Blood pressure is affected by 17 known variables. Smoking, overweight, salt consumption, stress, use of oral contraceptives, exposure to lead and cadmium – these among others factors, are all possible causes of hypertension. To that list we may eventually add allergy.

A few years ago, Lloyd Rosenvold, M.D., of Hope, Idaho, noticed that some of his patients developed high blood pressure from allergy to certain foods. Another doctor, George Fricke, M.D., of Sacramento, California, studied a group of twelve hypertensive people – some with blood pressure as high as 219/140 – in whom elimination of allergic foods brought blood pressure down to normal.

And in a study of food allergy and migraine, Dr. Ellen Gant, a neurologist in London, discovered that when a group of 15 hypertensive people avoided migraine producing foods, their blood pressure also returned to normal (Lancet, May 5, 1979). Surprising findings? Not really. High blood pressure is more than a simple matter of getting too much salt in the diet.

After all, we all know someone who salts his or her food heavily and has normal blood pressure. Whether blood pressure rises or not seems to be a matter of individual sensitivity to many factors, some of which doctors haven’t yet identified clearly. Allergy, it seems, is one of those factors, and it's presence could help to explain why certain foods or habits raise blood pressure in some people but not others.