Fasting, LCHF/Keto and hypertension.
A nutrition and health post.
In 2017 i had to go and see a very nice man about getting a new knee as one of mine had packed up and as my lovely GP said was “grinding metal”. In my case it was mostly that the knee joint that side had been slightly out of alignment for most of life and so it had worn away asymetrically , probably not helped by years worth of standing around procedure tables as a nurse and even more time humping big rucksack loads of gear over bigger mountains : what really didn’t help of course was that i was at least 35 lbs overweight, oddly about the same amount of weight i would carry on a multi-day hike.
In the summer of that year i had a partial knee replacement and i have to say that it was a pretty damned good experience of a hospital and healthcare generally, i have to say that it was done in an NHS treatment center and not the main hospital, which would have been a dire experience, and that one of my nurse colleagues looked after me….bringing both me and another patient from the same day and list an endless stream of coffee and biscuits on the first post-operative night. The downside is that when i first met the anaesthetist and he assessed me for his side of the deal was that he asked me if my blood pressure was normally as high as he measured it that morning : turns out that i had previously undiagnosed hypertension, potentially a much greater problem than a grindy knee !
I went home 2 days after surgery and duly made an appointment with my lovely GP who confirmed the finding and started me on an ‘ACE’ or angiotensin converting enzyme inhibitor’….a common first line treatment for essential hypertension : i monitored my blood pressure for a couple of weeks and my GP tweaked the dose slightly until i got an adequate dose response and then i largely took it as just being one of those things that happens as a result of being 60. I got into the habit of regularly taking my medicine and taking my own blood pressure with a store bought monitor….and then largely forgot about the whole thing as….just part of everyday life.
A more entertaining side happened in 2018 when i had to go and buy the same medicine in a rural French pharmacy : my spoken French is excruciatingly bad even when i try so i wrote out a short phrase list to explain to the nice pharmacist that i have a prescription (une ordonance) for a regular drug (medication habituelle) and basically….can i have it…plus pretty please (in French of course). All in all that was perhaps my finest excursion into the French language where the person i was speaking to at least seemed to understand what the hell i was talking about !
As many of my visitors will be aware i did something pretty radical in January of 2019 after realizing that i was not only obese and hypertensive , potentially in metabolic syndrome and also had newly emerging arthritis in my hands. I’d also failed in my post-operative plan to get fully mobile and thus a lot more fit again so what i did that was radically different to anything i’d done before was to try an honest experiment with low carbohydrate (LCHF/Keto) eating.
A few weeks after i started on the Keto diet a strange thing happened : i was working a long day outside basically tidying up and running a small bonfire to burn off debris from clearing a big bramble and invasive Rhodedendron patch, frequently having to stoop down and as quickly stand up with arm loads of brash to go on the fire. The strange thing that day was that i felt oddly weak and even slightly faint each time i stood up, i had to sit down rather a lot and wondered if i was just a bit hot and dehydrated from intermittently working next to the fire and the workload itself. Well, my partner brought me water and then a coffee, i carried on working but still felt generally a bit ‘off’ and it never occurred to me, a nurse, to do something as basic as check my blood pressure : later on that same evening when i did my BP was well down from it’s treated normal and i had a slight slap forehead moment !.
I could have and maybe should have anticipated that outcome because i’d already come across it in Dr David Unwin’s (GP) series of video’s about his experience in treating diabetic and pre-diabetic patients with low carbohydrate diets. If anything it showed me how little confidence i must have had in doing what i was but the numbers were clear enough : i stopped taking the ACE inhibitor and carefully monitored my blood pressure for the next few weeks until i could get a telephone conversation with my GP. As i once said, when i told my GP what had happened and the results of my blood pressure monitoring she ‘squealed like a little girl’ except in delight that i’d reversed my hypertension. As a side issue at the same time i also had a significant subjective change in the way that my hands felt , from often feeling cold and claw like and losing grip on hand tools my hands now felt warm and flexible and my grip strength returned to normal.
So….what’s the mechanism here ?
Lets just say that for the purposes of this post that i have a good enough understanding of the physiology of blood pressure, it was after all a key component of working in cardiothoracics and ICU : also then that i’m pretty sound with the endocrine chemistry side ie the renin-angiotensin-aldosterone system where we could say we threw a spanner in the works with my ACE inhibitor. For the purpose of this thread though it would be a lot more entertaining to look at the current paradigm which says ‘salt causes high blood pressure’.
‘What the numbers say’…..the research if you will, is that salt does modify blood pressure to a small extent : there is some good work that says reducing salt intake can reduce systolic pressure by as much as 3mm Hg (Mercury scale) . There is a problem here though in that my pre-treatment blood pressure was 160/100 and it really needs to be around 120/70 or thereabouts to be a safe number : thus in my case were i to take the low salt option i might have made that number 157/97 , not only hardly worth mentioning but also within the realms of measurement error. As it happens a small dose of an ACE inhibitor did the trick and dropped my dangerous BP to within an acceptable range…..the punch line here is that my experiment with Low Carbohydrate eating dropped it to below normal, in fact it made me quite faint on standing (Postural hypotension) an crucially my BP stayed within normal limits when i came off the ACE inhibitor.
My obvious conclusion here was that salt had very little to do with my hypertension, in fact i have generally increased my salt intake because i most likely lose some during fasting……the main conclusion i came to though is that it was much more likely that my high sugar, high carbohydrate and possibly high poly-fat diet that was responsible for my hypertension.
In the follow-up post to this one i’m going to look at the evidence for Salt vs Sugar..….which one is the killer ?