Articles

Vitamin E and Stroke

One of the recurrent themes of science-based medicine is that any medical intervention that can plausibly cause physiological benefit can also plausibly cause physiological harm.  There is no such thing as “it can’t hurt.” Sometimes the risk may be minuscule – but we should never assume that it is zero. Being “natural” or “holistic” or being blessed with some other alleged marketable virtue does not affect the risk vs benefit calculation of an intervention.

Vitamins are an excellent example. There is widespread sentiment that vitamins are harmless, and that supplementing with vitamins is therefore a no risk-possible benefit scenario. It is certainly reasonable to conclude from the evidence that vitamins (at usual supplemental levels) are low risk, compared to many other types of medical interventions. High doses, or megadoses, of vitamins, however, risk toxicity and this risk increases with the dose.

But even at sub-toxic doses vitamins should not be assumed to be risk free. This is especially true when we take a public health perspective – what is the net effect of large scale supplementation on the population? A new meta-analysis looking at the net effects of Vitamin E supplementation on stroke risk reinforces this caution.

Vitamin E has received a lot of attention recently because of its antioxidant effects. Oxidative stress plays a role in tissue damage, aging, and various disease processes, and so supplementing with anti-oxidants seems like an obvious treatment to mitigate this damage. However, biology is complex, and oxygen free radicals also play a role in cell signaling, for example, so that exogenously suppressing them may have negative unintended consequences.

For example, the emerging research regarding Vitamin E and heart disease is mixed and complex. Vitamin E supplements actually seem to increase total mortality and heart failure. However, observational studies show a decreased risk of cardiac disease in those who take Vitamin E. The difference may be that foods rich in Vitamin E come with a health benefit (which may be from the foods that are not eaten with such a diet), but vitamin pills do not convey this benefit. There may also be a difference between primary prevention (in those without prior cardiac events) where there is a net benefit and secondary prevention (in those who have suffered a cardiac event) where there is net risk. There may be subpopulations, like diabetics, who benefit more.

The bottom line at this time is that eating a healthful diet rich in fruits and vegetables is consistently associated with decreased risk of various diseases, including heart disease. However taking vitamin E supplements may not have this same benefit, and in fact may come with a net risk of increased heart disease and mortality.

What about stroke risk? While there are differences, stroke is also a vascular disease, like myocardial infarction, and the risk factors tend to be similar. In the new meta-analysis the researchers found:

In this meta-analysis, vitamin E increased the risk for haemorrhagic stroke by 22% and reduced the risk of ischaemic stroke by 10%. This differential risk pattern is obscured when looking at total stroke. Given the relatively small risk reduction of ischaemic stroke and the generally more severe outcome of haemorrhagic stroke, indiscriminate widespread use of vitamin E should be cautioned against.

Again we see a bottom line caution against supplementing with vitamin E. It is important to note that even a small increase in net stroke incidence has a huge effect on the general population. Stroke is a debilitating disease, potentially fatal, and a huge financial burden on the health care system. Even small percentage increases therefore have a huge societal effect. A 22% increased in hemorrhagic stroke is a very large clinical effect.

Conclusion

The research on vitamins in general and vitamin E in particular is messy and complicated. My overall impression of this research is that there is no consistent signal of net benefit for routine supplementation. There are many specific conditions in which specific supplementation is of benefit, but not routine supplementation for general health.

At the same time there is a consistent signal of benefit to having a healthful diet, the primary feature of which is to have a diet rich in fruits and vegetables. So in the end, after decades of research, what your mother always told you turns out to be the best advice – eat your vegetables.

Posted in: Herbs & Supplements, Nutrition

Leave a Comment (30) ↓

30 thoughts on “Vitamin E and Stroke

  1. windriven says:

    A remarkable feature of this is that, while the benefit may be small or even negative, Americans spend roughly $11 BILLION dollars each year on supplements(1). To put that in perspective, that is almost 100 times more than the 2009 budget for NCCAM(2). Money well spent, huh?

    (1) http://www.news-medical.net/news/20100607/TABS-Group-estimates-US-Vitamin-Minerals-and-Supplements-market-at-2411B.aspx

    (2) http://nccam.nih.gov/about/offices/od/directortestimony/0308.htm

  2. windriven says:

    And I had intended to add to the above:

    And more than 5 times NIH spending on heart disease research.

    http://report.nih.gov/rcdc/categories/

  3. ccbowers says:

    Why has this message taken so long to reach the general public, and worse physicians and other healthcare professionals? The idea of vitamins or supplements for “general health” is a fallacy, and this has been known for quite some time.

  4. crazyred says:

    I have read that excessive vitamin E supplementation has a blood thinning effect. Can this be the reason for an increased hemorrhagic stroke risk?

  5. threelittlepigs says:

    Are you including the “high-quality supplements” that naturopaths sell as vitamins? My family members will talk all day about how “conventional vitamins” (including prenatals) are not good for you, but they all take several different supplements that are supposed to be made from whole foods. They say those are good for you because they come from foods.

  6. windriven says:

    @threelittlepigs

    A nice 2 cup serving of collard greens, to pick a personal favorite, contains all sorts of good things for one’s body. To condense that down into ‘high-quality supplement’ pill form, something has to come out to reduce 2 cups to a few ml. Granted that some of that is water. What is the rest? Who says those discarded materials aren’t as beneficial or more beneficial than the materials kept? And who says those discarded materials do not act synergistically to provide the desired effect?

    I am not stating any of the above to be a scientific certainty, only suggesting that the source of an isolated nutrient may not have as much bearing as your family members believe.

  7. CarolM says:

    Oh thank God. I was just searching this site yesterday for Vitamin E articles..when I was younger and still having skin problems, E supps seemed to do wonders for me, healing the pimples quickly and making my skin smooth. I would dose with several 100 or 200 IU pills throughout the day. I compared notes with other women who said the same. It really does do *something* and it must have something to do with the blood-thinning effect.

    After years of not taking it, I got a small bottle last week but I will cease and desist forthwith. But can you believe it, I was at lawyer’s continuing ed last week, and one of the presenters advocated E to fight Alzheimer’s and other dementia. Because Vitamins are Good! what’s the harm?

    I should have objected but words failed me.

  8. KGelling says:

    A 22% increased in hemorrhagic stroke is a very large clinical effect

    But 0.08% (the absolute risk) is not! Tut, tut – spinning the relative risk to make a headline.

    Vitamin E supplementation reduced risk of an ischaemic stroke by 21 (0.21%) in 10,000 and increased risk in haemorrhagic stroke = 8 in 10,000 (0.08%)

    So vitamin E supplementation reduced absolute risk of a stroke by 12 in 10,000 (0.12%).

    Ishaemic strokes are more common (based on figures from placebo groups, the risk of ischaemic stroke = 215 in 10,000 and risk of haemorrhagic stroke = 36 in 10,000) but haemorrhagic stroke outcome is more severe.

    But as the results had borderline significance, I suspect the take-away message is that vitamin E has minimal effect on risk of stroke.

  9. David Gorski says:

    A remarkable feature of this is that, while the benefit may be small or even negative, Americans spend roughly $11 BILLION dollars each year on supplements(1). To put that in perspective, that is almost 100 times more than the 2009 budget for NCCAM(2).

    And it’s 1/3 the budget of the entire NIH.

  10. Dawn says:

    This is very interesting, Dr Novella. Especially since my mother, on the advice of her physician (I don’t recall GP or one of her specialists) has been taking Vitamin E (supplement level but not megadoses IIRC) for several years. He started her on it after an ultrasound showed blockages in her carotid arteries. He monitored her regularly (still does). After a few years, the blockages vanished (decreased size then absense documented on serial ultrasounds). Nothing else in her diet or medications changed.

    I realize it’s an anecdote, but I’ve always wondered if the blockages resolved on their own or the Vitamin E really helped.

    (I take a regular multivitamin and calcium daily. Ever since my gastric banding since I am unable to eat enough, especially fruits and vegetables, to get my daily requirements any other way.)

  11. daedalus2u says:

    I disagree that that any medical intervention that can plausibly cause physiological benefit can also plausibly cause physiological harm. A nutritious diet, sufficient sleep and moderate exercise are examples of interventions that can cause physiological benefits but no plausible mechanism for physiological harm.

    There is another hypothesis for why it seems like nutrients from dietary sources are beneficial but nutrients from supplements are not. All long-term diet studies are with self-selected diets. Non-self-selected diets are either too expensive to do trials on for long term, or people don’t follow them, or are to restrictive for any but short-term in patient nutrition studies.

    My hypothesis is that the oxidative stress setpoint is set by physiology, and diet choice is a control control mechanism for physiology to regulate its state of oxidative stress. When physiology has a low oxidative stress setpoint, the self-selected diet is one rich in antioxidants, green leafy vegetables and polyphenolic antioxidants. When physiology has a high oxidative stress setpoint, it self-selects a diet devoid of antioxidants, devoid of vegetable, rich in energy substrates of sugar and fat without ppolyphenolic antioxidants.

    Free radicals are important signaling molecules. Physiology wants dietary antioxidants to match the oxidative stress setpoint it is trying to reach. Physiology has unlimited capacity to destroy antioxidants via generating more superoxide, but there is a metabolic cost, and likely a physiological cost due to the excess superoxide generated to destroy the excess antioxidants.

    I think this is one mechanism by which supplemental antioxidants do cause harm, they are over and above what ever physiology is trying to achieve via a self-selected diet, so they force physiology to destroy them by generating more superoxide, and there is a health cost to that destruction. Vitamin E does interact with metabolism of vitamin K so excess vitamin E does interfere with vitamin K physiology.

    http://www.ncbi.nlm.nih.gov/pubmed/19019024

    There is another intervention that has no plausible adverse health consequences, that is restoring a more normal basal nitric oxide level. ;)

  12. windriven says:

    @daedalus

    Man, you take a broad view to ‘intervention.’ Is breathing an intervention too?

  13. daedalus2u says:

    Any change from your current status quo is an “intervention”.

    I don’t see how you can have any other definition.

    If you are living at 10,000 feet, moving to sea level is an intervention.

    Some interventions that are commonly done do have side effects. A gut full of parasites is therapeutic against Crohn’s disease. Removing those parasites makes Crohn’s disease worse.

    There are interventions that people have done and have given no thought to whether there are adverse effects or not, and now refuse to even consider that there might be adverse effects. There is considerable thought that differences in hygiene between the developed world and the undeveloped world is responsible for some of the adverse health effects observed in the developed world, obesity, allergies, and so on.

  14. Ken Hamer says:

    “I disagree that that any medical intervention that can plausibly cause physiological benefit can also plausibly cause physiological harm. A nutritious diet, sufficient sleep and moderate exercise are examples of interventions that can cause physiological benefits but no plausible mechanism for physiological harm.”

    When I was in my teens I enjoyed riding my bicycle, which was considered a good form of moderate exercise. Then one day I fell off it, suffered a concussion and a bruised kidney, and spent 8 days in the hospital.

  15. BillyJoe says:

    “A nutritious diet, sufficient sleep and moderate exercise are examples of interventions that can cause physiological benefits but no plausible mechanism for physiological harm. ”

    How simple is this:

    You can accidentally get a fruit seed caught in your oesophagus.
    You can fall out of your double bunk while asleep.
    You can run into a pot hole and fracture your ankle.

  16. BillyJoe says:

    Steven Novella said: “A 22% increased in hemorrhagic stroke is a very large clinical effect”

    KGelling replied: “But 0.08% (the absolute risk) is not! Tut, tut – spinning the relative risk to make a headline.”

    BillyJoe replies:
    You quoted Steven Novella out of context!
    (You aren’t a CAM supporter by any chance? ;))
    Here is the context:

    “Stroke is a debilitating disease, potentially fatal, and a huge financial burden on the health care system. Even small percentage increases therefore have a huge societal effect. A 22% increased in hemorrhagic stroke is a very large clinical effect.”

    You see the difference?
    Steven is talking about the burden on “the health care system”. Not your risk or my risk.
    Now answer this question: The burden on the health care system of haemorrhagic stroke is increased by…

    1) 0.08%
    2) 22%

  17. daedalus2u says:

    The examples of adverse effects are not necessary consequence of a nutritious diet, sufficient sleep and moderate exercise. The adverse effects that Dr Novella was talking about are. None of those examples are specific to a nutritious diet, sufficient sleep or exercise that is moderate. Any diet, nutritious or otherwise that contains seeds, any sleep in a high bunk, any movement where there are potholes could cause adverse consequences.

    In the example of vitamin E, the effects appear to be a necessary trade-off. There is a reduction in ischemic stroke and an increase in hemorrhagic stroke. The increase in hemorrhagic stroke appears to be due to the interactions of vitamin E with the cytochrome P450 enzymes that metabolize vitamin K.

    The relative increase was for a short period of time, the length of time of the trial. If excess vitamin E was taken over a lifetime, the increase might be larger. There may be other adverse effects from increased chronic bleeding which take longer than the trials to find, or which the trials did not look at. Subclinical hemorrhagic stroke could have adverse effects that would be worse in younger people or worse if they accumulated over longer periods of time.

  18. daedalus2u,

    Saying that choking on a seed is not a risk of a moderate diet because immoderate diets could result in the same thing is like saying that infection is not a risk of acupuncture because anyone poking you with a dirty needle could do the same thing. It’s just a risk.

    The generally recommended moderate diet with lots of fruits and vegetables has risks and benefits that (for most people) are better than the risk/benefit profile of the alternatives (not eating; parenteral feeding; enteral feeding; immoderate, unbalanced diets). That doesn’t mean it is risk-free. Someone switching from a twinkie diet to one recommended by their doctor containing actual food might get a fishbone stuck in their throat. Sucks, but true.

  19. oderb says:

    @billyjoe

    Not sure what your point – or Dr Novella’s – is as according to Billie Joe the absolute risk reduction for all strokes from taking Vitamin E is 12/100,000. Hard to argue that the burden of the health care system is worsened (though maybe not reduced given the greater damage from haemorrhagic stroke)

  20. For completeness I should have pointed out the absolute risks as well.

    To clarify the point I was trying to make – effects for the individual are quite small, largely because strokes (in the general population) are very uncommon. The same can be said for using aspirin to prevent strokes – while it is a blood thinner and reduces risk of stroke through that mechanism, the evidence does not support it’s use for primary prevention (but it does for secondary prevention) primarily because the baseline rate is so low studies do not reach statistical significance.

    But – when we consider the effect on society, the small percentage changes add up to a significant effect.

    Another point made in the paper is that hemorrhagic strokes tend to be more devastating than ischemic strokes, and that has to be taken into consideration when balancing effects on both.

  21. “Someone switching from a twinkie diet to one recommended by their doctor containing actual food might get a fishbone stuck in their throat. Sucks, but true.”

    A nitpick, I would consider the mercury in fish risk over the fishbone choking risk, any day. But I’m still bummed about having to cut back on canned tuna. I love me some tuna sandwich.

  22. WilliamLawrenceUtridge says:

    @daedalus2u

    I disagree that that any medical intervention that can plausibly cause physiological benefit can also plausibly cause physiological harm. A nutritious diet, sufficient sleep and moderate exercise are examples of interventions that can cause physiological benefits but no plausible mechanism for physiological harm.

    I would say that taking a vitamin supplement is a form of dosing that is not comparable to eating a broad, healthy diet, getting moderate exercise and sufficient sleep. Eating a healthy diet is comparable to eating a healthy diet (yes, I know…), getting moderate exercise and sufficient sleep. Taking a vitamin supplement is more akin to eating only “healthy thing” like eating only fruit, or only vegetables. It’s like getting a LOT of exercise. And like sleeping 10-12 hours per day. Per the courses I took in university (so, no sources and a grain of salt) Olympic athletes tend to die sooner than the rest of the population because of the stresses of that level of exercise on their body. The death curves for sleep peak at the high and low ends – so getting a lot more or a lot less than 8 hours is associated with higher rates of death. And if you eat only “healthy” foods, you’ll die of B12 anaemia, protein deficiency and other forms of nutritional deficits.

    Taking a vitamin supplement is not like the sensible, lifestyle advice we all get. It’s like taking that to an extreme (admittedly, a moderate extreme). Orthomolecular medicine however, is like running a marathon every second day; sleeping 20 hours per night; having your stomach burst from consuming 10 pounds of fruits and vegetables every hour.

    Or really, taking a multivitamin is like taking a multivitamin – turns out it has small but measurable risks. Every decision taken has a chance of benefit and a chance of harm and it’s a way of balancing out those chances.

    And I’ll also point out that every waiver at every gym I’ve ever seen has had a line saying “Before starting an exercise program it is recommended you consult your doctor”. There’s a reason for that – a legal reason and a real, common-sense reason. There’s always a chance you might blow an aneurysm.

    But there really is an interesting question in your statement – is it an absolute rule that all interventions affecting a physiological change can do either harm or good? That’d be a neat review article (or book).

  23. daedalus2u says:

    Eating seeds that give you a risk of choking to death is not a necessary aspect of a healthy diet. Being poked with needles and risking infection is a necessary aspect of acupuncture.

    You can eat a healthy diet that has no seeds that can be choked on, you can’t receive acupuncture that does not involve being poked with needles. If the “intervention” was “eat more seeds to get better nutrition due to eating seeds”, then yes, “choking on a seed” is a potential adverse effect of that “intervention”.

    The point I am trying to make is that the idea that all interventions have adverse side effects is an example of trying to apply false balance. When something is necessary, such as breathing or eating food, there are certain risks associated with those behaviors, and the precise risks depend on the precise details of the behavior. What we are interested in is differential risk due to the intervention. In other words, how does the risk profile change with the intervention.

  24. qetzal says:

    @deadalus,

    I don’t think your examples of intrinsically non-harmful interventions pass muster.

    Food allergies are an intrinsic harm that can be caused by an otherwise healthy diet. Exercise can lead to injuries. It’s not really fair to claim that exercise “in moderation” is somehow different. That would be like claiming a drug can’t have side effects as long as it’s administered at a side-effect-free dose. Even excessive sleep would have plausible negative effects. If nothing else, sleeping 20 hrs a day would likely be harmful simply due to the lack of physical activity.

    Besides, I think the original point is that the only way an “intervention” could truly have no potential for harm is if it has literally no effects at all. An intervention can’t help unless it can affect the body. If it can affect the body, then there is a chance the effect will be negative. IOW, it’s not that every intervention can be harmful to any given person under any given set of circumstances. It’s that claiming that “it (CAM) might help and it can’t hurt” is categorically wrong.

  25. daedalus2u says:

    For something like sleep there is an optimum level. More than that level is bad and also less than that level is bad. That optimum level likely changes with other things. If you are at the optimum level, changing it will cause adverse effects. If you are too high or too low, changing it to the optimum level won’t cause adverse effects.

    Eating foods you are allergic to will cause problems whether you are eating a nutritious diet or an non-nutritious diet. There is nothing about a nutritious diet intervention that compels consumption of things you are allergic to.

    It is “fair” to not attach the problems of over exercise to moderate exercise. It is not like the issue of drugs and side effects. Drugs have side effects not because of the dose, but because drugs are non-physiologic and have effects that are different than the target effect they are being administered for. You have to administer a drug in a sufficient dose to have the therapeutic effect.

    It is a form of denialism for the couch potato to rationalize not exercising even once a week because people who run a marathon every other day develop health problems. I appreciate that people do that, but their need to rationalize their decisions doesn’t make their reasoning valid.

  26. qetzal says:

    deadalus2u,

    The original claim was:

    [A]ny medical intervention that can plausibly cause physiological benefit can also plausibly cause physiological harm.

    You disagreed, claiming:

    A nutritious diet, sufficient sleep and moderate exercise are examples of interventions that can cause physiological benefits but no plausible mechanism for physiological harm.

    Getting a nutritious diet, sufficient sleep, and moderate exercise are not interventions. An intervention requires a change from one state to another. Interventions would include things like eating more vegetables, getting more sleep, and exercising more. All of these interventions have the potential to cause harm.

    You can’t get around that by saying ‘change to the optimal level’ because there’s no guaranteed way of doing that. It’s entirely plausible to go from a non-optimal level to an even less optimal level. IOW, there’s a plausible chance of harm.

    Many drugs are non-physiologic, but certainly not all. Estradiol and testosterone are drugs that are chemically identical to the substances produced by our bodies, yet they can clearly have adverse effects. Moreover, those effects can be mediated through exactly the same pathways targeted by the endogenous substance.

    Finally, I agree with your point about denialism but that’s a separate issue. It doesn’t bear on the truth of Dr. Novella’s original statement.

  27. daedalus2u says:

    If you are already eating a nutritious diet, then I agree, the intervention of eating a nutritious diet won’t do anything beneficial for you. It also won’t do anything harmful. If you are not eating a nutritious diet (which many people on Earth are not), then the intervention of eating a nutritious diet will have beneficial health effects. In either case eating a nutritious diet will not have adverse health effects.

    The same goes for sufficient sleep and appropriate levels of exercise. If you are already doing these things there is no benefit, but also no adverse effects. If you are not doing these things then there will be benefits.

    I agree that if you are already doing them, then they are not “interventions”. If you are not already doing them, then changing your living circumstances such that you start to do them is an “intervention”. An intervention that does not have adverse side effects.

    All hormone treatments are non-physiologic. The composition of the hormone may be bio-identical, but the mode of delivery is not. The non-physiologic delivery of a hormone may be better than the lack of the hormone (insulin by injection for example), but that does not make it a physiological delivery.

    The reason I bring this up and the reason am quite insistent on it is due to my nitric oxide research. If someone is in a state of insufficient basal NO/NOx, what I call nitropenia, then increasing their NO/NOx status via physiologically regulated pathways will have beneficial health effects with no adverse side effects.

    Non-physiologic NO/NOx deliveries do cause adverse side effects. Eating excess L-arginine causes side effects, every type of NO donor causes side effects. The reason they cause side effects is because there are a great many NO/NOx pathways and it is not technically possible to duplicate the physiological delivery of NO/NOx artificially to each and every one of them. Trying to deliver NO/NOx via non-physiological methods either delivers too much, or too little, or to the wrong tissue compartment at the wrong time and in the wrong form.

    It is similar to how every non-physiologic method of hormone delivery can cause adverse side effects. They may be minor (irritation at site of insulin injection), modest (swings of blood glucose level) or severe (autoimmune sensitization to insulin), or but there will be side effects. The side effects are a necessary consequence of delivering insulin in a non-physiologic manner. If you could replace the dysfunctional pancreas with a pancreas that was fully functional and functioning properly, and interfaced with the rest of the body exactly right (hard to do in diabetes type 1 because of autoimmune sensitization against pancreatic islets), then there wouldn’t be adverse effects of the “intervention”.

    The delivery of NO/NOx to different tissue compartments is like the “delivery” of electricity to different parts of a computer. Every part of a computer runs on electricity, but you can’t make a computer run better by supplying electricity other than through the pathways the computer was designed to receive it. If you try to supply exogenous electricity to the memory, you will screw it up big time because some of the electricity is there as signals and need to be supplied at the right place at the right time and in the right phase with everything else that is going on. Trying to supply more NO/NOx via non-physologic mechanisms is like trying to supply more electricity to a computer with jumper cables and expecting it to work better.

  28. qetzal says:

    deadalus,

    There’s no such intervention as ‘achieving the optimal level of X.’ Not in the real world.

    If someone is in a state of insufficient basal NO/NOx, what I call nitropenia, then increasing their NO/NOx status via physiologically regulated pathways will have beneficial health effects with no adverse side effects.

    Assume that’s true. The intervention in that case is increasing their NO/NOx status. Ideally, their NO/NOx status is increased to the optimal level. But it’s possible to increase it too much, right? And if that happened, it would have adverse effects right?

    Well there’s your a plausible physiological harm that could be caused by the intervention. However much we intend to only increase NO/NOx to the optimal level, it’s plausible we could overshoot and go too high. Maybe the individual being treated is much more sensitive than most people to whatever we’re doing to increase NO/NOx. Whatever the reason, in the real world, it would impossible to eliminate any chance of inducing excessive NO/NOx.

    As for hormones, you said earlier:

    Drugs have side effects not because of the dose, but because drugs are non-physiologic and have effects that are different than the target effect they are being administered for.

    Now you say:

    All hormone treatments are non-physiologic. The composition of the hormone may be bio-identical, but the mode of delivery is not.

    Perhaps I’m misunderstanding, but you seem to be saying that drugs have side effects only because they are non-physiologic. If we could somehow eliminate all non-physiologic aspects, that would eliminate all possibility of side effects. If that’s what you’re arguing, it’s wrong.

    I agree that injectable testosterone therapy (for example) is a non-physiologic delivery, and there can be side effects associated with that delivery (e.g. injection site reaction). But injectable testosterone can also cause side effects by acting through exactly the same physiological pathways as endogenous testosterone. The substance itself has the ability to cause side effects, whether it’s exogenous or endogenous. Being ‘non-physiologic’ has nothing to do with those intrinsic effects.

  29. daedalus2u says:

    I don’t think it is possible to increase the NO/NOx level too much by the technique I am using because the level is regulated and there are compensatory feedback pathways that can reduce the NO/NOx delivery. It is possible to get too much NO/NOx, but not by the technique I am using. Raising the basal NO/NOx level actually makes it more difficult to get too much NO/NOx because NO inhibits the activity of NFkB which causes the expression of iNOS which is what causes too much NO during sepsis.

    Suppose everyone was wearing a mask that restricted how much air they could breathe, and they had been doing this their whole lives, so everyone had been going through life wheezing through this restrictive mask. Would there be adverse effects of taking the mask off? Would there be a concern that people would get “oxygen poisoning” by being able to breathe without the artificial restriction of the mask? It would be possible to hyperventilate, but the normal regulation of breathing doesn’t let hyperventilation happen.

  30. KGelling says:

    @BillyJoe

    When reporting research, I think it is very important that the absolute risks are always quoted, otherwise you leave yourself open to accusations of hypocrisy and of being intentionally misleading.

Comments are closed.