JAMA - In a study involving a representative sample of U.S. adults, higher levels of arsenic in the urine appear to be associated with increased prevalence of type 2 diabetes, according to a report in the August 20, 2008 issue of JAMA.

Arsenic from inorganic sources is highly toxic and causes cancer in humans, according to background information in the article. Millions of individuals worldwide are exposed to drinking water contaminated with inorganic arsenic, including 13 million Americans whose public water supply contains more than the U.S. Environmental Protection Agency standard of 10 micrograms per liter. Exposure to high concentrations of the element in drinking water and in the workplace has been shown to be associated with diabetes, but little is known about the effect of lower levels on diabetes risk. In contrast, arsenobetaine - an organic arsenic compound derived eating seafood - is considered non-toxic.

Ana Navas-Acien, M.D., Ph.D., of the Johns Hopkins Bloomberg School of Public Health, Baltimore, and colleagues studied 788 adults age 20 and older who had their urine tested for arsenic levels as part of the government-conducted 2003-2004 National Health and Nutrition Examination Survey (NHANES).

Overall, 7.7 percent of the participants had type 2 diabetes. After adjusting for diabetes risk factors and biomarkers of seafood intake, participants with type 2 diabetes had a 26 percent higher level of total arsenic in their urine than those without the disease. Levels of arsenobetaine were similar between the two groups.

After the same adjustment for related factors, the researchers found that participants in the top one-fifth of total urine arsenic levels (16.5 micrograms per liter) had 3.6 times the odds of having type 2 diabetes as those in the lowest one-fifth (3.0 micrograms per liter), and those in the top one-fifth of dimethylarsinate levels (6.0 micrograms per liter) had 1.5 times the odds as those in the lowest one-fifth (2.0 micrograms per liter). Dimethylarsinate is a compound into which inorganic arsenic is metabolized before excretion.

“The potential role of arsenic in diabetes development is supported by experimental and mechanistic evidence,” the authors note. Insulin-sensitive cells that are exposed to insulin and sodium arsenite appear to take in less glucose than cells exposed only to insulin. Arsenic could also influence genetic factors that interfere with insulin sensitivity and other processes, or could contribute to oxygen-related cell damage, inflammation and cell death (which have also been related to diabetes).

“From a public health perspective, confirmation of a role for arsenic in diabetes development would add to the concerns posed by the carcinogenic, cardiovascular, developmental and reproductive effects of inorganic arsenic in drinking water, and could substantially modify risk assessment and risk-benefit analyses estimating the consequences of arsenic exposure,” the authors conclude. “Given widespread exposure to inorganic arsenic from drinking water worldwide, elucidating the contribution of arsenic to the diabetes epidemic is a public health research priority with potential implications for the prevention and control of diabetes” (JAMA. 2008;300[7]:814-822).

Editorial: Limit Arsenic Exposure While Research Continues

“Stemming the pandemic of type 2 diabetes is a public health priority and will require a multifaceted approach,” write Molly L. Kile, M.S., Sc.D., and David C. Christiani, M.D., M.P.H., M.S., of the Harvard School of Public Health, Boston, in an accompanying editorial. “This must include improving the understanding of the etiology of diabetes and identifying modifiable factors that can be incorporated into prevention strategies.”

“To date, this approach has focused on medication and lifestyle modification, but the role of environmental exposures must also be considered,” they continue. “While many questions remain about the role of arsenic in diabetogenesis, they can only be answered by additional research.”

“In the meantime, arsenic exposure from drinking water is a widespread environmental pollutant that affects millions of individuals around the world,” Drs. Kile and Christiani conclude. “It is prudent to minimize arsenic exposure while its effect on metabolic diseases continues to be researched” (JAMA. 2008;300[7]:845-846).

JAMA - In a large clinical trial involving patients who already had identified coronary artery disease, use of B vitamins was not effective for preventing death or cardiovascular events, according to a study published in the August 20, 2008 issue of JAMA, but the study was stopped early. The B vitamin supplements did succeed in lowering homocysteine blood levels.

“Observational studies have demonstrated that the concentration of total homocysteine in blood is associated with risk of coronary artery disease and stroke,” the authors provide as background information. Plasma total homocysteine levels can be lowered by oral administration of folic acid and vitamin B12. In this study, the authors’ objective was “to evaluate the effects of homocysteine-lowering treatment with folic acid plus vitamin B12 on mortality and cardiovascular events.”

Marta Ebbing, M.D. of Haukeland University Hospital, Bergen, Norway and colleagues, conducted a randomized controlled study with 3,096 patients in two Norwegian hospitals between 1999 – 2006. Patients were randomly assigned to one of four groups receiving a daily oral dose of one of the following treatments: folic acid, 0.8mg, plus vitamin B12 , 0.4mg, plus vitamin B6 , 40mg (n= 772); folic acid plus vitamin B12 (n = 772); vitamin B6 alone (n = 772); or placebo (n = 780). Patients were scheduled for follow-up visits with an interview, clinical examination, and blood sampling at one month, one year, and at a final study visit. The main outcome measure (primary end point) was a composite of all-cause death, nonfatal acute myocardial infarction (heart attack), acute hospitalization for unstable angina pectoris, and nonfatal thromboembolic stroke.

The study was stopped early because of concerns among the participants about preliminary results from another similar Norwegian study suggesting no benefits from the treatment and an increased risk of cancer from the B vitamins.

“Mean (average) plasma total homocysteine concentration was reduced by 30 percent after 1 year of treatment in the groups receiving folic acid and vitamin B12,” the authors report. “During a median (midpoint) 38 months of follow-up, the primary end point was experienced by a total of 422 participants (13.7 percent): 219 participants (14.2 percent) receiving folic acid/vitamin B12 vs. 203 (13.1 percent) not receiving such treatment and 200 participants (13.0 percent) receiving vitamin B6 vs. 222 (14.3 percent) not receiving vitamin B6.”

“… we could not detect any preventive effect of intervention with folic acid plus vitamin B12 or with vitamin B6 on mortality or major cardiovascular events among patients with stable coronary artery disease undergoing intensive conventional treatment. We found a numerically lower incidence of stroke and higher incidence of cancer in the groups receiving folic acid, but these observations were not statistically significant,” the authors conclude. “Our findings do not support the use of B vitamins as secondary prevention in patients with coronary artery disease” (JAMA. 2008; 300[7]: 795-804).

Men with signs of benign prostatic hyperplasia (BPH) can be helped with a daily dose of erectile dysfunction drug tadalafil (Cialis®) to relieve associated lower urinary tract symptoms (LUTS), according to a new study published in the October 2008 issue of The Journal of Urology. Researchers just released their report on a randomized, double-blind, placebo-controlled study of over 1000 men in ten countries.

Claus G. Roehrborn, MD, Professor of Urology, University of Texas Southwestern Medical Center, states, “Since reports of erectile dysfunction (ED) incidence, pathophysiology and treatment have shown a possible link between BPH LUTS and ED. PDE5 inhibitors like tadalafil (Cialis®) have received increased attention for treating BPH LUTS, although they are currently only approved for ED. The half-life of tadalafil is 17.5 hours, making it suitable as once daily therapy. Although the precise mechanism of action by which PDE5 inhibitors may alleviate LUTS is not completely understood, several putative mechanisms are currently under investigation.”

Men with signs of BPH may experience LUTS, such as urinary frequency, urgency, intermittence, nocturia, straining, incomplete emptying or a weak urinary stream. LUTS increase with age with an overall prevalence of greater than 50% in men 50 years or older. Drugs currently used to treat these symptoms can produce unwanted side effects, including dizziness, low blood pressure and sexual dysfunction.

Participants in the tadalafil study were required to have at least a 6-month history of LUTS secondary to BPH. Subjects with a high PSA (more than 10 ng/ml) were excluded, as were subjects with other complicating conditions or conflicting drug treatments. Anyone who had undergone treatment for erectile dysfunction or other BPH treatments underwent a 4-week treatment-free screening period. All participants then received placebo for 4 weeks prior to randomization. The 1056 subjects were then divided randomly into 5 groups that received a placebo, or doses of 2.5, 5.0, 10.0 or 20.0 mg/day of tadalafil.

Using the International Prostate Symptom Score (I-PSS), a validated seven-item questionnaire about LUTS occurring within the last month, the researchers found that all doses of tadalafil were superior to placebo for relieving LUTS, with statistically significant effects at 4, 8 and 12 weeks. The treatments decreased I-PSS scores from 3.9 to 5.2 points in the different dosage groups, a clinically meaningful improvement according to the guidelines of the American Urological Association. Of the doses studied, 5 mg per day of Cialis® improved the I-PSS by 4.9 points and provided the best risk-benefit profile (Courtesy of EurekAlert!, a service of AAAS).

Reference: “Tadalafil Administered Once Daily for Lower Urinary Tract Symptoms Secondary to Benign Prostatic Hyperplasia: A Dose Finding Study” by Claus G. Roehrborn, et al, appears in The Journal of Urology, Volume 180, Issue 4 (October 2008).

UC.edu - One in three U.S. public schools are in the “air pollution danger zone,” according to new research from the University of Cincinnati (UC). UC researchers have found that more than 30 percent of American public schools are within 400 meters, or a quarter mile, of major highways that consistently serve as main truck and traffic routes. Parents of school children may be unaware of this exposure.

Research has shown that proximity to major highways - and thus environmental pollutants, such as aerosolizing diesel exhaust particles - can leave school-age children more susceptible to respiratory diseases later in life.

“This is a major public health concern that should be given serious consideration in future urban development, transportation planning and environmental policies,” says Sergey Grinshpun, PhD, principal investigator of the study and professor of environmental health at UC. To protect the health of young children with developing lungs, he says new schools should be built further from major highways.

“Health risk can be mitigated through proper urban planning, but that doesn’t erase the immediate risk to school-age children attending schools that are too close to highways right now,” he adds. “Existing schools should be retrofitted with air filtration systems that will reduce students’ exposure to traffic pollutants.”

The UC-led team reports its findings in the September 2008 issue of the Journal of Environmental Planning and Management, an international scientific journal. This is believed to be the first national study of school proximity and health risks associated with major roadways.

For this study, Grinshpun’s team conducted a survey of major metropolitan areas representative of all geographical regions of the United States: Atlanta, Boston, Cincinnati, Denver, Philadelphia, Los Angeles, Memphis, Minneapolis and San Antonio. More than 8,800 schools representing 6 million students were included in the survey. Primary data was collected through the U.S. Department of Education’s National Center for Education Statistics. Schools within this data set were then geocoded to accurately calculate distance to the nearest interstate, U.S. highway or state highway.

Past research on highway-related air pollution exposure has focused on residences located close to major roads. Grinshpun points out, however, that school-age children spend more than 30 percent of their day on school grounds - in classrooms, after-school care or extracurricular activities. “For many years, our focus has been on homes when it comes to air pollution. School attendance may result in a large dose of inhaled traffic pollutants that - until now - have been completely overlooked,” he adds.

These past studies suggest this proximity to highway traffic puts school-age children at an increased risk for asthma and respiratory problems later in life from air pollutants and aeroallergens. This includes research from the UC Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS) which has reported that exposure to traffic pollutants in close proximity to main roads has been associated with increased risk for asthma and other chronic respiratory problems during childhood.

Grinshpun’s team found that public school students were more likely to attend schools near major highways compared to the general population. Researchers say the rapid expansion of metropolitan areas in recent years - deemed “urban sprawl” - seems to be associated with the consistent building of schools near highways, which puts school children at exposure risk to levels of air pollution that are unhealthy if not potentially dangerous.

Cocoa flavanols, the unique polyphenol compounds found naturally in cocoa (and thus dark chocolate), may increase blood flow to the brain, according to new research published in the Neuropsychiatric Disease and Treatment journal. The researchers suggest that long-term improvements in brain blood flow could impact cognitive behavior, offering future anti-aging potential for debilitating brain conditions including dementia and stroke.

In a scientific study of healthy, older adults ages 59 to 83, Harvard medical scientists found that study participants who regularly drank a cocoa flavanol-rich beverage made using the Mars, Incorporated Cocoapro® process had an eight percent increase in brain blood flow after one week, and 10 percent increase after two weeks.

In this first-of-its-kind study, the researchers found both short and long-term benefits of cocoa flavanols for brain blood flow, offering future potential for the one in seven older Americans currently living with dementia. When the flow of blood to the brain slows over time, the result may be structural damage and dementia. Scientists speculate that maintaining an increased blood flow to the brain could slow this cognitive decline.

“The totality of the research on cocoa flavanols is impressive. This is just one more study adding to an increasing body of literature connecting regular cocoa flavanol consumption to blood flow and vascular health improvements throughout the body,” said Harold Schmitz, Ph.D., chief science officer at Mars, Incorporated, which has supported research on cocoa flavanols for more than 15 years. “Though more research is needed, these findings raise the possibility that flavanol-rich cocoa products could be developed to help slow brain decline in older age.”

Cocoa flavanols and blood circulation - the evidence

Contrary to statements often made in the popular media, the collective research demonstrates that the vascular effects of cocoa flavanols are independent of general “antioxidant” effects that cocoa flavanols exhibit in a test tube, outside of the body. While research aimed at studying the potential role of cocoa flavanols in the context of blood vessel and circulatory function continues, a number of previously published studies already suggest that the consumption of cocoa flavanols can have important beneficial effects on the function of the body’s network of blood vessels. The body of research not only suggests that cocoa flavanols may provide a dietary approach to maintaining cardiovascular function and health, but also points at new possibilities for cocoa flavanol-based interventions for vascular complications associated with cognitive performance, skin health and age-related blood vessel dysfunction.

Future research on cocoa polyphenols

The high-flavanol cocoa powders made using the Mars Cocoapro® process are thoroughly characterized in terms of nutrient content, as well as standardized with respect to flavanol level and flavanol profile. Through the newly created Mars Botanical division, Mars will continue to develop and apply industry-leading analytical techniques and standards to further investigate the biomedical potential of cocoa flavanols. For more information on the many research studies on cocoa flavanols, visit healthy cocoa flavanols (Courtesy of EurekAlert!, a service of AAAS).

Source: Sorond FA, Lipsitz LA, Hollenberg NK, Fisher NDL. Cerebral blood flow response to flavanol-rich cocoa in healthy elderly humans. Neuropsychiatric Disease and Treatment. 2008;4:433-440.

Ragweed is a prolific pollen producer and the number one cause of seasonal allergy symptoms, but people who are allergic can takes steps to avoid the airborne culprits according to the American College of Asthma, Allergy and Immunology (ACAAI).

“About 25 percent of my patients have ragweed allergy, and I make sure they are well prepared for peak pollen season,” said ACAAI President Jay M. Portnoy, M.D., chief, Section of Allergy, Asthma and Immunology at Children’s Mercy Hospitals & Clinics in Kansas City, Mo.

“Since allergic rhinitis (also known as hay fever) can quickly develop into other complications, such as ear infections, sinusitis, recurrent sore throats, cough and headache, its important that ragweed allergy is treated and well controlled. Studies show it also can cause altered sleep patterns, fatigue, irritability and poor school performance. Accurate allergy diagnosis and proper treatment can eliminate or alleviate most of these problems,” he said.

Increasing amounts of ragweed pollen in the air can also trigger life-threatening asthma symptoms such as wheezing and difficulty breathing. Children with ragweed allergy are particularly at risk of developing asthma during peak pollen season. A three-year study of children with seasonal allergies found that 1 in 5 experienced asthma symptoms during pollen season, even though they had no previously reported history of asthma.

BE SNEEZE AND WHEEZE FREE. A single ragweed plant can produce up to 1 billion pollen grains. Since the pollen is light and becomes airborne with the gentlest of breezes, each grain can travel more than 100 miles from its source. The ACAAI offers the following tips to reduce exposure to pollen and control symptoms of allergic rhinitis and allergic asthma triggered by ragweed allergy.

FRIEND, OR FOE? If you have seasonal itchy, runny nose, sneezing, wheezing or watery eyes, allergy testing can determine whether or not you have ragweed allergy. An allergist can perform allergy tests, interpret them correctly and recommend avoidance tactics and treatment – such as medications and allergen immunotherapy (allergy shots) – that will help you enjoy life.

WHEN UNDER THE WEATHER. When dry weather conditions of late summer and autumn take hold, ragweed’s profuse pollen is released into the air, accounting for 75 percent to 90 percent of all pollen found from August through October in some regions. Peak ragweed pollen counts tend to occur around Labor Day and can persist into late September or even mid-October. If you are allergic to ragweed, oral or nasal antihistamines or cortisone nasal sprays taken before exposure to pollen can help prevent an outbreak of symptoms.

DON’T GIVE POLLEN THE TIME OF DAY. Peak pollen emissions can vary from plant to plant. Ragweed pollen is released onto the plant leaves at daybreak, then depending upon the dew and wind conditions, it usually is at it highest airborne level between 10:00 a.m. and noon. This would be a good time to avoid outdoor activities such as exercise and gardening, or wear a pollen mask to limit exposure. Also avoid windy weather.

KNOCK KNOCK, WHO’S THERE? Keep pollen out by keeping windows closed in your home and car. Use a high efficiency disposable pleated media filter with a MERV rating of 8 to 12 in your home air conditioning system and change it every three months. (A higher MERV means it is more effective in removing airborne allergens.) Change clothes after being outside and wash your hair before bedtime. Avoid wearing contact lenses when outdoors to keep pollen from irritating the eyes. Be sure to wash your hands after petting furry animals that have been outside.

KISSING COUSINS. Some people with ragweed pollen allergy also have an allergic reaction to certain foods including melons, bananas, cucumbers and zucchini. This cross-reaction is called oral allergy syndrome, which is itching or swelling of the lips, tongue, throat or roof of the mouth. Allergy testing may help identify foods that should be avoided.

MISTAKEN IDENTITY. Goldenrod is often blamed for hay fever, since its bright yellow flower blooms at about the same time as ragweed. However, it produces heavy, sticky pollen grains that do not become airborne but instead are spread by insects, so it is not the cause of hay fever allergy (Newswise).