Updated

The U.S. Food and Drug Administration on Monday proposed a rule revoking the right of companies to say soy protein protects the heart, while potentially allowing a more circumspect health claim.

The agency, which to date has never revoked a health claim, said studies published since it authorized the soy protein claim in 1999 had shown inconsistent results.

"Our review of that evidence has led us to conclude that the relationship between soy protein and heart disease does not meet the rigorous standard for an FDA-authorized health claim," the agency said in a statement.

The FDA said that if its proposed rule is finalized, it would consider allowing the use of a qualified health claim, which requires a lower scientific standard of evidence than an authorized claim.

PAIN DRUGS IN PREGNANCY TIED TO ADHD

The move comes nearly a decade after the FDA announced its intent to reevaluate the scientific evidence for certain health claims, including the one that soy protein may lower the risk of heart disease.

The American Heart Association has long advocated revoking the soy health claim. In a 2008 comment on the FDA's intent to reevaluate the evidence, the association said: "Direct cardiovascular health benefit of soy protein or isoflavone supplements is minimal at best."

In the same comment, the association urged the FDA not to allow the use of a qualified health claim.

"Consumer research conducted by AHA, the FDA and others has repeatedly shown that despite the presence of qualifying language, consumers do not understand qualified health claims and do not understand that they are based on limited and varying degrees of evidence," the organization said.

American Heart Association officials were not immediately available to comment on the FDA's most recent announcement.