Would US health improve (a lot) if many tobacco smokers shifted to marijuana?

The provocative question in the title of this post is prompted by this press report, headlined "Cigarette smoking costs weigh heavily on the healthcare system," on some notable new research about the health care costs attributed to tobacco use. Here are excerpts:

Of every $10 spent on healthcare in the U.S., almost 90 cents is due to smoking, a new analysis says. Using recent health and medical spending surveys, researchers calculated that 8.7 percent of all healthcare spending, or $170 billion a year, is for illness caused by tobacco smoke, and public programs like Medicare and Medicaid paid for most of these costs.

“Fifty years after the first Surgeon General’s report, tobacco use remains the nation’s leading preventable cause of death and disease, despite declines in adult cigarette smoking prevalence,” said Xin Xu from the Centers for Disease Control and Prevention (CDC), who led the study.

Over 18 percent of U.S. adults smoke cigarettes and about one in five deaths are caused by smoking, according to the CDC. Xu and colleagues linked data on healthcare use and costs from the 2006-2010 Medical Expenditure Panel Survey to the 2004-2009 National Health Interview Survey for a nationally-representative picture of smoking behavior and costs....

In [their] analysis, 9.6 percent of Medicare spending, 15.2 percent of Medicaid spending and 32.8 percent of other government healthcare spending by sources such as the Veterans Affairs department, Tricare and the Indian Health Service, were attributable to smoking.

Of the $170 billion spent on smoking-related healthcare, more than 60 percent was paid by government sources, they wrote in the American Journal of Preventive Medicine. Smoking-related healthcare costs affect most types of medical care, said Kenneth Warner at the University of Michigan School of Public Health. “Smoking infiltrates the entire body, through the blood stream, and causes disease in many of the body's organs,” he told Reuters Health in an email. Along with lung and heart problems, smoking can cause eye disease, skin problems and many cancers including pancreatic and bladder cancer, noted Warner, who was not involved in the new analysis.

“This study shows that, in addition to the human misery it inflicts, (smoking) imposes a substantial burden on the nation's health care institutions, especially those funded by the public's tax dollars,” he said.

The true cost of tobacco use may be even higher, Xu said. His study didn't include medical costs linked to other tobacco products like cigars and chewing tobacco.... “Smoking kills about 480,000 Americans each year and remains the leading cause of preventable death and disease in the United States. No matter what age, it is never too late to quit,” Xu said.

Of course, there are sure to be health risks and costs that will emerge if (and when) a lot more folks start smoking marijuana (especially if they become heavy users). But this research suggests that if a decent number of new marijuana smokers come from the ranks of tobacco users and that use of marijuana decreases tobacco use, there could be real health benefits and perhaps significant public health cost savings.