September 2nd, 2011
By: Alice Park
The government’s recent Dietary Guidelines for Americans had some familiar recommendations for health: eat more fruits and vegetables, exercise more and lower the amount of salt you eat.
Now a new study from Europe challenges that last piece of advice by suggesting that reducing dietary salt may not benefit your heart health after all. Previous studies have shown that people with high blood pressure can lower their risk of developing hypertension and heart disease by eating less salt. But in the new study, people who had the most salt in their diets actually had the lowest risk of dying from heart disease.
Yes, that’s right. The study involved 3,681 people without heart problems, most of whom also had normal blood pressure. Reporting in the Journal of the American Medical Association (JAMA), the researchers found that those with the highest levels of sodium in their urine (the most accurate way to measure how much salt a person consumes) were more than four times less likely to die from heart disease than those with the lowest intake of sodium. During the nearly eight years of follow up, the heart-related death rate was 0.8% among those with the highest sodium levels and 4% among those with the lowest levels.
“Yes, the findings surprised me and those of us at the American Heart Association (AHA),” says Dr. Ralph Sacco, president of the AHA and chairman of neurology at University of Miami. The AHA is hoping to get Americans to lower their sodium intake to 1,500 mg per day by 2020, far below the 2,300 mg daily maximum that the U.S. Department of Agriculture now advises.
“We have to remember that many people are at high risk for high blood pressure,” says Sacco. “And when we start going up in age, the proportion of people with high blood pressure approaches 70% to 80% or more, so your lifetime risk of high blood pressure is exceedingly high.”
Salt can play a role in blood pressure, and the current study confirmed this, finding that the systolic pressure (the upper number in the blood pressure reading) was slightly higher among those consuming the most salt, compared with those consuming the least. Even so, those people were at no higher risk of developing hypertension.
The current study fuels the brewing debate over whether low-salt standards should apply equally to everyone. Some experts suggest that certain people may be more sensitive to salt than others, or that people with normal blood pressure may not benefit from lowering their sodium intake. Most of the gold-standard studies on salt — in which people are randomly assigned to consume diets high or low in sodium — have involved people who either have hypertension or are at high risk of developing it. Based on that data, scientists just assumed that the same low-salt principle would benefit people at lower risk as well.
But as one of the study authors, Dr. Jan Staessen, professor of medicine at University of Leuven in Belgium, told JAMA in a Q&A, “If you decrease sodium intake a lot, you activate some of the systems that conserve sodium and they are known to have a negative influence on cardiovascular outcomes.” While it’s not know if this is indeed the reason for the contrary findings, it could explain why lower sodium levels were linked to greater heart problems in the trial.
Still, Sacco, as well as the authors, acknowledge that there might be other reasons for the surprising results. First, the study population was relatively young on the whole (participants’ ages ranged from 20 to over 60), and therefore at lower risk of hypertension than an older population. The impact that sodium can have on the heart may differ depending on age.
Second, the scientists took only one urinary sodium reading over a 24-hour period from each participant, and such readings can vary; an average of several measurements might have more accurately captured the participants’ true sodium intake.
And, finally, given the young age of the volunteers, an eight-year follow up may not have been long enough to capture the full risk of heart events or death from heart attacks, which tend to occur in advanced middle age and later.
It appears that the question about how salt affects heart risk is a complicated one. There is certainly strong and undisputed evidence that people with high blood pressure can lower their readings by reducing their salt intake. So it would stand to reason that the same applies to healthy people with normal blood pressure — even if there isn’t the gold-standard scientific evidence to support that.
Of course, dropping blood pressure too low comes with its own health risks — dizziness, fainting and even shock — but most U.S. adults aren’t at risk of hypotension. Sacco points out also that because high blood pressure is associated with both age and obesity, there’s good reason for large swaths of the American public to hold off on the sodium.
“Our population is aging, and more and more people are obese, and less physically active, so we felt that [the AHA's] recommendation for all Americans to lower their salt intake is important because a large proportion of Americans are intermediate to high risk for developing high blood pressure,” he says. “One study should not change all the other great evidence out there that says we should be lowering sodium. Lowering blood pressure even by a few millimeters can have an impact over a lifetime. So don’t reach for that salt shaker.”
November 18th, 2010
By: Helen Briggs
Fat cells taken from the waistline could hold promise in treating heart attacks, say researchers.
A pilot study on 14 patients in the Netherlands and Spain found that stem cells extracted from fat and delivered to the heart appeared to boost heart function after a heart attack.
Doctors now plan to extend the study to over 300 heart attack patients at 35 clinics in Europe.
A UK heart charity said the approach was “promising”.
The research, which was presented at the American Heart Association’s annual conference, followed 14 patients who had suffered a severe heart attack.
Doctors used liposuction to take fat from the abdomen of each patient, extracted millions of stem cells, then delivered these to the heart within 24 hours.
Ten of the patients were given stem cells; while four had a “dummy” treatment.
Six months on, the patients given stem cells had a lower amount of damaged muscle in their hearts – about 15% compared with 25% in the control group.
Lead author, Eric Duckers, of the Erasmus University Medical Centre in Rotterdam, Netherlands, said: “The study suggests that these cells can be safely obtained and infused inside the hearts of patients following an acute heart attack.”
Professor Jeremy Pearson of the British Heart Foundation, said small clinical trials in the last few years had tested whether stem cells from bone marrow could help the heart recover after a heart attack, “with some promising results”.
But he called for further research.
“This pilot study shows for the first time that stem cells from a patient’s fat tissue may be similarly beneficial, indicating a potential new and more convenient source of stem cells,” he said.
“However, since we still know very little about the way these cells could help to repair the damaged heart, there needs to be more research to understand what the stem cells actually do.
“That will help us to understand more about how they could be used for real patient benefit.”
The results of the study, known as Apollo, were not statistically significant, possibly because of its small size.
Researchers now plan a larger trial which will look at the treatment in more detail.
February 26, 2010
The healthiest food often has the least marketing muscle behind it. The Center for Science in the Public Interest recently published a comprehensive report on the subject, a persuasive indictment called “Food Labeling Chaos.”
Here are nine of the most common ways food labels lie, so you can prepare before your next trip to the grocery store.
“Made With Whole Grains”
Unbleached wheat flour is still the main ingredient; whole wheat flour is further down on the list, indicating that the product contains relatively little. One truth — the presence of whole grains — masks another; that whole grains make up an insignificant portion of the food.
Another factor to keep in mind is the presence of potassium bromate, a dough conditioner found in commercial bakery products and some flours, which is a major, but hidden cause of thyroid dysfunction. This ingredient may be used even in whole grain breads. For more information, please review this previous article.
Even if the first ingredient listed isn’t sugar, the product may contain more sugar than anything else. How is it possible? Just add up all the sugars that go by different names, such as sugar, corn syrup, high-fructose corn syrup and white grape juice concentrate.
There are 2.5 official servings in a 20 ounce soda bottles, meaning that 100 calories per “serving” is really 240 calories per bottle.
Everyone knows omega-3 fats are healthy, but that doesn’t mean every product emblazoned with the word is a healthy source of it. The FDA allows certain foods that are rich in two of the omega-3 fats to advertise that they can reduce the risk of coronary heart disease, but only if they’re also low in saturated fats or other risk factors. Which is why some unhealthy foods use a bit of marketing misdirection: the packaging has the word “omega-3,” but nothing specifically about heart health.
“Made With Real Fruit”
Usually the only thing approximating fruit is concentrate (sugar). If you want real fruit, buy real fruit. If you want candy, buy candy.
“0 Trans Fat”
Many reformulated foods are basically just as bad, but they scream one truth: “0 trans fats!” to obscure another: “still bad for your heart!”
“Free Range Eggs”
This means chickens must be granted the luxury of exactly five minutes of “access” to the outdoors every day. Those eggs you buy may have been raised ethically, with room enough for hens to roam the yard. But there’s no guarantee in the “free range” label.
The fibers advertised in many foods are mainly “purified powders” called inulin, polydextrose and maltodextrin. These “isolated” unnatural fibers are unlikely to lower blood cholesterol or blood sugar, as other fibers can.
Tastes Like Medicine!
The FDA allows food manufacturers to make certain pre-approved “qualified health claims” about the health benefits of nutrients in food. But marketers have stretched this inch into a long mile. For instance, food makers can’t say that their product “helps reduce the risk of heart disease” without FDA approval, so they say that it “helps maintain a healthy heart.”
That’s why several public health groups, including the American Heart Association and the American Cancer Society, have voiced concern about this trend.
February 22, 2010
By David Gutierrez
Vitamin D deficiency may triple a person’s risk of high blood pressure, according to a study conducted by researchers from the University of Michigan School of Public Health and presented at a meeting of the American Heart Association in Chicago.
“Our results indicate that early vitamin D deficiency may increase the long-term risk of high blood pressure in women at mid-life,” researcher Flojaune Griffin said.
The researchers recruited 559 white women from Tecumseh, Michigan, who were between 24 and 44 years old when the study began in 1992. The participants’ vitamin D blood levels were measured at the beginning of the study and once a year after that for 15 years.
At the beginning of the study, 5.5 percent of the women who were deficient in vitamin D suffered from high blood pressure, compared with only 2.8 percent of the women who had sufficient levels of the vitamin. At the end of the study in 2007, 10 percent of the women in the deficiency group had high blood pressure, compared with only 3.7 percent in the “sufficient” group.
“This is preliminary data so we can’t say with certainty that low vitamin D levels are directly linked to high blood pressure,” Griffin said. “But this may be another example of how what you do early in life impacts your health years later.”
Vitamin D is known to play a crucial role in producing strong bones and teeth. New research increasingly suggests that it also helps regulate the immune system and protect against cancer, autoimmune disorders and heart disease.
The body naturally produces vitamin D upon exposure to sunlight. A number of factors have led to widespread deficiency, however, especially at latitudes far from the equator. These factors include less time spent outside and overuse of sunscreen. Dark-skinned people living at extreme latitudes are also especially vulnerable, as their bodies produce less vitamin D from the same amount of sun than those of lighter-skinned people.