Pereira and colleagues1 found an inverse association between coffee consumption and the risk of type 2 diabetes mellitus. Because this relation was stronger for decaffeinated coffee intake, it is likely that constituents other than caffeine are involved in this beneficial association. We suggest that some of the involved mechanisms might be related to inhibition of iron absorption by polyphenol compounds present in coffee, be it regular coffee or decaffeinated coffee. The main phenolic compound in coffee, chlorogenic acid, is a potent inhibitor of nonheme iron absorption.2,3 Hurrell et al3 report that the polyphenolic content typical in a cup of instant coffee reduces iron absorption from a test meal by 60% to 90%. Among elderly participants in the Framingham Heart Study,2 each 236 mL/wk (1 cup per week) of coffee consumed was associated with 1% lower serum ferritin concentration.
Thank you for submitting a comment on this article. It will be reviewed by JAMA Internal Medicine editors. You will be notified when your comment has been published. Comments should not exceed 500 words of text and 10 references.
Do not submit personal medical questions or information that could identify a specific patient, questions about a particular case, or general inquiries to an author. Only content that has not been published, posted, or submitted elsewhere should be submitted. By submitting this Comment, you and any coauthors transfer copyright to the journal if your Comment is posted.
* = Required Field
Disclosure of Any Conflicts of Interest*
Indicate all relevant conflicts of interest of each author below, including all relevant financial interests, activities, and relationships within the past 3 years including, but not limited to, employment, affiliation, grants or funding, consultancies, honoraria or payment, speakers’ bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued. If all authors have none, check "No potential conflicts or relevant financial interests" in the box below. Please also indicate any funding received in support of this work. The information will be posted with your response.
Some tools below are only available to our subscribers or users with an online account.
Download citation file:
Web of Science® Times Cited: 5
Customize your page view by dragging & repositioning the boxes below.
More Listings atJAMACareerCenter.com >
Enter your username and email address. We'll send you a link to reset your password.
Enter your username and email address. We'll send instructions on how to reset your password to the email address we have on record.
Athens and Shibboleth are access management services that provide single sign-on to protected resources. They replace the multiple user names and passwords necessary to access subscription-based content with a single user name and password that can be entered once per session. It operates independently of a user's location or IP address. If your institution uses Athens or Shibboleth authentication, please contact your site administrator to receive your user name and password.