Back in June I dedicated a post to the effectiveness of blood pressure medication. It was triggered by the fact that there’s abundant data to suggest that cholesterol-lowering ‘statin’ medication is really very ineffective. And by that I mean that the vast majority of people who take statins will not benefit. I wondered whether the same might be true for blood pressure medication, and it turns out it is.
As a general rule, medical intervention tends to be most effective in people who are ‘sickest’ or at greatest risk of disease. So, logic dictates blood pressure medication will work best in people with the highest blood pressures to begin with. But what about people who have high blood pressure (hypertension) that is only ‘mild’ in nature?
Researchers from the generally respected collective known as the ‘Cochrane Collaboration’ have just published a review [1] of the relevant evidence here. They looked at data from studies in which people with systolic blood pressures (the higher blood pressure reading) of 140-159 mmHg and/or diastolic blood pressures (the lower reading) of 90-99 mmHg. Individuals in these trials had no prior history of cardiovascular disease (e.g. previous heart attack or stroke). Four studies which included about 9,000 patients in total were analysed. Average length of treatment was between 4 and 5 years. So, lots of people, and a decent duration of treatment too.
Results showed that in those treated with active medication (compared to placebo) were:
- At no reduced risk of developing heart disease
- At no reduced risk of stroke
- At no reduced risk of ‘total cardiovascular events’ (essentially heart attacks and strokes combined)
- At no reduced risk of overall risk of death
Here’s the authors’ conclusions:
Antihypertensive drugs used in the treatment of adults (primary prevention) with mild hypertension (systolic BP 140-159 mmHg and/or diastolic BP 90-99 mmHg) have not been shown to reduce mortality or morbidity [disease] in RCTs [randomised controlled trials].
Today’s British Medical Journal includes a news item about this study [2]. Here’s a quote from it:
James Wright, coordinating editor of the Cochrane Hypertension Group, told the BMJ that until now it has simply been assumed that treating mild hypertension, which is what most hypertensive patients have, is beneficial. He said that doctors and guideline writers have based their opinions on a combination of assumptions and data from clinical trials in which patients with mild hypertension were not analysed separately.
That comment regarding the assumption doctors have made here, struck a chord. It reckon there’s much we doctors do that we assume to be beneficial. Worse still, I think we’ll often call what we do ‘evidence-based’ even when we don’t have good evidence for it. As I remarked to a journalist yesterday, it’s one thing calling something evidence-based, and another something actually being based on good evidence.
Another quote in the BMJ piece comes from Professor Jerome Hoffman of UCLA and an expert in critical appraisal of medical literature. He said:
We’ve long known that almost all benefit from treating severe hypertension comes with lowering BP [blood pressure] just a little. On the other hand, efforts to lower BP to ‘normal,’ typically requiring multiple drugs, are not only usually unsuccessful but produce more harm than good, since adverse effects of intensive treatment outweigh the minimal marginal benefit of a little more BP ‘control.’ Drug treatment of mild hypertension….may be of great value to drug makers, but it was almost predictable that it would provide little or no benefit for patients.
David Cundiff, one of the authors of the Cochrane review has said that he “believes that the analysis should lead to dramatic changes in the way doctors treat mild hypertension, allowing patients to throw away their blood pressure pills and focus instead on far more effective as well as evidence based approaches…”
Dr Des Spence, a general practitioner and BMJ columnist is not so sure though. He’s quoted as saying:
Risk is abstract, and doctors and patients struggle with the concept and may not follow the guidelines. Doctors see a blood pressure of 156/98 and they prescribe. It’s easier to treat than not treat—you never get blamed for overtreating.
I’m broadly with Dr Spence on this. I’d be (pleasantly) surprised if doctors on the whole took this evidence on the chin and made meaningful changes to the way they manage mild hypertension. After all, a lot of what we doctors do is not evidence-based, so why start now?
References:
1. Diao D, Wright JM, Cundiff DK, Gueyffier F. Pharmacotherapy for mild hypertension. Cochrane Database Syst Rev2012;(8):CD006742
2. Lenzer J. Cochrane review finds no proved benefit in drug treatment for patients with mild hypertension. BMJ 2012;345:e5511
I suggest that Pre-HTN may now start at Systolic 145 mm Hg.
Slainte
PS Some hope.
” focus instead on far more effective as well as evidence based approaches…”
Ok, so what are they? HBP is very frustrating because you can try many things, none of which work significantly. So what are these other proven techniques?
Many older women are put onto diuretics to lower blood pressure.This often makes their lives a misery because they are constantly running to the loo. A lot of them are then reluctant to go out socially because they are worried about incontinence,or if they do, restrict their fluid intake.Not a terribly good idea ,as far as I can make out. One assumes the stuff must actually work, but at what cost to the patient?They seem to be a “just treat the symptom” medication, but aren`t there different causes of high blood pressure? Does anyone try to find out the root cause? And what effect to the general health would not drinking enough and staying indoors most of the time have? Do they also lose minerals and can these be easily replaced in the diet? I have not heard any mention of a special diet when these are prescribed.Also, what effect do they have in relation to UTI`s which are quite prevalent in older ladies and contribute to episodes of confusion, and subsequently catastrophic Falling Over? Having looked after my elderly mother for several years, I am of the opinion that many of the drugs prescribed to old people ,especially NSAIDS, diuretics and sleeping tablets actually do more harm than good in the long term. I would be most interested in your views on this subject, Dr Briffa.
Greensleeves
Here’s what David Cundiff followed on with “…such as exercising, smoking cessation, and eating a DASH (diet against systolic hypertension) or Mediterranean diet.” To be honest, I’m not sure which, if any, of these things has been subjected to randomised controlled trials and we have data that allows us to assess the impact of them in people with mild hypertension.
Vict — not sure what your problem is, because when I Google “diet against systolic hypertension” I get lots of references to the Dash diet. I would suggest Google DASH and hypertension.
Maybe what is now called mikd hypertension used to be called normal untill it was realised that if you call it hypertension then you can make money out of it.
Apparently the best way to lower blood pressure is to get a dog – not so daft as it sounds as they have a calming effect, they make you go for walks, and you end up taliking to more people (who are walking their dogs) which improves mood, decreases anxiety and is calming.
They also keep your garden free of cats.
Vict, try dashdiet.org
I was recently told that diabetics are often hypertensive, and those who are hypertensive very quickly become diabetics (That is to suggest, the causes of both are shared).
Further, a common feature of both those who develop hypertension and those who become diabetic is chronically high insulin.
Could it be said then, that hypertension, perhaps even mild hypertension, is driven (at least in part) by a high rate of carbohydrate consumption?
When I Google “diet against systolic hypertension”, all I get are articles (yours at the top) discussing whether it is effective – but I haven’t found what that diet actually is. Little help with that?
The DASH diet is often prescribed, along with exercise, to control HBP. Basically, it is a low fat, high grain diet in which sodium is restricted (with a recommendation of no more than 1500 mg per day.) When I first was diagnosed with mild HBP, I was given a diuretic. It didn’t work. Then, an ACE inhibitor was suggested. I declined, and decided to try the DASH diet with an exercise regimen. I did lose some weight, but my BP did no go down. I later switched to a low carb diet (maintaining the sodium restriction, which I now know isn’t necessarily the best thing to do.) On the low carb diet, my BP dropped. After a while, I stopped restricting sodium, but maintained my low carb diet. My BP did not rise. I imagine DASH works for some people. But, not for everyone.
At any rate, I never regretted declining the ACE inhibitor, despite the doctor’s strong insistence that I take it. I’ve gotten more benefit from the low carb diet than I would have ever gotten from a drug. And, no unpleasant side effects.
Mike S~ Yes that was my point… references to it, not explanations of it.
Tony K~ Thank you so much!
Craig … Yes, it could be said – and has. In his book, Good Calories, Bad Calories (titled The Diet Delusion in the UK), author Gary Taubes points to early scientific evidence that carbohydrate-rich diets raise blood pressure by causing the body to retain water, just as salt consumption is supposed to do.
As I note in my forthcoming book, Healing Your Hypertension (out in October), this was first noted by the German chemist Carl von Voit in 1860 — and was corroborated in 1919 by Francis Benedict, director of the Nutrition Laboratory of the Carnegie Institute of Washington, who described the phenomenon this way: “With diets predominantly carbohydrate, there is a strong tendency for the body to retain water, while with diets predominantly fat there is a distinct tendency for the body to lose water.”
Benedict was referring to the weight loss which occurs in the first few weeks of any diet that restricts either calories or carbohydrates (especially the latter). This initial weight is mostly water, not body fat, as many veteran dieters know. What is less well-known is that a corresponding effect of this water loss is a lowering of blood pressure.
Consuming a carbohydrate-rich diet causes the kidneys to hold on to salt that is already in the body, rather than to excrete it. In reaction to this, the body retains water to maintain the sodium concentration of the blood. This is the same result (water retention) that occurs when we consume more sodium.
“Removing carbohydrates from the diet works, in effect, just like the antihypertensive drugs known as diuretics, which cause the kidneys to excrete sodium, and water along with it,” early researchers noted. In fact, this drop in blood pressure is so considerable that it led critics of low-carbohydrate diets to worry publicly about the “low blood pressure resulting from … losses of … fluid, sodium, and other minerals.”
By the early 1970s, researchers concluded that this water-retaining effect of carbohydrates was due to the insulin that they stimulated the pancreas to secrete. This in turn forced the kidneys to re-absorb sodium rather than excrete it. (This made sense because insulin levels are generally higher in people with hypertension than in normal individuals.) So widely accepted was this notion that by the mid-1900s, diabetes textbooks were discussing the likelihood that chronically-elevated levels of insulin were causing hypertension in Type 2 patients. Unfortunately, no one considered this might also be true for non-diabetics.
Today, it is a well-demonstrated phenomenon that a low-carbohydrate diet causes the excretion of water (causing a reduction in blood pressure), and conversely, that carbohydrate consumption leads to retention of both salt and water (which elevates blood pressure). Therefore, it is ironic that doctors advise overweight hypertensives to lose weight in order to reduce their blood pressure by adopting the standard low-fat, high-carb diet. This is self-defeating, not only because low-fat diets have been shown to be effective ways to lose weight, but also because consuming more carbohydrates will cause water retention and an elevation of blood pressure.
Carbohydrate-rich diets also stimulate chronically high insulin levels (because insulin is needed to clear the bloodstream of the glucose that carbohydrates break down to in the digestion process; so the more carbohydrates that are consumed, the more insulin is required) — and insulin has a very direct influence on raising blood pressure. Harvard researchers found that it stimulates the nervous system with the same “flight-or-fight” response triggered by adrenaline, thus increasing the heart rate and constricting blood vessels, resulting in an increase in blood pressure. “The higher the insulin level, the greater the stimulation of the nervous system,” the researchers discovered. “And if insulin levels remain high, the result would be constantly elevated blood pressure.”
This is one reason hypertension appears so frequently with diabetes. But it should be remembered that high-carb diets (which featured consumption of sugar and refined carbohydrate foods, such as bread, baked goods, snack foods, and sodas) also stimulate elevated levels of insulin even in people without diabetes. Furthermore, these early researchers found that elevated insulin levels cause hypertension, independent of any of the risk factors. – Jim Healthy
Jim Healthy~ Great summary, thank you!
If I were a betting man I’d wager the presentation of hypertension is indicative of some measure of background inflammation that has been a persistent feature over some time. Inflammation arises from presenting the body with circumstances it doesn’t like. Essentially it is a stress issue but with a wide and inclusive interpretation applied to the term.
Stress can be psychological in origin causing stress hormones to knock physiological processes off balance, or the departure from an optimal and prudent diet that could involve surplus carbohydrates or could include a surfeit of polyunsaturated fats, or it could arise from from a deficit of anti-oxidants. It could be pyscho-social in origin, and this is a favoured cause of heart disease championed by Dr Malcolm Kendrick, author of The Great Cholesterol Con.
I would think treating blood pressure is largely a waste of time unless it somehow reduces background inflammation which would be best achieved by modifying the patients exposure to the factors that might be causally related to the inflammation. If you have a burst pipe you turn of the tap and intervene the flood and the water that causes it. Only then is worth your time to mop up. Influences behind medicine prefer the GP to mop up while leaving the water flowing.
If I recall Dr Stephen Sinatra discusses inflammation and blood pressure in the ‘Earthing’ book he co-authored. He also introduces the idea of ‘zeta potential’ as can apply to cells in the blood. Zeta potential is a new field to be researched but it is my belief it may be a rich seam for potential to contribute to understanding hypertension, inflammation, and heart disease. ‘Earthing’ theory also redefines the inclusiveness of the term anti-oxidant.
Rath and Pauling proposed a deficit of vitamin C, an anti-oxidant, could be the cause of heart disease, and now we might wonder if the deficit could permit a rise in oxidative stress, that might in turn lead to inflammation, that might then in turn lead to a rise in BP to be detected by the trusty sphygmometer.
Rath and Paulings thesis was trashed by the establishment and Arie Brand, a friend of Dr Kendrick, has been quite forensic in determining how their thesis was laid to rest. Rath and Paulings thesis may not have been fully authentic for describing one cause in a possible ensemble of causes but it held promise and pointed the way away from the very inauthentic cholesterol hypothesis. It was a low-input solution to lucrative problem. That probably was its’ weakest feature.
We’d probably do well to factor activity into the daily routine, avoid high GL carbs so far as we can, enjoy butter and other animal fats, consign margarine to the trash can, manage work related stress better, and redress electrical isolation from Earths’ valuable free electrons. We might see BP residing in more normal ranges and we might see incidence of heart disease in decline.
The trouble is the certainty in these things is elusive and the will to correct illness and symptom in close proximity to cause reduces the opportunities for making money. If I did go to the bookies to place the bet a successful payout would be unlikely.
Dr Kendrick recently blogged about blood pressure, had you seen it Dr Briffa?, and he also hosts a feature contributed by Arie Brand. Link to them here and here.
I’ve noticed a slight improvement in my HBP since eating the paleo based diet, which funnily enough is almost the polar opposite of the DASH diet. The DASH diet encourages a diet mainly of grains, and low fat products, but the paleo diet’s philosophy is that grains were introduced to the human diet relatively recently in the course of our evolution, (just 10,000 years ago), while for roughly 2 million years before that happened, our diet was that of mostly wild game meat and vegetables. My typical diet is very high in saturated (animal) fat, I eat a lot of bacon and eggs, saussages, avocado, coconut, some whole fat (unhomogenised) dairy, nuts, and veggies (actuallly I do need to eat more veggies). I avoid anything processed, so break, pasta, things with preservatives and artificial stuff. Like I said, I’ve noticed some slight improvement, but not enough to make me feel content.
Years ago I lost 50 pounds in weight and greatly lowered very high blood pressure to slightly lower than the average BP for my age, by simply lowering my intake of, and eventually avoiding completely, food containing added salt. So I never eat cheese, cornflakes, bacon, ham, etc. And I eat unsalted pastured butter rather than the slightly salted butter I used to eat.
There is an interesting video on you tube by Robert Lustig which proves a link between high sugar diets and HTN, worth a look. Sugar: the bitter truth
It is not serious to make nay conclusions after 4 years. I am sure all of the participants want to live much more. One more thing – if someone is put on meds it doesn’t mean that nonmedication treatment is put off. The rule is – start nonmedication treatment and if it is not effective enough, add meds. I have a big experience and have realised that people easy keep diet or physical activity. What they can’t cope with is stress. Sometimes I think that depression is a natural reaction to the stress, but if it persist for a long time – turns in a disease.
Both my husband and I have recently stopped eating bread and potatoes. I was already on a low ish carb diet, restricting sugars and refined carbs, having lost 20lb 4 years ago on Atkins. I was recently eating only 2 or 3 slices wholemeal/sunflower loaf a day and plenty of fish, salads, and veg, and red meat twice a week. On this regime my BP remained slightly high. My husband ate 3 or 4 slices of bread. We stopped a month or so ago, substituting with a little ryvita, oatcakes or rice cakes. We still have a little couscous or pasta salad, the occasional social cake or biscuit etc so we are not wheat free entirely. My BP has dropped from around 145/89 to 119/82. My husband also experienced a smaller drop but his BP was less elevated. I could hardly believe it. I also feel very relaxed – see Jim Healthy above. DK if it’s the salt in bread, the low carb effect or something to do with wheat itself. But then it could be the potatoes…….? Whatever it is, I am very pleased.
I was relating the story to a friend who has experienced the same effect after giving up bread.