NEWS BRIEFS – April 2015

SCIENTISTS HAVE FOUND THAT A COMPOUND IN MILK THISTLE SEEDS CAN BE USED TO SHRINK BRAIN TUMOURS

Milk Thistle Shown to Shrink Brain Tumours

Scientists have found that a compound in milk thistle seeds known as silibinin can be used to treat, slow the growth of, and shrink brain tumours that occur as a part of Cushing disease, without the need for brain surgery. (Cushing disease is a rare hormone condition caused by a tumour in the pituitary gland in the brain. A much higher percentage of dogs and horses get Cushing disease than humans. It is not to be confused with Cushing’s Syndrome. In 80 to 85% of Cushing disease cases, the tumour can be removed by brain surgery and the other cases involve treatment with intense side effects. Silibinin has been shown to be safe for humans and is currently used for the treatment of liver disease and poisoning.)

In Cushing disease, the pituitary tumour secretes high amounts of the stress hormone adrenocortico-tropin (ACTH) followed by the release of cortisol from the adrenal glands, leading to weight gain, elevated blood pressure, and muscle weakness. In this study on mice, after silibinin treatment, tumour cells resumed normal ACTH production, tumour growth slowed down, and symptoms of Cushing disease disappeared. Silibinin may also work for lung tumours, acute lymphoblastic leuk-emia, or multiple myeloma, the report suggested. The researchers have applied for a patent and plan human clinical trials. If trials succeed, future patients may be able to avoid brain surgery.

This study will be published in a future issue of the journal Nature Medicine. Meanwhile, it was posted online February 9, 2015, where it can be purchased at http://tinyurl.com/neev2w2

LOW VITAMIN D STATUS PREDICTS MORE SEVERE STROKES

A new study has found that stroke patients with low vitamin D levels were more likely than those with normal vitamin D levels to suffer severe strokes and have worse health outcomes even months after a stroke. (Low vitamin D has been associated in past studies with neurovascular injury, which is damage to the major blood vessels supplying the brain, brainstem, and upper spinal cord.) Researchers studied whether low blood levels of 25-hydroxyvitamin D, a marker of vitamin D status, is predictive of ischemic stroke severity and poor health after stroke in 96 stroke patients treated between January 2013 and January 2014 at a U.S. hospital. They found that patients who had low vitamin D levels had about two-times larger areas of dead tissue resulting from obstruction of the blood supply compared to patients with normal vitamin D levels. For each 10 nanograms per milliliter reduction in vitamin D level, the chance for healthy recovery in the three months following stroke decreased by almost half, regardless of patient age or initial stroke severity.

This research was presented in Nashville on February 11, 2015 at the American Stroke Association International Stroke Conference.

BREAKTHROUGH USES BACTERIA TO KILL CANCER TUMOURS

In this study, researchers injected a weakened strain of Clostridium novyi-NT bacteria spores directly into tumours in six cancer patients. They then observed as the bacteria grew within the tumours and then killed off the cancer cells. C. novyi-NT, which lives in soil, is a close relative of the bacteria that causes botulism. Before injecting C. novyi-NT into the patients, the researchers weakened it by removing its dangerous toxin. Five of the six test patients are still alive; the only patient who died did so from unrelated causes several months after receiving the bacteria injection.

In an exclusive interview, study author Dr. Ravi Murthy explained that when tumours reach a certain size, parts of them do not receive oxygen, which makes them resistant to conventional therapies such as radiation and chemotherapy. However, C. novyi-NT thrives under these conditions, hones in on the low-oxygen areas and destroys tumours from the inside while sparing normal tissue. C. novyi-NT also triggers an immune response to cancer. Essentially, C. novyi-NT causes a potent cancer-killing infection in the tumour.

This study was presented January 31, 2015 at the annual Symposium on Clinical Interventional Oncology in Hollywood, Florida. The report will be published in a future issue of a peer-reviewed journal and is not yet available to access online.

STUDY REVEALS IDEAL RUNNING RANGE FOR IMPROVED LONGEVITY

A new study has found that while moderate running or jogging confers life extension benefits, strenuous jogging results in the same mortality risk as not exercising at all. (In the U.S., about 54 million people run regularly, according to background information with the study.)

Out of a pool of about 5,000 healthy adults, scientists followed nearly 1,100 healthy joggers and 413 sedentary people for over 12 years. The strenuous joggers were found to be as likely to die during that time period as the sedentary non-joggers. Light joggers fared best and moderate joggers fared second-best. The dose of running that was most favourable for reducing mortality was between one and 2.4 hours per week, with running limited to no more than three days per week. The best pace was slow or average; average is about five miles per hour.

These results suggest that long-term strenuous endurance exercise may induce pathological structural remodeling of the heart and large arteries. The good news is that the researchers found benefit even in jogging less than an hour a week, or even once a week, compared to not jogging at all.

These findings were published in the February 10, 2015 edition of the Journal of the American College of Cardiology. The full report can be downloaded online at http://tinyurl.com/k6535a5 for a fee.

NATURE, ART, RELIGION FOUND TO BE ANTI-INFLAMMATORY AGENTS

A study has found that positive emotions, such as those associated with natural wonders, great art, or religion, are powerful anti-inflammatory agents that work through the immune system to lower the risk of numerous inflammation-related disorders. Examples would include looking at the Grand Canyon, looking at a great work of art, or staring at the Sistine chapel ceiling. The researchers have linked positive emotions, especially the awe we feel when touched by the beauty of nature, art, or spirituality, with an effect on the immunity that lower the levels of pro-inflammatory cytokines, which are proteins that signal the immune system to work harder. While cytokines are necessary for herding cells to the body-wide battlegrounds to fight infection, disease, and trauma, sustained high levels of cytokines are associated with poor health and such disorders as diabetes Type II, heart disease, arthritis, and even Alzheimer’s disease and clinical depression. (It has been long known that a healthy diet and lots of sleep and exercise bolster defences against physical and mental illnesses. But this study is one of the first to look at the role of positive emotions.)

In answer to why awe would be a potent predictor of reduced pro-inflammatory cytokines, the lead study author suggested that awe is associated with curiosity and a desire to explore, the opposite of responses found during inflammation, in which individuals typically withdraw from others or their environment. This study was pre-released online ahead of publication in an upcoming issue of the journal Emotion. The full report can be read online at http://tinyurl.com/n565wrk for a small fee.

DID YOU KNOW…?

A study has suggested that a key compound in green tea – epigallocatechin-3-gallate or EGCG – may trigger a cycle that kills oral cancer cells, while leaving healthy cells alone. This study was published in the February 2015 issue of Molecular Nutrition and Food Research. It is accessible at http://tinyurl.com/mt78ln8 for a fee.

HEALTHY DIET MAY LOWER RISK OF COPD

Scientists have found that an unhealthy diet could be a contributing factor in the development of COPD or chronic obstructive pulmonary disease. In fact, study participants who followed a healthy diet showed a one-third reduced risk of COPD. (COPD, the third leading cause of death, is a group of conditions such as chronic bronchitis and emphysema that cause airway obstruction and breathing problems. Smoking is the primary cause of COPD, accounting for 80-90% of all cases. For the remaining 10-20%, it is believed that secondhand smoke, air pollution, and genetic factors are involved.)

The study team assessed the effects of diet on the risk of COPD among 73,228 women and 47,026 men from 1986 to 1998. Scientists assessed information on weight, physical activity, smoking, medical history, and other risk factors both at the start and every two years. Those with the highest scores for diet had 33% less risk of COPD compared to those with the lowest scores. A healthy diet was defined as the Alternate Healthy Eating Index 2010, which is high in vegetables, whole grains, polyunsaturated fats, nuts, and omega-3 fatty acids – and low in red and processed meats, refined grains, and sugary drinks, with moderate alcohol consumption. The researchers explained that the lungs exist in an oxygen-rich environment, subject to free radicals, and may be protected by higher antioxidants and lower oxidants in a healthy diet.

This study was published online February 3, 2015 by the British Medical Journal and can be read in full at http://tinyurl.com/kbuemnu free of charge.

RED WINE COMPOUND FOUND TO INHIBIT AGE-RELATED MEMORY DECLINE

New research shows that resveratrol may help prevent age-related decline in memory. (Resveratrol is an antioxidant found in the skin of red grapes, as well as in red wine, peanuts, and some berries. This compound has been widely touted for its potential to prevent heart disease. Some experts have speculated that resveratrol may also have positive effects on the hippocampus, an area of the brain that is critical to functions such as memory, learning and mood. But this is the first animal study to produce evidence of apparent benefits in terms of learning, memory and mood function. This needs to be tested in humans.)

For the control rats who did not receive resveratrol, spatial learning ability was largely maintained, but ability to make new spatial memories significantly declined be-tween 22 and 25 months, which is old age for rats. By contrast, both spatial learning and memory improved in the resveratrol-treated rats. Neurogenesis, which is the growth of new neurons, doubled in the rats given resveratrol compared to the control rats. The resveratrol-treated rats also had significantly improved blood flow and a lower level of chronic inflammation in the hippocampus.

This study provides novel evidence that resveratrol treatment in late middle age can help improve memory and mood function in old age. The molecular mechanisms that underlie the improved cognitive function following resveratrol treatment are not yet known. Because both humans and animals show a decline in cognitive capacity after middle age, the findings may have implications for treating memory loss in the elderly. Resveratrol may even be able to help people afflicted with severe neurodegenerative conditions such as Alzheimer’s disease.

This study was reported recently in Scientific Reports and the full-text report has now been made available at http://tinyurl.com/neo325f free of charge.

MEDITATION MAY HELP PRESERVE BRAIN MATTER AS WE AGE

A new study has found that meditation may be associated with greater preservation of the gray matter in the brain, the neuron-containing tissue responsible for processing information.

It is generally believed that our brains deteriorate with advanced age, but evidence suggests that this process begins during the mid-to-late 20s. A different study published January 2014 in Cognitive Science suggested that brains slow down as we age as a result of a greater accumulation of experiences, not from age-related cognitive decline.

Past research has associated meditation with improved cognitive functions such as attention, memory, processing speed, and for reducing pain, anxiety and depression.

The researchers recruited 100 volunteers, aged 24 to 77. Of these, 50 had meditated for between 4 and 46 years and 50 had never engaged in the practice. Using MRI scans, researchers scanned the brains of each participant. While the researchers identified reduced gray matter with increasing age, which they expected, they were surprised to find that the meditation group showed, at all ages, significantly lower gray-matter loss in numerous brain regions, compared with those in the non-meditation group. Commenting via email, team member Florian Kurth stated that they had expected “rather small and distinct effects located in some of the regions previously associated with meditating,” but instead found “a widespread effect of meditation that encompassed regions throughout the entire brain.”

(Detracting from the study, different lifestyles were not taken into account so a cause-and-effect link has not been established.)

This study was posted online by Frontiers of Psychology. The full-text report is now available online at http://tinyurl.com/ovwh4aw free of charge.

CROSSING OR STOPPING AT INTERSECTIONS FOUND TO BE HEALTH RISK

Scientists have concluded that when drivers are forced to stop at red lights, they are exposed to extremely high levels of small but dangerous bits of air pollution known as nanoparticles, compared to other areas. Pedestrians regularly crossing streets at these intersections may also be at greater risk of these pollutants. The researchers tracked the exposure of drivers to nanoparticles as they drove their cars during a normal workday. (Cars are known to emit nanoparticles, harmful pollutants linked to increased risk of lung and heart diseases. The World Health Organization has linked air pollution to 7 million premature deaths worldwide every year.)

At red lights, peak nanoparticle exposure was 29 times higher than when the cars were in free-flowing traffic. Spending just 2% of a journey passing through intersections with traffic lights contributed to about 25% of total exposure of the drivers to these harmful particles. Two reasons for this much greater exposure to nanoparticles while at red lights are that the vehicles are closer together and that drivers rev engines to accelerate quickly when the light turns green.

The study author suggested pedestrians consider other routes less dependent on traffic-light crossings and local transport agencies synchronize traffic signals to reduce waiting time. The best ways to limit your exposure, he suggested, are to keep vehicle windows shut and fans off, and try to increase the distance between you and the car in front where possible.

This study was released online February 12, 2015 by the journal Atmospheric Environment, subject to minor changes before appearing in an upcoming print issue. This version can be viewed at http://tinyurl.com/naxw9hr for a fee.

WORSE STROKE OUTCOMES IN ELDERLY MAY BE DUE TO LEAKIER GUT

Researchers have found a potential reason for the generally poorer recovery among elderly persons after a clot-caused stroke and their greater risk of death following such strokes. That underlying reason may be that elderly individuals have leakier guts. This animal study found that molecules and bacteria cross the intestinal walls in both aged mice (18-20 months) and young ones (8-12 weeks) after a stroke; however, only the young were able to clear bacterial infection and resolve the inflammation. After an experimentally induced stroke, with the middle cerebral artery blocked for 90 minutes and then reopened, aged mice had 200 times more bacteria in their abdominal lymph nodes than younger mice; also, they more frequently tested positive for infection in other organs outside the intestinal area. Interleukin-6, a substance produced by the immune system in response to injury or infection and a marker of sepsis (a life-threatening inflammatory response to infection), increased in all mice after stroke but remained elevated in the aged mice, making them 50% more likely to die within seven days.

This suggests that the high mortality in the elderly after stroke is related to intestinal permeability, or leaky gut, and bacteria getting out of the gut and causing sepsis. Therapies targeting the gut to reduce intestinal permeability may lower the severity of inflammation and improve the prognosis of aged stroke patients, the researchers said. (Some experts have suggested that gut permeability may be improved by use of antioxidants, dietary fiber, digestive enzymes, and probiotics.)

This study was presented February 13, 2015 in Nashville at the American Stroke Association International Stroke Conference. It has not yet been published or posted.

UNDERACTIVE THYROID LINKED TO WATER FLUORIDATION

Researchers have found that water fluoridation above a certain level is associated with a 30% higher rate of underactive thyroid, or hypothyroidism. They examined the populations of different urban areas, both using fluoridated water and using un-fluoridated water. The concentration of fluoride in the municipal water supply was up to one milligram of fluoride per litre of water or one part per million (ppm). And they looked at the national prevalence of underactive thyroid diagnosed by family doctors in these areas. After taking account of influential factors such as female sex and older age, both of which are linked to increased risk of hypothyroidism, they found an association between rates of the condition and levels of fluoride in the drinking water. Higher rates of hypothyroidism were found in areas where water fluoridation concentration exceeded 0.7 mg per liter or 0.7 ppm. Even in areas where water fluoride levels were just 0.3 mg per liter or 0.3 ppm, hypothyroidism rates were at least 30% higher. The scientists were unable to control other potent fluoride sources such as toothpaste use and tea consumption. Both are naturally high in fluoride. This is an observational study and so no definitive conclusions can be drawn about cause-and-effect.

This study was released online February 24, 2015, ahead of publication in the Journal of Epidemiology & Community Health. It can be accessed now at http://tinyurl.com/ph3acb8 with fee.

SOUND SLEEP KEEPS YOUR STEM CELLS YOUNG

In a new study, scientists have found that environmental stress is a major factor in driving DNA damage in adult hematopoietic stem cells. (Hematopoietic stem cells are blood cells that give rise to all the other blood cells.) Under normal conditions, many of the different types of tissue-specific adult stem cells, including hematopoietic stem cells, exist in a state of dormancy where they rarely divide and have very low energy demands.

This study has shown that this state of dormancy protects hematopoietic stem cells from DNA damage and therefore protects them from premature aging. However, under conditions of stress, such as during chronic blood loss or infection or sleep deprivation, these cells are rudely jolted into action and driven into a state of rapid cell division in order to produce new blood cells and repair the damaged tissue. The stem cells go from a state of rest to very high activity within a short space of time, requiring them to rapidly increase their metabolic rate, synthesize new DNA, and coordinate cell division. Suddenly having to simultaneously execute these complicated functions dramatically increases the likelihood that something will go wrong and damage the DNA of the cell as it is attempting repair. This can cause either the death of the stem cell, or potentially the acquisition of mutations that may cause cancer. This essentially links physiologic stress with mutations in stem cells and in turn, with aging and cancer.

This study was released online February 18, 2015 at the site of the journal Nature, which will print-publish it in a later issue. Meanwhile, the full-text study can be read at http://tinyurl.com/pnqk7ju for a fee.

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