Last post we discussed that doctors consider blood pressure below 120/80 as normal. However, even though the label for blood pressure less than 80 diastolic is “normal,” it does not mean there is no benefit from having lower than “normal” diastolic blood pressure.
The data and graph (1) at the end of the 1979 report from the Society of Actuaries and Association of Life Insurance Medical Directors of America shows that lower is better. Similarly, many medical research studies since then have confirmed these findings.
For example, a study (2) 23 years ago showed that there is no “threshold” below which the benefits of lower diastolic blood pressure level off. The study examined diastolic blood pressures down to 70. And it showed that the lower the diastolic blood pressure, the less the risk of stroke and heart attack. So it is better to have a diastolic of 70 than of 75.
Recent studies, such as (3), continue to show that stroke risk from higher blood pressure increases in the “prehypertensives.” Namely, those with diastolic between 85 and 89 had a 79% increased risk. Likewise, even a diastolic between 80 and 85 had an increased risk of 22%.
Complications, Complications, Complications
Hence, some of the discussion (4) among doctors treating hypertension is whether to lower the treatment threshold. In general, the treatment threshold being used today is less than 90 diastolic. Study after study confirms the value of getting your blood pressure lower than the upper limit of “normal”. And, as discussed, the benefit continues to increase down to at least 70 diastolic.
In short, the only reason to discuss how much to lower someone's blood pressure is because of the side effects of the drugs that treat hypertension. Specifically, you have to weigh the side effects and complications of treatment against the risk of stroke and cardiac disease that results from higher blood pressure.
But if you can lower blood pressure without using drugs, the side effects and complications are no longer part of the discussion. And there is no side effect from getting a higher potassium to sodium ratio in a healthy person. Yes, you have to have good kidneys, and not have one of the rare and unusual diseases that require a low potassium intake. Otherwise, getting more potassium and less sodium will only improve your health and longevity.
All of the studies mentioned used medication to lower blood pressure. But multiple other studies have shown how to lower blood pressure without medications, using diet and lifestyle changes. Lowering the amount of sodium, or increasing the amount of potassium, in the diet will lower blood pressure and reduce associated health problems.
Doing both will improve the potassium to sodium ratio even more. And generally, the higher the ratio, the better the blood pressure will be.
How To Find Food Potassium Tables
You can find links to tables of foods that are high in potassium and low in sodium by clicking the tab at the top of the page, “Links to Potassium Food Tables”. Choose some high potassium substitutes in each category of food you include in a meal, and you will improve your health.
1. Society of Actuaries and Association of Life Insurance Medical Directors of America. Blood Pressure Study 1979. Blood Pressure Study 1979. Society of Actuaries & Association of Life Insurance Med. Directors of America (1980).
2. Blood pressure, stroke, and coronary heart disease. Part 1, Prolonged differences in blood pressure: prospective observational studies corrected for the regression dilution bias. MacMahon S, Peto R, Cutler J, Collins R, Sorlie P, Neaton J, Abbott R, Godwin J, Dyer A, Stamler J. Lancet 1990 Mar 31;335(8692):765-74.
3. Effects of intensive blood pressure lowering on cardiovascular and renal outcomes: a systematic review and meta-analysis. Lv J, Neal B, Ehteshami P, Ninomiya T, Woodward M, Rodgers A, Wang H, MacMahon S, Turnbull F, Hillis G, Chalmers J, Perkovic V. PLoS Med. 2012;9(8):e1001293. doi: 10.1371/journal.pmed.1001293. Epub 2012 Aug 21
4. Presence of baseline prehypertension and risk of incident stroke: a meta-analysis. Lee M, Saver JL, Chang B, Chang KH, Hao Q, Ovbiagele B. Neurology. 2011 Oct 4;77(14):1330-7. doi: 10.1212/WNL.0b013e3182315234. Epub 2011 Sep 28.