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VItamin E increase risk of Stroke. Fact or Hoax?
Introduction
Dietary supplementation is very common in United States, it's estimated about more than half of adult population consume dietary supplements. And about 12.7% from those, consume vitamin E supplement.
Vitamin E supplement become popular, since publications from observational studies that showed Vitamin E may protect against cardiovascular disease and offers others health benefits such as fertility, lowering cancer risk, and for skin usage.
Vitamin E is an organic trace element as a lipid soluble molecule and has antioxidant properties. It best known for its ability to inhibit lipid peroxidation by scavenging reactive oxygen species and to preserve cell membranes.
Cardiovascular disease is largely attributable to atherogenesis, and lipid peroxidation plays a central role in atherogenesis. This has raised hopes that antioxidants including vitamin E may protect against cardiovascular disease.
Things to Know
A number of large controlled trials has investigated the effects of vitamin E on incident cardiovascular disease. The results were largely disappointing.
There is no overall effect of vitamin E on main composite end points, including heart attack, total stroke, or death due to cardiovascular disease, were found.
Instead, new concerns have been raised that high dose vitamin E may increase the risk for all cardiovascular related mortality. But, there are some weakness on the trials, one of them is the trials doesn't count cardiovascular disease clinical diversitiy.
Stroke doesn't represent a single well defined entity; the mechanisms underlying ischaemic and haemorrhagic events are different. Thus, using composite main outcomes may dilute effects on individual outcomes.
The evidence for stroke, including stroke subtypes, is studied again. Vitamin E may be beneficial for incident ischaemic stroke but detrimental for incident haemorrhagic stroke. Since stroke is major cause of death and causes many morbidity, also the common usage of vitamin E supplement is needed to do further research about it.
Vitamin E and Stroke
Seven clinical trials provided information about total stroke and none of the results from the individual trials suggested that vitamin E significantly alters the risk for total stroke compare to placebo.
Interesting results is showed by analyzing the effect of vitamin E on each type of stroke. The results is contradictrory.
From five trials about vitamin E and haemorrhagic stroke as outcomes. Vitamin E increase the risk to have hemorrhagic stroke compare to placebo about 22%.
And from five trials, effect of vitamin E for ischaemic stroke is estimated. It found that there is a slight risk reduction about 10% in having ischaemic stroke.
Potential biological mechanisms
Until now, complete understanding about pathophysiological mechanisms explaining these results is still unkown. Vitamin E is proved in pre-clinical study, that can inhibit platelet aggregation and adhesion, but it's effects on platelets function in normal patient still undetermined.
Vitamin E is associated with risk reduction of venous thromboembolism among women randomised and proven by large scale trial. An alternative hypothesis is that vitamin E interferes with activation of vitamin K dependent clotting factor and exerts an anticoagulant effect.
The antioxidant properties of vitamin E is agreed by the scientist but optimal dose for achieving that beneficial effects is unknown.
Vitamin E effects in hemorrhagic stroke is not clearly defined. Maybe it related to vitamin E role in platelet function thus increases the risk of having hemorrhagic. Interestingly, risk of bleeding apart from intracranial cavity isn't significant.
Summary
Eventhough, from those studies we can see scientific prove evidence about vitamin E effects on stroke, it is important to keep in mind that other preventive strategies are far stronger than vitamin E alone.
Other preventive strategies for stroke, such as hypertension control, regular exercise, cholesterol control, smoking abstinence, and moderate alcohol concumption are substantially decrease the risk of stroke. And Vitamin E may not add further risk reduction.
It is important to note about uncontrolled Vitamin E supplement may have bad effects on our health.
Maybe it's better to limit our Vitamin E consumption about 200 mg/day.
Source: British Medical Journal 2010
Dietary supplementation is very common in United States, it's estimated about more than half of adult population consume dietary supplements. And about 12.7% from those, consume vitamin E supplement.
Vitamin E supplement become popular, since publications from observational studies that showed Vitamin E may protect against cardiovascular disease and offers others health benefits such as fertility, lowering cancer risk, and for skin usage.
Cardiovascular disease is largely attributable to atherogenesis, and lipid peroxidation plays a central role in atherogenesis. This has raised hopes that antioxidants including vitamin E may protect against cardiovascular disease.
Things to Know
A number of large controlled trials has investigated the effects of vitamin E on incident cardiovascular disease. The results were largely disappointing.
There is no overall effect of vitamin E on main composite end points, including heart attack, total stroke, or death due to cardiovascular disease, were found.
Instead, new concerns have been raised that high dose vitamin E may increase the risk for all cardiovascular related mortality. But, there are some weakness on the trials, one of them is the trials doesn't count cardiovascular disease clinical diversitiy.
Stroke doesn't represent a single well defined entity; the mechanisms underlying ischaemic and haemorrhagic events are different. Thus, using composite main outcomes may dilute effects on individual outcomes.
The evidence for stroke, including stroke subtypes, is studied again. Vitamin E may be beneficial for incident ischaemic stroke but detrimental for incident haemorrhagic stroke. Since stroke is major cause of death and causes many morbidity, also the common usage of vitamin E supplement is needed to do further research about it.
Vitamin E and Stroke
Seven clinical trials provided information about total stroke and none of the results from the individual trials suggested that vitamin E significantly alters the risk for total stroke compare to placebo.
Interesting results is showed by analyzing the effect of vitamin E on each type of stroke. The results is contradictrory.
From five trials about vitamin E and haemorrhagic stroke as outcomes. Vitamin E increase the risk to have hemorrhagic stroke compare to placebo about 22%.
And from five trials, effect of vitamin E for ischaemic stroke is estimated. It found that there is a slight risk reduction about 10% in having ischaemic stroke.
adopted from http://mypotik.blogspot.com
Potential biological mechanisms
Until now, complete understanding about pathophysiological mechanisms explaining these results is still unkown. Vitamin E is proved in pre-clinical study, that can inhibit platelet aggregation and adhesion, but it's effects on platelets function in normal patient still undetermined.
Vitamin E is associated with risk reduction of venous thromboembolism among women randomised and proven by large scale trial. An alternative hypothesis is that vitamin E interferes with activation of vitamin K dependent clotting factor and exerts an anticoagulant effect.
The antioxidant properties of vitamin E is agreed by the scientist but optimal dose for achieving that beneficial effects is unknown.
Vitamin E effects in hemorrhagic stroke is not clearly defined. Maybe it related to vitamin E role in platelet function thus increases the risk of having hemorrhagic. Interestingly, risk of bleeding apart from intracranial cavity isn't significant.
Summary
Eventhough, from those studies we can see scientific prove evidence about vitamin E effects on stroke, it is important to keep in mind that other preventive strategies are far stronger than vitamin E alone.
Other preventive strategies for stroke, such as hypertension control, regular exercise, cholesterol control, smoking abstinence, and moderate alcohol concumption are substantially decrease the risk of stroke. And Vitamin E may not add further risk reduction.
adopted from http://www.ap-foodtechnology.com
It is important to note about uncontrolled Vitamin E supplement may have bad effects on our health.
Maybe it's better to limit our Vitamin E consumption about 200 mg/day.
Source: British Medical Journal 2010
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