Taking a probiotic could help prevent the decline in memory and thinking that can accompany aging

 Findings from a new study suggest that taking a probiotic could help prevent the decline in memory and thinking that can accompany aging. This research may pave the way for new, non-invasive treatments that leverage the gut microbiome to mitigate cognitive decline in the aging population.

 

The researchers found that when study participants with mild cognitive impairment received the probiotic Lactobacillus rhamnosus GG (LGG) for three months, their cognitive scores increased. This cognitive improvement was also associated with changes in their gut microbiome.

 

“The implication of this finding is quite exciting, as it means that modifying the gut microbiome through probiotics could potentially be a strategy to improve cognitive performance, particularly in individuals with mild cognitive impairment,” said Mashael Aljumaah, a microbiology doctoral candidate at the University of North Carolina at Chapel Hill and North Carolina State University. “This adds a new layer to our understanding of the microbiome brain-gut connection and opens up new avenues for combating cognitive decline associated with aging.”

 

Aljumaah, who is also affiliated with King Saud University in Saudi Arabia, will present the findings at NUTRITION 2023, the annual flagship meeting of the American Society for Nutrition held July 22-25 in Boston.

 

“Many studies focus on severe forms of cognitive diseases such as Alzheimer's and dementia, but these conditions are more advanced, making them significantly harder to reverse or treat,” said Aljumaah. “In contrast, we focused on mild cognitive impairment, which can include problems with memory, language, or judgment. Interventions at this stage of cognitive impairment could slow down or prevent the progression to more severe forms of dementia.”

 

The study involved 169 participants between 52 and 75 years old who were divided into two groups depending on whether they had no neurological issues or mild cognitive impairment. Within each group, participants either received the LGG probiotic or a placebo in a double-blind, randomized clinical trial lasting three months. The researchers selected the LGG probiotic because prior research had shown its potential beneficial effects in animal models.

 

To investigate the study participants’ gut microbiomes, the researchers used 16S rRNA gene sequencing to identify and compare bacteria present in stool samples. They then used whole genome sequencing to gain insights into the functional roles of the bacteria identified.

 

The analysis revealed that microbes in the genus Prevotella were present in a higher relative abundance in participants with mild cognitive impairment than those with no cognitive impairment. This suggests that gut microbiome composition could serve as an early indicator for mild cognitive impairment, offering opportunities for earlier interventions to slow cognitive decline.

 

For study participants who had mild cognitive impairment and received the LGG probiotics, the Prevotella relative abundance decreased. This change coincided with improved cognitive scores, suggesting that cognitive health in older adults could be improved by manipulating the gut microbiota.

 

“By identifying specific shifts in the gut microbiome associated with mild cognitive impairment, we're exploring a new frontier in preventive strategies in cognitive health,” said Aljumaah. “If these findings are replicated in future studies, it suggests the feasibility of using gut microbiome-targeted strategies as a novel approach to support cognitive health.”

 

The researchers are now working to understand the specific mechanisms of how microbes like Prevotella influence the gut in a way that improves brain health. Specifically, they are exploring how certain molecules produced by these bacteria modulate the functionality of neuroprotective hormones that can cross the blood-brain barrier.

 

Daily prune consumption supports cardiovascular health in aging population

 

A pair of new studies presented as abstracts today at the American Society of Nutrition (ASN) annual meeting report that daily prune consumption has promising effects on several biomarkers related to cardiovascular health. Conducted in postmenopausal women and men 55 years and older, the studies reveal:

• In men, long-term prune consumption improved HDL cholesterol and the total cholesterol to HDL ratio, while decreasing oxidative stress and the inflammatory biomarker C-reactive protein (CRP).
• In older women, long-term prune consumption had no negative effect on various metabolic measures related to heart disease risk including total cholesterol, total triglycerides, fasting glucose, and insulin levels.

The results of both studies were presented at the ASN annual flagship meeting in Boston, MA. The ASN convenes researchers, practitioners, global and public health professionals, policymakers and advocacy leaders, industry, media, and other related professionals to advance nutrition science and its practical application.

“Currently, there are a limited number of randomized controlled trials conducted in aging men and women that explore the relationship between prune consumption and cardiovascular-related blood biomarkers,” said Mary Jane De Souza, PhD, FACSM, FANK, Distinguished Professor, Pennsylvania State University, and principal investigator of the postmenopausal women study. “We want to advance the research on this topic area to better understand how prune consumption relates to cardiometabolic health outcomes, especially in the aging population that often experiences an elevated risk for cardiovascular disease.”

Cardiovascular diseases are among the leading causes of death in the United States1 and risk factors include high cholesterol levels, diabetes, obesity, and aging.2 One of the primary dietary recommendations to lower cardiovascular disease risk is to consume a wide variety of fruits and vegetables.3 As a whole fruit with no added sugars, prune consumption may support healthy dietary patterns and promote better outcomes related to cardiovascular health.

“It is exciting to see research on prune consumption and cardiovascular health expand,” says Andrea N. Giancoli, MPH, RDN, Nutrition Advisor, California Prune Board. “While all fruits and vegetables provide essential nutrients, prunes make for an easy, convenient and versatile snack or recipe ingredient that is accessible year-round and can help support consumers’ cardiovascular health goals.”

These two studies represent the latest additions of research on prune consumption and human health. Previous research has shown that daily prune consumption can help support gut health, bone health, and weight management.

References:

1. Center for Disease Control and Prevention, National Center for Health Statistics (2023, January 18). Leading causes of death. https://www.cdc.gov/nchs/fastats/leading-causes-of-death.htm
2. Center for Disease Control and Prevention (2023, March 21). Know Your Risk for Heart Disease. https://www.cdc.gov/heartdisease/risk_factors.htm
3. American Heart Association (n.d.). The American Heart Association Diet and Lifestyle Recommendations. https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/nutrition-basics/aha-diet-and-lifestyle-recommendations

Strawberry consumption may improve cognitive function in older adults

 

Daily strawberry consumption was linked to improved cognitive function, lower blood pressure and higher antioxidant capacity in a randomized clinical trial presented today at Nutrition 2023, the annual meeting of the American Society of Nutrition (ASN). The study was conducted at San Diego State University and builds on previous research demonstrating the cardiovascular, metabolic and cognitive health benefits of strawberries.

The double-blind, placebo-controlled study was conducted in 35 healthy men and women, aged 66 to 78. The participants consumed 26 grams of freeze-dried strawberry powder, equivalent to two servings of strawberries daily, or a control powder for eight weeks each.

Following strawberry consumption, cognitive processing speed increased by 5.2%, systolic blood pressure decreased by 3.6% and total antioxidant capacity significantly increased by 10.2%. Waist circumference decreased by 1.1% during both the control and intervention arms of the trial. While consuming the control powder, participants experienced increased serum triglycerides.

“This study demonstrates that consuming strawberries may promote cognitive function and improve cardiovascular risk factors like hypertension,” said Shirin Hooshmand, professor in the School of Exercise and Nutrition Sciences at San Diego State and principal investigator on the study. “We’re encouraged that a simple dietary change, like adding strawberries to the daily diet, may improve these outcomes in older adults.”

Strawberries are a source of many bioactive compounds. In addition to providing 100% of our daily vitamin C needs, strawberries contain heart-healthy nutrients like folate, potassium, fiber, phytosterols and polyphenols.

Previous clinical trials have connected strawberry consumption to improvements in several markers for cardiovascular disease, including reduced total and LDL cholesterol (TC) and lower blood pressure. The link between strawberry consumption and brain health has also been well explored in both clinical and population-based studies. Strawberries and pelargonidin, a biochemical primarily found in strawberries, were associated with a reduced risk of Alzheimer’s dementia in studies conducted at Rush University. Long-term observational studies, including the Health Professionals Study and the Nurses' Health Study, found that strawberry consumers had lower rates of cognitive decline.

Mild exercise for three months enhances cognitive function and brain efficiency in older adults

Maintaining and promoting cognitive function in older adults can be aided by regular exercise. While previous research has focused on the effects of moderate- to high-intensity aerobic exercise programs lasting anywhere from six months to a year on executive function--controlled by the prefrontal cortex—the challenge lies in motivating individuals to engage in and adhere to rigorous exercise routines.

Building upon prior investigations conducted by investigators at the University of Tsukuba and the University of California, Irvine, it has been observed that even brief sessions of mild exercise, such as walking and yoga, can stimulate the brain and yield temporary improvements in cognitive performance. However, until now, the impact of long-term mild aerobic exercise on brain function in humans, as well as the underlying mechanisms involved, remained unexplored.

For this study, a group of healthy middle-aged and older adults (aged 55-78) were randomly divided into two groups: one performed low-intensity bicycle exercise three times a week for three months (exercise group), while the other group continued their normal daily routine (control group). The research team evaluated the participants' executive function using a Stroop test and assessed prefrontal cortex activity during the task using functional near-infrared spectroscopy before and after the intervention.

The findings revealed that the exercise group exhibited significant improvement in executive function compared to the control group. Notably, when analyzing the data by age, the benefits of mild exercise were particularly pronounced in the older adult group (aged 68-78). The underlying brain mechanism behind this improvement involved an increase in the efficient activation of the prefrontal cortex. In other words, executive function was high while corresponding brain activation was relatively low. These results suggest that even three months of mild exercise can strengthen the brain's functional networks, enabling the prefrontal cortex to be utilized more efficiently during the Stroop test.

This groundbreaking discovery highlights the positive impact of stress-free mild exercise over a three-month period in strengthening the prefrontal cortex and enhancing cognitive function among older adults. The findings are expected to contribute to the development of new exercise programs and strategies that improve executive function and are easily accessible for older individuals with low physical fitness levels and limited motivation to exercise.

Majority of older adults with cognitive impairment still drive

 

Researchers highlight the importance of caregivers having conversations with care recipients and health care professionals about driving

Peer-Reviewed Publication

MICHIGAN MEDICINE - UNIVERSITY OF MICHIGAN

The majority of older adults with cognitive impairment are still driving, despite concerns raised by caregivers and others, a Michigan Medicine study in a South Texas community finds.

Researchers assessed more than 600 adults over 65 years old in Nueces County, Texas, who had cognitive assessment scores that indicated a likelihood of impairment.

Of those people with cognitive impairment, 61.4% were current drivers, and around one-third of all caregivers had concerns about their care-recipient driving. The results are published in the Journal of the American Geriatrics Society.

“It is likely appropriate that some with mild cognitive impairment are still driving, but for some it may not be,” said senior author Lewis B. Morgenstern, M.D., professor of neurology, neurosurgery and emergency medicine at University of Michigan Medical School and professor of epidemiology at the U-M School of Public Health.

“Patients and caregivers should discuss these issues with their health care providers and consider on the road driving evaluations to ensure safety.”

Approximately one in nine Americans aged 65 and older, or 6.7 million people, are estimated to live with Alzheimer’s disease and millions more have related dementias.

These conditions may affect neuropsychological and visual skills that reduce the ability to drive safely. A 2017 review of motor vehicle crash risk found that dementia had medium to large effects on driving impairment and that people with dementia have an increased likelihood of failing a road test compared to those without.

Investigators initially set out to study the driving prevalence of older Latino and non-Latino white adults, finding no significant differences between the two populations. However, the more cognitive impairment any individual had, the less likely they were to be driving.

Just over 35% of caregivers had concerns about their care recipient’s ability to drive safely, even though many study participants limited their total amount of driving and avoided driving at night or in the rain.

The discussions between caregivers and people with cognitive impairment about driving are difficult, with concerns over the loss of autonomy and potential embarrassment. When a person with cognitive impairment stops driving, that may also increase the workload of a caregiver.

Researchers say it’s best to start conversations surrounding driving earlier while the care recipient is able to understand and actively participate in the discussion.

“Close family may have discussions with aging loved ones about Advance Driving Directives,” Morgenstern said. “These are agreements between an aging person and a loved one about having conversations about driving cessation.”

Volunteering in late life may protect the brain against cognitive decline and dementia

Key Takeaways:

• Volunteering later in life may protect the brain against cognitive decline and dementia.
• New study of older adults found better memory and executive function among those who volunteered.
• Watch the video.

(Sacramento) Volunteering in late life is associated with better cognitive function — specifically, better executive function and episodic memory. Those are the findings of a new study from UC Davis Health presented today (July 20) at the Alzheimer’s Association International Conference 2023 in Amsterdam.

“We hope these new data encourage individuals of all ages and backgrounds to engage in local volunteering — not only to benefit their communities, but potentially their own cognitive and brain health,” said Donna McCullough, Alzheimer’s Association chief mission and field operations officer.

Volunteer activities — such as supporting educational, religious, health-related or other charitable organizations — allow older adults to be more physically active, increase social interaction and provide cognitive stimulation that may protect the brain. However, there has been a lack of information on the relationship between volunteering and cognitive function, especially in large, diverse populations.

Yi Lor, an epidemiology doctoral student at UC Davis, and Rachel Whitmer, the study's principal investigator, examined volunteering habits among an ethnic and racially diverse population of 2,476 older adults. The participants are in the Kaiser Healthy Aging and Diverse Life Experiences Study (KHANDLE) and the Study of Healthy Aging in African Americans (STAR).

The study group had an average age of 74 and contained 48% Black, 20% white, 17% Asian and 14% Latino participants. A total of 1,167 (43%) of the participants reported volunteering in the past year.

The researchers found that volunteering was associated with better baseline scores on tests of executive function and verbal episodic memory. This was true even after adjusting for age, sex, education, income, practice effects and interview mode (phone versus in-person).

Those who volunteered several times per week had the highest levels of executive function.

“Volunteering may be important for better cognition in late life and could serve as a simple intervention in all older adults to protect against risk for Alzheimer’s disease and associated dementias,” Lor said. “Our next steps are to examine whether volunteering is protective against cognitive impairment, and how physical and mental health may impact this relationship.”

Volunteering was also associated with a trend toward less cognitive decline over the follow-up time of 1.2 years, but this association did not reach statistical significance.

“You’re not in control of your family history or age — you can’t turn back the clock. But you are in control of how you spend your day and life,” Whitmer said. “Volunteering is about keeping your brain active. It’s also about socializing, which keeps you engaged and happy, and potentially lowers stress.”

Resources

• Video: Volunteering in Late Life May Protect the Brain from Dementia
• Media kit (b-roll and interview soundbites)
• Whitmer Lab

Omega-3 fatty acids appear promising for maintaining lung health

 

NIH-funded study supports new role for nutrient found in fish, dietary supplements.

Omega-3 fatty acids, which are abundant in fish and fish oil supplements, appear promising for maintaining lung health, according to new evidence from a large, multi-faceted study in healthy adults supported by the National Institutes of Health. The study provides the strongest evidence to date of this association and underscores the importance of including omega-3 fatty acids in the diet, especially given that many Americans do not meet current guidelines. Funded largely by the National Heart, Lung, and Blood Institute (NHLBI), part of NIH, the study results were published in the American Journal of Respiratory and Critical Care Medicine. 

“We know a lot about the role of diet in cancer and cardiovascular diseases, but the role of diet in chronic lung disease is somewhat understudied,” said corresponding author Patricia A. Cassano, Ph.D., director of the Division of Nutritional Sciences at Cornell University in Ithaca, New York. “This study adds to growing evidence that omega-3 fatty acids, which are part of a healthy diet, may be important for lung health too.”

There’s increased interest in trying to understand whether nutritional interventions could contribute to lung disease prevention efforts. Past studies have suggested that omega-3 fatty acids may help, due largely to their established anti-inflammatory actions. However, robust studies of this association have been lacking, until now. 

To learn more, researchers developed a two-part study investigating the link between omega-3 fatty acid levels in the blood and lung function over time. In the first part, the researchers conducted a longitudinal, observational study involving 15,063 Americans from the NHLBI Pooled Cohorts Study — a large collection of NIH-funded studies that helps researchers to study determinants of personalized risk for chronic lung disease.   

The participants studied were generally healthy when the study began, and the majority had no evidence of chronic lung disease. They comprised a racially diverse group of adults, with an average age of 56 years, and 55% were female. The researchers followed participants for an average of seven years and up to 20 years. 
 
The longitudinal study showed that higher levels of omega-3 fatty acids in a person’s blood were associated with a reduced rate of lung function decline. The researchers observed the strongest associations for docosahexaenoic acid (DHA), an omega-3 fatty acid that is found at high levels in fatty fish such as salmon, tuna, and sardines. DHA is also available as a dietary supplement.

In the second part, the researchers analyzed genetic data from a large study of European patients (over 500,000 participants) from the UK Biobank. They studied certain genetic markers in the blood as an indirect measure, or proxy, for dietary omega-3 fatty acid levels to see how they correlated with lung health. The results showed that higher levels of omega-3 fatty acids — including DHA — were associated with better lung function. 

One caveat of the current study is that it only included healthy adults. As part of this ongoing project, researchers are collaborating with the COPDGene study(link is external) to examine blood levels of omega-3 fatty acids in relation to the rate of decline in lung function among people with chronic obstructive pulmonary disease or COPD — including heavy smokers — to determine if the same beneficial associations are found.

“We’re starting to turn a corner in nutritional research and really moving toward precision nutrition for treating lung diseases,” said study first author Bonnie K. Patchen, Ph.D., a nutritionist and member of Cassano’s research team at Cornell. “In the future, this could translate into individualized dietary recommendations for people at high risk for chronic lung disease.” 

For now, the researchers point out that the U.S. Department of Agriculture’s Dietary Guidelines for Americans(link is external) recommends that people eat at least two servings of fish per week, which most Americans fall far short. In addition to fish and fish oil, other sources of omega-3 fatty acids include nuts and seeds, plant oils, and fortified foods.

“This large population-based study suggests that nutrients with anti-inflammatory properties may help to maintain lung health,” said James P. Kiley, Ph.D., director of the NHLBI’s Division of Lung Diseases. “More research is needed, since these findings raise interesting questions for future prospective studies about the link between omega-3 fatty acids and lung function.”