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12 February 2011

A diet-soda stroke? Study says zero-calories equals risk

Think you're being healthy by drinking diet soda?

Maybe not.

A study described at the American Stroke Association's International Stroke Conference concluded there could negative consequences associated with consuming too many sugar substitutes, including a higher risk of vascular events.

CNN reports salt intake was also associated with a higher risk of stroke.

Still, the study is controversial. Some point out that participants reported how much diet soda they consumed voluntarily, meaning results don't stem from a controlled setting.

"There is no scientific evidence to support the idea that diet soda uniquely causes increased risk of vascular events or stroke," the American Beverage Association said in a statement.

Researchers used voluntary participants to examine factors related to stroke and heart attacks. About 900 participants at said they drank no diet soda, and about 160 said they consumed more than one diet soda every day.

Phys Ed: More Bone (and Less Fat) Through Exercise

For those requiring additional reasons to show up at the running path or at the gym in the dreary heart of winter, science has come up with a compelling new motivation. Exercise can, it appears, keep your bone marrow from becoming too flabby.

This idea is the focus of a series of intriguing recent experiments by Janet Rubin, a professor of medicine at the University of North Carolina and other researchers. For the work, scientists removed bone marrow cells from mice and cultured them. The cells in question, mesenchymal stem cells, are found in bone marrow in both animals and people, waiting for certain molecular signals to tell them to transform into either bone cells, fat cells or, less commonly, something else.

After a stem cell differentiates, of course, it can no longer be anything else: once a fat cell, always a fat cell; once a bone cell, etc. So the fate of marrow stem cells determines the strength and quality of the bone. If a stem cell becomes a fat cell, then the portion of the skeleton to which it might have migrated as a bone cell will be that littlest bit punier. In a study published late last year by researchers at the University of Southern California, the femurs of healthy adults, some in their 20s, others past age 55, were scanned with magnetic resonance imaging. The researchers found that, in both young and old, the amount of fat in the leg’s bone marrow was inversely related to the amount of bone. The more fat in the marrow, the less bone in the thigh.

But what drives a particular stem cell to become a fat cell instead of a bone cell, and does exercise play a role? Earlier experiments by Clinton Rubin, Janet Rubin’s brother and the director of the Center for Biotechnology at Stony Brook University, had shown that mice placed on platforms that were gently vibrating — in an approximation of the forces generated by the muscular contractions of a gentle stroll — developed more bone density than mice who just sat around. Closer examination of the marrow in these experimental mice found that specific genes and gene transcription factors had been stimulated by the vibrations and had, in turn, directed the stem cells to transform into bone.

Something similar happened when Janet Rubin worked directly with the stem cells themselves, even though she was setting them up to become fat cells. To that end, she and her colleagues bathed them in what she calls “a sweet soup,” a medium infused with extra insulin and other elements that normally would encourage the stem cells to differentiate into fat. “They love to become fat cells,” Dr. Rubin said. “It’s discouragingly easy to nudge them in that direction.”

But when the mesenchymal stem cells were stimulated with mechanical vibrations, when they were, in effect, exercised, they did not all become fat cells. “There was a really striking difference in outcomes,” Dr. Rubin said. Her earlier studies with high-magnitude mechanical signals closely approximated a brisk cellular jog. Now she applied lower-magnitude vibrations twice a day, with a rest period of several hours in between. Once again, the stem cells did not all differentiate into fat, even though their cell medium was highly fat-inducing. Dr. Rubin suspects that complicated issues of biochemical signaling underlay the stem cells’ response to the dual-dose regimen. She is currently completing experiments she says she hopes will clarify the mechanisms involved.

Already, though, the findings would appear to have compelling, real-world implications. If you don’t want fatty bone marrow and unhealthy bones, Dr. Rubin said, consider breaking up moderate-intensity workouts into several sessions interspersed throughout the day. Dr. Rubin herself often now works out twice a day for 30 minutes, rather than, as she once did, for a single hourlong bout. “This is the first time in my career that something I’ve done in the lab has changed how I exercise,” she said.

Many questions remain, of course. It’s not clear, for one, whether fat cells generated in bone marrow remain in the marrow or move around to pad, say, the thighs. It’s also not known how exercise affects stem cells located outside the bone marrow. Can it prevent the birth of fat cells all over the body? In Clinton Rubin’s experiments with mice, the vibrated animals wound up with less overall body fat than the control mice, but the reasons are unknown.

Still, one lesson is indisputable. Don’t sit still more than you need to, Dr. Rubin said, and don’t let your children loll about either. “One of the concerns raised” by these experiments, she said, “is that if you make fat cells when you’re young, then you’ve lost any opportunity to have that particular cell be bone,” and the fat cell will remain just that, for life.

Could chocolate and oranges help prevent frailty in old age?

A study by The University of Nottingham is hoping to establish the health benefits from cocoa and vitamin C.

Researchers who are trying to find ways of helping us maintain muscle mass as we grow old have received funding of £270,000 from the Dunhill Medical Trust to carry out their Chocolate Orange Study.

The study is being run by Beth Philips a postgraduate research associate in the Department of Clinical Physiology. The department is a world leader in the research of skeletal muscle, with a focus on muscle protein synthesis and degradation.

Using state-of-the-art technology — a contrast enhanced ultrasound machine — Beth is monitoring the impact of cocoa and vitamin C on the amount of blood flow that reaches the muscle in both fasted and fed conditions.

In the UK there are now more people over the age of 65 than there are under the age of 18. It is projected that by 2033 the number of people aged 85 and over will reach 3.2 million — that will account for five per cent of the population.

Falling is one of the major causes of premature death in elderly people. From the age of 50 onwards we lose up to 0.4 per cent of our muscle mass every year. This makes us less mobile, more prone to fractures and at higher risk of a potentially life-threatening fall.

Beth said: "There is a well-established correlation between premature mortality and muscle mass loss in the elderly. We have shown that as we age the blood flow to our legs in response to feeding is impaired. This means that fewer nutrients and oxygen are able to reach our muscles which may contribute to muscle wasting and ultimately frailty. We want to know if cocoa and vitamin C can help slow down this deterioration."

Researchers will take blood samples and muscle biopsies from a group of volunteers aged between 18 - 28 and 65 - 75. The study will involve the insertion of four fine canulae for blood sampling, four muscle biopsies and the previously mentioned contrast-enhanced ultrasound measures to assess any changes in blood flow to the leg muscles.

The tests will be carried out in Derby at the University's School of Graduate Entry Medicine.

Coffee, energy drinkers beware: Many mega-sized drinks loaded with sugar, MU nutrition expert says

COLUMBIA, Mo. – Starbucks recently announced a new-sized 31-ounce drink, the "Trenta," which will be in stores this spring. The mega-sized coffee joins the ranks of other energy drinks that can pack plenty of caffeine and calories. Ellen Schuster, a University of Missouri nutrition expert, says that Americans should be wary of extra calories and sugar in the quest for bigger, bolder drinks.

"The sheer size of new coffee and energy drinks increases consumers' potential for unhealthy calorie and sugar consumption," said Schuster, state specialist for MU Extension and the College of Human Environmental Sciences. "A 'Trenta'-sized Starbuck's lemonade could include 21 teaspoons of sugar – much more than should be consumed at one time, or in one day."

Excess sugar is common in many prepared beverages. According to the U.S. Department of Health and Human Services, people who consume drinks with added sugars consume more total calories, and studies have found that drinking sweetened beverages is related to weight gain.

Health experts at the Mayo Clinic note that moderate consumption of coffee and other caffeinated beverages is unlikely to cause harm, but large quantities in excess of 500 mg, or more than four cups of coffee, can cause difficulty sleeping, irritability, restlessness, stomach problems and irregular heartbeat. Especially of concern is caffeine consumption among children and adolescents.

"Energy and coffee beverages are subject to the same nutrition rules as other foods and drinks; it's all about moderation," Schuster said. "Ideally, it's best to avoid drinking calories, because drinks leave you less full than solid foods. By eating calories in the form of high-calorie, high-sugar drinks, people crowd out other nutritious foods. However, like any indulgence, it's fine to order a 'Trenta' drink as an occasional treat."

11 February 2011

Lifestyle beats genes in longevity race

An article published online on December 22, 2010 in the Journal of Internal Medicine reveals that our own actions may be more important than inherited factors in dictating how long we live.

For the current investigation, Lars Wilhelmsen and colleagues at the University of Gothenburg evaluated data from the 1913 Men epidemiological study, which enrolled 855 fifty-year-old men in 1963. Subjects provided anthropomorphic, parental and lifestyle data, and were examined for cardiovascular health and other functions. The men were re-evaluated at the ages of 54, 60 and 67.

Thirteen percent of the participants were still living at 90 years of age. These survivors were likelier at age 50 to be nonsmokers, drink moderate amounts of coffee, have higher socio-economic status and have lower serum cholesterol levels compared with men who failed to reach this age, yet the number of years attained by the men's parents did not appear to influence their own longevity.

The most important predictive factors at ages beyond 50 included having low blood pressure and good cardiorespiratory function. When predictive factors at all examinations were analyzed, being a nonsmoker, consuming low amounts of coffee, being of higher socioeconomic status, having low serum cholesterol, and possessing good physical working capacity emerged as significant.

"Our study shows that hereditary factors don't play a major role and that lifestyle has the biggest impact," stated professor emeritus Lars Wilhelmsen of Sahlgrenska Academy at the University of Gothenburg. "We're breaking new ground here. Many of these factors have previously been identified as playing a role in cardiovascular disease, but here we are showing for the first time that they are important for survival in general."

"The study clearly shows that we can influence several of the factors that decide how old we get," he added. "This is positive not only for the individual, but also for society as it doesn't entail any major drug costs."

10 February 2011

Want More Efficient Muscles? Eat Your Spinach

After taking a small dose of inorganic nitrate for three days, healthy people consume less oxygen while riding an exercise bike. A new study in the February issue of Cell Metabolism traces that improved performance to increased efficiency of the mitochondria that power our cells.

The researchers aren't recommending anyone begin taking inorganic nitrate supplements based on the new findings. Rather, they say that the results may offer one explanation for the well-known health benefits of fruits and vegetables, and leafy green vegetables in particular.

"We're talking about an amount of nitrate equivalent to what is found in two or three red beets or a plate of spinach," said Eddie Weitzberg of the Karolinska Institutet in Sweden. "We know that diets rich in fruits and vegetables can help prevent cardiovascular disease and diabetes but the active nutrients haven't been clear. This shows inorganic nitrate as a candidate to explain those benefits."

In fact, up until recently nitrate wasn't thought to have any nutritional value at all. It has even been suggested that this component of vegetables might be toxic. But Weitzberg and his colleague Jon Lundberg earlier showed that dietary nitrate feeds into a pathway that produces nitric oxide with the help of friendly bacteria found in our mouths. Nitric oxide has been known for two decades as a physiologically important molecule. It opens up our blood vessels to lower blood pressure, for instance.

The new study offers yet another benefit of nitrate and the nitric oxides that stem from them. It appears that the increased mitochondrial efficiency is owed to lower levels of proteins that normally make the cellular powerhouses leaky. "Mitochondria normally aren't fully efficient," Weitzberg explained. "No machine is."

Questions do remain. The new results show that increased dietary nitrate can have a rather immediate effect. But it's not yet clear what might happen in people who consume higher levels of inorganic nitrate over longer periods of time. Weitzberg says it will be a natural next step to repeat the experiment in people with conditions linked to mitochondrial dysfunction, including diabetes and cardiovascular disease, to see if they too enjoy the benefits of nitrates.

"Among the more consistent findings from nutritional research are the beneficial effects of a high intake of fruit and vegetables in protection against major disorders such as cardiovascular disease and diabetes," the researchers concluded. "However, the underlying mechanism(s) responsible for these effects is still unclear, and trials with single nutrients have generally failed. It is tempting to speculate that boosting of the nitrate-nitrite-NO pathway may be one mechanism by which vegetables exert their protective effects."

As an interesting aside, Weitzberg says that the benefits of dietary nitrates suggest that powerful mouthwashes may have a downside. "We need oral bacteria for the first step in nitrate reduction," he says. "You could block the effects of inorganic nitrate if you use a strong mouthwash or spit [instead of swallowing your saliva]. In our view, strong mouthwashes are not good if you want this system to work."

Tennis-mad teen overcomes rare condition that caused spine to curve

TENNIS-mad teenager James Taylor thought he might never be able to play the sport again when a rare painful condition caused his spine to curve.

The 15-year-old, from Edgbaston, faced having metal rods fitted down his back or gruelling spinal fusion surgery when he was diagnosed with Scoliosis.

Athletic James started to suffer from excruciating back pain in June last year and the only NHS treatment was to have a back brace for four years or go under the knife for a high risk major operation.

But that is when mum Alison Taylor, a nursery nurse, discovered there were also new advanced therapy treatments and embarked on the alternative that has now seen James return to the tennis courts.

“Finding out that I had Scoliosis was life changing,” said James, a pupil at Harborne High School.

“Finding out that I had Scoliosis was life changing,” said James, a pupil at Harborne High School.

“I am passionate about tennis and I knew that if I had my spine fused I would never be able to play again. Sitting on the side-lines watching my friends having fun was soul destroying.”

Scoliosis affects just 0.4 per cent of young people and causes the spine to curve. It can eventually crush vital internal organs.

Scoliosis SOS has developed an advanced therapy combined with exercise that manipulates the spine without surgery.

“When my parents told me about the treatment I was ecstatic,” added James, who wants to be a sports therapist. “I love sports so doing exercises to keep my back in good condition and to avoid surgery was not a problem.

“It was amazing to believe that even though my spine was curving, I could prevent it from getting worse by doing a few simple movements. It has given me a new lease of life and I’m looking forward to the summer as I missed out on so many tennis games last year.”

Jo Head, consultant physiotherapist at Scoliosis SOS, said the therapy involves posture re-education, physiotherapy and osteotherapy.

“Hospital consultants are sending more and more patients to us as this is an emerging field,” said Mr Head.

“It is about regaining muscle imbalance in the spine and teaching the brain to stand in line with central alignment. It involves stretches for the spine and avoids surgery.”

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7 February 2011

Eating Poorly Can Make You Blue: Trans-Fats Increase Risk of Depression, While Olive Oil Helps Avoid Risk

Researchers from the universities of Navarra and Las Palmas de Gran Canaria have demonstrated that the ingestion of trans-fats and saturated fats increase the risk of suffering depression, and that olive oil, on the other hand, protects against this mental illness.

They have confirmed this after studying 12,059 SUN Project volunteers over the course of six years; the volunteers had their diet, lifestyle and ailments analyzed at the beginning of the project, over its course and at the end of the project. In this way the researchers confirmed that despite the fact that at the beginning of the study none of the volunteers suffered from depression, at the end of the study 657 new cases had been detected.

Of all these cases, the participants with an elevated consumption of trans-fats (fats present in artificial form in industrially-produced pastries and fast food, and naturally present in certain whole milk products) "presented up to a 48% increase in the risk of depression when they were compared to participants who did not consume these fats," affirmed Almudena Sánchez-Villegas, Associate Professor of Preventive Medicine at the University of Las Palmas de Gran Canaria, first author of the article.

In addition, the study demonstrated a dose-response relationship, "whereby the more trans-fats were consumed, the greater the harmful effect they produced in the volunteers," the expert stated.

Furthermore, the team, directed by Miguel Ángel Martínez-González, Professor of Preventive Medicine at the University of Navarra, also analyzed the influence of polyunsaturated fats (abundant in fish and vegetable oils) and of olive oil on the occurrence of depression. "In fact, we discovered that this type of healthier fats, together with olive oil, are associated with a lower risk of suffering depression," emphasized the researcher and director of the SUN Project.

150 million persons depressed worldwide

Thus, the results of the study corroborate the hypothesis of a greater incidence of the disease in countries of the north of Europe compared to the countries of the south, where a Mediterranean dietary pattern prevails. Nevertheless, experts have noted that the incidence of the disease has increased in recent years, so that today some 150 million persons are affected worldwide, where it is the principal cause of loss of years of life in those countries with a medium-to-high per capita income.

This due, according to Almudena Sánchez Villegas, "to radical changes in the sources of fats consumed in Western diets, where we have substituted certain types of beneficial fats -- polyunsaturated and monounsaturated in nuts, vegetable oils and fish -- for the saturated and trans-fats found in meats, butter and other products such as mass-produced pastries and fast food."

In addition, the research -- published in the online peer reviewed journal PLoS ONE -- has been performed on a population with a low average intake of trans-fats, given that it made up only 0.4% of the total energy ingested by the volunteers. "Despite this, we observed an increase in the risk of suffering depression of nearly 50%. On this basis," concluded Miguel A. Martínez, "we derive the importance of taking this effect into account in countries like the U.S., where the percentage of energy derived from these foots is around 2.5%."

Finally, the analysis, headed by the University of Navarra and the University of Las Palmas de Gran Canaria, suggests that both depression as well as cardiovascular disease are influenced in a similar manner by diet, and might share similar mechanisms in their origin. This hypothesis is further suggested by numerous studies that indicate the harmful effect of trans-fats and saturated fats on the risk of cardiovascular disease.

Kidney stones and clogged arteries may be linked

Reuters Health) - Young adults who've had kidney stones may also have an increased risk of clogged arteries, a new study says.

This does not mean that one causes the other, but instead the two conditions might have some common root cause, according to the paper published in the Journal of Urology.

"People who have kidney stones could be sort of the canary in the mine shaft," said Dr. Marshall Stoller, professor of urology at the University of California in San Francisco, and an author on the paper.

Slightly less than four percent of people had kidney stones at some point in the 20 year study. These people had about a 60-percent increased risk of getting clogged arteries later in their lives.

People tend to think of a kidney stone as a urinary problem, "but we need to be cognizant of the fact that the kidney is a blood filter," Stoller said, and can show signs of problems in the arteries as well.

High cholesterol, high blood pressure, smoking, and diabetes can all increase the risk of clogged arteries, which can lead to both heart attacks and strokes. These two diseases combined killed more than 589,000 people in 2005, according to the American Heart Association.

That people with kidney stones have an increased risk of clogged arteries is not really a surprise, said Andrew Evan, professor of medicine at Indiana University-Purdue University in Indianapolis, who was not involved in the study.

Previous studies have linked kidney stones with high blood pressure, which increases the risk of developing clogged arteries. But as far as what can lead to clogged arteries, "is it the higher blood pressure, or is it the kidney stones themselves?" Evan said. "We really don't know that."

About 5 percent of adults in the US have had kidney stones, according to the National Institute of Diabetes and Digestive and Kidney Diseases, a slightly higher proportion than in the study.

The study involved more than 5000 young adults between 18 and 30 years old who came back for exams at regular intervals over the next 20 years.

At the 20-year exam, the researchers analyzed the thickness of the wall of participants' carotid arteries. (A thicker-than-normal artery wall is a sign of the arteries getting clogged up.) And that's when they found that people who'd reported having kidney stones were 60 percent more likely to have clogged arteries, compared to people without kidney stones.

A problem with the study is that it included all people with kidney stones together in one group, Evans said. There are a number of different reasons people can get kidney stones such as too having much calcium in the urine, sustained dehydration, or a hereditary disorder. Not all may have an increased risk of clogged arteries, although more research is needed to shed some light on the issue.

In the meantime, you can reduce your risk of getting kidney stones by drinking enough to urinate about two liters a day and by cutting down on salt and meat, Stoller said.

And the American Heart Association advises that to reduce the risk of clogged arteries, people should exercise, eat a healthy diet, and not smoke.

"This is a warning sign," Stoller said. "The kidney stone is the tip of the iceberg."

Early Antibiotic Use Can Lead to Increased Risk of Childhood Asthma, Study Suggests

When babies are given antibiotics, their risk of developing asthma by age 6 may increase by 50 percent. This relationship between antibiotic use in babies less than six months old and risk of developing asthma was documented in a study conducted by Norwegian University of Science and Technology (NTNU) researcher Kari Risnes.

The research was conducted while Risnes was a visiting researcher at Yale University, and resulted in the recent online publication of the article in the American Journal of Epidemiology.

"Asthma is a very common disease. At the same time, about one-third of infants in our study were treated with antibiotics by the time they were six months old. This proportion is about 30 per cent in other Western countries," says Risnes.

The Yale study followed 1400 children and mothers from the beginning of pregnancy until the children were six years old.

"We found that the risk that children would have asthma as six year olds was 50 per cent higher when they had been given antibiotics as a baby. That is a significant increase," Risnes says.

While previous research has suggested an association between asthma and antibiotics, those studies may have been biased because antibiotics are used to treat respiratory tract infections that could themselves be early symptoms of asthma.

The study sought to eliminate this bias by excluding children who were treated for respiratory infections from the study. The study also considered a long list of other risk factors -- such as whether or not the mother, father or a sibling had asthma. That aspect also brought a surprise, Risnes said.

"We actually found that the relationship between antibiotic use in the first six months of life and asthma was particularly strong in children from families without a history of asthma," said Risnes.

"What we think is that antibiotics interfere with the beneficial bacteria found in the gut. These bacteria aid in helping the baby's immune system to mature. When the bacteria are affected, it can cause the child to have an "immature" immune system, which in turn leads to allergic reactions," says Risnes.

She believes that the results should remind doctors and policymakers of the consequences of overuse of antibiotics. While in Norway, for example, the policy is to limit the prescription of antibiotics "this is an additional reminder to doctors and parents that we should avoid unnecessary use whenever possible," she said.