This week, David Katz, M.D., director of the Prevention Research Center at Yale University School of Medicine and HuffPost blogger, asked for your most pressing health questions. Many of you responded with personal stories about dieting, chronic illness, and genetically-modified foods. Below, Dr. Katz responded to one such question.
Q: Dear Dr. Katz,
I recently read information from an established naturopath that the number of people on blood pressure medicine in the U.S. is abnormally high because of the lowering recommendations for what is "normal" blood pressure. She cites a Scandinavian country where "average" blood pressure is much higher than the recommendations in the U.S. Intuitively, I know there are many differences in the U.S. diet and lifestyle and those of the Scandinavian country mentioned.
Of course, my suspicion is that the pharmaceutical companies in the U.S. have influenced the "normal" number through any number of ways, including funding research. Can you comment on that?
Of course, diet and lifestyle are the first courses of intervention, as we know that both have contributed greatly to the un-healthing of Americans (even those who were perfectly healthy when they first arrived -- I'm thinking of the many Japanese women I know whose health has suffered greatly from the American diet).
How much is blood pressure influenced by genetics?
What is the range of normal blood pressure? What are the signs that one would benefit from taking medicine to control blood pressure? And how does one determine the relative benefit given the side effects of the medicines popularly prescribed?
Thank you for your fun, smart and honest blogs. I post many of them on Facebook.
(And I'd still love to see if doing visceral manipulation would lower the incidents of prostate cancer -- obviously a long-term study.)
Sincerely, Pam Yenawine, CST-D, Louisville, KY
A: Wow -- there are quite a few questions folded into this one! I think I feel my blood pressure rising...
Actually, the news here is pretty reassuring all around. There are, to be sure, drug company-sponsored studies in this area. But for the most part, those are studies of specific drug effects, not studies of the association between blood pressure and health outcomes at the population level. Those have been funded mostly by the NIH here in the United States and corresponding health agencies abroad. The guidelines for treating blood pressure in the U.S. originate with the National Heart Lung and Blood Institute, and specifically with a group called the Joint National Committee convened specifically to address this topic.
The evidence is pretty clear that as blood pressure rises over 70 diastolic and 100 systolic, health risks slowly rise in tandem, particularly the risk of stroke. As the numbers get above 90 diastolic and/or 140 systolic (measured, by the way, in millimeters of mercury), the risks begin to rise briskly. I generally like to see blood pressure in my patients below 80 diastolic and below 120 systolic.
Average blood pressure goes up with age, and averages will be higher the older the population. Also, higher averages can be tolerated without harm where overall health is good. In the context of poor diet, lack of exercise, or other coronary risk factors, the impact of even slightly elevated blood pressure is exaggerated.
There are no symptoms of high blood pressure, but a doctor can detect early indications of harm by assessing the heart, examining the retinas, doing a test of kidney function, and with an electrocardiogram or echocardiogram. If medication is recommended to you and you are dubious about it, ask about the findings from such tests. Is there evidence that blood pressure is harming you? If yes, treatment certainly makes sense. If no, you have time to verify that your blood pressure is really high -- and not just high in the doctor's office (so-called "white coat hypertension").
That said, formal recommendations for treating high blood pressure very clearly state that lifestyle is the first and best medicine. Therapeutic Lifestyle Changes (TLC) include improvements to diet, more physical activity, and weight loss when warranted. These have been shown to exert as great an effect on blood pressure as medication -- they just take a bit more work!
With my patients, I do the following: I always emphasize TLC if they are willing. If blood pressure is high enough to warrant treatment and my patient prefers medication, I prescribe it -- there are many safe and effective ones from which to choose. The evidence is clear that treatment matters; Stroke rate in the U.S. has declined decisively over recent decades due almost entirely to better detection and treatment of high blood pressure.
If my patient is willing to try TLC and is in no acute danger, that's what we do -- over a span of months, with medication an option if TLC doesn't get the job done (or the patient doesn't really change their behavior). If I believe TLC can work, but my patient is in acute danger, I prescribe medication and work on TLC at the same time -- and remove the medication when lifestyle changes can take over.
Finally, blood pressure is best treated holistically. Severe or poorly-managed stress could be the reason for it, and if so, blood pressure is merely a sign of the underlying condition. Always best to look for causes -- and treat as close to them as possible. That's when the really good stuff happens!
Dr. David L. Katz; www.davidkatzmd.com
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