Here is a story that we always knew was true. It’s similar to the makers of light beer. At the end of the day it’s still beer and at the end of the day, it’s still a cigarette.The nation’s largest tobacco company knew as early as the 1970s that smokers of light cigarettes took larger puffs that delivered greater amounts of tar, according to a newly released memo.

The 1975 Philip Morris USA correspondence was released by the Senate Commerce Committee in advance of a hearing Tuesday examining the rating system that allows tobacco companies to market cigarettes as regular, light or ultra-light.

The current rating system gives smokers a false sense that cigarettes with less tar and nicotine are healthier, according to a memorandum produced by Democratic congressional staffers.

The Federal Trade Commission allows companies to make statements about tar and nicotine levels as long as they’re based on a standardized system. That system uses a machine that smokes every cigarette the same way.

People, however, don’t smoke the same way. Some breathe in more deeply. Others hold their fingers over the cigarette’s vent holes, which increases smoke intake. Research has shown that smokers of “light” cigarettes take longer, deeper puffs and smoke more cigarettes a day to compensate for the lower level of nicotine.

“In a lot of ways switching to light cigarettes can be more deadly,” said Sen. Frank Lautenberg, D-N.J.

Lautenberg, a member of the committee, sponsored legislation last year that would prohibit manufacturers from using descriptions such as “light” or “low tar” on a package label or in advertising. He hopes the hearing could generate more support for banning such labels.

Among the documents to be reviewed is the one from Philip Morris, which said the larger puffs taken by smokers of light cigarettes “increased the delivery of the cigarette’s particulate matter,” which consists mostly of tar.

Philip Morris, part of Altria Group Inc., acknowledges on its Web site that smokers should not assume that light or ultra light cigarettes are safer than full-flavor brands.

“There is no safe cigarette. ‘Medium,’ ‘mild,’ ‘light’ and ‘ultra light’ cigarettes are no exception,” the company’s Web site says. Despite the warnings, the Campaign for Tobacco-Free Kids says tobacco companies aggressively market light cigarettes to smokers concerned about their health. And smokers of those products feel that their brands offer fewer risks than regular cigarettes.

The National Cancer Institute has for several years called for a change in the way that cigarettes are labeled. In 2001, it said people most concerned about smoking risks are those most likely to use brands labeled as light or ultra light.

“Choosing lower-yield cigarettes is not likely to reduce tar intake and resulting disease risks. Furthermore, marketing and promotion of reduced yield products may delay genuine attempts to quit,” the agency said. “There is no evidence that switching to light or ultra-light cigarettes actually assists smokers in quitting.”

If you continue to smoke, regardless of the type of cigarette, or cigar or whatever, the outcome will always be the same.