DEAR MAYO CLINIC:

After 30 years of smoking, I was able to quit the habit 12 years ago. Since then, I've been chewing about 15 pieces of nicotine gum every day.

Can you tell me how this might be affecting my health?

I'm in good health overall, but my HDL is still too low despite daily exercise and taking 4,800 milligrams of fish oil daily.

ANSWER:

The good news is that by stopping smoking, you've significantly reduced your risk of heart disease and cancer, especially lung cancer.

The not-so-good news is that continued, long-term use of nicotine replacement therapy could potentially cause other health problems.

The purpose of nicotine gum is to deliver small doses of nicotine to your body, which allow you to better manage your withdrawal symptoms and cravings as you quit smoking.

When you smoke, you inhale nicotine and more than 4,000 harmful chemicals. More than 60 of those substances are known to cause cancer. Replacing smoking with a pure nicotine alternative, such as nicotine gum, eliminates all those other chemicals, and that's definitely a benefit.

Typically, people use nicotine replacement therapy for about four to six months. This therapy delivers a much lower dose of nicotine than cigarette smoke does. However , some 3 to 6 percent of ex-smokers become dependent on nicotine replacement and -- as in your situation -- end up using it for years. When examined apart from smoking, the long-term effects of nicotine exposure aren't clear.

Some research indicates that, over time, using nicotine gum may possibly put you at increased risk of developing diabetes.

The risk of cancer associated with long-term nicotine replacement therapy appears to be minimal. A recent report linked long-term exposure to even low levels of nicotine to a possible increased risk of mouth cancer in susceptible individuals.

Studies have clearly shown that cigarette smoking changes cholesterol levels, raising both total cholesterol and low-density lipoprotein, or LDL (the "bad" cholesterol), while lowering high-density lipoprotein, or HDL (the "good" cholesterol). Whether it's specifically the nicotine that affects cholesterol levels, or one of the other chemicals in tobacco smoke, the research has yet to show. However, most studies of nicotine replacement medications do not show any of these adverse changes in cholesterol values. In fact, in smokers who stopped smoking with a nicotine patch, their cholesterol levels began to change toward normal. But my recommendation would be that you stop your nicotine gum use now.

Because you've been using nicotine gum for so long, it's probably become an ingrained behavior, sustained by nicotine dependence.

Some people are able to gradually reduce their dependence on nicotine gum by substituting regular or sugar-free gum. If that doesn't work, you may want to seek assistance from a tobacco-cessation expert who can help guide you through a behavioral program to change the habit part of your nicotine gum use. This may include switching to another nicotine replacement medication, or taking one of the tobacco-cessation medications available in pill form to overcome your nicotine gum use.

When you quit smoking 12 years ago, nicotine gum was one of the few tobacco cessation medications available. Since then, many other medications have been introduced, including nicotine patches, a nicotine inhaler, a lozenge and two pills: bupropion and varenicline. These medications are used to assist smokers in quitting, but some of them may be helpful to a person in your situation as well.

Switching to a long-acting tobacco cessation medication, such as the patch or one of the pills, can help you control withdrawal symptoms as you stop using nicotine gum. These medications can also help break the behavioral cycle of feeling a need to use the nicotine gum. Once you've stopped chewing nicotine gum, you will likely find it much easier to taper off the patch or stop the medication.

Although the specific health effects of nicotine exposure are unclear, long-term use of nicotine replacement therapy isn't a good idea.

If you have trouble quitting on your own, talk to you doctor about finding a tobacco cessation program in your area that can help.

In addition, every state in the United States and every province in Canada has a telephone quitline staffed by tobacco intervention specialists who can help you with nicotine gum dependence, too.

Just call 1-800-QUIT NOW.

-- Lowell C. Dale, M.D., Medical Director, Mayo Clinic Tobacco Quitline, Mayo Clinic, Rochester, Minnesota

Medical Edge from Mayo Clinic is an educational resource and doesn't replace regular medical care.

To submit a question, write to: medicaledge@mayo.edu, or Medical Edge from Mayo Clinic, c/o TMS, 2225 Kenmore Ave., Suite 114, Buffalo, N.Y., 14207.

(c) 2009 MAYO FOUNDATION FOR MEDICAL EDUCATION AND RESEARCH. ALL RIGHTS RESERVED DISTRIBUTED BY TRIBUNE MEDIA SERVICES, INC.

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