NEW YORK (TheStreet) -- In a coup, consumer activists have forced beer makers to reveal their ingredients in an effort to bring more transparency to the industry. Investors will spend some time sorting out the repercussions.
On Thursday, both Anheuser Busch Inbev (BUD) and MillerCoors (a joint venture of SABMiller (SBMRY) and Molson Coors (TAP - Get Report)) posted the ingredients to some of their most popular brands online after food blogger Vani Hari created a petition on FoodBabe.com, questioning whether their beers contained harmful allergens.
Hari began the petition on Wednesday, amid suspicion that many mainstream beers contained harmful ingredients like high fructose corn syrup, stabilizers, artificial colorings and even fish swim bladders, as she wrote on her website.
The petition quickly gained steam, adding upwards of 40,000 signatures in 24 hours, as many food enthusiasts had similar questions.
"I grew concerned about the beer after discovering there is a long list of additives the government has approved for use," she wrote.
Both beer companies responded immediately, posting ingredients online within hours of the petition catching national spotlight.
As of Friday's close, Anheuser-Busch shares were down 0.66%, SABMiller shares were up 0.59% and Molson Coors shares were down 0.34%.
Anheuser-Busch posted the ingredients for its two top-selling brands on its website, tapintoyourbeer.com. It lists the same ingredients for Budweiser and Bud Light: Water, barley malt, rice, yeast and hops.
The company went on to say on its website that ingredients for its other popular brands would be posted "in the coming days."
Meanwhile, MillerCoors revealed the ingredients of Miller Lite, Coors Light and six other brands on its Facebook page. Most are made from water, barley malt, corn, yeast and hops, the company said.