The Federal Trade Commission, winning applause from anti-smoking groups, ruled Monday that it has the power to decide whether a 1985 R.J. Reynolds Tobacco Co. advertisement was false and deceptive.

The commission's decision overturned a 1986 ruling by Administrative Law Judge Montgomery K. Hyun, who had held that the ad, titled "Of Cigarettes and Science" and printed to look like a newspaper editorial, was protected by the First Amendment guarantee of free speech.

The ad said that evidence linking smoking to heart disease was nothing more than opinion or judgment.

Hyun's decision followed a FTC complaint that charged the ad was false and misleading in claiming that cigarette smoking was not as hazardous as Americans had been led to believe.