Polluting the brain
New research has linked living in air-polluted urban areas with a significantly increased risk of dementia and Alzheimer’s disease, at least for women. The study, led by researchers from the University of Southern California, was based on data from thousands of women between the ages of 65 and 79 living throughout the U.S. who participated in the Women’s Health Initiative Memory Study.
Tiny, inhalable air pollution particles known as PM2.5, which mainly come from power plants and automobiles, are the source of the long-term damage. The research team found that older women living in places where PM2.5 levels exceed the U.S. Environmental Protection Agency’s standard are 81 percent more at risk for global cognitive decline, and 92 percent more likely to develop dementia, including Alzheimer’s. In the general population, these findings indicate that air pollution could be responsible for about 21 percent of dementia cases in women. The adverse effects of pollution were stronger in women who carry the APOE4 gene, which increases the risk for Alzheimer’s.
“Microscopic particles generated by fossil fuels get into our body directly through the nose into the brain,” said Professor Caleb Finch of the USC Leonard Davis School of Gerontology, who co-authored the study. “Cells in the brain treat these particles as invaders and react with inflammatory responses which, over the course of time, appear to exacerbate and promote Alzheimer’s disease.”
Concurrent to their analysis of women participating in the memory study, the USC scientists also conducted research in female mice. Over a period of 15 weeks, they chronically exposed which carried the APOE4 gene to nano-sized air pollution. They found that, compared to a control group, mice carrying the gene accumulated as much as 60 percent more amyloid plaque, the clusters of protein fragments that cause Alzheimer’s to progress, in their brains.
Their study appeared in the journal Translational Psychiatry. Although it included only women and female mice, future planned studies will include both sexes to determine how long-term exposure to PM2.5 affects men, as well as to examine how it interacts with cigarettes and other pollutants.
Eating a diet rich in protein can help older adults maintain muscle strength as they age – and it doesn’t have to come from meat or other animal products, according to new research.
Using data from participants in the Framingham Osteoporosis Study, which included about 3,000 men and women, researchers found that greater dietary protein intake is related to higher muscle mass and overall muscle health in both sexes. Those benefits held true whether the participants’ main sources of protein were animal- or plant-based foods. Plant foods that are significant protein sources include beans, nuts and seeds, wild rice, steel-cut oats, potatoes, corn and broccoli, among others.
“We know that dietary protein can improve muscle mass and strength. However, until now, we did not know if one protein food source was better than another in accomplishing optimal results,” lead author Dr. Kelsey M. Mangano said. “This study is significant as it suggests that higher protein intake form any food source will benefit muscle mass and strength in adults.” Mangano is an assistant professor of nutritional sciences at UMass Lowell, and an adjunct faculty member at Hebrew SeniorLife Institute for Aging Research, a Harvard Medical School affiliate. Results from the study were published in the American Journal of Clinical Nutrition.
Multiple medication risks
The many chronic health conditions people face as they age often means they are prescribed multiple medications. When older adults take five or more medicines, which is called “polypharmacy” by health experts, the risk for harmful side effects increases. A recent analysis of a large German study of older adults found that polypharmacy was linked to increased frailty–characterized by weakness, decreased endurance, and decreased ability to function. Frailty can, in turn, increase the risk for falls, disability, and even death.
The researchers examined information from nearly 2,000 older adults in Germany who participated in the ESTHER study, which began in 2000. People in the study were between 50 and 75 years old when it began, and follow-ups occurred after two, five, eight and 11 years. At the eight-year mark, doctors visited the participants at their homes for a geriatric assessment, which included a look at all the medications participants were taking–both prescription and over the counter. Based on those assessments, they placed participants into three groups:
- People who took from zero to four medicines [non-polypharmacy]
- People who took five to nine medicines [polypharmacy]
- People who took 10 or more medicines [hyper-polypharmacy]
After adjusting for differences in patients’ histories, including illnesses, and excluding medicines and supplements not known to cause side effects, the research team found that seniors at risk for frailty, as well as those who were already frail, were more likely to be in the polypharmacy or hyper-polypharmacy groups. Those who took between five and nine medicines were 1.5 times more likely to become frail within three years compared with people who took fewer than five. People taking more than 10 medicines had twice the risk of near-term frailty compared to the non-polypharmacy group.
The researchers concluded that when possible, reducing multiple prescriptions for older adults is a promising approach to lessen the risks for frailty. “In a perfect world, your physician would talk about your medications with a pharmacist and a geriatrician. This might help to reduce avoidable multiple drug prescriptions and possibly also lessen medication-induced risks for frailty and other negative effects of unnecessary, avoidable polypharmacy,” said study co-author Kai-Uwe Saum, Ph.D. The study was published in the Journal of the American Geriatrics Society.
Exercise and biological age
Exercise helps to keep one young – even at the cellular level, according to new research. A study conducted at the University of California San Diego School of Medicine found that older women who do little physical activity, sitting for more than 10 hours a day, have cells that are biologically older by eight years compared to women who are more active.
Nearly 1,500 women, ages 64 to 95, participated in the study as part of the larger Women’s Health Initiative, a national, longitudinal study investigating the factors which contribute to chronic diseases in postmenopausal women. Participants both completed questionnaires and wore an accelerometer on their right hips for seven consecutive days during waking and sleeping hours in order to track their movements.
The study found that participants who had fewer than 40 minutes of moderate to vigorous physical activity per day, or who were sedentary for more than 10 hours per day, also had shorter telomeres – tiny caps which are found on the ends of DNA strands and function like the plastic tips of shoelaces. Telomeres protect chromosomes from deterioration and get progressively shorter with age. Shortened telomeres are a natural consequence of aging, but health and lifestyle factors, such as obesity and smoking, may accelerate that process, contributing to cardiovascular disease, diabetes and major cancers.
“Our study found cells age faster with a sedentary lifestyle. Chronological age doesn’t always match biological age,” said Aladdin Shadyab, Ph.D., lead author of the study. “We found that women who sat longer did not have shorter telomere length if they exercised for at least 30 minutes a day, the national recommended guideline. Discussions about the benefits of exercise should start when we are young, and physical activity should continue to be part of our daily lives as we get older, even at 80 years old.”
Shadyab said future studies examining how exercise relates to telomere length in younger people and in men also are planned. The current study was published in the American Journal of Epidemiology.
Blueberry brain boost?
Blueberries are a known “superfood,” delivering significant amounts of disease-fighting antioxidants, fiber and vitamin C. Recently, another item was added to the list of blueberries’ potential health benefits by researchers at the University of Exeter in England, where a small study connected drinking concentrated blueberry juice with improvements in brain function for older people.
In the study, 26 healthy people aged 65-77 either drank about an ounce of concentrated blueberry juice every day for 12 weeks or were given a placebo. The concentrate delivered the equivalent of just over 8 ounces of blueberries. People who ate more than five portions of fruits and vegetables were excluded from the research, and study participants were told to stick to their normal diets throughout. Before and after the 12-week period, participants took a range of cognitive tests while an MRI scanner monitored their brain function, and their resting brain blood flow also was measured.
The researchers claimed that, compared to the placebo group, seniors who drank the blueberry concentrate showed significant improvements in several areas of brain function. Dr. Joanna Bowtell, who led the research, said, “Our cognitive function tends to decline as we get older, but previous research has shown that cognitive function is better preserved in healthy older adults with a diet rich in plant-based foods. In this study we have shown that with just 12 weeks of consuming 30 millileters of concentrated blueberry juice every day, brain blood flow, brain activation and some aspects of working memory were improved in this group of healthy older adults.”