The finding adds to mounting evidence that tobacco smoke and alcohol are worse for health as a combination, beyond the individual exposure risks, said Shannon Bailey, Ph.D., an associate professor in the UAB Department of Environmental Health Sciences and a co-lead author on the study.

The study is published in the journal Free Radical Biology and Medicine .

"This new data is a significant finding considering the combined effect of alcohol and cigarette smoke exposures, and the implications for public health," Bailey said.

The researchers reported on mice exposed to smoky air in a laboratory enclosure and fed a liquid diet containing ethanol, the intoxicating ingredient in alcohol drinks.

Mice exposed to second-hand smoke and who drank ethanol had 110 percent more liver fibrosis proteins than mice who breathed filtered air. Additionally, the twice-exposed mice had 65 percent more liver fibrosis proteins than mice who breathed smoky air but did not drink ethanol. Fibrosis is scar-like tissue in the liver that can lead to cirrhosis.

A study from the same UAB researchers in 2007 found the combination of second-hand smoke and ethanol increased the biological signs of heart disease in mice.

Second-hand smoke kills 53,000 nonsmoking Americans every year and is a known cause of lung cancer, heart disease, low birth weight and chronic lung ailments, according to the American Cancer Society.

Excessive alcohol consumption is ranked as the third-leading cause of preventable death in the United States, according to data collected by the Centers for Disease Control and Prevention.

The new study highlights the need to further probe negative biological impacts from single or multiple risky behaviors, and the compounding effect of environmental hazards such as second-hand smoke, said Scott Ballinger, Ph.D., an associate professor in the UAB Department of Pathology and a co-lead author on the study.

In addition to measuring liver fibrosis proteins in the study mice, the researchers looked at other signs of advancing liver disease like DNA damage, unhealthy cholesterol and oxidative stress.

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Cholesterol levels: The optimal target is less than 100 milligrams per deciliter (mg/dL) for low-density lipoprotein (LDL) cholesterol. For high-density lipoprotein (HDL) cholesterol, the recommended level is more than 50 mg/dL for women and more than 40 mg/dL for men.

A physician can help with a treatment plan to meet these guidelines. A healthy diet, regular physical activity, weight loss, smoking cessation and limited alcohol consumption all are beneficial. Medications also may be needed. For example, research has shown that most adults with high blood pressure and diabetes require multiple drug therapies to reach blood pressure goals.

The bottom line: Risks and complications from diabetes and heart disease are intertwined. People with diabetes who manage heart disease risks can help avoid life-threatening complications.

Mayo Clinic Women's HealthSource is published monthly to help women enjoy healthier, more productive lives. Revenue from subscriptions is used to support medical research at Mayo Clinic. To subscribe, please call 800-876-8633, extension 9751, or visit www.bookstore.mayoclinic.

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