My twice-daily walks with my border collie, Clair DeNoon, are the highlights of my day. A new report from the American Heart Association will put an extra spring in my steps on these walks. A panel of experts from the American Heart Association has weighed all the available evidence on pet ownership and cardiovascular disease. The verdict: Having a pet—a dog in particular—likely lowers the risk of heart disease. Some of the connection can be attributed to the extra walks dog owners take. Companionship also contributes. If dog ownership is heart healthy, should everyone who cares about heart health have a dog? No. According to the heart association panel, “the primary purpose of adopting, rescuing, or purchasing a pet should not be to achieve a reduction in cardiovascular risk.”
• Fast-food restaurants deliver filling, inexpensive meals and snacks. But there’s usually a hidden added cost: a wallop of salt (sodium) that isn’t good for cardiovascular health. Even with the current clamor for reducing sodium in the American diet, and industry promising to do just that, the amount of sodium in prepared foods hasn’t changed much since 2005, according to a report published in the latest issue of JAMA Internal Medicine. The average sodium in chain restaurant items increased 2.6% between 2005 and 2011. In packaged foods, it fell on average 3.5%. While some are calling for tighter government regulation on the sodium content in processed and restaurant foods, you can take action now.
In the past decade, a remarkable series of experiments from laboratories all over the world has begun to show what causes aging—and how to slow it. In the latest example of such aging research, two of my Harvard Medical School colleagues, cardiologist Richard T. Lee (co-editor in chief of the Harvard Heart Letter) and stem cell biologist Amy Wagers and their teams have found a substance that rejuvenates aging hearts in mice. The researchers joined the circulation of an old mouse with a thick, stiffened heart to that of a young mouse. After four weeks, the heart muscle of the old mouse became dramatically thinner and more flexible. The team then identified a substance called growth differentiation factor 11 (GDF11) as the probable “anti-aging” substance. It’s too soon to tell if this discovery will ever help humans with heart failure. But it reveals that there are substances naturally present in all living things that cause aging and that retard it. By understanding them, we may someday be able to slow aging.
Is red meat bad for your heart? A new study suggests it is, but not for the reasons you might expect—like the saturated fat or cholesterol in red meat. A team from a half dozen U.S. medical centers says the offending ingredient is L-carnitine, an amino acid that is abundant in red meat. Their work shows that eating red meat delivers L-carnitine to bacteria that live in the human gut. These bacteria digest L-carnitine and turn it into a compound called trimethylamine-N-oxide (TMAO), which has been shown to cause atherosclerosis, the disease process that leads to cholesterol-clogged arteries, in mice. There’s still a long way to go before we know the full story about L-carnitine and heart disease, but this work suggests that cutting back on L-carnitine (and avoiding L-carnitine supplements) may be good steps for heart health.
Salt is a cheap, easy way to turn on taste buds. That’s one reason why it’s in so many of the foods we eat. It’s so commonly used that most Americans consume more than double the recommended daily limit for it. Three new studies in BMJ (formerly the British Medical Journal) once again confirm the relationship between salt intake and health problems. They show that reducing salt intake can help lower blood pressure and lower the odds of having a heart attack or stroke or developing heart failure. They also show that consuming more potassium is also linked to lower blood pressure and lower risk of stroke. Current dietary guidelines recommend that Americans get no more than 1 teaspoon of salt a day. That’s the equivalent of 2,300 milligrams (mg) of sodium a day. Most Americans get much more than that. It’s possible to cut back by avoiding processed and packaged foods, using herbs and spices to season food instead of salt, and other strategies. It’s best to get potassium from food, especially fruits and vegetables. Green leafy vegetables, beans, and bananas have a lot of potassium.
Chest pain brought on by exercise or stress, a condition known as angina, holds back millions of Americans from living life to the fullest. There’s long been a perception that angina symptoms in women are different than they are in men. Doctors often use the term “typical angina” to describe the angina symptoms that men relate. Symptoms more commonly described by women have been dubbed “atypical angina”—suggesting that women are somehow experiencing an unusual manifestation of heart trouble. A new Harvard study shows that women and men probably experience the same symptoms, but describe them differently. By any name or description, chest discomfort is crucial for women—and their doctors—to pay attention to. And that means acknowledging the possibility of angina no matter how a women describes suspicious chest-related symptoms.
Chelation therapy removes metals that have built up in the body. It is an FDA-approved way to treat mercury, lead, and other types of heavy-metal poisoning, as well as for iron overload (hemochromatosis) and some types of anemia. It has also been touted as an alternative therapy that can cure heart disease. Results from the 10-year, $31 million Trial to Assess Chelation Therapy (TACT) show that it slightly reduced the risk of heart problems in heart attack survivors. Proponents of chelation therapy will say this proves what they’ve been preaching. But the editors of JAMA, which published the trial results say that the findings “should serve to dissuade responsible practitioners from providing or recommending chelation therapy for patients with coronary disease and should discourage patients with previous MI [heart attack] from seeking this therapy with the hope of preventing subsequent cardiovascular events.”
The results of a new trial being made public today should get everyone interested in following a Mediterranean-style diet. What makes these new results so important is that they come from a randomized controlled trial, what many consider to be the gold standard of medical research. In the five-year trial, there were fewer heart attacks, strokes, and deaths from cardiovascular disease among participants who followed a Mediterranean-type diet than among those following a low-fat diet. A Mediterranean-style approach to food represents a diet of abundance, not restriction. Add not smoking and daily physical activity to this flexible eating strategy and you have a blueprint for protecting, and perhaps even improving, health.
The message that drinking a little alcohol is good for the heart has gotten plenty of attention. A new study linking alcohol with increased risk of dying from various cancers may temper that message a bit. About 4% of cancer deaths worldwide are related to alcohol use. A new study shows the in the United States, alcohol causes 3.5% of cancer deaths, or about 20,000 cancer-related deaths each year. The most common alcohol-related cancers were mouth, throat, and esophageal cancer in men, and breast cancer in women. At the same time, drinking alcohol in moderation (no more than two alcoholic drinks a day for men and no more than one a day for women) has been linked to lower rates of heart disease and deaths related to it. Advances in genetics may one day let us predict more accurately who can use alcohol in moderation and who should avoid it completely. Until then, it’s best to personally weigh the benefits and risks, ideally with a trusted health care provider.
As a huge, snowy Nor’easter barrels into New England, I’m thinking about all the shoveling I’ll be doing over the next couple days. Luckily I have three teenagers to help. But now that I’m of an AARP age, I have to be more mindful of the cardiovascular effects of shoveling. Snow shoveling is a known trigger for heart attacks. Emergency rooms in the snowbelt gear up for extra cases during significant snow storms. What’s the connection? Many people who shovel snow rarely exercise. Picking up a shovel and moving hundreds of pounds of snow, particularly after doing nothing physical for several months, can put a big strain on the heart. Pushing a heavy snow blower can do the same thing. Cold weather also contributes. Tips for protecting the heart include shoveling many light loads instead of fewer heavy ones, taking frequent breaks, and hiring a teenager.