What's Hot
What's Hot
News flashes are posted here frequently to keep you up-to-date with the latest advances in health and longevity. We have an unparalleled track record of breaking stories about life extension advances.
Testosterone improves muscle mass and performance in postmenopausal women
November 29 2013. An article published online on November 25, 2013 in the journal Menopause describes a study of hysterectomized women that compared the effects of varying doses of testosterone on sexual function, lean body mass and muscle performance.
"Recently, there has been a lot of interest in testosterone treatment in postmenopausal women for sexual dysfunction and other various health conditions," commented lead author Grace Huang, MD, who is a research physician in the department of endocrinology at Brigham and Women's Hospital in Boston. "However, no previous studies have evaluated the benefits and negative effects of testosterone replacement over a wide range of doses."
The study included 71 postmenopausal women who had undergone hysterectomy with or without ovary removal. The women were divided to receive weekly injections of a placebo or 3, 6.25, 12.5 or 25 milligrams testosterone enanthate for 24 weeks. Blood samples were analyzed for testosterone levels, and sexual function, lean and fat body mass, muscle strength and power, and physical function were assessed before and after treatment.
Improvements in sexual function, desire, arousal and sexual frequency were associated with increases in free testosterone, as were increases in lean body mass and measures of muscle power, with those who received 25 milligrams experiencing a significant effect. Dr Huang noted that "A primary concern with testosterone therapy is that it can cause symptoms of masculinization among women. These symptoms include unwanted hair growth, acne and lower voice tone. It's important to note that very few of these side effects were seen in our study."
While testosterone was not associated with adverse effects in this trial, the U.S. Food and Drug Administration has not approved the hormone for women. The authors suggest the initiation of long-term clinical trials to further evaluate testosterone's risks versus benefits.
—D Dye
Nutrient supplementation delays HIV progression
November 27 2013. The November 27, 2013 issue of the Journal of the American Medical Association reported the outcome of a study of HIV-infected individuals which found a benefit for supplementation with vitamins and selenium in reducing the progression of the disease.
"Micronutrient supplementation has improved markers of HIV disease progression (CD4 cell count, HIV viral load) and mortality in clinical trials; however, these studies were conducted either in the late stages of HIV disease or in pregnant women," note authors Marianna K. Baum, PhD, and her associates. "To our knowledge, there are no studies testing the effect of long-term micronutrient supplementation in early stages of HIV disease in antiretroviral therapy-naive adults."
The trial included 878 men and women who had not received treatment with antiretroviral therapy (ART). Participants were randomized to receive a daily supplement containing the B complex, vitamin C and vitamin E; vitamins plus 200 micrograms selenium, selenium alone or a placebo for two years. Blood samples obtained at the beginning of the trial and every three months thereafter were analyzed for CD4 cell counts, which decline with HIV progression. Viral load and other factors were measured twice per year over the course of the study.
Among subjects who received the vitamins and selenium, a 54% lower risk of reaching a cell count of 250 per microliter or less (which is the level used in Botswana to determine when antiretroviral therapy should be initiated) was observed in comparison with the placebo group. A reduction was also observed in the risk of a CD4 cell count of 250 per microliters or less, AIDS-defining conditions or AIDS related death, whichever occurred first.
"This evidence supports the use of specific micronutrient supplementation as an effective intervention in HIV-infected adults in early stages of HIV disease, significantly reducing the risk for disease progression in asymptomatic, ART-naive, HIV-infected adults," the authors conclude.
—D Dye
Plant compound combo combats cancer
November 25 2013. The November, 2013 issue of The Journal of Cancer published the results of research that uncovered a significant effect for a cocktail of six plant compounds in inhibiting the growth and survival of cultured breast cancer cells.
"We hypothesized that a super combination of known phytochemicals used at bioavailable levels could induce 100% killing of breast cancer cells without toxic effects on normal cells and that microarray analysis would identify potential genes for targeted therapy of breast cancer," write Madhwa H. G. Raj, PhD, of Louisiana State University and colleagues.
The team compared the effects of a control substance to a combination of curcumin, genistein, indole-3-carbinol, resveratrol, quercetin, and C-phococyanin from spirulina in two breast cancer cell lines as well as in cultured noncancerous stem cells. They observed an 80% inhibition of migration and invasion, and the initiation of apoptosis that resulted in the death of 100% of the breast cancer cells treated with the compounds, while treated control cells remained unharmed. Several genes were identified whose expression was downregulated, and four were identified that were highly upregulated in treated cancer cells.
The authors suggest that "Future experiments include animal studies using mouse xenograft model to evaluate the in-vivo toxicity and efficacy of the phytochemical super cocktail treatment to prevent and/or regress breast cancer tumors as well as possible use of the highly up-regulated novel genes as markers to follow-up progress of therapy."
"One of the primary causes of both the recurrence of breast cancer and deaths is a small group of cancer stem cells that evade therapy," Dr Raj commented. "These often multi-drug-resistant cells have the ability to generate new tumors, so it is critically important to develop new approaches to more effective and safer treatment or prevention of breast cancer."
—D Dye
Reducing three factors could cut cardiovascular disease risk by nearly half in obese men and women
November 22 2013. The results of a pooled analysis that appeared online on November 22, 2013 in The Lancet predict that up to half the cases of obesity-associated heart disease and stroke could be prevented by controlling blood pressure, glucose and cholesterol.
Goodarz Danaei of Harvard School of Public Health and colleagues selected 97 prospective studies that included over 1.8 million men and women for their analysis. They determined that the presence of hypertension, elevated cholesterol and high blood glucose account for up to half of the greater risk of heart disease experienced by overweight individuals and three quarters of their increased risk of stroke. "If we control these risk factors, for example through better diagnosis and treatment of hypertension, we can prevent some of the harmful effects of being overweight or obese," Dr Danaei observed.
"Large, long-term population studies like this one are a very powerful tool, allowing researchers to disentangle individual factors and understand how they each contribute to our risk of disease," noted Professor Stephen Hill, who is Chair of the Medical Research Council's Molecular and Cellular Medicine Board, which contributed funding to the research. "It's interesting that, even when blood pressure, blood sugar and cholesterol are brought under control, obese individuals are still at a higher risk of heart attack and stroke. This suggests that other factors might be at play, which is likely to be of interest for future research into the consequences of obesity."
"Controlling hypertension, cholesterol, and diabetes will be an essential but partial and temporary response to the obesity epidemic," stated study coauthor Majid Ezzati, who is a professor of global environmental health at Imperial College London. "As we use these effective tools, we need to find creative approaches that can curb and reverse the global obesity epidemic."
—D Dye
Follow-up study affirms benefit of fish oil supplementation, low fat diet in men with prostate cancer
November 20 2013. An article published online on October 29, 2013 in the journal Cancer Prevention Research reported the results of a study involving men with prostate cancer which confirmed positive effects for a low fat diet combined with fish oil supplements in reducing the risk of cancer recurrence. The study is a post-hoc analysis of a trial involving 48 men which found that a low fat diet supplemented with fish oil resulted in reduced prostate cancer cell proliferation in comparison with cancers in men who consumed a traditional Western diet.
The current study measured pro-inflammatory compounds in excised prostate cancer tissue and determined the cell cycle progression (CCP) score, which is used to predict cancer recurrence. "This is of great interest, as the CCP score in prostate cancer is known to be associated with more aggressive disease and can help predict which patients will recur and potentially die from their cancer," commented lead researcher William Aronson, who is a clinical professor of urology at the University of California Los Angeles and chief of urologic oncology at the West Los Angeles Veterans Affairs Medical Center.
"We found that CCP scores were significantly lower in the prostate cancer in men who consumed the low-fat fish oil diet as compare to men who followed a higher fat Western diet," Dr Aronson reported. "We also found that men on the low-fat fish oil diet had reduced blood levels of pro-inflammatory substances that have been associated with cancer."
"These studies are showing that, in men with prostate cancer, you really are what you eat," Dr Aronson concluded. "The studies suggest that by altering the diet, we may favorably affect the biology of prostate cancer."
—D Dye
Rosemary extract shows promise for memory enhancement
November 18 2013. Neuroscience 2013, held November 9-13, 2013 in San Diego, was the site of a presentation by Susan Farr, PhD of Saint Louis University of a benefit for extracts of rosemary and spearmint in an animal model of memory loss. The extracts contain antioxidants which help reduce aging-associated oxidative stress, which is believed to contribute to cognitive impairment that occurs among the aged.
Using the SAMP8 mouse model of accelerated aging, Dr Farr's team tested the effect of three different doses of two rosemary extracts containing 60% or 10% carnosic acid. They additionally tested three doses of a spearmint extract that contained 5% rosmarinic acid. Another group of mice that received an inert substance served as controls.
After 90 days of treatment, administration of three behavioral tests revealed that animals that received the highest dose of the rosemary extract containing 60% carnosic acid had the strongest memory and learning enhancement effects. Benefits were also observed in association with the rosemary extract that contained 10% carnosic acid and with the spearmint extract. A marker of oxidative stress was reduced in the brains of all animals that received rosemary or spearmint in comparison with the control group.
"We found that these proprietary compounds reduce deficits caused by mild cognitive impairment, which can be a precursor to Alzheimer's disease," reported Dr Farr. "This probably means eating spearmint and rosemary is good for you. However, our experiments were in an animal model and I don't know how much--or if any amount--of these herbs people would have to consume for learning and memory to improve."
"Our research suggests these extracts made from herbs might have beneficial effects on altering the course of age-associated cognitive decline," she added. "It's worth additional study."
—D Dye
Increased calcium intake linked with lower risk of death from all causes over median of nine years
November 15 2013. On November 5, 2013, the journal PLOS ONE reported the finding of Hong Kong researchers of an association between increased calcium intake and a lower risk of mortality from all causes over a median of 9.1 years of follow-up.
The study included 3,139 Chinese men and women aged 65 years or older upon enrollment in a prospective study that examined risk factors for osteoporosis. Dietary questionnaire responses were analyzed for calcium intake from food consumed over the previous year. The subjects were additionally queried concerning whether or not they used calcium supplements.
Over a 9.1 year median, 529 deaths occurred, of which 114 were attributed to cardiovascular disease. A 37% lower risk of dying from any cause was observed among subjects whose calcium intake was among the top 25% of participants at over 762 milligrams (mg) per day in men and 688 mg per day for women in comparison with subjects whose intake was among the lowest 25% of participants (quantified as 458 mg per day or less for men and 417 mg per day or less for women). An insignificant reduction in cardiovascular mortality was also associated with increased calcium intake. Additionally, a reduction in the risk of dying from any cause over follow-up was found to be associated with calcium supplement use.
"To our knowledge, no study has examined the association between dietary calcium intake and all-cause and cardiovascular disease mortality in Chinese population," the authors announce. Because the current study's population had a relatively low intake of calcium, they suggest that supplementation recommendations take into consideration individual population characteristics.
—D Dye
Reduced vitamin B12 levels linked to increased progression of white matter lesions
November 13 2013. The journal PLOS One published an article on October 14, 2013 which reports the discovery of researchers in the Netherlands of a protective effect for higher vitamin B12 levels against the progression of periventricular white matter lesions, a common feature of cerebral small vessel disease. Progression of the lesions has been associated with cognitive impairment, urinary disturbances and gait abnormalities.
The study included 107 men and women diagnosed with a first time lacunar stroke, which results from the occlusion of one of the arteries that provides blood to the brain's deep structures. Blood samples obtained within three months of the event were assayed for plasma vitamin B12 levels. Magnetic resonance imaging (MRI) of the brain at the beginning of the study and after two years was used to evaluate periventricular and deep white matter lesions.
Twenty-nine percent of the participants experienced progression of periventricular white matter lesions and 39.3% had deep white matter lesion progression at the two-year follow-up visit. The researchers observed a 42% greater risk of periventricular white matter lesion progression for every 50 picomole per liter decrease in vitamin B12. Subjects whose B12 levels were considered deficient at less than 150 picomoles per liter had an approximately three times greater risk of periventricular white matter lesion progression in comparison with those whose levels were higher. An association with vitamin B12 levels was not observed for deep white matter lesion progression.
Ellen C. van Overbeek and her colleagues suggest several possible protective mechanisms for vitamin B12 including homocysteine reduction, improved blood-brain barrier integrity and other factors. They write that "Our results imply that patients with cerebral small vessel disease could benefit from supplementation of vitamin B12 to prevent further progression of white matter lesions over time."
—D Dye
Risedronate plus calcium and vitamin D improve bone density in men treated for epilepsy
November 11 2013. The results of a double-blinded trial reported online on September 6, 2013 in the journal Epilepsia reveal the finding of a beneficial effect for calcium and vitamin D in helping to protect against the loss of bone density that is associated with the use of antiepileptic drugs, including phenytoin, Phenobarbital, carbamazepine, primidone and valproate.
Fifty-three men who were treated with antiepileptic drugs for at least two years prior to enrollment in the Anti-Epileptic Drug and Osteoporosis Prevention Trial (ADOPT) were randomized to receive risedronate (a bisphosphonate drug that helps prevent fractures) or a placebo for 12 weeks. All participants received 1,000 to 1,500 milligrams calcium and 500 to 750 international units (IU) vitamin D per day. (Subjects who had deficient vitamin D levels were treated with an injectable form of the vitamin prior to enrollment.) Bone mineral density of the upper femur, lumbar spine and total body was assessed by dual energy x-ray absorptiometry (DXA) before treatment, and at one and two years. While participants who received risedronate experienced a 70% improvement in bone density in comparison with values obtained prior to treatment, the improvement in the placebo group was nearly as great, at 69%.
"Long-term use of antiepileptic drugs is associated with loss of bone mass and increased risk of osteoporosis," noted lead author Dr Antonio Lazzari of the Veterans Administration Boston Healthcare System in Massachusetts. "Our study is the first longitudinal trial of a bisphosphonate (risedronate), along with calcium and vitamin D supplementation, in preventing and treating bone loss in male veterans with epilepsy receiving antiepileptic drug therapy."
While risedronate provided superior results in the current study, the authors caution that treatment with the drug should be limited to five years if possible, in order to avoid the associated risks of jaw osteonecrosis and atypical femoral fractures.
—D Dye
Trial finds reduced inflammation in heart disease patients supplemented with coenzyme Q10
November 8 2013. The results of a randomized trial reported on November 6, 2013 in Nutrition Journal found a reduction in inflammation and an increase in antioxidant enzyme activities in individuals with coronary artery disease who were supplemented with coenzyme Q10 (CoQ10).
Researchers in Taiwan divided 42 men and women who were being treated with statin drugs for coronary artery stenosis to receive 300 milligrams CoQ10 per day or a placebo for twelve weeks. Blood samples collected at the beginning and end of the trial were analyzed for CoQ10, vitamin E, inflammation markers including C-reactive protein, tumor necrosis factor-alpha (TNF-alpha) and interleukin 6, and the antioxidant enzymes superoxide dismutase (SOD), catalase and glutathione peroxidase.
Plasma coenzyme Q10 and vitamin E levels significantly increased among CoQ10-supplemented participants by the end of the trial. The authors remark that "Coenzyme Q10 not only protects vitamin E against superoxide-driven oxidation but also regenerates vitamin E during antioxidation processes."
Subjects who received CoQ10 experienced a reduction in interleukin-6 and TNF-alpha, indicating a decline in inflammation, as well as elevations in SOD, catalase and glutathione peroxidase that resulted in a significant increase in comparison with the placebo group. The authors conclude that "Coronary artery disease patients might benefit from using coenzyme Q10 supplements to increase their antioxidation and anti-inflammation capacity during statins therapy."
—D Dye
Blueberries could help protect against metabolic syndrome effects
November 6 2013. Researchers from the University of Maine report a protective effect for wild blueberries against some of the adverse effects related to metabolic syndrome, which increases the risk of heart disease and diabetes. The findings were described in an article published on November 6, 2013 in Applied Physiology, Nutrition, and Metabolism. "The metabolic syndrome is a group of risk factors characterized by obesity, hypertension, inflammation, dyslipidemia, glucose intolerance and insulin resistance, and endothelial dysfunction," explained study coauthor Dorothy Klimis-Zacas, who is a professor of clinical nutrition at the University of Maine.
The study tested the effect of a blueberry-enriched diet in a rat model of metabolic syndrome. Thirty-six obese rats and an equal number of lean animals received a diet containing the human equivalent of two cups per day blueberries or a control diet for eight weeks. Aortic vessel vasoconstriction and vasorelaxation, which evaluate endothelial function, and other factors were assessed at the end of the treatment period. "Endothelial dysfunction is a landmark characteristic of metabolic syndrome, and the obese Zucker rat, an excellent model to study the metabolic syndrome, is characterized by vascular dysfunction," Dr Klimis-Zacas observed. "The vascular wall of these animals shows an impaired response to vasorelaxation or vasoconstriction which affects blood flow and blood pressure regulation."
Obese rats underwent improvements in the balance between constricting and relaxing factors, indicating better endothelial function. "We have previously documented the cardiovascular benefits of a polyphenol-rich wild blueberry in a rat model with impaired vascular health and high blood pressure," Dr Klimis-Zacas noted. "Our new findings show that these benefits extend to the obese Zucker rat, a widely used model resembling human metabolic syndrome."
Dr Klimis-Zacas concluded that "by normalizing oxidative, inflammatory response and endothelial function, regular long-term wild blueberry diets may also help improve pathologies associated with the metabolic syndrome."
—D Dye
How metformin works
November 4 2013. The journal Nature Medicine published a research letter on November 3, 2013 that reveals a mechanism for metformin in lowering blood sugar. "The key is that metformin doesn't work to lower blood glucose by directly working on the glucose," explained lead researcher Gregory R. Steinberg, who is an associate professor at McMaster University in Hamilton, Ontario. "It works on reducing harmful fat molecules in the liver, which then allows insulin to work better and lower blood sugar levels."
Dr Steinberg and his associates tested the effects of metformin in mice that developed fatty liver and prediabetes as the result of genetic modification of two proteins involved in fatty acid metabolism. "Unlike the majority of studies using genetic mouse models, we haven't deleted an entire protein; we have only made a very minor genetic mutation, equivalent to what might be seen in humans, thus highlighting the very precise way metformin lowers blood sugar in type 2 diabetes," noted lead author Morgan D. Fullerton.
When the animals were given metformin, blood sugar levels were not reduced, indicating that proper fat metabolism is needed for the drug to work. "What was really surprising was that when obese mutant mice were given metformin, the most common and inexpensive drug prescribed to type 2 diabetics, the drug failed to lower their blood sugar levels," Dr Steinberg stated. "It indicates the way metformin works isn't by directly reducing sugar metabolism, but instead by acting to reduce fat in the liver, which then allows insulin to work better."
"Fat is likely a key trigger for prediabetes, causing blood sugar to start going up because insulin can't work as efficiently to stop sugar coming from the liver," he noted. "This discovery offers a huge head start in finding combination therapies (and more personalized approaches) for diabetics for whom metformin isn't enough to restore their blood sugar to normal levels."
—D Dye
Higher vitamin C levels associated with lower risk of stomach cancer
November 1 2013. The November 2013 issue of the American Journal of Clinical Nutrition reports a protective effect for higher plasma vitamin C levels against gastric adenocarcinoma in Chinese men and women.
The current study involved follow-up participants in the Linxian General Population Nutrition Intervention Trial, which concluded in 1991. Blood samples collected between 1999 and 2000 were analyzed for plasma vitamin C levels. Four hundred sixty-seven men and women diagnosed with gastric adenocarcinoma and 618 subjects with esophageal squamous cell carcinoma were compared with 948 subjects who did not have the diseases.
A lower risk of gastric cancer was observed in association with higher plasma vitamin C levels. Participants with normal vitamin C levels, defined as greater than 28 micromoles per liter, had a 27% lower risk of gastric cancer in comparison with those whose levels were low at 28 micromoles per liter or less. A meta-analysis that included the current study and two other cohort studies resulted in similar findings. No association for vitamin C levels with esophageal squamous cell carcinoma was determined.
Authors Tram Kim Lam and colleagues remark that vitamin C may help protect the cells from oxidative DNA damage and other adverse effects of H. pylori infection, which is a common cause of gastric cancer. They note that H. pylori is not believed to increase the risk of esophageal squamous cell cancer, which could explain the lack of protective effect for vitamin C against this type of cancer that was observed in this study.
"This study was the largest prospective cohort study on the association between circulating vitamin C and gastric adenocarcinoma risk to date and the first prospective evaluation of the relation with esophageal squamous cell carcinoma," they announce. "Results based on our meta-analysis of prospective cohort studies suggest that plasma vitamin C is inversely associated with gastric adenocarcinoma incidence."
—D Dye
