(CNN) A new report by the US surgeon general points to tobacco smoking as the leading cause of preventable disease, disability and death in the United States -- and notes that smoking cessation is beneficial at any age.
Yet about two-fifths of smokers are not routinely told by their physicians to stop smoking, US Surgeon General Dr. Jerome Adams said in a press conference on Thursday.
As the nation's doctor, he said that number "jumped out" at him.
"Forty percent of smokers who see a health provider each year aren't advised by those health providers to quit," Adams said during the press conference.
While there are interventions already approved by the US Food and Drug Administration -- such as counseling and certain medications -- to help people quit smoking, Adams said that "two-thirds of smokers who try to quit don't use FDA-approved medications and counseling."
Behavioral counseling has been found to increase chances of quitting smoking and seven medications have been approved for helping adults quit smoking: five forms of nicotine replacement therapy and two non-nicotine medications, varenicline and bupropion, according to advice from the surgeon general.
The advice accompanies the surgeon general's 700-page report on smoking cessation, released Thursday by the US Department of Health and Human Services.
"Behavior counseling and FDA approved medications, according to the science compiled in this report, actually double the chance that someone can successfully quit when used in concert," Adams said.
"What I want people to take away is we know what works," he said.
The new report also notes that "there is presently inadequate evidence to conclude that e-cigarettes, in general, increase smoking cessation" and more research is needed in that area.
"E-cigarettes are a continually changing and diverse group of products that are used in a variety of ways. Therefore it is difficult to make generalizations about their effectiveness for cessation based on studies of a particular e-cigarette," Adams said.
"Now, that said, it is very important that you all understand I've heard powerful accounts from individuals who have used e-cigarettes to quit smoking traditional combustible cigarettes, and there are some studies that are actually reviewed in this report documenting that certain types of e-cigarettes may be associated with quitting in some adult smokers," he said. "But it's also important that we use the entire body of available science to guide our current recommendations."
While more research is needed, "I want to be crystal clear -- youth use of any tobacco product, including e-cigarettes, is unsafe," he added.
Matthew Myers, president of the nonprofit Campaign for Tobacco-Free Kids, said in a written statement, "This report is a timely reminder that effective and overdue FDA regulation of e-cigarettes is critical in order to prevent e-cigarettes from addicting a new generation of kids and to assist smokers by determining which, if any, e-cigarette products are effective at helping smokers quit."
The new report also highlights "considerable disparities" that exist in the prevalence of smoking across the United States and how some groups of people have greater access to smoking cessation tools than others.
"More than half of adults who smoke try to quit in any given year, yet face several challenges," Adams said. "Many groups have been left behind by the progress we've made over the last several decades. Cigarette smoking remains highest among LGBTQ adults, people with disabilities or limitations, American Indians and Alaska Natives and people with mental conditions or substance use disorders."
He added, "People want to quit. We know what works. Not enough of them are getting it, and there are terrible disparities in who is and is not getting access to effective and evidence-based treatments."
In general, cigarette smoking has been on the decline in the United States, reaching an all-time low of about 14% in 2018.
"The steady decline in the number of Americans who smoke cigarettes is one of the great public health victories of recent decades," HHS Secretary Alex Azar said in a written statement on Thursday.
"Americans who quit cigarettes can add as much as a decade to their life expectancy. Unfortunately, millions of Americans still smoke cigarettes. But the good news is that, as the Surgeon General's report shows, we know more than ever before about effective ways to help Americans quit. Working together, we can make tobacco-related disease and death a thing of the past," he said.
The new surgeon general report is the first since 1990 to focus solely on quitting smoking.
"This report highlights that quitting smoking is one of the most important things that people can do to improve their health," said Adams, who added that he lost both of his grandfathers to smoking-related conditions.
"I didn't even know until this report came out that you can add as much as 10 years -- a decade -- to your life expectancy by quitting smoking," he said. "In addition to the human toll, smoking-related illnesses cost the US more than $300 billion each year."
The major conclusions of the new report include that more than 3 out of 5 US adults who have ever smoked cigarettes have quit and that smoking cessation can be increased by raising the price of cigarettes, adopting comprehensive smoke-free policies, implementing mass media campaigns, requiring pictorial health warnings and maintaining comprehensive statewide tobacco control programs.
"All of those are proven interventions that save money and save lives," Adams said.
Harold Wimmer, national president and CEO of the American Lung Association, applauded the new report in a written statement on Thursday.
"The Surgeon General has made it clear: quitting smoking is the best thing you can do for your health, at any time in your life. The American Lung Association emphasizes the importance of quitting tobacco use altogether, rather than switching to another tobacco product, like e-cigarettes," Wimmer said in the statement. "The Surgeon General's findings add urgency to ensuring everyone has access to lifesaving, proven quit-smoking treatments, as well as the need for new science and research to ensure both youth and adults can end their tobacco addiction for good."