Last post we discussed that below 120/80 is considered normal blood pressure. However, even though less than 80 diastolic is labeled “normal,” it does not mean there is no benefit from having lower than “normal” diastolic blood pressure.
A graph (1) based on data from the Society of Actuaries and Association of Life Insurance Medical Directors of America 1979 report shows that lower is better. Many medical research studies since then have confirmed these findings.
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 showed that the lower the diastolic blood pressure the less the risk of stroke and heart attack. So as the graph shows, 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 is increased in the “prehypertensives.” Those with diastolic between 85 and 89 were at 79% increased risk. Even those with diastolic between 80 and 85 had an increased risk of 22%.
Complications, Complications, Complications
Some of the discussion (4) among doctors treating hypertension is whether to lower the treatment threshold being used today to less than 90 diastolic. Study after study has confirmed the value of getting the blood pressure lower than “normal”. The benefit continues to increase to at least 70 diastolic.
The only reason for having the discussion of how much to lower someone's blood pressure is because of the side effects of the drugs that treat hypertension. You have to weigh the side effects and complications of treatment against the risk of stroke and cardiac disease that results from the higher blood pressure.
If you can lower blood pressure without using drugs, the side effects and complications are no longer part of the discussion. There is no side effect from getting a higher potassium to sodium ratio. 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. The higher the ratio, the better the blood pressure will be.
You can find links to tables of foods that are high in potassium and low in sodium on the list of posts page. Pick 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. 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.