1/30/2008

Exercise Really Can Make You Younger, Study Shows

The study suggests that 30 minutes of moderate exercise five times a week has significant benefits

People who take exercise are biologically younger - by up to nine years - than those who don’t.

This striking finding may explain why exercise reduces the risk of heart attacks, diabetes, cancer, and other degenerative diseases. It actually suggests that active adults have cells that are measurably “younger” than those of inactive ones.

A team from King’s College London looked at biological molecules called telomeres that act as a clock, measuring the passage of the years. Telomeres are the caps at the end of the chromosomes, designed like the tips of a shoelace to protect them from damage.

In youth, telomeres are long, but they get shorter as we age, leading to a growing risk of damage. In the new study published in Archives of Internal Medicine the King’s team, together with colleagues from New Jersey, have shown that active people have longer telomeres than inactive ones.

They used data from the Twin Research Unit at King’s College to compare identical and non-identical twins, whose average age was just under 50. The study included more than 2,400 volunteers - mostly women - with an age range from 18 to 81.

Professor Tim Spector and Dr Lynn Cherkas from King’s, and Professor Abraham Aviv of New Jersey Medical School, asked the volunteers to fill in questionnaires about the amount of exercise they had done in the previous year. They also established whether they were smokers, their body mass index (BMI), and their socioeconomic status.

They found there was a significant link between telomere length in the volunteers’ white blood cells and the amount of exercise they took. This remained significant when adjusted for smoking, BMI, and social class.

Because genes also influence telomere length, the team checked the results by looking at a smaller group of identical twins. These pairs shared the same genes, but differed in their levels of everyday activity.

This confirmed that the link between telomere length and activity is also found in identical twins - powerful evidence that there is more to it than genetics.

The actual difference between active and inactive people was quite large. Dr Cherkas said: “Overall, the difference in telomere length between the most active subjects and the inactive subjects corresponds to around nine years of ageing.”

The team concludes: “The US guidelines recommend that 30 minutes of moderate-intensity physical activity at least five days a week can have significant health benefits.

“Our results underscore the vital importance of these guidelines. They show that adults who partake in regular physical activity are biologically younger than sedentary individuals.”

Professor Spector said: “Our study, performed on a large cohort, indicates that differences in telomere length between active and inactive individuals cannot be explained by variations in genes, smoking, BMI and socioeconomic status.

“A sedentary lifestyle appears to have an effect on telomere dynamics – thus providing a powerful message that could be used by clinicians to promote the potentially anti-aging effect of regular exercise.’

In a commentary in the same journal, Dr Jack Guralnik of the US National Institute on Ageing, says the results are provocative, but that more research is needed to prove them true.

“Persons who exercise are different from sedentary persons in many ways, and although certain variables were adjusted for in this analysis, many additional factors could be responsible for the biological differences between active and sedentary persons” he writes.

“Nevertheless, this article serves as one of many pieces of evidence that telomere length might be targeted in studying ageing outcomes.

Source: www.timesonline.co.uk

Diuretics Best for Hypertension and Metabolic Syndrome

Diuretics appear to be as good or better than other blood pressure drugs for treating hypertension in patients with metabolic syndrome, especially black patients, according to a U.S. study.

People with hypertension and metabolic syndrome are at high risk for complications of cardiovascular disease.

Researchers at Case Western Reserve University and University Hospitals Cases Medical Center in Cleveland analyzed data from the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT).

It included 42,418 people with hypertension and at least one other risk factor for cardiovascular disease who were randomly assigned to take either the diuretic chlorthalidone (15,255), the calcium channel blocker amlodipine besylate (9,048), the alpha-blocker doxazosin mesylate (9,061), or the ACE inhibitor lisinopril (9,054).

Each drug was used to start treatment, and other drugs were added if necessary to control blood pressure. The majority of patients were followed for an average of 4.9 years, but the alpha-blocker part of the trial was halted after an average of 3.2 years due to increased rates of cardiovascular disease.

Among the patients in the study, 23,077 met the criteria for metabolic syndrome, which is defined as hypertension plus at least two of the following factors: diabetes or pre-diabetes; a body-mass index (BMI) of at least 30; high triglyceride levels; or low levels of high-density lipoprotein ("good" cholesterol).

"No differences were noted among the four treatment groups, regardless of race or metabolic syndrome status for the primary end point (nonfatal myocardial infarction [heart attack] and fatal coronary heart disease)," the study authors wrote.

Among patients with metabolic syndrome, those taking the diuretic had a lower rate of heart failure than those taking the other three drugs. Patients who took the ACE inhibitor and the alpha-blocker also had an increased risk of combined cardiovascular disease.

"The lack of benefit of the agents with the most favorable metabolic profile [i.e., ACE inhibitors and alpha-blockers] was especially marked in black participants with metabolic syndrome," the researchers wrote.

"The magnitude of excess risk of end-stage renal [kidney] disease [70 percent], heart failure [49 percent] and stroke [37 percent] and the increased risk of combined cardiovascular disease and combined coronary heart disease strongly argue against the preference of ACE inhibitors over diuretics as the initial therapy in black patients with metabolic syndrome. Similar high risk was noted for those randomized to the alpha-blocker versus the diuretic."

The researchers concluded that the findings "fail to provide support for the selection of alpha-blockers, ACE inhibitors, or calcium channel blockers over thiazide-type diuretics to prevent cardiovascular or renal outcomes in patients with metabolic syndrome, despite their more favorable metabolic profiles."

Source: www.washingtonpost.com

1/28/2008

Critical Things to Know about Your Cholesterol

How's your cholesterol? Here's a guess: If you're healthy, you probably have no idea. New surveys show women tend to be clueless about their risks of heart disease, especially when it comes to managing their cholesterol.

High cholesterol can lead to clogged coronary arteries, which can cause heart attack and stroke.

But this kind of ignorance is anything but bliss. The reason: The artery clogging that makes heart disease the Number One killer of women late in life begins much earlier - in your 20s, 30s, and 40s - and that's when your cholesterol numbers may be sounding alarms. So, are you ready to start paying attention? Here, the things all women need to know now.

1. High cholesterol is surprisingly common.

Researchers with the Framingham Heart Study recently delivered a nasty surprise: Nearly a quarter of women in the study who are in their early 30s have borderline-high levels of bad cholesterol, as do more than a third in their early 40s and more than half in their early 50s. A third of women in all three age groups have low levels of good cholesterol.

Bad cholesterol, also known as low-density lipoprotein, or LDL, contributes to heart disease by laying down artery-clogging plaque; good cholesterol, or high-density lipoprotein (HDL), helps clear it away. "The double whammy of high LDL and low HDL is particularly dangerous," says Framingham researcher Vasan Ramachandran, M.D., of the Boston University School of Medicine.

2. Your doctor may miss the problem.

Though women are better than men about seeing a doctor regularly, the care they receive isn't as good when it comes to preventing and treating cardiovascular disease, according to new studies. "Perhaps doctors still haven't gotten the message that women need to control cholesterol," says Chloe Bird, Ph.D., author of one of these studies and a senior sociologist at the nonprofit RAND Corporation. Bird found that doctors are less likely to monitor and control cholesterol in women than in men, even when the women are at super-high risk of heart attack.

Part of the problem, she says, may be that many women see only a gynecologist. This isn't to say that OB-GYNs can't be good primary care doctors, but you have to make sure the doc is willing to monitor your heart health, especially if you already have diabetes or a heart issue. That means she should order cholesterol checks as part of your regular blood work and discuss the results with you. What does "regular" mean?

3. Your numbers may trick you.

Many people misunderstand the roles of so-called good and bad cholesterols, according to cardiologist and lipidologist Pamela Morris, M.D., of the Medical University of South Carolina in Charleston. "What we've learned is that HDL and LDL are independent predictors of a woman's heart attack risk," she explains. "We see women with high HDLs having heart attacks when their LDL is also high, and we also see heart attacks in women with very low LDL but also low HDL."

What that means to you: It's important to keep track of both. A woman wants to keep her HDL above 60 (the level at which HDL helps prevent disease) and her LDL below 100. If your HDL drops below 50 or LDL rises above 160, you need to take immediate action. That may include an LDL-lowering drug such as a statin, and it definitely includes a commitment to a heart-healthy diet and lifestyle.

4. You may need an "inflammation" test.

The math used to estimate your heart disease risk is a little misleading. If your LDL rises above the danger line of 160 or your HDL drops below 50, the math says you have an elevated risk of a heart attack within 10 years. But that warning may actually underestimate your risks beyond 10 years, Morris says. So when she has a female patient with cholesterol numbers in the intermediate range - LDL above 130 or HDL under 60 - she often takes a close look at the woman's whole-body inflammation level.

You can't see this kind of inflammation, but it's actually an independent measure of heart attack risk. You measure it by adding a test for high-sensitivity C-reactive protein (hs-CRP) to the usual cholesterol blood work. CRP, essentially a body chemical, usually rises anytime your body becomes inflamed. And since artery clogging is associated with inflammation, high CRP is viewed as a marker for clogged arteries. That means your C-reactive protein levels may help you and your doctor decide how aggressively you need to control borderline-high-cholesterol levels with drugs, diet, and exercise.

5. These foods are your best friends.

Certain classes of food chemicals can actively and powerfully lower a person's bad cholesterol. Two - soluble fiber and phytosterols - have so much science behind them that they've become part of standard medical prescriptions for treating high cholesterol. But dietitian Janet Brill, Ph.D., R.D., author of "Cholesterol Down," also recommends regularly eating almonds, ground flaxseed, apples, soy protein, and olive oil. Preliminary research suggests they all have cholesterol-lowering powers. "Each one works in a slightly different way," Brill says. "So together, you get a synergy that can dramatically lower cholesterol."

Almonds and olive oil are high in monounsaturated fats, which are thought to blend with LDL molecules in a way that speeds LDL's clearance from the blood by the liver. Flax is high in both soluble fiber, which lowers LDL by absorbing cholesterol from both food and bile inside the intestines, and omega-3 fatty acids, which studies show have anti-inflammatory effects. Other foods especially high in soluble fiber include oat bran, oatmeal, and apples. (Soluble fiber is different from insoluble fiber, the kind found in whole-grain bread and bran cereal. That's good for you, too, but it won't affect your cholesterol.) Soy may mimic natural estrogens in their LDL-clearing effects. Phytosterols are the plant version of animal sterols (a.k.a. cholesterol) and lower LDL by competing with it for absorption into the body. They're found in supplements or phytosterol-enhanced margarine such as Benecol.

You don't need any of these foods if your LDL is low, but experts still recommend them for everyone. What about steak, eggs, and cheese? They sure won't help your cholesterol, because they all contain a lot of it. But it's more important to focus on foods that lower your numbers rather than simply avoiding the bad stuff, experts say.

6. Good cholesterol may have a bad side.

The higher your HDL, the better, right? That's been the current thinking, due to HDL's protective effect. But here's a surprise you may have read about in some news reports: Studies are showing that HDL may actually have harmful proteins capable of boosting heart disease risks. A test to determine whether your HDL has the harmful proteins may be available in a few years. In the meantime, if your HDL is lower than 60, it's still OK to raise it a little as long as you don't go overboard. How? Try getting a lot of omega-3s from fish or fish oil, exercising regularly, controlling your weight, and avoiding smoking.

7. Your heart loves long walks.

Walking 10 miles a week brings lasting improvements in your heart health, according to researchers at Duke University Medical Center. The funny thing is, if you jog those 10 miles, you won't get quite as much benefit. "Duration appears to be key," says Duke's Cris Slentz, Ph.D., an exercise physiologist. "Jogging or walking 10 miles both burned around 1,200 calories, but in our studies, one took about two hours and the other, three."

Longer stints of exercise, even moderate exercise, may burn more belly fat - the little rolls of skin near your navel and the fat deep inside your abdomen. The latter is linked to metabolic syndrome, a condition associated with a host of cardiovascular risk factors including low HDL, high blood pressure, and high triglycerides (a kind of blood fat that contributes to heart disease).

Should you aim for weight loss as well as long walks? If you're overweight, absolutely. But understand that shedding a few pounds will make only a small dent in your cholesterol. Canadian researchers recently found that overweight women who lost about 25 pounds - no easy task - saw their LDL drop about 10 percent and their HDL rise by the same amount.

Source: cnn.com

See also: Top 10 Tips for a Healthy Heart

1/25/2008

Can Yogurt Really Boost Your Health?

One of the hottest food marketing trends these days involves adding live bacteria to dairy products as a way to boost health.
A lawsuit challenges the health claims of Activia,a probiotic yogurt.Dannon claims Activia can help regulate your digestive system.

Now lawyers have filed a class-action lawsuit against yogurt maker Dannon, one of the biggest sellers of “probiotic” yogurts, saying the claims of a health benefit dupe consumers. The company’s Activia and DanActive line of yogurt products contain live bacteria and claim to help regulate digestion and boost the immune system. The suit, filed in United States District Court in California, seeks redress for consumers who purchased the yogurt products based on what it says are “bogus claims.'’

“Deceptive advertising has enabled Dannon to sell hundreds of millions of dollars worth of ordinary yogurt at inflated prices to responsible, health- conscious consumers,” said Los Angeles attorney Timothy G. Blood, of the firm Coughlin Stoia Geller Rudman & Robbins.

In response, Dannon issued a statement saying it “stands by the claims of its products and the clinical studies which support them.'’

“All of Dannon’s claims for Activia and DanActive are completely supported by peer-reviewed science and are in accordance with all laws and regulations,'’ said the statement. “Dannon’s advertising has always been and will continue to be absolutely truthful, and Dannon will vigorously challenge this lawsuit.”

Probiotics are defined as live microorganisms that, in sufficient amounts, confer a health benefit on the host. A growing body of research links probiotics to relief of digestive tract complaints such as irritable bowel syndrome, yeast infections, and diarrhea that results from certain illnesses. The idea behind probiotics is to increase the amount of beneficial bacteria in people’s intestinal tracts as a way to aid digestion, boost the body’s natural defenses and fight off harmful bacteria that can cause health problems.

Although the scientific evidence shows that probiotics really can help, questions remain about how well that research translates into the real world, where some marketers may add untested amounts of the bacteria to various foods. While there are thousands of different probiotics, only a handful have been tested in clinical trials and been shown to deliver specific health benefits when eaten regularly. Most probiotic products can be found in the dairy case or as dietary supplements.

Dannon’s Activia line has been a marketing success story for the company, surpassing $100 million in sales in the United States its first year. The yogurt includes a form of Bifidobacteria that survives passage through the digestive tract, arriving in the colon as a living culture. The company claims that “once there, it plays a beneficial role in your intestinal ecosystem.'’ The yogurts are backed by a high-profile advertising campaign as well as a Web site. The site includes a link to company-sponsored studies showing that the bacteria used in Activia significantly improves regularity in study subjects.

The firm’s DanActive line, meanwhile, contains a different type of bacteria the company claims “helps strengthen your body’s defense.'’

The Food and Drug Administration doesn’t do much to guide consumers on the issue, simply policing food packages to make sure that companies do not try to equate probiotic products with disease-curing drugs.

A 2006 report from the American Society for Microbiology noted that “at present, the quality of probiotics available to consumers in food products around the world is unreliable.”

Source: well.blogs.nytimes.com