Hazards of cigarette smoking extend way beyond the lungs

Sure, just about everybody knows that smoking causes lung cancer and respiratory and heart problems. But its adverse effects don't stop there. Far from it.

"Some people are very health conscious even though they smoke and know a lot about the various problems associated with smoking," said John Spangler, M.D., professor of family and community medicine at Wake Forest Baptist Medical Center and a recognized expert in tobacco use and smoking cessation. "But other people aren't as informed, so, overall, the less publicized, more unusual effects of smoking are not well known."

The harsh reality is that cigarette smoking inflicts damage throughout the body. The list of conditions that smoking can cause, contribute to, increase the risk of or worsen runs from high blood pressure, type 2 diabetes and stroke to gum disease, arthritis and erectile dysfunction.

Cigarette smoke does such diverse harm because it contains somewhere between 4,000 and 9,000 different chemicals, hundreds of which are toxic, including around 70 known to be carcinogenic.

"When you smoke, these various chemicals get into the bloodstream, are carried to all parts of the body and go right to the most susceptible cells," Spangler said. "That's why there's such a wide array of negative effects from cigarettes."

One of the main culprits is carbon monoxide, the gas produced by the incomplete burning of any material containing carbon. It reduces the ability of red blood cells to carry essential oxygen to tissues in the brain, heart and other parts of the body, which can result in problems ranging from shortness of breath to heart failure.

Most of the other malevolent agents are the chemicals found in tar, the resinous matter generated by burning tobacco that builds up in the lungs. The effects of these chemicals include inflaming the linings of blood vessels and other soft tissues, reducing the body's ability to fight infections, slowing the healing process and causing the release of free radicals, unstable molecules that react with other molecules and produce different disorders, including cancer, in different types of cells throughout the body. There are also cancer-specific compounds in tar that directly damage cell DNA and generate tumors in the lungs and other organs, such as the pancreas, kidneys and liver.

Perhaps surprisingly, tobacco's best known component -- nicotine -- is not among its most lethal.

"Nicotine doesn't cause the cancer or the emphysema," Spangler said. "It causes the addiction."

The nicotine in cigarette smoke activates the brain circuits that regulate feelings of pleasure in the same way as other drugs, such as heroin. Nicotine levels peak within 10 seconds of inhalation but dissipate quickly, as do the associated feelings of reward, which causes the smoker to continue smoking to maintain the drug's pleasurable effects and prevent withdrawal.

"Nicotine isn't totally harmless," Spangler said. "It increases your blood pressure a little bit, for example, but its side effects are relatively minor and it's generally regarded safe enough that the FDA allows it to be sold over the counter as a smoking-cessation aid."

Research has shown that all cigarettes pose the same high level of health risks, including those marketed as "low-yield," "natural" or "additive-free." Other modes of smoking tobacco -- cigars, pipes, hookahs -also present serious health hazards.

"Even if you don't inhale the chemicals get into your body through your mouth, plus the second-hand smoke through your nose," Spangler said. "And water pipes are not safer at all. The water cools the smoke so it doesn't feel as irritating, but that's all it does. The vast majority of the harmful chemicals are still in there. And there's an incredible amount of second-hand smoke exposure with hookahs."

What about e-cigarettes? They and other electronic nicotine delivery systems (ENDS) produce vapor, not smoke, through the heating of nicotine-infused liquid, sometimes with flavoring added.

"The liquid in e-cigarettes is generally regarded as safe," Spangler said. "There are long-term health concerns, and we don't yet know what those may be, but we do believe that in the short term using e-cigarettes is safer than continued cigarette smoking."

However, he noted, the contents of the liquid, flavorings and heating elements in ENDS have not been closely regulated, and examples of all three have been found to contain hazardous elements. And the batteries of some electronic cigarettes have exploded, causing severe burns.

Quitting smoking is clearly the best way to avoid health risks. And it can have almost immediate benefits. The risk of heart attack, for example, begins to decrease within 48 hours of stopping to smoke.

"It's never too late to quit," Spangler said.

But that doesn't have to mean going cold turkey.

"The easier way to quit smoking is to have your brain's pleasure center kept relatively 'happy' with nicotine from a patch, gum or lozenge while you work on the habit aspects of smoking," he said. "Changing behavior takes a lot of work, so you don't want to be fighting the addiction, too. The nicotine medications double or even triple the success rate."

Family members and friends can contribute, too.

"Smokers who are really trying to quit need help," Spangler said. "It's hard. They've probably been smoking their entire adult lives, and they have to learn how to be non-smokers. Positive support is very important.

"A smoker trying to quit needs a cheerleader, not a drill sergeant."