This article was reviewed and certified

An independent, credentialed expert reviewed this content for accuracy before publication. CertREV records that the review took place and stands behind it.

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What this certificate confirms

• A credentialed expert reviewed the content

  Paul V Williams's credentials were verified by CertREV and matched to this article's subject.

• Claims were checked against the evidence

  The expert reviewed the article's health claims and requested edits before signing off.

• The certified version is recorded

  The exact text the expert approved is fingerprinted, so any later change is detectable.