In private Facebook groups devoted to natural treatments for cancer and other ailments, hundreds of thousands of members tell each other that baking soda, apple cider vinegar, and frankincense are cures doctors don't want you to know about.

Parents of children with autism have their own groups devoted to unscientific treatments — like swallowing bleach — that they believe will "heal" their children.

Facebook yesterday announced that it was taking steps to limit the reach of these false and sometimes dangerous claims by treating them as similar to clickbait or spam.

The announcement was the latest move by Facebook, which along with Google has recently started taking more aggressive action against medical misinformation on their platforms, where it thrived for years.


Facebook will "down-rank" posts it believes contain health misinformation, meaning those posts will appear in the news feeds of fewer users, and less prominently.

The down-ranking will also apply to posts from Facebook groups devoted to natural treatments, which will show up less in the news feeds of group members.

Facebook's News Feed algorithms will use use keywords and phrases, which the company has identified with the help of health-care professionals, to predict which posts might contain sensational health claims.

"Misleading health content is particularly bad for our community," Travis Yeh, a Facebook product manager, wrote in a blog post. "So, last month we made two ranking updates to reduce (1) posts with exaggerated or sensational health claims and (2) posts attempting to sell products or services based on health-related claims."

Misleading health content is particularly bad for our community.

Facebook has always said that its mission is to connect people with each other. In the case of medical misinformation, it has been a place where vulnerable and desperate people can connect to those who promise to know how to "cure" any disease.

The announcement of Facebook's latest move against medical misinformation comes a week after the Washington Post reported on the popular, private Facebook groups where hundreds of thousands of cancer patients and their families seek natural alternatives to medical treatment.

In groups like "Alternative Cancer Treatments" (7000 members), "Colloidal Silver Success Stories" (9 000 members) and "Natural healing + foods" (more than 100,000 members), members trade anecdotes as proof that alternative treatments can cure various cancers and other illnesses.

In March, Facebook announced it would take measures to combat anti-vaccine content on their platforms.