If you aren't in perfect health, then your immune system may need help.

zarkovBeta-glucan is a family of complex carbohydrates that serve as structural elements in the cell walls of plants, yeasts, and mushrooms. LifeLink’s beta-glucan comes from baker’s yeast. This supplement is now of great interest to medical researchers because of its ability to stimulate immune function, to improve cholesterol profiles, and to inhibit (or even reverse) cancer progression. Its immune effects are broad and can be directed at many health problems, including:

  • cancer
  • high cholesterol
  • hypertension
  • allergies
  • diabetes
  • wounds
  • over-eating, obesity
  • viral infections, such as hepatitis, HIV
  • bacterial infections
  • parasitic infections

Immune system modulation. The body’s first lines of defense against infections involve physical barriers and the destruction of invading microorganisms by antibodies. Pathogens that manage to evade these defenses will (one hopes) trigger further defensive processes known as ‘cell-mediated immunity’. Beta-glucan operates at both of these stages of immunity..

Beta-glucan acts in very complex ways upon the immune system. It stimulates the production of various signaling molecules, and these, in turn, activate immune cells. In this way, beta-glucan activates a wide variety of immune defenses, protecting the body against infections by viral, bacterial, fungal and protozoal pathogens, and even defending it against cancer.

Cancer-fighting properties. Beta-glucan’s anti-cancer effects result from its ability to modulate the immune system. And its immune effects derive from its activation of macrophage cells. Macrophages are immune cells that trap and engulf foreign cells and particles, scavenge cellular debris, and destroy infectious agents such as viruses, parasites, bacteria, and fungi.

Studies in cell culture, in lab animals, and in humans have shown that the anti-tumor activity initiated by beta-glucan can be long-lived and can occur even when beta-glucan is given orally one month prior to the presence of a tumor. Some of the cancer types that have been shown to be sensitive to beta-glucan supplementation include:

  • breast cancer
  • lymphoma
  • colon cancer
  • sarcoma
  • liver cancer
  • lung cancer

Pollen allergies. Pollen allergies are caused by a poorly regulated immune system. Beta-glucan seems to improve immune regulation. Researchers at Meiji University have shown that beta-glucan “is able to alleviate cedar pollen-induced allergic symptoms.”

Ingredient in red wine may prevent some blinding diseases

Resveratrol – found in red wine, grapes, blueberries, peanuts and other plants – stops out-of-control blood vessel growth in the eye, according to vision researchers at Washington University School of Medicine in St. Louis.

The discovery has implications for preserving vision in blinding eye diseases such as diabetic retinopathy and age-related macular degeneration, the leading cause of blindness in Americans over 50.

The formation of new blood vessels, called angiogenesis, also plays a key role in certain cancers and in atherosclerosis. Conducting experiments in mouse retinas, the researchers found that resveratrol can inhibit angiogenesis. Another surprise was the pathway through which resveratrol blocked angiogenesis. The findings are reported in the July issue of the American Journal of Pathology.

“A great deal of research has identified resveratrol as an anti-aging compound, and given our interest in age-related eye disease, we wanted to find out whether there was a link,” says Washington University retina specialist Rajendra S. Apte, MD, PhD, the study’s senior investigator. “There were reports on resveratrol’s effects on blood vessels in other parts of the body, but there was no evidence that it had any effects within the eye.”

The investigators studied mice that develop abnormal blood vessels in the retina after laser treatment. Apte’s team found that when the mice were given resveratrol, the abnormal blood vessels began to disappear.

Examining the blood-vessel cells in the laboratory, they identified a pathway – known as a eukaryotic elongation factor-2 kinase (eEF2) regulated pathway – that was responsible for the compound’s protective effects. That was a surprise because past research involving resveratrol’s anti-aging effects had implicated a different mechanism that these experiments showed not to be involved.

“We have identified a novel pathway that could become a new target for therapies,” Apte says. “And we believe the pathway may be involved both in age-related eye disease and in other diseases where angiogenesis plays a destructive role.”

Previous research into resveratrol’s influence on aging and obesity had identified interactions between the red-wine compound and a group of proteins called sirtuins. Those proteins were not related to resveratrol’s effects on abnormal blood vessel formation. Instead, the researchers say that in addition to investigating resveratrol as a potential therapy, they also want to look more closely at the eEF2 pathway to determine whether it might provide a new set of targets for therapies, both for eye disease and other problems related to abnormal angiogenesis.

Apte, an assistant professor of ophthalmology and visual sciences and of developmental biology, says because resveratrol is given orally, patients may prefer it to many current treatments for retinal disease, which involve eye injections. The compound also is easily absorbed in the body.

In mice, resveratrol was effective both at preventing new blood vessels and at eliminating abnormal blood vessels that already had begun to develop.

“This could potentially be a preventive therapy in high-risk patients,” he says. “And because it worked on existing, abnormal blood vessels in the animals, it may be a therapy that can be started after angiogenesis already is causing damage.”

Apte stresses that the mouse model of macular degeneration they used is not identical to the disease in human eyes. In addition, the mice received large resveratrol doses, much more than would be found in several bottles of red wine. If resveratrol therapy is tried in people with eye disease, it would need to be given in pill form because of the high doses required, Apte says.

There are three major eye diseases that resveratrol treatment may help: age-related macular degeneration, diabetic retinopathy and retinopathy of prematurity. Age-related macular degeneration involves the development of abnormal blood vessels beneath the center of the retina. It accounts for more than 40 percent of blindness among the elderly in nursing homes, and as baby boomers get older, the problem is expected to grow, with at least 8 million cases predicted by the year 2020.

In diabetic retinopathy, those blood vessels don’t develop beneath the retina. They grow into the retina itself. Diabetic retinopathy causes vision loss in about 20 percent of patients with diabetes. Almost 24 million people have diabetes in the United States alone.

Retinopathy of prematurity occurs when premature babies with immature retinas experience an obstruction in blood flow into the retina. In response, those children often develop abnormal blood vessels that can cause retinal detachment and interfere with vision. Worldwide, that condition blinds 50,000 newborn babies each year.

Apte says the pathway his laboratory has identified may be active not only in those blinding eye diseases, but in cancers and atherosclerosis as well. If so, then one day it might be possible to use resveratrol to improve eyesight and to prevent cardiovascular disease and some types of cancer, too.

Khan AA, Dace DS, Ryazanov AG, Kelly J, Apte RS. Resveratrol regulates pathologic angiogenesis by a eukaryotic elongation factor-2 kinase-regulated pathway, American Journal of Pathology, vol. 177, pp. 481-492. July, 2010. DOI:10.2353/ajpath.2010.090836

Vitamin D and mental agility in elders

At a time when consumer interest in health-enhancing foods is high, Agricultural Research Service (ARS)-funded scientists have contributed to a limited but growing body of evidence of a link between vitamin D and cognitive function.

Cognitive function is measured by the level at which the brain is able to manage and use available information for activities of daily life. Alzheimer’s disease, the most common form of age-related dementia, affects about 47 percent of adults aged 85 years or older in the United States. Identifying nutritional factors that lower cognitive dysfunction and help preserve independent living provides economic and public health benefits, according to authors.

The study, which was supported by ARS, the National Institutes of Health, and others, was led by epidemiologist Katherine Tucker with the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University in Boston, Mass. Tucker collaborated with HNRCA laboratory directors Irwin Rosenberg, Bess Dawson-Hughes and colleagues.

Metabolic pathways for vitamin D have been found in the hippocampus and cerebellum areas of the brain involved in planning, processing, and forming new memories. This suggests that vitamin D may be implicated in cognitive processes.

The study involved more than 1,000 participants receiving home care. The researchers evaluated associations between measured vitamin D blood concentrations and neuropsychological tests. Elders requiring home care have a higher risk of not getting enough vitamin D because of limited sunlight exposure and other factors.

The participants, ages 65 to 99 years, were grouped by their vitamin D status, which was categorized as deficient, insufficient, or sufficient. Only 35 percent had sufficient vitamin D blood levels. They had better cognitive performance on the tests than those in the deficient and insufficient categories, particularly on measures of “executive performance,” such as cognitive flexibility, perceptual complexity, and reasoning. The associations persisted after taking into consideration other variables that could also affect cognitive performance.

The 2009 study appears in the Journals of Gerontology, Series A, Biological Sciences and Medical Sciences.

Jetting off without the jet lag

Everyone hates the jet lag – the nighttime insomnia, loss of appetite, decreased alertness, and depressed mood – that accompanies travel to locations in different time zones. The symptoms of jet lag are caused by misalignment of a person’s internal body clock (also known as the circadian clock) and external time. Now, Gregor Eichele and colleagues, at the Max Planck Institute for Biophysical Chemistry, Germany, have provided new insight into the molecular mechanisms responsible for resetting the internal circadian system in the mouse. One of their key observations indicates that modulating the speed with which the adrenal gland shifts its rhythmic production of glucocorticoid hormones to the new light/dark cycle (the equivalent of the new time zone when considering human travel) regulates the resetting of the entire internal body clock. The authors suggest that their data point to new potential therapies to overcome jet lag.

In an accompanying commentary, Mary Harrington, at Smith College, Northampton, discusses how these data have implications not only for those who suffer jet lag but also for those who perform rotating shift work, which has been linked to many serious health problems, including breast cancer, stroke, and cardiovascular disease. She also cautions that it will be important to determine whether treatments for jet lag that allow the body clock to shift rapidly are actually better for one’s health than the slower adjustments that occur naturally.

Science Centric | 24 June 2010 12:40 GMT


Poor Control of Diabetes May Be Linked to Low Vitamin D

Vitamin D deficiency is highly prevalent in patients with Type 2 diabetes and may be associated with poor blood sugar control, according to a new study.

The results are being presented at The Endocrine Society’s 92nd Annual Meeting in San Diego.

“This finding supports an active role of vitamin D in the development of Type 2 diabetes,” said study co-author Esther Krug, MD, an assistant professor of medicine at The Johns Hopkins University School of Medicine and an endocrinologist at Sinai Hospital, Baltimore.

Krug and her colleagues reviewed the medical charts of 124 patients with Type 2 diabetes who came to an endocrine outpatient clinic for specialty care from 2003 to 2008. Patients’ age ranged from 36 to 89 years. All patients had a single measurement of their serum 25-hydroxyvitamin D levels as part of their evaluation at the clinic. The researchers divided the patients into quartiles based on vitamin D level.

Despite receiving regular primary care visits before referral to the endocrine clinic, 91 percent of patients had either vitamin D deficiency (defined as a level below 15 nanograms per deciliter, or ng/dL) or insufficiency (15 to 31 ng/dL), the authors reported. Only about 6 percent of patients were taking vitamin D supplements at their first visit.

Additionally, the investigators found an inverse relationship between the patients’ blood levels of vitamin D and their hemoglobin A1c value, a measure of blood sugar control over the past several months. Lower vitamin D levels were discovered in patients with higher average blood sugars as measured by HbA1c, Krug said. Compared with whites, blacks had a higher average A1c and lower average vitamin D level.

“Since primary care providers diagnose and treat most patients with Type 2 diabetes, screening and vitamin D supplementation as part of routine primary care may improve health outcomes of this highly prevalent condition,” she said.

ScienceDaily (June 21, 2010)