.
For people who have normal kidney function and aren't on meds that cause potassium to go up or be retained, more dietary potassium helps reduce blood pressure. Somewhat absurdly, most of us get our potassium from reduced fat milk, coffee, chicken and beef, OJ or grapefruit juice, fries and chips. We get roughly 3,000 milligrams (less for women) of the recommended 4,700 the DGAC thinks we should be eating/ingesting. There's a list of high-potassium foods that starts with baked potatoes and their skins and includes lots of fresh (or canned) foods: beet green, carrot juice, nonfat plain yogurt, some fishes, and of course, bananas and other fruits.
I'm going to read more of the DGAC report and will be eager to find out how many of the recommendations make it into the final 2010 Dietary Guidelines. It sure makes sense to me, but a lot of folk would have to gradually adapt to less sodium and some countries are going that route.
Then there's the issues of affording a healthy diet and of food companies going along with with what the Advisory Committee recommends.