Nowhere in medicine is there more confusion than the issue of salt as a cause of high blood pressure. At the 2006 meeting of the American Association of Clinical Endocrinologists, Dr. Abdul-Rahman of Newark, Delaware reported that people who lowered blood insulin levels had a significant reduction in high blood pressure even though they also markedly increased their salt intake (Endocrinology Practice, Volume 12, 2006).

These obese patients increased their daily salt intake from less than two grams a day to more than 20 grams a day. They avoided starchy and sugary foods and lost around 12 pounds in six weeks. They did not count calories. Their average blood sugars dropped from 106 to 98, average fasting insulin from 21 to 14 mu/ml and average systolic blood pressure from 96 to 88. Some of the patients were able to stop their blood pressure drugs. This study and others show that high blood insulin levels are an important cause of high blood pressure, and that these people can lower insulin levels by avoiding refined carbohydrates and losing weight.

If humans are like rats, those with high blood pressure will live longer when they exercise, even if their blood pressures do not return to normal. Rats can be bred to develop a genetic trait in which they develop high blood pressure, but when they exercise, they live much longer than the rats that do not exercise (Medicine & Science in Sports & Exercise, May 2006).

Having high blood pressure can kill you. It increases your chances of suffering a heart attack, stroke, or kidney disease. Exercise usually lowers high blood pressure because high blood pressure usually is determined by blood volume. Anything that reduces blood volume also reduces high blood pressure. That's why diuretics are the most effective drugs to lower high blood pressure. Exercising for a few minutes usually does not lower high blood pressure, but exercising for several hours dehydrates you and usually does lower high blood pressure. This study shows that even if exercise does not lower high blood pressure in rats, it still helps them to live longer, and the same may apply to you.

Gabe Mirkin, M.D.

Dr. Gabe Mirkin has been a radio talk show host for 25 years and practicing physician for more than 40 years; he is board certified in Sports Medicine and three other specialties.

Dr. Mirkin's daily features on fitness have been heard on CBS Radio News stations since the 1970's. He has written 16 books including The Sportsmedicine Book, the best-selling book on the subject that has been translated into many languages. His latest book is The Healthy Heart Miracle, published by HarperCollins.

Dr. Mirkin is a graduate of Harvard University and Baylor University College of Medicine. A Boston native, Dr. Mirkin did his residency at the Massachusetts General Hospital. He has served as a Teaching Fellow at Johns Hopkins Medical School, Assistant Professor at the University of Maryland, and Associate Clinical Professor in Pediatrics at the Georgetown University School of Medicine. He has run more than forty marathons and is now a serious tandem bicycle rider with his wife, nutritionist Diana Mirkin.