Heart disease is the number one killer of Americans, according to the National Heart, Lung and Blood Institute of the National Institutes of Health. The most common form of heart disease is coronary heart disease (CHD), which occurs when the coronary arteries become narrowed or clogged and cannot supply enough oxygen-rich blood to the heart. High amounts of a clotting protein called fibrinogen ¾ levels of which tend to increase as people grow older ¾ are associated with coronary artery, cerebral vascular and peripheral vascular diseases. However, a recent study published in the December issue of Alcoholism: Clinical & Experimental Research shows that moderate consumption of alcohol may decrease production and circulating levels of fibrinogen by up to 20 percent.
"This is a very significant finding," said Gerald M. Fuller, senior study author and professor of cell biology at the University of Alabama at Birmingham. "Anything that we can take naturally that reduces high circulating levels of fibrinogen by 15 to 20 percent could have a big impact in terms of coronary artery diseases." He added that "epidemiological studies have overwhelmingly demonstrated the importance of fibrinogen as a risk factor, and diminishing it by a small amount can have a truly profound effect."
Researchers studied the impact of daily consumption of moderate amounts of alcohol - equivalent to roughly two drinks per day - at two levels: using an animal model (in vivo) and liver-derived cells (in vitro). The animal-study findings demonstrated an 18 to 20 percent decrease in the circulating levels of fibrinogen. This decrease was fully reversible and non gender specific. The cell study found that alcohol also diminished fibrinogen production by 20 percent. In other words, moderate drinking appeared to reduce levels of fibrinogen both where it is circulated as well as where it is produced.
"We’re all interested in fibrinogen for health," said Russell F. Doolittle, professor of biochemistry at the University of California at San Diego, "but like anything else, too much of a good thing is bad." Doolittle explained that "fibrinogen’s purpose is to change into a fibrin clot. That’s a good thing when it keeps your blood from spilling all over the floor. It’s a bad thing when it occurs internally, if you have a clot that gets loose in the circulation and blocks blood flow."
People are more likely to die from heart disease than cancer, stroke, lung diseases or accidents. Each year, more than 500,000 Americans die from heart attacks caused by CHD. A study published in the January issue of Lancet estimated that one out of every two men and one of every three women age 40 or younger have a lifetime risk of developing CHD. Although CHD has a strong connection to lifestyle choices - such as smoking, physical inactivity, obesity, high blood cholesterol and high blood pressure - there are some developments, such as increasing levels of fibrinogen, that occur naturally as one ages.
"As we get older there is a gradual accumulation of fibrinogen in the blood," said Fuller. "This happens in the fourth, fifth and sixth decades of life. It’s not a huge amount, but we don’t need to see a huge increase for it to become a risk factor." Fuller’s study suggests that older populations can enjoy a glass or wine or beer per day while simultaneously diminishing fibrinogen levels in their systems.
"We’re not advocating that people drink a lot," Fuller pointed out. "We are not even suggesting that people begin drinking moderate amounts of alcohol. Our findings do suggest, however, that moderate consumption could have a benefit, if these findings hold up in human studies."
He cautioned that "too much alcohol is toxic, it’s like a poison to the system. Excessive amounts of alcohol quickly override any positive benefits that alcohol may offer, not to mention the psycho-social burdens associated with alcohol dependence."
In future studies, Fuller hopes to isolate the exact molecule(s) involved. This information could then be used to construct pharmacological remedies for people who produce too much fibrinogen but cannot drink, such as older people who are on a restricted diet.
Funding for this Addiction Science Made Easy project is provided by the Addiction Technology Transfer Center National Office, under the cooperative agreement from the Center for Substance Abuse Treatment of SAMHSA.
Articles were written based on the following published research:
Fuller, G.M., Wang, Z., & Barker, T.H. (1999, December). Alcohol at moderate levels decreases fibrinogen expression in vivo and in vitro. Alcoholism: Clinical and Experimental Research, 23(12), 1927.