If you're in the habit of washing down over-the-counter painkillers with a slug of strong coffee or a slurp of soda, you might want to switch to water instead. Mixing large doses of caffeine with acetaminophen, one of the most commonly used painkillers in the United States, could lead to liver damage.

These findings, reported in the October 2007 issue of the journal Chemical Research in Toxicology, were the result of a preliminary laboratory study conducted by scientists at the University of Washington in Seattle.

The scientists found that caffeine can triple the amount of the toxic byproduct NAPQI (N-acetyl-p-benzoquinone imine), which is produced by liver enzymes following the breakdown of acetaminophen. The same toxin has been identified as a cause of liver damage and liver failure.

Acetaminophen is found in a number of prescription drugs and over-the-counter medications used for the treatment of pain and fever, including Tylenol and its generic equivalents. Several popular painkillers designed to treat menstrual discomfort and migraine headaches contain a combination of acetaminophen and caffeine.

A survey conducted by the Slone Epidemiology Center of Boston University revealed that acetaminophen is the most commonly used drug in the United States, taken weekly by approximately one in five American adults. Although the medication is safe and effective when taken by healthy individuals as directed, it can have dangerous consequences when it is used inappropriately.

In the United States, inappropriate ingestion of acetaminophen is the leading cause of acute liver failure. Tragically, approximately 80 percent of patients diagnosed with this condition die within a few days or weeks.

Caffeine isn't the only substance that doesn't mix well with acetaminophen. For years, physicians have warned their patients to avoid consuming excess alcohol while taking acetaminophen-containing medications since the combination can lead to permanent liver damage and even death.

Because the liver filters toxins from the blood, it is especially vulnerable to injury. Early symptoms of liver damage include fatigue, weakness, abdominal pain and loss of appetite.

As it progresses, liver disease can produce yellowing skin, easy bruising and itching. Advanced cases are characterized by swelling in the legs and abdomen, confusion and gastrointestinal bleeding.

Combinations of acetaminophen and excessive quantities of alcohol or caffeine aren't the only causes of liver damage. One of the biggest culprits is the typical American diet.

Nonalcoholic fatty liver disease, a condition related to over-nutrition and obesity, can range in severity from mild to life-threatening. Mild cases of fatty liver disease may not cause any noticeable signs or symptoms, but in worse cases, the condition can lead to cirrhosis of the liver and ultimately death.

Scientists at Saint Louis University recently evaluated the effects of a high-fat, high-sugar diet on sedentary mice. Within just four weeks, the mice exhibited dangerous elevations in liver enzymes and signs of developing type 2 diabetes.

In a similar study at Children's Hospital in Boston, researchers demonstrated that diets rich in rapidly digested carbohydrates contributed not only to weight gain but also to fatty liver disease. For the study, the researchers fed one group of mice rations with a high glycemic index, while the other group of mice received rations with a low glycemic index.

In the human diet, foods with a high glycemic index include sugar, white bread, white rice and most prepared breakfast cereals. These foods, which are favorites among Americans, tend to raise blood sugar levels very quickly.

Examples of foods with a low glycemic index are most vegetables and fruits as well as beans and unprocessed grains. These foods tend to raise blood sugar levels very slowly.

After six months, the mice consuming the low glycemic index rations were found to be leaner, with normal amounts of fat in their blood, bodies and livers. The mice on the high glycemic index diet, on the other hand, had double the normal amount of fat in their blood, bodies and livers.

Given the popularity of high glycemic index foods in the American diet, it's not surprising that fatty liver disease is becoming increasingly common, not only among adults but also among overweight children.

The good news is that in some cases, fatty liver disease and mild forms of liver damage can be reversed. Avoiding the use of acetaminophen with excessive quantities of alcohol and caffeine and eating a wholesome diet are two simple strategies that might do more than just improve the health of your liver —they could save your life.

Rallie McAllister is a board-certified family physician, speaker and the author of several books, including "Healthy Lunchbox: The Working Mom's Guide to Keeping You and Your Kids Trim." Her website is www.rallieonhealth.com. To find out more about Rallie McAllister, M.D., and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate Web page at www.creators.com.

??

??

??

??