Brief Intense Exercise Better Than Endurance Training for Preventing Cardiovascular Disease

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New research published April 5 in the American Journal of Human Biology reveals that high intensity exercise is more beneficial than traditional endurance training.

"Cardiovascular disease (CVD) is a leading cause of mortality throughout the world and its risk factors have their origins in childhood," said lead author Duncan Buchan from the University of the West of Scotland. "Our research examines the effects of brief, intense exercise when compared to traditional endurance exercise on the markers of CVD in young people."

Buchan's team recruited a group of volunteer school children, forty seven boys and ten girls, and randomly divided the group into moderate (MOD) and high intensity (HIT) exercise teams.

The two groups performed three weekly exercise sessions over 7 weeks. The HIT group's training consisted of a series of 20 meter sprints over 30 seconds. In contrast the MOD group ran steadily for a period of 20 minutes.

By the end of the study the MOD group had completed 420 minutes of exercise while the HIT group had trained for a shorter 63 minutes. The estimated energy expenditure for the HIT intervention was 907.2 kcal in comparison to 4410 kcal for the MOD group.

The results revealed that both groups demonstrated improved CVD risk factors. However, the total exercise time over seven weeks was six times higher for the MOD group compared to the HIT group. Thus, significant improvements in CVD risk factors in the HIT group occurred in only 15% of the total exercise time.

These findings demonstrate that brief, intense exercise is a time efficient means for improving CVD risk factors in adolescents. Although limited to relatively small samples, the findings demonstrate significant improvements in cardiorespiratory fitness, blood pressure, body composition and insulin resistance in healthy adolescent youth after a 7 week intervention of different exercise intensities.

"This is the first study to demonstrate the effects of a novel interval training programme on both traditional and novel CVD risk factors in adolescents," concluded Buchan. "Larger scale and extended interventions must be undertaken so that the long term impact and effects of intermittent training programmes on unfavourable metabolic profiles may be investigated further."

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Strawberries may slow precancerous growth in the esophagus

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Eating strawberries may be a way to help people at risk of esophageal cancer protect themselves from the disease, according to a new study by researchers at The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC – James) and researchers in China.

Dr. Tong Chen will present the findings during a press briefing at 8 a.m. April 6 at the American Association for Cancer Research (AACR) 102nd meeting 2011 in Orlando, Fla. The study is the first-ever collaborative Ohio State cancer clinical trial to be conducted in China.

"We concluded from this study that six months of strawberry treatment is safe and easy to consume. In addition, our preliminary data suggests that strawberries decreased histological grade of precancerous lesions and reduced cancer-related molecular events," said Chen, lead author, and assistant professor in the division of medical oncology, department of internal medicine at Ohio State. She is also a member of the Molecular Carcinogenesis and Chemoprevention program in Ohio State's Comprehensive Cancer Center.

Previously published research by Chen and colleagues found that freeze-dried strawberries significantly inhibited tumor development in the esophagus of rats. Based on these results, the researchers embarked on a phase Ib clinical trial in China to investigate the effects of freeze-dried strawberries on patients with esophageal precancerous lesions.

"We found that daily consumption of strawberries suppressed various biomarkers involved in esophageal carcinogenesis, including cell proliferation, inflammation and gene transcription," Chen said.

Each of the 36 study participants ate 60 grams (about two ounces) of freeze-dried strawberries daily for six months. The researchers obtained biopsy specimens before and after the strawberry consumption. The results showed that 29 out of 36 participants experienced a decrease in histological grade of the precancerous lesions during the study.

"We predict that the majority of patients with precancerous lesions in their esophagus will develop esophageal cancer over subsequent decades," said Chen. "Our study is important because it shows that strawberries may slow the progression of precancerous lesion in the esophagus. Strawberries may be an alternative, or may work together with other chemopreventive drugs, for the prevention of esophageal cancer. But, we will need to test this in randomized placebo-controlled trials in the future."

Esophageal cancer is the third most common gastrointestinal cancer and the sixth most frequent cause of cancer death in the world, said Chen, who also holds a doctorate in Public Health. Chen and her team are studying esophageal squamous cell carcinoma which makes up 95 percent of cases of esophageal cancer worldwide. The survival rate of this type of esophageal cancer is very low, with only 10 percent of patients living 5 years after diagnosis.

Esophageal squamous cell carcinoma is quite common in China, Japan, the Transkei region of South Africa, Iran, France and Puerto Rico.

"Since this clinical trial is being conducted in China, considerably more effort is required to establish and complete the trial than is typically necessary at our own institution. Nevertheless, we have established a team of highly collaborative investigators who are working well together," said Chen.

China has the largest population in the world, and the number of potential participants for clinical trials is higher than in any other country in the world.

"We believe that establishing collaborative research teams will enhance clinical research, and that our project will 'open doors' for multiple other trials in China," Chen said.

In the United States, Canada and Europe, the risk factors for developing esophageal cancer include tobacco and alcohol use, along with poor diet lacking fruits and vegetables.

In Asia, additional risk factors include dietary intake of salty food and of food contaminated with various mycotoxins, deficiencies in dietary vitamins and minerals and thermal injuries due to the consumption of hot beverages.

More than 16,000 new cases of esophageal cancer will be diagnosed in the United States this year, according to the American Cancer Society.

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Choline Can Increase Heart Risk

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Choline – a natural semi-essential vitamin – when taken in excess, promoted atherosclerotic heart disease. Over the past few years we have seen a huge increase in the addition of choline into multi-vitamins - even in those marketed to our children - yet it is this same substance that our study shows the gut flora can convert into something that has a direct, negative impact on heart disease risk by forming an atherosclerosis-causing by-product."

In studies of more than 2,000 subjects altogether, blood levels of three metabolites of the dietary lipid lecithin were shown to strongly predict risk for cardiovascular disease: choline (a B-complex vitamin), trimethylamine N-oxide (TMAO, a product that requires gut flora to be produced and is derived from the choline group of the lipid) and betaine (a metabolite of choline).

"The studies identify TMAO as a blood test that can be used in subjects to see who is especially at risk for cardiac disease, and in need of more strict dietary intervention to lower their cardiac risk," said Stanley Hazen, M.D., Ph.D., Staff in Lerner Research Institute's Department of Cell Biology and the Heart and Vascular Institute's Department of Cardiovascular Medicine and Section Head of Preventive Cardiology & Rehabilitation at Cleveland Clinic, and senior author of the study.

Healthy amounts of choline, betaine and TMAO are found in many fruits, vegetables and fish. These three metabolites are commonly marketed as direct-to-consumer supplements, supposedly offering increased brain health, weight loss and/or muscle growth.

These compounds also are commonly used as feed additives for cattle, poultry or fish because they may make muscle grow faster; whether muscle from such livestock have higher levels of these compounds remains unknown.

"Knowing that gut flora generates a pro-atherosclerotic metabolite from a common dietary lipid opens up new opportunities for improved diagnostics, prevention and treatment of heart disease," Dr. Hazen said. "These studies suggest we can intelligently design a heart healthy yogurt or other form of probiotic for preventing heart disease in the future. It also appears there is a need for considering the risk vs. benefits of some commonly used supplements."

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Vegans' elevated heart risk requires omega-3s and B12

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People who follow a vegan lifestyle — strict vegetarians who try to eat no meat or animal products of any kind — may increase their risk of developing blood clots and atherosclerosis or "hardening of the arteries," which are conditions that can lead to heart attacks and stroke. That's the conclusion of a review of dozens of articles published on the biochemistry of vegetarianism during the past 30 years. The article appears in ACS' bi-weekly Journal of Agricultural and Food Chemistry.

Duo Li notes in the review that meat eaters are known for having a significantly higher combination of cardiovascular risk factors than vegetarians. Lower-risk vegans, however, may not be immune. Their diets tend to be lacking several key nutrients — including iron, zinc, vitamin B12, and omega-3 fatty acids. While a balanced vegetarian diet can provide enough protein, this isn't always the case when it comes to fat and fatty acids. As a result, vegans tend to have elevated blood levels of homocysteine and decreased levels of HDL, the "good" form of cholesterol. Both are risk factors for heart disease.

It concludes that there is a strong scientific basis for vegetarians and vegans to increase their dietary omega-3 fatty acids and vitamin B12 to help contend with those risks. Good sources of omega-3s include salmon and other oily fish, walnuts and certain other nuts. Good sources of vitamin B12 include seafood, eggs, and fortified milk. Dietary supplements also can supply these nutrients.

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Vitamins & Supplements: Safety First

Source: Health Behavior News Service, part of the Center for Advancing Health.

Vitamins, herbs and other dietary supplements are sold as natural alternatives to pharmaceuticals and many people turn to them in an attempt to improve their health. Others seek supplements to lose weight or after hearing that they can help with serious medical conditions. These products are now used at least monthly by more than half of all Americans—and their production, marketing and sales have become a $23.7 billion industry, according to the Nutrition Business Journal.

98-year-old Bob Stewart, a retired podiatrist and senior Olympian, credits his use of supplements for his healthy aging. Writer Betsy McMillan, a mother of two now adult children, however, nearly suffered permanent liver damage due to a supplement that contained potentially fatal levels of niacin.

Unlike pharmaceuticals—which must be FDA-approved as safe and effective before they can be marketed—supplements are considered as foods by regulators and assumed to be safe until proven otherwise. Although pharmaceutical manufacturers face inspections to ensure that the right dose is in the right pill without dangerous contaminants, supplements do not undergo such intense government scrutiny.

Despite many reports of health problems, only one supplement has ever been pulled from the market: the stimulant ephedra, which was banned in 2004 following reports of deaths. With such little regulation and oversight, safe supplement use requires that consumers be cautious and savvy.

“Supplement is a broad term that includes vitamins, minerals, herbs and botanicals,” says Carol Haggans, a registered dietician and science and health communication consultant for the Office of Dietary Supplements of the National Institutes of Health. Herbs and botanicals are derived from plants, while other supplements may include animal sources. Vitamins are essential nutrients made up of organic compounds, while minerals is an imprecise term for certain chemical elements necessary to life, like calcium.

“They’re regulated under the umbrella of foods and are not intended to treat, diagnose, mitigate, cure or prevent disease. If something claims to do that, then it becomes a drug under FDA regulation,” Haggans says.

She adds, “The FDA has instituted ‘good manufacturing practices’ (GMP) that manufacturers must follow to ensure the identity and quality of supplements and they can take enforcement action if it’s unsafe or unfit for human consumption, but they do not routinely test products.” Once manufacturers implement these practices, they can display a seal on their packaging, noting their compliance.

But Dr. Bob Linden, a general practitioner and author who has used supplements but also has seen problems with them in patients, says he’s rarely seen the GMP seal in stores where he lives in Connecticut, despite the agency’s plan to complete most of the implementation by last year.

Looking for Safer Products

So how can consumers protect themselves and find high-quality products? Haggans says that several independent organizations test products and offer their seal of approval only to those that pass. “Those can give some assurance that the product is properly manufactured, contains the ingredients listed on the label and doesn't contain harmful levels of contaminants,” she says. Consumer Reports Health also regularly reviews supplements but may require a subscription for full access to information.

“I think people use them primarily because they think they’re natural [and from] plants,” Linden says. “They also think they’re safe because you don't need a prescription.” He has taken supplements himself for arthritis. But he also had one patient who suffered liver damage after taking a supplement containing Chinese skullcap, which is known to be dangerous to the liver but is still on the market.

“They can’t label them as treating disease, on the bottle, they say it’s ‘promoting health,’” Linden says. “But people do take them specifically for [diseases], such as St. John’s wort for depression.”

Managing Interactions and Dosing

Like drugs, supplements can combine with other medications in unhealthy ways. “Dietary supplements can interact with both over-the-counter and prescription medication,” Haggans says. “That’s one reason we tell people to talk with their doctors about all the supplements that they're taking.” For example, the anticoagulant medicine warfarin (Coumadin) can interact with gingko biloba and with garlic and cause bleeding. St. John’s wort, which is often used to treat depression, can weaken the effects of birth control pills and other medications. Vitamins C and E can also potentially interfere with chemotherapy used to treat cancer.

Doctors might not know about interactions between supplements and prescriptions and since supplement labels don’t list warnings, patients need to do their own research: look for guidance from the sites listed in the resource section and talk to a nutritionist or check with reliable sources at “health food” stores or reputable “wellness” centers. This is a situation where watching carefully for side effects is especially important and consumers are mostly on their own to be vigilant.

Some supplements can be monitored by testing blood levels. This can be expensive but it might also reduce problems related to potential toxicity or unusual individual reactions. Check with your doctor to see if blood tests might be suitable for you.

Researching Appropriate Supplements

The scientific evidence supporting the use of supplements is often weaker than that available for drugs because of the lack of legal requirements to prove safety and efficacy. “You can get a lot of conflicting evidence depending on where you look,” Haggans says.

The Office of Dietary Supplements, the National Center for Complementary and Alternative Medicine, and the Memorial Sloan-Kettering Cancer Center all keep regularly updated fact sheets on the most commonly used herbs, supplements and vitamins.

Beyond that, there are several important principles to keep in mind if you take supplements. First, “Natural is not always safe,” Haggans says. Both arsenic and poison mushrooms are completely natural but deadly to eat. Second, never rely on a single study or personal story to provide definitive evidence.

In contrast, review articles—particularly those done under the rigorous standards of the Cochrane Collaboration—can be a high quality source of evidence. “Review articles like Cochrane Reviews look at the totality of the evidence in different populations,” Haggans says, which is especially important since studies of nutrition often have conflicting results.

For example, beta-carotene was once thought to be a universal cancer fighter—but long-term studies found that smokers and other people at high risk for lung cancer who took it actually increased their risk of contracting the disease and their risk of early death from other causes.

Avoiding Overdose

Dose is also a critical consideration. “Many nutrients have an upper limit,” Haggans says. “More is not better and above certain amounts, they can be toxic.” She notes that iron is one mineral that is dangerous in high doses. Niacin—as McMillan unfortunately found out—is another.

The use of supplements—like much of American life—is highly susceptible to fashion. The “in” supplements of the 1980s and 90s like gingko biloba and ginseng were followed by an antioxidant fad for vitamins A, C and E in the 2000s. The 1994 study on beta-carotene and smoking and a 2005 finding that high-dose vitamin E may do harm took some steam out of those trends. Currently, omega-3 fatty acids and vitamin D are the headline makers. Overall, the supplement industry has grown dramatically, continuing to increase sales despite the recession.

Given this—and given the fact that some risky supplements like the Chinese skullcap that harmed Dr. Linden's patient remain on the market—it’s important that people considering them “do their homework,” as Haggans puts it. “Go to a trusted source like your doctor for information.” At the least, your doctor can help you weigh the evidence.

Narrowing Your Choices

Linden suggests closely following directions on products’ bottles. He adds, “Stay away from supplements [advertised for] weight loss—you don’t know what you're getting and it’s looking for trouble.” Some weight-loss supplements and some sold as sexual aids have been found to contain prescription medications that were illegally manufactured.

Stewart’s advice is to stick to supplements that are essentially unaltered whole foods, like flaxseed and vinegar. “The type of food we have now in grocery stores is terrible,” he says, echoing the complaints of nutrition experts about over-processed and chemical-laden foods.

Supplements can be helpful in some cases but they are less well regulated than drugs and have many of the same side effects, drug interactions and toxicities at high doses seen with pharmaceuticals. Consequently, they should be used with care and with guidance from a doctor.

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Pneumonia Death Rate Lower Among People Who Take Statins

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Taking statins could help prevent people dying from pneumonia, according to a study by the London School of Hygiene and Tropical Medicine.

The researchers found that the risk of death in the six month period after diagnosis of pneumonia was substantially lower among those who were already receiving the cholesterol-lowering drugs compared with those who were not.

Previous studies have suggested that statins may be associated with a more favourable outcome after bacterial infection.

This study, published online in the British Medical Journal on April 4, supports a possible protective effect of statins against mortality in patients with pneumonia.

But the researchers point out that as they looked at patients who were already taking the medication when they developed pneumonia, a randomised clinical trial is needed to determine whether starting a statin at the time of diagnosis has a similar effect

Funded by the Wellcome Trust and the Medical Research Council, the team of epidemiologists used data from The Health Improvement Network (THIN), a database of computerised medical records of doctors' practices in the UK, to identify statin users for the study.

They matched each statin user, who were aged over 40 at first prescription of a statin between 1995 and 2006, with up to five non-statin users.

Patients with a record of pneumonia were followed for six months to see if they died and the scientists found that 13% (109 out of 847) of statin users died compared with 20% (578 out of 2927) of non-statin users.

While the study tried to minimise confounding variables, the researchers point out that they cannot rule out the possibility that unknown differences between statin users and non-users could have contributed to the results.

Lead author Dr Ian Douglas, lecturer in epidemiology at LSHTM, said: "Statins are safe, cheap, and an easy intervention in terms of delivery.

"Given the potential low number needed to treat to prevent a death suggested by this study, we believe that a strong case exists for randomised trials of statins in people with serious infection to determine if a simple and practical intervention at the point of diagnosis of pneumonia has a beneficial effect."

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Routine periodic fasting is good for your health

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Fasting found to reduce cardiac risk factors, such as triglycerides, weight, and blood sugar levels


Fasting has long been associated with religious rituals, diets, and political protests. Now new evidence from cardiac researchers at the Intermountain Medical Center Heart Institute demonstrates that routine periodic fasting is also good for your health, and your heart.

Today, research cardiologists at the Intermountain Medical Center Heart Institute are reporting that fasting not only lowers one's risk of coronary artery disease and diabetes, but also causes significant changes in a person's blood cholesterol levels. Both diabetes and elevated cholesterol are known risk factors for coronary heart disease.

The discovery expands upon a 2007 Intermountain Healthcare study that revealed an association between fasting and reduced risk of coronary heart disease, the leading cause of death among men and women in America. In the new research, fasting was also found to reduce other cardiac risk factors, such as triglycerides, weight, and blood sugar levels.

The findings were presented Sunday, April 3, at the annual scientific sessions of the American College of Cardiology in New Orleans.

"These new findings demonstrate that our original discovery was not a chance event," says Dr. Benjamin D. Horne, PhD, MPH, director of cardiovascular and genetic epidemiology at the Intermountain Medical Center Heart Institute, and the study's principal investigator. "The confirmation among a new set of patients that fasting is associated with lower risk of these common diseases raises new questions about how fasting itself reduces risk or if it simply indicates a healthy lifestyle."

Unlike the earlier research by the team, this new research recorded reactions in the body's biological mechanisms during the fasting period. The participants' low-density lipoprotein cholesterol (LDL-C, the "bad" cholesterol) and high-density lipoprotein cholesterol (HDL-C, the "good" cholesterol) both increased (by 14 percent and 6 percent, respectively) raising their total cholesterol – and catching the researchers by surprise.

"Fasting causes hunger or stress. In response, the body releases more cholesterol, allowing it to utilize fat as a source of fuel, instead of glucose. This decreases the number of fat cells in the body," says Dr. Horne. "This is important because the fewer fat cells a body has, the less likely it will experience insulin resistance, or diabetes."

This recent study also confirmed earlier findings about the effects of fasting on human growth hormone (HGH), a metabolic protein. HGH works to protect lean muscle and metabolic balance, a response triggered and accelerated by fasting. During the 24-hour fasting periods, HGH increased an average of 1,300 percent in women, and nearly 2,000 percent in men.

In this most recent trial, researchers conducted two fasting studies of over 200 individuals — both patients and healthy volunteers — who were recruited at Intermountain Medical Center. A second 2011 clinical trial followed another 30 patients who drank only water and ate nothing else for 24 hours. They were also monitored while eating a normal diet during an additional 24-hour period. Blood tests and physical measurements were taken from all to evaluate cardiac risk factors, markers of metabolic risk, and other general health parameters.

While the results were surprising to researchers, it's not time to start a fasting diet just yet. It will take more studies like these to fully determine the body's reaction to fasting and its effect on human health. Dr. Horne believes that fasting could one day be prescribed as a treatment for preventing diabetes and coronary heart disease.

To help achieve the goal of expanded research, the Deseret Foundation (which funded the previous fasting studies) recently approved a new grant to evaluate many more metabolic factors in the blood using stored samples from the recent fasting clinical trial. The researchers will also include an additional clinical trial of fasting among patients who have been diagnosed with coronary heart disease.

"We are very grateful for the financial support from the Deseret Foundation. The organization and its donors have made these groundbreaking studies of fasting possible," added Dr. Horne.

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