In The News: December 2012

 

The Journal of Alzheimer's Disease published a study that evaluated the effects of a nutritional supplement combination on cognitive function in older men and women.*

Forty-one participants aged 65 and older were assigned capsules providing 290 mg eicosapentaenoic acid (EPA) and 203 mg docosahexaenoic acid (DHA); 84 mg lycopene and 240 mg Ginkgo biloba extract daily for three years. The control group consisted of 622 participants with no supplement intake or serious diseases. Tests of cognitive function, including attention, memory, language, and reasoning skills, were administered at the beginning and end of the study.

Although memory scores improved in both groups, the increase was larger in those who received the supplements compared to the controls. Language ability and attention declined in those who did not receive the supplements, while remaining stable in supplemented participants. When test scores were evaluated as a whole, significant improvement occurred only in supplemented subjects.

Editor's Note: Mechanisms for EPA and DHA in maintaining cognitive function are well known, and include the fatty acids' anti-inflammatory and brain cell membrane-stabilizing properties. Although omega-3 fatty acids have an antioxidant effect, they are also subject to lipid peroxidation, therefore, combining them with compounds that have antioxidant properties such as lycopene could improve their benefits.

Higher Vitamin B6 Levels Associated with Lower Risk of Invasive Breast Cancer

 

An article published online in the journal Cancer Epidemiology, Biomarkers & Prevention reports the finding of researchers at the University of Hawaii Cancer Center of an association between higher levels of the active form of vitamin B6 known as pyridoxal-5'-phosphate (PLP) and a lower risk of invasive breast cancer in postmenopausal women.*

The study included 1,412 women enrolled in the Multiethnic Cohort in Hawaii and Southern California prospective study. Seven hundred six invasive breast cancer patients were matched for age, ethnicity, menopausal hormone use, and other characteristics with an equal number of women without the disease.

Women whose plasma PLP levels were among the top 25% of participants were found to have a 30% lower risk of invasive breast cancer in comparison with those whose levels were among the lowest fourth.

Editor's Note: When the risk was evaluated according to breast cancer type, a significant association was observed between higher PLP levels and estrogen receptor-positive, progesterone receptor-positive, and estrogen receptor- and progesterone receptor-positive tumors.

A report published in Pediatrics reveals a decrease in the incidence of wintertime acute respiratory tract infections in children supplemented with vitamin D.*

The trial included 247 children residing in Mongolia, which receives limited winter sunlight. Participants had a median serum 25-hydroxyvitamin D concentration of 7 ng/mL at the beginning of the study (a severely deficient level associated with reduced sunlight exposure). One hundred forty-three children received milk fortified with 300 IU vitamin D per day, and 104 subjects received unfortified milk for seven weeks beginning in late January.

At the trial's conclusion, vitamin D levels increased among those who received vitamin D-fortified milk while remaining the same among the control group. Parents of subjects who received vitamin D reported 48% fewer respiratory infections in their children over the course of the study compared with those whose children did not receive the vitamin.

Editor's Note: Although observational studies have associated a lower risk of the infections with higher vitamin D levels, the investigation is one of the first randomized, double-blinded trials to study the effects of vitamin D supplementation on childhood acute respiratory infections. The amount of vitamin D provided was tiny, but since the children were so severely deficient, even this small amount provided substantial benefit. Children living in modern societies should be taking over 1,000 IU a day of vitamin D in the wintertime months.

 

The Journal of Clinical Investigation reported the discovery of Cedars-Sinai researchers of a protective effect for vitamin B3 against methicillin-resistant Staphylococcus aureus (MRSA), a type of staph infection that is resistant to antibiotic treatment.*

The finding is the result of research concerning a rare disorder known as neutrophil-specific granule deficiency, which involves a mutation in the gene C/EBPε that regulates some of the body's antimicrobial factors. Afflicted individuals have weakened immune systems that render them vulnerable to infections such as staph.

The team determined that a high dose of a form of vitamin B3 known as nicotinamide or niacinamide stimulates C/EBP, which enhances white blood cells' ability to combat staph infections. When the vitamin was tested in human blood, it boosted the immune system's staph-killing ability up to 1,000-fold in a matter of hours compared to treatment with saline.

The researchers suggest that targeting C/EBPε with other compounds could also help treat staph infections.

Editor's Note: In mice that received injections of 250 mg nicotinamide per kilogram body weight prior to non-MRSA staph infection, bacterial counts in the animals' spleens and kidneys were 100-fold lower after 48 hours compared with animals injected with saline.

Engaging in health-promoting lifestyle behaviors during one's golden years can result in a longer life, even among the very old, according to research described in the British Medical Journal.*

The study included 1,810 men and women who were at least 75 years old participating in a longitudinal study on dementia and aging. Interviews conducted upon enrollment obtained information concerning the participants' smoking status, alcohol intake, leisure activities, social networks, chronic diseases and other factors. The group was followed for 18 years, during which 91.8% died.

Men and women who had a low-risk profile, characterized by healthy lifestyle behaviors, participation in one or more leisure activities, and having a rich or moderate social network lived a median of 5.4 years longer than those who had a high-risk profile that included none of these factors.

Editor's Note: Even among people over the age of 85 and those with chronic health conditions, a healthy lifestyle appeared to prolong life by four years. Physical activity was the single biggest predictor of longevity. People who performed regular exercise lived an average of two years longer than people who did not.

 

The journal Neurology published the finding of Australian researchers of an association between high normal plasma glucose levels and a decrease in brain volume in nondiabetic men and women.*

The study included 266 men and women between the ages of 60 and 64 enrolled in the PATH Through Life Study, which is a longitudinal study of aging. Fasting plasma glucose and other factors were measured upon enrollment and those with glucose levels of 110 mg/dL (classified as impaired fasting hyperglycemia by the World Health Organization) or higher were excluded. MRI scans of the brain were conducted at the beginning of the study and four years later.

Dr. Cherbuin and his colleagues uncovered a significant association between a decline in volume in the brain's hippocampus and amygdala (cerebral structures affected by aging and neurodegeneration) and higher plasma glucose levels within this nondiabetic population.

Editor's Note: When asked if there is a specific level at which plasma glucose would begin to be considered risky, Dr. Cherbuin replied, "We found that the top two highest quarters (or quartiles) had significantly more shrinkage than the lowest one which might suggest a tentative cut-off of 92 mg/dL. However, because overall the association with hippocampal atrophy across all glucose levels was relatively uniform, more evidence was needed to point to a specific cut-off." These findings provide another reason to strive for fasting glucose levels below 86 mg/dL of blood.

The journal Molecular Nutrition & Food Research published an article that suggests a beneficial effect on the brain for a polyphenol found in green tea known as epigallocatechin-3-gallate (EGCG).*

Yun Bai and colleagues cultured adult mouse hippocampal neural progenitor cells with varying concentrations of EGCG or no EGCG for 24 hours. A significant increase in the number of neural progenitor cells was found in cultures that received higher amounts of EGCG. Similar findings were obtained upon examination of the dentate gyrus area of the brain in adult mice that were treated with the compound.

The researchers then evaluated the effects of EGCG on memory and learning in mice by administering the compound or no EGCG prior to training the animals in a maze. They observed a reduction in the amount of time needed to find a hidden platform in EGCG-treated mice.

Editor's Note: The authors remark that "Based on previous safety and pharmacokinetic studies, it is likely that a daily 1,500–1,600 mg bolus of EGCG in humans would achieve physiological levels similar to those in the sera of EGCG-treated (20 mg/kg) mice. Oral doses of similar magnitudes have been used in clinical trials, although EGCG in this potency has not been administered to humans on a regular basis."

 

The journal Pediatrics contained a report by Canadian researchers which reveals a greater prevalence of deficient vitamin D levels in children hospitalized with critical illnesses.*

J. Dayre McNally, MD, PhD, of Children's Hospital of Eastern Ontario Research Institute and colleagues examined serum 25-hydroxyvitamin D levels in 326 critically ill children between the ages of six months and thirteen years who were admitted to the intensive care units of six Canadian hospitals. 25 hydroxyvitamin D levels of lower than 50 nmol/L were found in 69% of the children tested. Vitamin D deficiency was associated with lower ionized calcium levels, a greater likeliness of the necessity of catecholamine use (administered in cases of shock), longer intensive care unit stays and increased Pediatric Risk of Mortality scores, which are used to evaluate illness severity.

Editor's Note: The authors remarked that, "Further research will determine whether targeted vitamin D supplementation or rapid restoration will improve outcome."

 

A report published online in The Journal of Nutrition, Health & Aging reveals a greater risk of inflammation among institutionalized older individuals whose levels of the mineral selenium were deficient.*

The current study included 336 men and women between the ages of 65 and 101 years who were residents of long-term health facilities in Taiwan. Blood samples were analyzed for the inflammatory cytokine interleukin-6 (IL-6), selenium, and other factors.

Selenium deficiency, defined as having a serum selenium level of less than 80 mcg/L, was detected in 35.6% of the men and 43.2% of the women participating in the study. An increased risk of deficiency was associated with rising levels of IL-6. Among those whose IL-6 levels were among the top 25% of participants, the risk of selenium deficiency was more than double that of subjects whose IL-6 levels were among the lowest quarter.

Editor's Note: The authors write that, "Future studies should aim to further clarify the linkage between selenium and IL-6, and possible benefits and disadvantages of intervention."

 

The 244th National Meeting & Exposition of the American Chemical Society was the site of a presentation of the discovery of a protective effect for resveratrol against the decline in mobility and balance that can occur during aging or with disorders such as Parkinson's disease.*

Jane E. Cavanaugh, PhD, and her associates fed 2, 10, and 22 month old mice diets enhanced with resveratrol or pinostilbene (a resveratrol analog) for 8 weeks. Motor function and balance were evaluated before and after treatment.

While older mice initially experienced more missteps when attempting to navigate a balance beam, fewer missteps occurred after 4 weeks of resveratrol treatment, resulting in performance similar to that of younger animals. In an attempt to determine the mechanism involved, the team pretreated neural cells with resveratrol or pinostilbene prior to exposing them to dopamine (a neurotransmitter that can induce cell death in high concentrations), and observed a protective effect in treated cells.

Editor's Note: It was determined that the compounds helped prevent free radical damage generated by dopamine breakdown and activated specific protein signaling pathways that may promote survival. (One hypothesis concerning the role of dopamine in Parkinson's disease is that dopamine itself may be damaging the cells that produce it.)