Drinking one to two cups of coffee a day may lower the risk of heart failure, according to reviewers analyzing recent research.

When they looked at a handful of studies examining the link between java and heart health, they found that moderate coffee consumption might bestow positive effects, despite concerns about caffeine possibly hurting the heart.

"The American Heart Association published a guideline statement saying that coffee may be harmful and that it may increase the risk of heart failure," said lead author Elizabeth Mostofsky, a research fellow at Beth Israel Deaconess Medical Center in Boston.

"Since then, other studies have been done," she said. "We summarized the literature and found that across the studies, moderate coffee consumption may reduce a person's risk."

When Mostofsky and her colleagues analyzed the results of five studies published from 2001 to 2011 -- four conducted in Sweden and one in Finland -- they found that drinking the equivalent of about two 8-ounce cups of coffee may lower heart failure risk as much as 11 percent.

But moderation is key.

Heavy coffee drinking, defined in the review as drinking four to five cups a day, provides consumers with no extra protection and may even be dangerous.

The findings, published Tuesday in the journal Circulation: Heart Failure, did not provide a precise explanation for why coffee may help lower heart failure risk. Nor did they distinguish between caffeinated and decaffeinated coffee, although they pointed out that caffeine is in most of the coffee consumed in the places studied.

Some studies have shown that drinking coffee increases blood pressure. And high blood pressure, which affects 1 in 3 adults in the United States, is a major risk factor for heart failure, causing the heart muscle to weaken and potentially give out.

But the researchers explained that habitual coffee consumption might help people build up a tolerance of its effects, so that regular drinkers would no longer experience a spike in blood pressure.

"Chronic coffee use may actually blunt some of the effects," said Dr. Elizabeth Ross, a cardiologist and spokeswoman for the American Heart Association. (The association publishes the journal in which the review appeared, but Ross was not involved with its publication.)

Prior research has also suggested that coffee consumption might help lower risk the for Type 2 diabetes, which increases the likelihood of heart failure. A 2009 study in the Archives of Internal Medicine found that with each cup coffee that a person consumed daily, the risk for diabetes dropped 7 percent.

"There is a lot of research showing that coffee has antioxidant benefits. That's the main mechanism that people tend to focus on," said Mostofsky, suggesting a possible link between coffee and the decreased risk for diabetes. "But it requires further research."

"You get to the truth in small steps," Ross said. "This is really just a first step looking more directly at how caffeine affects the heart. I don't think it settles the issue."

She stressed that the results might be reassuring for people who consume moderate amounts of coffee. But the findings do not mean that individuals who don't now consume coffee should pick up the habit, she said, adding that coffee is not a "health drink."

"If you want to protect your heart, you need to eat well, not smoke and get exercise," Ross said. "Those are the main things you need to do."

Loading Slideshow...

  • Coffee (Or At Least, The Caffeine!) Can Help You Proofread Better

    The caffeine in coffee could actually help you to <a href="http://psycnet.apa.org/psycinfo/2011-23154-001/" target="_hplink">spot grammar errors</a>, according to a new study in the <em>Journal of Experimental Psychology</em>. Researchers found that <a href="http://bodyodd.msnbc.msn.com/_news/2011/10/26/8498728-tank-up-on-java-unleash-your-inner-editor-says-study?ocid=twitter" target="_hplink">caffeine helped students to correct errors</a> in subject-verb agreement and verb tense, MSNBC reported. However, the caffeine still didn't seem to make a difference at identifying misspelled words -- sorry.

  • Coffee Could Lower Women's Depression Risk

    Women who drink a few cups of <a href="http://www.huffingtonpost.com/2011/09/27/coffee-cuts-depression-women_n_982122.html" target="_hplink">caffeinated coffee have a lower risk of depression</a> than women who don't drink any coffee, according to a Harvard study. That research, published in the <em>Archives of Internal Medicine</em>, shows that women who drink two to three cups of coffee a day have a 15 percent lower risk, while women who drink four or more cups of coffee a day have a 20 percent lower risk. Study research Dr. Albert Ascherio <a href="http://www.huffingtonpost.com/2011/09/27/coffee-cuts-depression-women_n_982122.html" target="_hplink">told HuffPost</a> earlier that "caffeine is known to affect the brain," because it "modulates the release of mood transmitters." "I'm not saying we're on the path to discovering a new way to prevent depression," he said. "But I think you can be reassured that if you are drinking coffee, it is coming out as a positive thing."

  • Coffee Could Save Your Brain

    ... Well, maybe. A study in the <em>Journal of Alzheimer's Disease</em> suggests that there's something in coffee -- though researchers have yet to determine what exactly that "something" is -- interacts with caffeine to boost the levels of granulocyte colony stimulating factor (GCSF), a growth factor that seems to be able to <a href="http://www.huffingtonpost.com/2011/06/24/coffee-could-ward-alzheimers_n_882931.html" target="_hplink">fight off Alzheimer's disease in mice</a>. The amount of coffee needed in the study is equivalent to about four or five cups of coffee for humans. Researchers said <a href="http://www.j-alz.com/press/2011/20110621.html" target="_hplink">GCSF likely has this effect</a> because it causes stem cells in the bone marrow to come into the brain and remove the beta-amyloid plaques associated with Alzheimer's disease. It also has a role in forming brain cell connections and creating new brain neurons, researchers said.

  • Coffee Could Lower Men's Prostate Cancer Risk

    A Harvard School of Public Health study shows that men who drink six cups of coffee a day have a 60 percent decreased <a href="http://www.huffingtonpost.com/2011/05/18/coffee-can-cut-prostate-c_n_863472.html" target="_hplink">chance of developing a dangerous form of prostate cancer</a>, as well as a 20 percent decreased chance of developing any other kinds of prostate cancer. The study, published in the <em>Journal of the National Cancer Institute</em>, also shows that just <a href="http://jnci.oxfordjournals.org/content/early/2011/05/17/jnci.djr151.abstract" target="_hplink">drinking just some coffee a day</a> -- just one to three cups -- could still cut prostate cancer risk by 30 percent.

  • Coffee Could Ward Off The World's Most Common Cancer

    New research presented at the American Association for Cancer Research conference shows that coffee could help to <a href="http://www.huffingtonpost.com/2011/10/24/coffee-most-common-cancer_n_1025089.html" target="_hplink">ward off basal cell carcinoma</a>, the most common cancer in the world. Researchers from Brigham and Women's Hospital and Harvard Medical School found that women who drink three or more cups of caffeinated coffee a day have a 20 percent lower risk of the skin cancer, while men had a 9 percent lower risk. Decaf coffee didn't seem to have the same protective effect -- so "our study shows that the inverse association with BCC appears due to caffeine, not other components in the coffee consumption," study researcher Fengju Song, Ph.D., earlier <a href="http://www.huffingtonpost.com/2011/10/24/coffee-most-common-cancer_n_1025089.html" target="_hplink">told HuffPost</a>.

  • Coffee Could Protect You From Type 2 Diabetes

    Drinking coffee is associated with a <a href="http://archinte.ama-assn.org/cgi/content/abstract/169/22/2053" target="_hplink">lower Type 2 diabetes risk</a>, with more coffee consumption linked to a greater decrease in risk, according to an <em>Archives of Internal Medicine</em> review of studies from 2009. In that review, researchers looked at data from more than 450,000 people in 18 studies, and found that for every extra cup of coffee drank a day, a person's risk of Type 2 diabetes decreased by 7 percent. However, researchers cautioned that "the putative <a href="http://archinte.ama-assn.org/cgi/content/abstract/169/22/2053" target="_hplink">protective effects of these beverages</a> warrant further investigation in randomized trials."

  • Coffee Could Decrease Parkinson's Risk

    Drinking <a href="http://www.ncbi.nlm.nih.gov/pubmed/20182023" target="_hplink">a few cups of coffee a day</a> could lower the risk of developing Parkinson's disease by as much as 25 percent, according to a study published last year in the <em>Journal of Alzheimer's Disease</em>. In that review of studies, which was published in the <em>Journal of Alzheimer's Disease</em>, researchers examined 26 studies that involved 125,000 British people, to find that <a href="http://www.telegraph.co.uk/health/healthnews/7815087/Coffee-can-cut-chances-of-developing-Parkinsons-disease-according-to-new-research.html" target="_hplink">two or three cups of coffee</a> seemed to have the optimal effect, <em>The Telegraph</em> reported.

  • Related Video

    The benefits of coffee