Many health professionals recommend eating less salt. But why is too much salt bad for your health? Lorraine Rapp and Linda Lowen, hosts of WRVO's health and wellness show Take Care, recently spoke with Dr. Norman Kaplan of the University of Texas Southwestern Medical Center, whose textbook on high blood pressure, "Kaplan's Clinical Hypertension," is in its 10th edition.
Lorraine Rapp: So when it enters our system, what actually takes place in the body that causes it to have harmful effects on our blood pressure?
Dr. Norman Kaplan: Well, there is a difference among people in how sensitive their blood pressure is to taking in salt. But, if you want to make a general statement, we’re eating twice or more the amount of salt than we believe is healthy. And that extra salt is held on by the kidneys. The kidneys usually get rid of any extra salt we eat. But a lot of people hold on to too much of that salt, and our blood is basically a salt solution, so it expands the amount of fluid within the circulation. And that’s like putting too much water into a pipe. The blood pressure obviously goes up when there is too much fluid volume.
Linda Lowen: Dr. Kaplan, is this a universal response of most human bodies to salt. Is it just salt alone, or is it in combination with other dietary factors?
Dr. Kaplan: Well, other dietary factors can play a role, but it’s really mainly the sodium. Now, about 80 percent of the sodium that we take in to our body comes not at the table when we add it with a salt shaker, but it’s in the foods that have been processed. Anything that’s canned or packaged likely has had salt added to it, and there are two reasons. First of all, we like salt. The taste of salt is something we learn to enjoy. The other reason that the people that process our foods add salt is that it increases the volume. So, if you take a can of soup, they’ve had some extra salt put into it because they can increase the volume that’s in that can. The reason we started using salt was as a preservative, but once we’ve got a refrigerator we don’t need salt in the food to be a preservative, we can preserve food perfectly well without the salt.
Linda: Okay, you talked about processed foods, it’s important to eliminate that, and also it’s hidden in things like bread and rolls—I was surprised to find they are a high source of sodium.
Dr. Kaplan: Oh, yes. It’s what we call hidden salt, because you really can’t tell it unless you compare it to a very low sodium type of food. But, the food processers are learning and there has been a definite, although still fairly small, reduction in the average amount of salt that is in our processed foods. It’s tough for an individual person to do it because we have to have foods that we don’t make that are processed in one way or another, so it’s the food processers that we are really trying to convince to cut down the sodium in the food.
More of this interview can be heard on Take Care, WRVO's health and wellness show Sunday evening at 6:30. Support for this story comes from the Health Foundation for Western and Central New York.