I recognise that I spent a lot of time telling people what does not cause heart disease, and what does not protect against heart disease. My sister told me… ‘well, what advice would you give people, then?’ I usually shrug my shoulders and reply ‘there is no shortage of advice around, I don’t think I need to add to the daily bombardment.’
However, I shall break the habit of a lifetime and, with slight trepidation, announce that I strongly believe that Potassium is good for you. If you consume more of it you will, most likely, live both longer and in better health.
How much should you consume? A couple of extra grams a day should do the trick. Having said this, I do recognise that most people will not have the faintest idea how much potassium they consume and, frankly, neither do I. But you are probably not consuming enough, and your kidneys will easily get rid of any excess.
For those who are not keen on bananas, spinach and broccoli, and other foods high in potassium, you could take it as a tablet. Potassium bicarbonate or potassium citrate appears to be the best formulation. Depending on which brand you decide to buy, it should cost about £15 – 20/year.
Why this sudden potassiumophilia? Well, there is a growing body of research which points to the fact that potassium is very good for you. The first time I became aware that it might be good for you was when I first looked at the Scottish Heart Health study. The researchers looked at twenty seven different ‘factors’ they thought might cause, or protect against, heart disease – and overall mortality. The authors noted that:
“[There was] an unexpectedly powerful protective relation of dietary potassium to all-cause mortality,” the study concluded.
The paper showed that:
- Men consuming an average of 5400 mg of potassium per day vs 1840 mg were 55% less likely to die during 7.6 year study (the highest one-fifth of men vs the lowest one-fifth of men)
- Men consuming an average of 5400 mg of potassium per day vs 3350 mg were 22% less likely to die during 7.6 year study (the highest one-fifth of men vs the second highest one-fifth of men)
- Women consuming an average of 4500 mg of potassium per day vs 1560 mg were 59% less likely to die during 7.6 year study (the highest one-fifth of women vs the lowest one-fifth of women)
- Women consuming an average of 4500 mg of potassium per day vs 2700 mg were 15% less likely to die during 7.6 year study (the highest one-fifth of women vs the second highest one-fifth of women
The study can most easily be found here http://www.ncbi.nlm.nih.gov/pubmed/9314758
I immediately liked this finding. Mainly because it was almost completely unexpected, and unexpected findings are always far more likely to be correct than expected findings. Also, this was a very large effect indeed. It turned out that increased potassium consumption was very nearly as protective as smoking was damaging.
Of course, this was an observational study, so I filed it under – most interesting – but did nothing much more about it. As the authors said themselves: ‘ Potassium excretion was very significantly related to risk of death from all causes, having a protective role, whereas its role in coronary events was weaker and that of sodium excretion weak and even paradoxical. These results are unifactorial, without correction other than for age and sex. Our findings need corroboration from elsewhere and more detailed analysis with more events from longer follow-up.’
Since then, a large number of other studies have followed up, and appear to have confirmed that potassium has considerable health benefits. Some of these studies were not just observational, they were interventional. Here is summary of the potential beneficial effects. Potassium:
- lowers blood pressure
- lowers the risk of arrhythmias
- lowers the risk of cardiovascular disease
- lowers the risk of stroke
- lowers the risk of heart attacks
- lowers the risk of cancer, and
- lowers the risk of death
These benefits have been confirmed in a number of different studies. However, as this is a blog, I am not going to turn it into a medical paper and provide references for every statement, so I will stick to a couple of referenced studies. (If enough people are interested I can point you at additional papers).
With regard to blood pressure, a study published in 1997 found that adding roughly 2 grams (2000 mg) of potassium per day lowered blood pressure in older people by 15/8 mm Hg. As good, if not better, than any antihypertensive drug1. And with no side-effects at all.
When it comes to stroke, it has been found that having a low potassium level is a very potent risk factor for both bleeding (haemorrhagic) and clotting (ischaemic strokes). In an American study it was found that in those with low potassium levels the relative risk of ischaemic stroke increased by 206%. The relative risk increased by 329% for haemorrhagic stroke2.
Admittedly, these two studies were done in people with high blood pressure to start with, but these effects are also found in healthy people. However, to my mind, the most important thing about potassium is that I cannot find any study, anywhere, which suggests that increasing potassium consumption may be harmful. In short, it seems to be something that does only good.
I do recognise that a lot of doctors will shudder at the thought of adding potassium to the diet, as they have all been taught that a high potassium level is something terribly dangerous. A condition that needs immediate treatment, or else it will cause arrhythmias and death.
It is true that you need to be careful of adding potassium to the diet of patients taking medications that can raise potassium levels. These are mainly drugs used to lower blood pressure. However, even in this group the risk of overdosing on potassium is exceedingly small. For everyone else the risk seems to be zero. This is why I now recommend potassium supplementation as a good way to live a longer, healthier life.
My goodness, I think this is the first time I have ever recommended a dietary supplement. Must go and lie down.
1: ‘Long term potassium supplementation lowers blood pressure in elderly hypertensive subjects’ Fotherby M.D. et al: Int J Clin Practice 1997 41(4): 219 – 222)
2: Smith NL, et al: ‘Serum potassium and stroke risk among treated hypertensive adults.’ Am J Hypertens. 2003 Oct;16(10):806-13