In my long and winding road around cardiovascular disease I have often visited the same themes a few times. In part, this is because we are not dealing with Newtonian physics here. If billiard ball A strikes billiard ball B, at five metres per second, at an angle of 45 degrees, billiard ball B will move off at angle C at velocity D, assuming perfect elasticity. This will always happen, every single time.
On the other hand, with CVD, the complexity of human physiology and psychology, environmental factors, genetics the time of day, even sunspot activity – can have an effect – so some people have reported.
‘Space proton flux and the temporal distribution of cardiovascular deaths.
The influence of solar activity (SA) and geomagnetic activity (GMA) on human homeostasis has long been investigated. The aim of the present study was to analyse the relationship between monthly proton flux (> 90 MeV) and other SA and GMA parameters and between proton flux and temporal (monthly) distribution of total and cardiovascular-related deaths. The data from 180 months (1974-1989) of distribution in the Beilinson Campus of the Rabin Medical Centre, Israel, and of 108 months (1983-1991) from the Kaunas Medical Academy, were analysed and compared with SA, GMA and space proton flux (> 90 MeV). It was concluded: monthly levels of SA, GMA and radiowave propagation (Fof2) are significantly and adversely correlated with monthly space proton flux (> 90 MeV); medical-biological phenomena that increase during periods of low solar and/or geomagnetic activity may be stimulated by physical processes provoked by the concomitant increase in proton flux; the monthly number of deaths related (positively or negatively) to SA are significantly and adversely related to the space proton flux (> 90 MeV).’1
Oh yes, I do cast my net far and wide when looking at cardiovascular disease, as I feel I must. Quite what we are all supposed to do when the space proton flux is greater than 90MeV, I am not certain. Perhaps a tin foil hat would become appropriately protective headgear. By the way, this paper can be found in the National Institutes of Health on-line library – Pubmed. Referenced, peer-reviewed, and everything.
The point being? The point being that if you are looking for ‘billiard ball’ certainty, you are not going to find it here. If you were to do absolutely everything that I believe to be protective against cardiovascular disease, you will shift the odds in your favour, but you could still get struck down by a heart attack or stroke.
Anyway, with that proviso firmly in place, I shall move ahead, or maybe backwards. On the basis that some subjects need a second visit, I have decided to return to look at vitamin C again. First, because I have just been harangued by someone who believes that if you take high doses of vitamin C every day, you can reverse/cure heart disease completely and utterly. He also felt that I had completely ignored the work of G C Willis ‘The reversibility of atherosclerosis’, and also the research of Pauling and Rath on vitamin C.
It is true that I have not actually mentioned Willis before, but I have certainly written at length of Pauling and Rath. However, I realise that time passes, people forget things, and previous blogs settle to the bottom of the sediment layer. Therefore, it is not a bad idea to refresh things from time to time. I am also returning to vitamin C and the issues around it, because I have been getting a lot of correspondence about lipoprotein (a) (Lp(a)) recently. It seems this lipoprotein is gaining increasing attention. Of course, vitamin C and Lp(a) are tightly bound together.
Time, I think, for a quick refresher about this whole area. Particularly as it helps to confirm my central hypothesis that CVD is a disease of blood clotting, and you would struggle to explain the vitamin C/Lp(a) axis in any other way.
To begin. At some point in the distant past, our ancestors lost the ability to manufacture vitamin C. This happened, so I recently read, around sixty-one million years ago. Seems a long way back, but there you go. It has happened to some other animal groups, but not many. Quite why it occurred is unclear. You probably think you know, but I suspect you are wrong.
Interestingly, and as a bit of an aside, vitamin C is synthesized through a multi-step process, and the original molecule is glucose. Humans lack the last step in the process. Perhaps, because of this, glucose and vitamin C have some interesting interactions in the body. Mainly, it seems, that high levels of glucose prevent vitamin C from entering cells. Particularly immune cells, which need a lot of vitamin C to operate effectively. Make of that what you will.
Moving on, because humans cannot synthesize their own vitamin C, we must obtain it from within our diet. If we do not manage to eat enough, we will end up with scurvy. Scurvy presents with many different symptoms, but the one I am going to focus on in this blog is bleeding.
Bleeding occurs, because vitamin C is essential for collagen synthesis – a critical building block of supportive tissue throughout the body. Loss of collagen leads to break down of various structures in the body. For example, the walls of blood vessel walls which, start to break down and ‘crack.’
As blood vessel walls crack, they leak, and bleed. This leads to the best known symptom of scurvy, which is bleeding gums. This was well recognised several hundred years ago, mainly in sailors who had a highly-restricted diet during long voyages. In scurvy there is also bleeding in many other blood vessels, but you can’t easily see it. The usual cause of death in severe scurvy is internal bleeding.
On the positive side, after sixty-one million years, or so, evolution came up with a partial solution to the early stages of scurvy. Namely, the synthesis of a substance to block the cracks in the blood vessel walls, and control the bleeding. This substance is, or course, lipoprotein (a).
Lipoprotein (a) (Lp(a)) is synthesized in the liver, and it travels around in the bloodstream, looking for any cracks in blood vessels walls a.k.a. damaged endothelium. When a crack is spotted Lp(a) is attracted to the area and sticks very firmly, and cannot easily be removed. Of course, the rest of the blood clotting system also moves into action, so all hell breaks loose. Therefore Lp(a) becomes mixed up with platelets, red blood cells, fibrin, and almost everything else in the blood, including all the other lipoproteins.
However, Lp(a) has a very special trick up its sleeve. It mimics plasminogen.
After a blood clot forms, anywhere in the circulation, it has to be broken down, and removed – once the blood vessel underneath it has repaired. I liken this (not very accurately) to road works. If the road surface is damaged, the repair team comes in, sets up barriers and traffic lights and suchlike, then they repair the road. Then all the barriers, and traffic lights, and suchlike, must be removed.
Within a blood vessel, removal of barriers, and traffic lights, is a tricky exercise. Where does the blood clot go? Once a large blood clot has formed, over a ‘crack’ in the wall, it cannot stay there forever, restricting, or totally obstructing, blood flow. On the other hand, if the entire clot simply broke off, and travelled down the artery, it would get stuck as the artery narrowed – causing a complete blockage. Not a good idea.
Ergo, there is a need for a process that removes blood clots that have formed within blood vessels. It is called thrombolysis, or fibrinolysis. To ‘lyse’ means to break down.
The main player in thrombolysis is plasminogen. It becomes incorporated into (almost) all blood clots that form. It is activated by tissue plasminogen activator (t-PA). This turns plasminogen into plasmin, the ‘active’ enzyme that slices fibrin apart [fibrin is a long, and very strong, string of fibrinogen molecules that wraps round blood clots and binds them together].
t-PA can be manufactured and given to people who have heart attacks and strokes, to break apart the blood clots that are blocking the arteries in the brain, or the heart. You may have heard of t-PA referred to as a ‘clot-buster.’ Great stuff, but not so good if your stroke is due to a bleed in the brain, rather than a blood clot. In which case….
t-PA has been around for a while now and, with heart attacks at least, has mainly been superseded by angioplasty. Which is to open up the blocked artery, and stick a metal support (stent) into the artery. T-PA is still use in ischaemic strokes. That is, after you have had a brain scan to work out what sort of stroke you are having.
Sorry to appear to be going off in different directions here, but the systems of blood clotting are highly complex, and I think that explaining where Lp(a) fits in, is important.
Lp(a) is actually a lipoprotein, just like LDL. In fact, it is exactly like LDL, because it is basically LDL. It is the same size and shape, it contains triglyceride and cholesterol. However, it differs in one important aspect. Whilst LDL has a protein stuck to it called apolipoprotein B-100, Lp(a) has another protein stuck to it called apolipoprotein (a). Which is why it is called lipoprotein (a).
The fascinating thing about the protein, apolipoprotein (a), is that is has almost exactly the same chemical structure as plasminogen. So close, that you could hardly tell it apart. However, apolipoprotein (a) is completely unaffected by t-PA. It does not convert to plasmin, it is inert. So, when you want to break down a clot (fibrinolysis), the parts that have Lp(a) incorporated into it, cannot be broken down.
Which means that if you have a high Lp(a) level, you will develop bigger and more difficult to break down blood clots. Exactly what evolution had in mind for creatures that cannot manufacture vitamin C, and need to plug cracks in artery walls when the vitamin C level falls. However, not so good, if you want to stop atherosclerosis from developing.
Because these Lp(a) rich blood clots have to go somewhere, and the only place that they can go is to be absorbed into the artery wall itself, and then broken down. However, these clots are more difficult to break down, so, with repeated clots over the same area of artery wall, bigger and bigger plaques will grow.
That, anyway, is the theory.
What G.C. Willis did in 1957 was to study guinea pigs. Guinea pigs are another animal that does not synthesize vitamin C. He made them scorbutic (vitamin C deficient a.k.a. scurvy). Actually, he did not make them all scorbutic. He had a control group of twelve guinea pigs that he put on a vitamin C deficient diet, then injected them with vitamin C. None of these twelve guinea pigs developed any measurable atherosclerosis.
On the other hand, those guinea pigs on a scorbutic diet rapidly developed atherosclerosis. When I say rapidly, I mean within days. I think this point is worth repeating. If you make a guinea pig scorbutic, it will develop plaques, identical to those found in human arteries within days.
Willis then started feeding his guinea pigs vitamin C, and he found that the lipid filled plaques quite rapidly disappeared. He describes what he saw happening to the guinea after they were fed vitamin C.
‘The results of this investigation indicate that early lesions of atherosclerosis are quickly resorbed. The stages of this process are first a fading of lipid staining in the region of the internal elastic membrane with later a disappearance of all extracellular fat. Active phagocytosis of lipid by macrophage occurs, and when these macrophages finally disappear no evidence of the lesion remains.’ 2
I shall translate that passage for those with a non-science background.
What Willis found was that if you remove vitamin C from the guinea pig diet, they develop fat filled atherosclerotic plaques within days. If you then add vitamin C to the diet again, the plaques rapidly disappear (within days). The process of removal appears to be that the fat/lipid is ingested (phagocytosed) by white blood cells – known as macrophages.
However, if you let the plaques grow for too long, it is far more difficult to get rid of them.
‘More advanced lesions are considerably more resistant to reversal. Extensive lipid deposits clear in some parts of plaque but islands of intensely staining lipid persists in other parts. The macrophage response to such areas is only slight.’
It seems that if you don’t get rid of the plaque pretty much straight away, you don’t get rid of it at all. [Or maybe he didn’t wait long enough to see what happened over months, or years. Although my childhood memory of guinea pigs is that they tend to drop dead at the slightest excuse].
Of course, this was guinea pigs, not humans, so we must be careful not to extrapolate too far. However, previously, Willis had studied humans. Not many, only sixteen. Ten people with identified plaques were given vitamin C, six were not. In those ten treated with vitamin C, the plaques got bigger in three, stayed the same in one, and reduced in size in six. In those six not given vitamin C, three remained the same, and in three the plaques got bigger. Interesting, but hardly cast-iron proof of anything.
At this point there are a number of strands to gather together. We now know that humans cannot synthesize vitamin C, so we need to eat it. Without enough vitamin C, our blood vessels crack and bleed, and in severe cases we bleed to death.
In order to provide a degree of protection against vitamin C deficiency (scurvy), we produce lipoprotein (a) to fill up the cracks the blood vessels. However, unsurprisingly, a high level of lipoprotein (a) Lp(a) is associated with a higher rate of CVD.
‘In summary, elevated Lp(a) levels associate robustly and specifically with increased CVD risk. The association is continuous in shape without a threshold and does not depend on high levels of LDL or non-HDL cholesterol, or on the levels or presence of other cardiovascular risk factors.’ 3
This raises two inter-connected questions. Does vitamin C supplementation lower Lp(a) levels, and does it reduce the risk of CVD? It is of course entirely possible that vitamin C could reduce CVD risk by protecting blood vessels from ‘cracking’ without having any effect on Lp(a) levels.
Now you would think that this would have been an area of research interest to someone…. Anyone. However, the only people who seem to have looked at this area in any details are Linus Pauling (double Nobel prize winner, now dead) and Matthias Rath. A man whose reputation within the mainstream medical profession makes that of Andrew Wakefield look like mother Teresa. This from Wikipedia:
‘The Sunday Times (Johannesburg) has described Rath as an “international campaigner for the use of natural remedies” whose “theories on the treatment of cancer have been rejected by health authorities all over the world.”
On HIV/AIDS, Rath has disparaged the pharmaceutical industry and denounced antiretroviral medication as toxic and dangerous, while claiming that his vitamin pills could reverse the course of AIDS. As a result, Rath has been accused of “potentially endangering thousands of lives” in South Africa, a country with a massive AIDS epidemic where Rath was active in the mid-2000s. The head of Médecins Sans Frontières said “This guy is killing people by luring them with unrecognised treatment without any scientific evidence”; Rath attempted to sue him.
Rath’s claims and methods have been widely criticised by medical organisations, AIDS-activist groups, and the United Nations, among others Former South African President Thabo Mbeki and former Minister of Health Manto Tshabalala-Msimang have also been criticised by the medical and AIDS-activist community for their perceived support for Rath’s claims According to doctors with Médecins Sans Frontières, the Treatment Action Campaign (a South African AIDS-activist group) and a former Rath colleague, unauthorised clinical trials run by Rath and his associates, using vitamins as therapy for HIV, resulted in deaths of some participants. In 2008, the Cape High Court found the trials unlawful, banned Rath and his foundation from conducting unauthorised clinical trials and from advertising their products, and instructed the South African Health Department to fully investigate Rath’s vitamin trials.’
Matthias Rath even managed to fall out with Linus Pauling, before Pauling’s death, and law suits ensued. Rath has also successfully sued the BMJ, received £100,000 in damages. So, as you can see, not really a poster boy for mainstream medical research.
I include this information, as I think it is critical to the entire Vitamin C discussion. Because Matthias Rath is viewed as absolute scientific poison this has made the whole area of vitamin C supplementation a complete no-go area for any respectable scientist. If, as a doctor, you try to suggest that vitamin supplementation may be a possible treatment for, say, CVD, you might as well hand you licence over to the authorities at the same time – to save them the trouble of striking you off the medical register (almost a joke, but not quite).
So, essentially, we have a huge void here. The only research that I have ever seen (maybe I missed some) to establish if vitamin C supplementation does actually lower Lp(a) levels was done by Matthias Rath. And, according to him, it does. More so, in those with higher levels to start with. I am not referencing this research, but I would suggest you have a look around Rath and Pauling and vitamin C and Lp(a). See what you think. I think the research is robust.
With regard to the critical question, does vitamin C reduce the risk of CVD [with or without lowering Lp(a)]. I would say, case currently unproven. This does not mean that it does not (in fact I believe that it probably does). What I mean by ‘case currently unproven’ is that no-one has done a large scale interventional study using vitamin C to find out if it really reduces CVD.
The problem here is that such a study is almost certainly never going to be done. There is no way anyone can make money from doing such a study. Vitamin C cannot be patented, so if a company spend several hundred million ‘proving’ that vitamin C reduced CVD death, they would never get any money back.
You would have to find a Governmental organisation, tax payer funded, to do such a study. And with Matthias Rath around, that just ain’t going to happen. No-one would touch it.
However, there is one way to definitely reduce Lp(a) levels, and that is to take l-carnitine. Here, from a study called ‘L-carnitine reduces plasma lipoprotein(a) levels in patients with hyper Lp(a)’
‘L-carnitine, a natural compound stimulating fatty acid oxidation at the mitochondrial level, was tested in a double blind study in 36 subjects with Lp(a) levels ranging between 40-80 mg/dL, in most with concomitant LDL cholesterol and triglyceride elevations. L-carnitine (2 g/day) significantly reduced Lp(a) levels… the reduction being more dramatic in the subjects with the more marked elevations. In particular, in the L-carnitine group, 14 out of 18 subjects (77.8%) had a significant reduction of Lp(a) vs only 7 out of 18 (38.9%) in the placebo group. In a significant number of subjects the reduction of Lp(a) resulted in a return of this major cardiovascular risk parameter to the normal range.’ 4
Does this then result in a reduction in CVD risk? The answer is that I do not know, for sure. A meta-analysis of L-carnitine supplementation has been done. This consisted of five trials on three thousand people. L-carnitine supplementation did show some benefit – which did not reach statistical significance, but came very, very close.
For those of you who like a bit of statistics, here we go
‘The interaction test yielded no significant differences between the effects of the four daily oral maintenance dosages of L-carnitine (i.e., 2 g, 3 g, 4 g, and 6 g) on all-cause mortality (risk ratio [RR] = 0.77, 95% CI [0.57-1.03], P = 0.08)’5
CI [0.57 to 1.03] – close, but no cigar.
To put this into figures anyone can understand. In the intervention groups (those taking L-carnitine) there were 83 deaths. In the control group (those not taking L-carnitine) there were 106 deaths. Total study population was 3108, split in two groups: control and intervention. This gets as close to statistical significance as you can get (virtually). In fact, if this had been a statin trial, you would never have heard the end of it. ‘Ladies and gentlemen a 22% reduction in overall mortality with L-carnitine supplementation.’ [Oh, what fun statistics are].
So, what do we know?
- A high level of Lp(a) is associated with a higher risk of CVD.
- There is a probable causal mechanism linking Lp(a) to CVD death
- Lp(a) is synthesized in animals that cannot make their own Vitamin C
- A lack of vitamin C causes blood vessels to crack open – and potentially leads to atherosclerotic plaques development
- Animal models have shown that a lack of vitamin C does lead to rapid atherosclerotic plaque development, and that replacement of vitamin C causes rapid regression of atherosclerosis
- Some evidence from humans suggest that vitamin C supplementation causes regression of atherosclerotic plaques
- Vitamin C supplementation does seem to lead to a reduction in Lp(a) levels
- L-carnitine supplementation does lead to a reduction in Lp(a) levels
- L-carnitine supplementation may reduce overall mortality.
What would I now recommend? If you have a high Lp(a) level take lots of vitamin C and l-carnitine and see if your Lp(a) level falls. If it does, keep taking lots of vitamin C and l-carnitine for the rest of your life. If it does not fall? Not sure.
As for the rest of us? Well I have no idea how much vitamin C anyone should take, or how much l-carnitine is required. There is literally no area of medicine that is less clear than our true vitamin requirements. You can find a thousand shouty people supporting high vitamin supplementation – any or all vitamins.
My view. I do not think the RDAs for vitamins are remotely accurate, or useful. They were established in times of absolute deficiency. The agreed Vitamin B12 levels, for example, were based on seven people, over sixty years ago, and remain unchanged to this day. All seven had pernicious anaemia (caused by vitamin B12 deficiency).
So, I do not believe in the RDAs at all. They are often, I believe, too low for optimal health. I can see no harm coming to people from taking lots of vitamin C or lots of l-carnitine. So, supplement away. You will probably reduce your risk of dying from CVD.