With blood pressure, is lower always better?

Raised blood pressure is believed to be a risk factor for cardiovascular diseases such as heart disease and stroke. Studies show that, in a population, the higher the blood pressure, the greater the risk of cardiovascular disease. This has led to some researchers suggesting that the lower the blood pressure is, the better.

However, we have seen examples in the past where this ‘lower is better’ concept seems misguided. For example, we know that low levels of cholesterol are associated with an increased risk of death, principally because of an association with an increased risk of cancer. See here for more about this. There is also evidence that more intensive pharmacological lowering of blood sugar levels in diabetics speeds their demise. See here for more about this. It really does seem that when it comes to markers of disease, lower is not necessarily better.

So, what about blood pressure? It’s important to bear in mind, I think, that blood pressure is what forces blood into tissues to feed and oxygenate them. Very low blood pressure can kill. However, is it not possible that at a certain blood pressure life can go on, but the quality of that life is somewhat impaired? This is certainly what I and some other practitioners see in practice. I can tell you from experience that there seems to be very few individuals wandering around with a blood pressure of 90/60 who feel bursting with vitality and energy. And when measures are taken to help restore blood pressure to higher levels, these individuals usually feel much better.

The other thing to bear in mind is that even though studies may show an association between lower blood pressure and reduced risk of cardiovascular disease, that does not necessarily mean that more intensive drug treatment to lower blood pressure will lead to better outcomes (just look at the diabetes example above).

This issue was the focus of a recent review published by researchers from the so-called Cochrane Collaboration. In this review, researchers amassed data from 7 trials and a total of 22,000 patients who had been treated with medication for high blood pressure [1]. A commonly aimed-for target for blood pressure is 140/90. What the researchers did was compare individuals who had had their blood pressures lowered to 140-160/90-100 with those who had had theirs lowered to less than or equal to 135/85. What they were essentially asking is whether lowering blood pressure to lower than the common target of 140/90 led to improvements in outcome.

Compared with those with higher blood pressures, those who had their blood pressure lowered to 135/85 or less saw:

NO reduced risk of heart attack
NO reduced risk of stroke
NO reduced risk of heart failure
NO reduced risk of kidney failure (end-stage renal disease)
NO reduced risk of overall risk of death

In other words, there were no benefits from more intensive blood pressure lowering with medication. The authors concluded: ‘there is no evidence to support aiming for a blood pressure target lower than 140/90 mmHg in any hypertensive patient.’ As we’ve seen before, lower is not necessarily better.

References:

1. Arguedas JA, et al. Treatment blood pressure targets for hypertension. Cochrane Database of Systematic Reviews 2009, Issue 3, Article Number: CD004349.

14 Responses to With blood pressure, is lower always better?

  1. Steve 29 July 2009 at 3:23 pm #

    If I’m not mistaken, high blood pressure is just one effect of a compromised health condition. Treating one marker with drugs while ignoring the underlying cause of the high blood pressure is pretty silly and the non-results of the trials are not surprising! The pharma industry dutifully creates drugs to treat conditions and consider themselves successful when the specific condition improves, regardless of whether the mortality is addressed. It might be worse, or it might do nothing. Whatever the case, the drug sells briskly and patients are no better for it.

  2. diamond 29 July 2009 at 7:48 pm #

    There was no reduced risk as mentioned because 135/85 is hardly low enough! It’s like saying ‘I didn’t get strong curling 5 lbs, I know… I’ll curl 7 lbs!’. I guarantee you that 95% of people out there don’t come close to 90/60 (except my wife, routinely 110/60-70. Curiously she eats a lot of pasta, considered by many of us to be a ‘bad’ carb inflammatory marker. oh well…) IF that study got people down to 115/70… now show me THAT study.

  3. ethyl d 29 July 2009 at 10:04 pm #

    Taking drugs long-term to manage symptoms is not the same thing at all as restoring the body to health. The patients still had high blood pressure; all the drugs did by artificially forcing blood pressure lower was to cover up the problem. But the problem was still there, and hence patients still ended up with heart conditions. Blood pressure medications do nothing to eliminate the cause of high blood pressure.

  4. Jamie 29 July 2009 at 10:08 pm #

    To be of any value, that review really needed to do a comparison with the risks of attaining a substantially lower blood pressure in the order of <120/80. To say that, as there is no reduction in risk between 140/90 & 135/85, there is no need to try any harder is a bit misleading without that comparison to lower figures. If, all things considered, you can show there is no relative difference between 140/90 & 110/70 say, then you can focus efforts on other risk areas.

  5. Dr John Briffa 30 July 2009 at 5:17 am #

    diamond and jamie

    135/85 was not the blood pressure of the lower bp comparison group, it was LESS THAN OR EQUAL TO 135/85 (not the same thing)

    Also, the researchers attempted to assess whether this difference might not be great enough to detect a benefit by re-analysing the data. Here’s what they did and the result:

    “One possible argument against the findings of this review is that the minimum difference in the targets chosen in this review, 5 mmHg, was not great enough to demonstrate mortality and morbidity benefits. This argument can be tested in this meta-analysis by including only those trials where the difference in the targets was at least 10 mmHg. In fact placing this restriction on the review only excludes the middle group ( lower than 85 mmHg) of the HOT trial. A re-analysis with exclusion of the < 85 mmHg diastolic blood pressure group leads to a greater weighted mean difference in target diastolic blood pressure (10.3 mmHg) between the two groups and a greater difference in the mean achieved blood pressures of 5/4 mmHg. More importantly it led to no appreciable changes in the RR for mortality nor for any of the primary morbidity outcomes, and the conclusions remain the same as described above.”

    So, it is possible that lower blood pressures are beneficial, but again the evidence does not support this. Any suggestion that lower is better is just guessing, unless you have other data that supports this view that you have not presented here.

  6. Anne 30 July 2009 at 2:10 pm #

    My blood pressure ranges between roughly 85/55 and 90/60 and my heart rate is around 72 – I feel fine with plenty of energy. My blood pressure used to be a bit higher, around 110/70 and my heart rate around 80 but then I started a Paleo diet and regular weight lifting just over two years ago and I think that’s why everything has got lower.

    Anne

  7. audrey wickham 31 July 2009 at 9:08 am #

    My father’s side of the family all have a naturally low blood pressure which gets higher as we get older. My G.P. took my BP three times in a row and found that it was high. I was put on a drug. I went to stay with friends on Mauritius for a month; my friend is a G.P. and he took my BP all the time and never once was it high. I concluded that it was either that I couldn’t find a parking space at my G.P’s surgery or that NTL were driving me mad again. I now go to a surgery that has a good car park and I changed my server. No tablets – Blood pressure normal.

  8. Margaret Wilde 31 July 2009 at 10:14 pm #

    Surely it makes a big difference which type of blood pressure lowering medication was taken?

  9. R Vasudevan 1 August 2009 at 2:07 pm #

    With high BP, the blood vessels particularly the tiny ones are stretched with the risk of rupturing. Commonsense suggests that the lower the pressure, less will be the strain on the vessels.
    However, drugs can only be a stop-gap solution to high BP. A holistic approach is necessary to ensuring sound health.

  10. Bob Willis 1 August 2009 at 2:57 pm #

    Hi,
    My bp has always been high. Thats OK I thought, I’ve got a good pump! At age 55 I was recommended medication, but declined it. At 63, needing knee surgery, I was told that if my bp did not come down, surgery could/would not be done.
    I therefore took the medication. after surgery my GP argued that at my age with brain blood vessals becoming weaker,it was a good idea to remain on the medication in order to reduce the risk of stroke.
    If this is a valid reason then I have no objectoin to taking med. even if there is no underlying problem with my system as a whole.

  11. Trinkwasser 11 August 2009 at 11:24 pm #

    You ever see someone take their first dose af a beta blocker? I did! You know that guy in Star Trek who turned into a puddle of liquid and slept in a bucket? That’s exactly what he resembled, at one stage he couldn’t even sit on a chair without sliding onto the floor. We had to pour him into his car and drive him home.

    When mother was overmedicated she had some episodes a bit like that. Now she is on mimimal meds and stays around 110/60 and copes very well for a 94 year old. Mine’s gradually gone back up from 120/80 to around 140/85 – originally it was 150/95 or so and increasing until I started to low carb which produced a dramatic drop. I’m still on a minimal dose of olmesartan so there’s plenty of leeway to increase it if the effect of the diet is overtaken by the effect of ageing, which seems to be occurring.

    I think I hear my pulse rushing in my ears more at night but apart from that little to indicate the change.

    “If I’m not mistaken, high blood pressure is just one effect of a compromised health condition. Treating one marker with drugs while ignoring the underlying cause of the high blood pressure is pretty silly and the non-results of the trials are not surprising!”

    Yes that’s really the key, addressing the insulin resistance and high BG in my case made such an improvement there was talk of eliminating the medication at one stage. Using meds to overcome the effects of a poor diet doesn’t work so well as improving the diet. Eat your dietician . . .

  12. Tina 26 February 2010 at 2:14 am #

    I am one of those people who walk around with an average of 90/60 blood pressure. Most times I’m ok but once in a while, especially when I’m menstrating (sorry men but I felt I had to mention it), I feel light headed and have to be very careful when I stand up from a seated position. I can also sporadically feel my heart pounding in my chest for a few brief seconds.

    Something’s telling me that this is not good. I’ve mentioned it to several doctors but they all say that as long as my blood pressure is not high then I’m fine.

    Is there a way to naturally raise my blood pressure?

    Tina

  13. Steve 10 March 2012 at 1:49 am #

    The problem will all medical studies and research is this, and the question that always has to be asked and investigated, “Who funded the research, where is the money coming from and what stock portfolios do the medical researchers have within their own personal investments”. I am very serious about this and most researchers refuse to disclose this information. They refuse. It reminds of a YAHOO news article that stated “caffeine raises blood pressure”. When you read the actual research notes the average point raise was 2 points in systolic pressure, so you can honestly say caffeine raises blood pressure but that is insignificant. What was disturbing though was who funded that research and why. This is happening on a significant level within the medical field just like politicians who take on lobby money and make decisions based on that. I just read research on how ‘walking” will lower your blood pressure and come to find out after reading the whole extensive research papers, it lowered blood pressure by 10 points. It’s all relative. So people 150 – 170 in a systolic measure – it still did not bring their blood pressure within an acceptable means . Yes it lowered it but they never got past that plateau, yet the research headline article states it lowered blood pressure. This is why I do not agree that walking lowers blood pressure for most people and we have sugar coated exercise to be “easy”. The heart is a muscle slightly than the fist, it is a muscle that if not exercised on an aerobic level it will weaken, it will. And, it’s different than other muscles because it is a electro-mechanical pump. The people that I have seen eliminate blood pressure medicine are those doing extensive aerobic cardio, consistently year round and at least 4 days a week – not gardening, not washing windows, not painting the house, not walking 3-4 mph pace. The reason the whole health industry took the approach of get up and go and sugar coated exercise routine it is because Americans did not want to work hard at exercise and the compromise was, “Oh you can walk, garden, do housework, etc….” . 30 years of doing of doing wellness care, those that do extensive hard working aerobic exercise on a consistent basis are the ones that are eliminating blood pressure pills but eh whole catch 22 is this, we have an aging population, where most have never exercised and now at age 50 they have plaque build up, they are at risk for doing extensive aerobic exercise – they could easily have a stroke or heart attack. Even having a stress test at that age does not guarantee anything as it is a “capture in time” and it does not simulate weather – cold and hot, exercising outdoors at specific times of day and how the body reacts or varied terrain (no, a slant on a treadmill doesn’t cut it). This is why this idea of exercise should be pushed at a young age, extensive, consistent, and AEROBIC and not writing articles about washing windows, gardening or walking your dog to lower pressure

  14. BloodPressureCharts.net 12 June 2012 at 2:14 pm #

    Wow, this flies in the face of everything most people think they know about the benefits of lowering high blood pressure.

    I read the article below the other day which states that people whose blood pressure was lowered a bit (as a result of eating dark chocolate) had a 39% lower risk of heart attack or stroke.

    http://www.sciencedaily.com/releases/2010/03/100330092809.htm

    It’s a mine field what to believe!

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