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Rate of Sickness

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Summary of Rate of Sickness

Scientific Information on Rate of Sickness

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Human Effect Matrix

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The Human Effect Matrix looks at human studies to tell you what supplements affect Rate of Sickness.

Full details on all Rate of Sickness supplements are available to Examine members.
Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Supplement Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
grade-b Minor Very High See all 3 studies
Upper respiratory tract infections and cold symptoms seem to see a small to medium reduction when echinacea is used as a prophylactic. However, it's unclear which doses and demographics benefit more and which benefit less, and the inconsistency of studies suggests that only some people may see a benefit.
grade-b Minor Very High See all 15 studies
There is evidence for a modest reduction in the risk for respiratory tract infections in general, likely coming largely from upper respiratory tract infections, and more meaningful when vitamin D levels are very low (a small number of people). There is also some evidence for a modesty reduction in pneumonia and influenza, though more research is needed to be very confidence in this.
grade-b - Moderate See all 28 studies
When used as a prophylactic, vitamin C's effects are very inconsistent, and overall it doesn't seem to reliably reduce the risk of getting a common cold. It's possible that those undergoing extreme exercise (a known risk factor for developing colds) see a meaningful reduction in risk, however this is based on much less research and requires further study. It's unclear if other infectious diseases are affected by vitamin C supplementation.
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