Drink for Your Heart but Abstain for Cancer?

The latest piece of evidence on the risks of drinking alcohol comes from researchers at Oxford University who studied more than 1.2 million women in the United Kingdom. They found that drinking alcohol may account for about 13 percent of all breast , liver, rectal and upper digestive tract cancers in women.

More shocking, even small amounts of alcohol seemed to increase the cancer risk. When compared with women who drank two or fewer alcoholic beverages per week, those drinking up to six alcoholic beverages had a 2 percent greater risk for cancer in general; those consuming between seven and 14 drinks per week had a 5 percent increased risk for cancer; and those consuming 15 or more per week had a 15 percent increased risk for cancer.

Using these findings, Dr. Michael Lauer, director of the Division of Prevention and Population Sciences at the National Heart, Lung, and Blood Institute in Bethesda, Md., wrote in the study's editorial that "there is no level of alcohol consumption that can be considered safe."

But with all we've heard in the past about the supposed health benefits of alcohol, can this really be the case?

Most experts say no.

"The editorialists … seem to be rather extreme in their views," said Dr. Charles Poole, associate professor of epidemiology in the Gillings School of Global Public Health at the University of North Carolina. "I have seldom seen such a one-sided dismissal of the hypothesis that moderate alcohol use may have cardiovascular benefits."

Alcohol for a Healthy Heart?

A study published in the British Medical Journal in May 2006 found that women who drank alcohol at least one day a week had about a 35 percent lower risk of coronary heart disease than women who drank alcohol less than once a week. For men, however, those who drank daily saw the largest reduction in risk when compared with nondrinkers -- about 41 percent.

The Fine Line Between Health and Illness

But it seems that the quantity of alcohol consumption plays a big role in whether you will see the risks or the benefits of a good buzz.

A meta-analysis (or overview of old studies) published in the Journal of the American Medical Association in 2003 found that light to moderate alcohol consumption could lower the risk for stroke, while heavy alcohol consumption raised the stroke risk.

Researchers found that those who consumed more than about 60 grams of alcohol per day, or about five drinks, had a 64 percent increase in overall stroke risk. But those who drank 12 grams of alcohol per day, or about one drink, experienced an 83 percent decrease in overall stroke risk.

Based on the body of available evidence on the benefits and risks of alcohol consumption, the American Cancer Society recommends that drinkers limit intake to one drink per day for women and two drinks per day for men.

Drink for Your Heart, or Stop Drinking for the Cancer Risk?

For some, this decision to start drinking for the heart benefits or stop drinking because of the increased cancer risk should be based on personal medical history.

"In light of the findings from [this study], women who are concerned about their cancer risk versus their risk of cardiovascular disease might want to discuss the potential risks and benefits of even low alcohol intake with their health care providers," said Susan Gapstur, associate director of Cancer Prevention and Control within the Robert H. Lurie Comprehensive Cancer Center at Northwestern University in Chicago.

And for those with a history of certain diseases such as breast cancer, experts said the heart-protective benefits of alcohol might not outweigh the overall increase in cancer risk caused by drinking.

"I think women at high breast cancer risk due to strong family history, or due to their own personal history, might be better off if they were to restrict alcohol intake to under one drink per day on average," said Dr. Tim Byers, associate dean of the Colorado School of Public Health at the University of Colorado at Denver.

The End Result: Alcohol's Effect on Life Expectancy

But for those whose personal history offers no added risk for alcohol consumption, taking a look at the overall life expectancy of alcohol drinkers might help to sway one's decision on whether the buzz is really worth it.

A study published in the journal Epidemiology in November 1998 found that light to moderate drinkers had the lowest risk of death compared with nondrinkers. Those who drank between one and seven alcoholic beverages a week experienced a 20 percent reduction in overall mortality.

When the researchers looked more closely at why light to moderate alcohol drinkers had less risk of death, they found that this group experienced a reduction in death from heart disease, thereby suggesting that the moderate alcohol consumption could have some protective benefits for the heart.

The Final Word on Alcohol

Based on the many studies finding that moderate alcohol consumption can have a heart-protective benefit, many experts said that moderate drinkers should not worry about this latest research finding an increased risk in cancer.

"A small decrease in [cardiovascular] risk more than compensates for an increased risk of rare cancers," said Dr. Alan Kristal, member and associate head of the Cancer Prevention Program at the Fred Hutchinson Cancer Research Center in Seattle. "You have to die of something, and no doubt how you live affects what you die [from], but not 'if' and maybe not 'when.'"
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Heart CT Means High Radiation Exposure

Test Packs Dose Equal to 600 X-Rays; Doctors Say Scan Indispensable for Some Patients
A test commonly ordered by cardiologists across the country to diagnose heart disease exposes patients to radiation doses equivalent to 600 chest X-rays, researchers have found.

The test is called a cardiac CT angiogram, or cardiac CTA for short, and it is a relatively new way to look for potentially dangerous blockages in the heart arteries.

The study, released Tuesday in the Journal of the American Medical Association, is the first to look at radiation exposure from this test, and it is important because of the risk for developing cancer from radiation exposure.

"The strength of [this study] is that it is the first available survey of radiation doses in cardiac CTA," said Dr. Thomas Gerber, study author and associate professor of medicine and radiology at the Mayo Clinic in Rochester, Minn. "That information wasn't known, but it is conceivably important because of the risks of ... radiation."
However, the authors and experts in the field caution that this study should not send patients and doctors fleeing from an important way to diagnose heart disease.

"Not all cardiac CT is evil," said Gerber. "It is valuable in patients who have symptoms of heart disease."

Cancer Risk and Radiation

The risk of dying from cancer because of the radiation exposure from one cardiac CTA is difficult to estimate, but the American Heart Association puts the additional risk at around 0.05 percent in a statement released in the journal Circulation.

The actual radiation dose here may also not be as big as it initially sounds.

Radiation is commonly measured in units called millisieverts, or mSv. Authors studied almost 2,000 patients who had a cardiac CTA, and they found that the average radiation dose from these CT scans was 12 mSv.

Gerber said, "This is four times the annual background radiation [that everyone gets] from substances [in the environment] such as radon."

So in other words, an encounter with a heart CT scan equals four years worth of the radiation one would encounter in their day-to-day lives.

"It is important for patients' understanding to compare the test dose to annual background radiation ... instead of to chest X-rays," said Dr. Gilbert Raff, director of the Ministrelli Center for Advanced Cardiovascular Imaging at the William Beaumont Hospital. "Modern technology has reduced the chest X-ray [radiation] dose so substantially that it is no longer a fair or reasonable target to use."

Comparing Cardiac CTA to Other Tests

It is also important for patients to recognize that the radiation dose from cardiac CTA is comparable to the radiation exposure with other common tests used by cardiologists to look at blockages in the heart arteries.

Gerber says patients getting a stress test with imaging (where pictures are taken of the heart during exercise) get about the same dose of radiation. A cardiac catheterization procedure, in which a cardiologist puts a catheter and contrast dye into the heart arteries and takes pictures, typically exposes patients to about half as much radiation, but it is an invasive procedure and carries other risks.

"I think the most important ... lesson is that the dose is comparable to noninvasive imaging with stress scanning, which is the most common test we use in patients with ... chest pain," Raff said.

Dr. Christopher Cannon, senior investigator for the TIMI study group at the Brigham and Women's Hospital agreed. "We need to review all cardiac tests, not just CT angiograms."

More Can Be Done to Lower Radiation Exposure

The study also examined several techniques that are used to reduce radiation exposure when doing a cardiac CTA.

Researchers found that, while these techniques were associated with a significantly reduced radiation dose, not all centers were using these methods consistently. Importantly, these radiation reducing techniques did not affect the quality of the image obtained.

"One objective of this type of study [is] to raise awareness and make sure that [we] use all the means that we have available to reduce radiation dose," Gerber said. "The techniques available today are better than those studied in 2007. We [now] have revolutionary new technology that will probably reduce radiation dose from an [average] of 12 mSv to an [average] of 3 mSv."

Dr. Armin Zadeh, associate director of Cardiac CT at the Johns Hopkins University agreed. "The take-home message is that if you use cardiac CT responsibly, you can achieve good results with radiation exposures, which are very reasonable compared to other imaging tests."
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U.S. Heart Attacks Becoming Less Severe

Some experts say, better control of blood pressure, other factors may be boosting survival.

First-time heart attacks in the United States aren't as deadly now as they have been in past decades, a long-running study finds.

"We know that deaths from heart disease are going down," said Dr. Merle Myerson, director of the cardiovascular disease prevention program at St. Luke's-Roosevelt Hospital in New York City, and lead author of a report in the Jan. 20 issue of Circulation. "One reason why is that heart attacks are less severe. People are not coming in with these massive heart attacks that are killing them."

The study, with data on more than 10,000 first heart attacks that occurred in four widely separated U.S. areas, found only a marginal decrease in the heart attack death rate -- from 5.3 percent in 1987 to 3.8 percent in 2002. That is of only "borderline statistical significance," Myerson said.

But analysis of 20 indicators of severity -- such as the damage-indicating changes seen in electrocardiograms, or biomarker molecules released by damaged heart tissue -- show a clear trend toward lowered severity, she said.

For example, heart attacks with elevations in the ST-designated portion of the ECG, an indicator of severe damage, were seen in 27.7 percent of attacks in 1987 and 20.9 percent in 2002, an average reduction of 1.9 percent per year.

The percentage of cases of cardiogenic shock, in which the heart is so damaged that it cannot pump blood to the body, decreased by 5.7 percent per year, while the percentage of cases with abnormal biomarkers such as creatine kinase or troponin decreased by a modest, but statistically significant, 0.7 percent a year.

The finding comes from the ongoing Atherosclerosis Risk in Communities Study, done in North Carolina, Maryland, Minnesota and Mississippi. It includes rural, city and suburban areas, so the findings show what is happening all over the country, Myerson said.

It's not clear why the decrease has occurred, she said. "It could be better preventive measures, reducing risk factors such as high blood pressure and obesity, or it could be better treatment in the hospitals," she sad. "While this study doesn't say it, it points to some influence from both. We need more research to answer the question."

One factor that does not seem to have improved is public awareness of the symptoms of a heart attack and the need to call for medical help quickly, Myerson said. "The time to get to the hospital after symptoms begin has not improved," she said. There was no significant change in the percentage of people who arrived at a hospital less than two hours after the onset of symptoms -- about one in every three cases.

Most people do know that crushing chest pain is a clear warning signal, but "it's not always crushing pain," Myerson said. "It can be a feeling of indigestion or shortness of breath, lightheadedness or discomfort in another part of the body."

When there is uncertainty, it is better to act than to do nothing, she said. "If you are having chest pain with exertion, chest pain that comes and goes, with shortness of breath, it is always best to call for help or go to the hospital if you are near one," she added.

Medical authorities say it is best to call for help by dialing 911. Emergency medical personnel can arrive in minutes and begin treatment immediately.

"This study offers an opportunity to get the message out," said Dr. Alice K. Jacobs, a professor of medicine at Boston University and past president of the American Heart Association. "If you get to the hospital faster, the chance of a better outcome is improved. That is an important message for the public."
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