Heart Health Archive

A high HDL cholesterol level may not be as beneficial as once believed.

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If you're hoping to avoid heart disease, you probably keep tabs on your blood cholesterol values — especially your low-density lipoprotein (LDL), or "bad" cholesterol. Too much LDL in the bloodstream helps to create the plaque that accumulates inside arteries, raising the risk of a heart attack. The lower your LDL, the lower your risk of having a heart attack.

In contrast, high-density lipoprotein (HDL) has long been known as the "good" cholesterol. These particles are known to patrol blood vessels, grabbing cholesterol from both the bloodstream and artery walls and ferrying it to the liver for recycling and disposal. In population-based studies, people with high HDL levels tend to have fewer heart attacks, while those with lower HDL values have more.

Research we're watching

People in drug studies sometimes experience positive effects even when they take inactive, fake pills (the so-called placebo effect). But sometimes, they experience negative effects from the fake drug — a phenomenon known as the nocebo effect. A new study suggests that the nocebo effect may explain some of the muscle pain and weakness reported by people who take cholesterol-lowering statins.

The study, in the May 2, 2017, Lancet, involved more than 10,000 people randomly assigned to take a statin or a placebo. The study was "double blind," meaning neither the participants nor the researchers knew who was taking statins. After about three years, the statin proved effective, and all the participants were offered the choice of taking the drug. Most of them continued in this "unblinded" study for an additional two years, and 65% opted to take the statin.

Recent findings raise concerns about lowering diastolic blood pressure — the second number in your blood pressure reading — too far.

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More of us than ever before are taking medications to lower our blood pressure. Longstanding guidelines suggest that most people should aim for a systolic blood pressure (the first number in a reading) no higher than 140 millimeters of mercury (mm Hg). But in 2015, the results of the Systolic Blood Pressure Intervention Trial (SPRINT) suggested that reaching a target of 120 mm Hg could further reduce the risks associated with high blood pressure, including heart attack, stroke, heart failure, and death.

Yet reaching that lower target often requires three blood pressure medications, which can increase the likelihood of side effects. Two observational studies and one clinical trial have raised concerns about lowering blood pressure — particularly diastolic pressure — too far. Diastolic blood pressure (the second number in a reading) represents the pressure between beats when the heart relaxes. "When your systolic blood pressure gets too low, it can manifest as lightheadedness, fainting, and weakness. But low diastolic pressure by itself doesn't have any symptoms," says Dr. Paul Conlin, professor of medicine at Harvard Medical School and chief of medicine at the VA Boston Healthcare System.

Research we're watching

Earlier studies have shown that wrist-worn activity trackers can accurately record the number of steps a wearer takes. However, few studies have determined how well they monitor heart rate.

Researchers at the University of Wisconsin in Madison studied four wrist-worn activity trackers — Basis Peak, Fitbit Surge, Fitbit Charge, and Mio Fuse — to determine the accuracy of their heart rate monitoring in 40 healthy women and men ages 30 to 65. The researchers fitted each participant with four trackers—two on each wrist. Using the trackers as well as an ECG machine, the researchers measured the wearers' heart rates at one-minute intervals for 10 minutes while they were sitting. They then repeated the measurements while the participants walked on a treadmill for 10 minutes. When they compared the readings from the ECGs and the trackers, they found that all of the readings were more consistent when the participants were resting than when they exercised.

Dietary supplements and herbal remedies are big business. Unlike conventional drugs, these products do not undergo extensive testing before they can be sold. Many do not produce the health benefits they promise, and some cases are harmful.

While frightening, fainting is not always serious, though it’s important to be aware that it may be a sign of an underlying problem with the blood vessels or heart.

Do a little research, follow a few rules, and make polite requests.

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Going out for dinner can be a nice way to unwind with family or friends. But if you're watching your salt intake, restaurants aren't always so relaxing. Much of their fare is loaded with sodium, a main component of salt. In fact, some entrees at popular chains contain far more than 2,300 milligrams (mg) of sodium — the recommended limit for an entire day's worth of food (see "Super-salty entree examples").

Limiting sodium is especially important for people with high blood pressure, because excess salt worsens this common condition, leaving you more prone to heart attack and stroke. If you eat out only once a month, you probably needn't worry too much. But Americans tend to eat out far more frequently — about five times a week, on average. So it's worth learning some strategies for staying within your salt budget when you eat away from home.

Three telltale symptoms occur in 75% of all strokes, often in combination. Don't ignore them — even if they're short-lived.

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Every 40 seconds, someone in the United States has a stroke. Also known as "brain attacks," strokes result from an injury to a blood vessel that limits blood flow to part of the brain. Rapid diagnosis and treatment can prevent potentially devastating disability or death — which is why everyone should know the common warning signs of a stroke.

In 2013, the American Stroke Association unveiled a stroke awareness campaign based on the mnemonic FAST. Around that the time, a national survey suggested that 28% of Americans didn't know any stroke symptoms, and nearly half weren't sure what to do if they experienced or witnessed the symptoms of a stroke. But four years later, things seem to be improving.