Walnuts may be Good for the Gut and Help Promote Heart Health

Katie Bohn wrote . . . . . . . . .

Walnuts may not just be a tasty snack, they may also promote good-for-your-gut bacteria. New research suggests that these “good” bacteria could be contributing to the heart-health benefits of walnuts.

In a randomized, controlled trial, researchers found that eating walnuts daily as part of a healthy diet was associated with increases in certain bacteria that can help promote health. Additionally, those changes in gut bacteria were associated with improvements in some risk factors for heart disease.

Kristina Petersen, assistant research professor at Penn State, said the study — recently published in The Journal of Nutrition — suggests walnuts may be a heart- and gut-healthy snack.

“Replacing your usual snack — especially if it’s an unhealthy snack — with walnuts is a small change you can make to improve your diet,” Petersen said. “Substantial evidence shows that small improvements in diet greatly benefit health. Eating two to three ounces of walnuts a day as part of a healthy diet could be a good way to improve gut health and reduce the risk of heart disease.”

Previous research has shown that walnuts, when combined with a diet low in saturated fats, may have heart-healthy benefits. For example, previous work demonstrated that eating whole walnuts daily lowers cholesterol levels and blood pressure.

According to the researchers, other research has found that changes to the bacteria in the gastrointestinal tract — also known as the gut microbiome — may help explain the cardiovascular benefits of walnuts.

“There’s a lot of work being done on gut health and how it affects overall health,” said Penny Kris-Etherton, distinguished professor of nutrition at Penn State. “So, in addition to looking at factors like lipids and lipoproteins, we wanted to look at gut health. We also wanted to see if changes in gut health with walnut consumption were related to improvements in risk factors for heart disease.”

For the study, the researchers recruited 42 participants with overweight or obesity who were between the ages of 30 and 65. Before the study began, participants were placed on an average American diet for two weeks.

After this “run-in” diet, the participants were randomly assigned to one of three study diets, all of which included less saturated fat than the run-in diet. The diets included one that incorporated whole walnuts, one that included the same amount of alpha-linolenic acid (ALA) and polyunsaturated fatty acids without walnuts, and one that partially substituted oleic acid (another fatty acid) for the same amount of ALA found in walnuts, without any walnuts.

In all three diets, walnuts or vegetable oils replaced saturated fat, and all participants followed each diet for six weeks with a break between diet periods.

To analyze the bacteria in the gastrointestinal tract, the researchers collected fecal samples 72 hours before the participants finished the run-in diet and each of the three study diet periods.

“The walnut diet enriched a number of gut bacteria that have been associated with health benefits in the past,” Petersen said. “One of those is Roseburia, which has been associated with protection of the gut lining. We also saw enrichment in Eubacteria eligens and Butyricicoccus.”

The researchers also found that after the walnut diet, there were significant associations between changes in gut bacteria and risk factors for heart disease. Eubacterium eligens was inversely associated with changes in several different measures of blood pressure, suggesting that greater numbers of Eubacterium eligens was associated with greater reductions in those risk factors.

Additionally, greater numbers of Lachnospiraceae were associated with greater reductions in blood pressure, total cholesterol, and non-HDL cholesterol. There were no significant correlations between enriched bacteria and heart-disease risk factors after the other two diets.

Regina Lamendella, associate professor of biology at Juniata College, said the findings are an example of how people can feed the gut microbiome in a positive way.

“Foods like whole walnuts provide a diverse array of substrates — like fatty acids, fiber and bioactive compounds — for our gut microbiomes to feed on,” Lamendella said. “In turn, this can help generate beneficial metabolites and other products for our bodies.”

Kris-Etherton added that future research can continue to investigate how walnuts affect the microbiome and other elements of health.

“The findings add to what we know about the health benefits of walnuts, this time moving toward their effects on gut health,” Kris-Etherton said. “The study gives us clues that nuts may change gut health, and now we’re interested in expanding that and looking into how it may affect blood sugar levels.”

Source: The Pennsylvania State University

Artificial Intelligence Might Help Spot, Evaluate Prostate Cancer

Amy Norton wrote . . . . . . . . .

In another step toward using artificial intelligence in medicine, a new study shows that computers can be trained to match human experts in judging the severity of prostate tumors.

Researchers found that their artificial intelligence system was “near perfect” in determining whether prostate tissue contained cancer cells. And it was on par with 23 “world-leading” pathologists in judging the severity of prostate tumors.

No one is suggesting computers should replace doctors. But some researchers do think AI technology could improve the accuracy and efficiency of medical diagnoses.

Typically, it works like this: Researchers develop an algorithm using “deep learning” — where a computer system mimics the brain’s neural networks. It’s exposed to a large number of images — digital mammograms, for example — and it teaches itself to recognize key features, such as signs of a tumor.

Earlier this month, researchers reported on an AI system that appeared to best radiologists in interpreting screening mammograms. Other studies have found that AI can outperform doctors in distinguishing harmless moles from skin cancer, and detecting breast tumor cells in lymph node samples.

The new study looked at whether it’s possible to train an AI system to detect and “grade” prostate cancer in biopsied tissue samples. Normally, that’s the work of clinical pathologists — specialists who examine tissue under the microscope to help diagnose disease and judge how serious or advanced it is.

It’s painstaking work and, to a certain degree, subjective, according to study leader Martin Eklund, a senior researcher at the Karolinska Institute in Sweden.

Then there’s the workload. In the United States alone, more than 1 million men undergo a prostate biopsy each year — producing more than 10 million tissue samples to be examined, Eklund’s team noted.

To create their AI system, the researchers digitized more than 8,000 prostate tissue samples from Swedish men ages 50 to 69, creating high-resolution images. They then exposed the system to roughly 6,600 images — training it to learn the difference between cancerous and noncancerous tissue.

Next came the test phase. The AI system was asked to distinguish benign tissue from cancer in the remaining samples, plus around 300 from men who’d had biopsies at Karolinska. The AI results, the researchers reported, were almost always in agreement with the original pathologist’s assessment.

And when it came to grading the severity of prostate tumors with what’s called a Gleason score, the AI system was comparable to the judgment of 23 leading pathologists from around the world.

Much work, however, remains. A next step, Eklund said, is to see how the AI system performs across different labs and different pathology scanners, which are used to create digital images.

But one day, he said, AI could be used in a number of ways — including as a “safety net” to make sure a pathologist didn’t miss a cancer. It might also improve efficiency by prioritizing suspicious biopsies that pathologists should examine sooner.

Studies like this are a necessary step toward incorporating AI into medical practice, said Dr. Matthew Hanna, a pathologist at Memorial Sloan Kettering Cancer Center in New York City.

But, he stressed, “there’s still a long road ahead.”

Hanna, who was not involved in the study, is also a spokesperson for the College of American Pathologists.

Like Eklund, he said that any AI system would have to be validated across different centers, and different pathology scanners. And ultimately, Hanna said, studies will need to show that such technology can be used effectively in pathologists’ real-world practice.

There are practical realities, too. At the moment, Hanna pointed out, only a relative minority of pathology labs use digital systems in patient care. That’s key because for any AI algorithm to work, there have to be digital images to analyze. Most often, pathologists still study tissue using the classic approach — glass slides and a microscope.

What’s clear is that machines won’t be replacing humans — at least in the foreseeable future.

“This technology is coming,” Hanna said. “But as opposed to replacing doctors, it will transform how they deliver care — hopefully for the better.”

The study was reported online in The Lancet Oncology.

Source: HealthDay


Today’s Comic

Why Patients with Dementia Could Benefit from Cooking

Robert Firpo-Cappiello wrote . . . . . . . . .

Paula Wolfert knew something was wrong.

In 2010, at age 72, the award-winning cookbook writer noticed an unsettling development: Her previously sharp memory—for exotic ingredients, complex recipes, and the names of hundreds of friends she’d made traveling the world—was slipping. Now she struggled to remember the foreign languages she’d mastered; even reading English became a challenge. The words seemed to be “floating on the page,” she told friends.

At first Wolfert’s closest friends, and even some doctors, dismissed her memory lapses as age related. Wolfert wasn’t convinced, and as her memory continued to decline, she sought advice from a neurologist who took her medical history, conducted memory and cognitive tests, and had her undergo an MRI. Based on these results, the neurologist diagnosed her with mild cognitive impairment, which can be a precursor to Alzheimer’s disease.

After a lifetime of inspiring home cooks and acclaimed chefs such as Alice Waters and Thomas Keller with groundbreaking cookbooks that include Couscous and Other Good Food from Morocco (Harper & Row, 1973) and The Cooking of the Eastern Mediterranean (HarperCollins, 1994), Wolfert had acquired a reputation as an innovative thinker who was passionate about what she believed in. When she was a child, a psychologist told Wolfert’s parents that the little girl was a “renegade.”

That spirit has remained strong in the face of her diagnosis and decline in cognitive abilities. “Despite her struggles, Paula wants to continue cooking as long as it is safe,” says Emily Kaiser Thelin, author of Unforgettable: The Bold Flavors of Paula Wolfert’s Renegade Life (Grand Central Life & Style, 2017). The two women spent hours talking, reviewing recipes, and working in the kitchen together as Thelin crafted the hybrid biography/cookbook. “Paula told me, ‘This illness takes forever, and I’m determined to make it take as long as it can.'” (Wolfert no longer gives interviews, but a close circle of friends and associates, including Thelin, occasionally speak on her behalf.)

For Wolfert, coping with cognitive impairment—and the eventual confirmation that she has Alzheimer’s dementia—has meant not just eating well (she’s long embraced a Mediterranean diet that focuses on lean meats and fatty fish, fresh fruits, and vegetables) but also continuing to cook. Now, though, she’s cooking in a new way, one that helps her maintain the physical activity and social support that are increasingly recognized as important in dealing with dementia. “While Paula can no longer follow recipes,” Thelin says, “she’s still able to improvise basics, especially with someone else in the kitchen to help. She focuses on simple ingredients such as wild-caught salmon and mackerel and a rainbow of fresh vegetables, and simple techniques such as steaming to create bountiful lunches for herself.”

Wolfert also meets with friends at a local community center where she hosts a “memory cafe,” an informal social gathering for people with Alzheimer’s and other forms of dementia or cognitive challenges and their caregivers. She also travels to Washington, DC, as a spokesperson for the Alzheimer’s Association. As her grandmother once told her, you can’t win a war if you’re not willing to fight.

Wolfert’s neurologist, Catherine A. Madison, MD, director of the Ray Dolby Brain Health Center in San Francisco, has encouraged Wolfert’s healthy eating habits and efforts to remain engaged socially. She also has persuaded Wolfert to meditate and exercise. Under Dr. Madison’s guidance, Wolfert started jogging for 20 minutes on a treadmill, meditating for 15 minutes using an app, and attending yoga and qigong classes. Her friends have been amazed at how the previously exercise-averse Wolfert has taken to these new physical activities.

A few small studies suggest that cooking may be beneficial in the fight against cognitive decline. Larger studies, however, suggest that it may be the socializing aspect of cooking and other interactive activities that is more important.

A large retrospective analysis conducted by researchers at University College London, published in PLOS Medicine in 2019, looked at data from more than 10,000 mid-to-late-life participants in the Whitehall II study, which began in 1985 and required participants to complete cognitive tests five times between 1997 and 2016. The analysis of cognitive test results and other health records strongly suggests that greater frequency of social interactions at age 60 is associated with higher cognitive performance in later life and a lower risk of developing dementia.

These results echo those of earlier work, such as a research review published in the Journal of Aging Research in 2012 that suggests that physical activity, intellectual stimulation, and socialization improve cognition and overall well-being in people with age-associated cognitive impairments and may provide a similar benefit for those with dementia.

In one of the first studies to examine the role of cooking in brain health, published in the American Journal of Recreation Therapy in 2003, Suzanne Fitzsimmons, MS, a nurse practitioner and former instructor in therapeutic geriatric care at the University of North Carolina Greensboro, and the late Linda L. Buettner, PhD, former professor of gerontology and therapeutic recreation, found that cooking in a safe environment helped reduce passivity and agitation in adults in assisted living who had varying degrees of dementia.

“Cooking has a powerful meaning for older adults,” says Fitzsimmons. “For some, it can be integral to feelings of self-worth and identity.” The cooking programs that Fitzsimmons led for adults in group settings—inspired by the theory that maintaining roles and activities people are used to is key as they age—have been shown to increase appetite, encourage people to join a social gathering, and relieve stress.

“I was amazed that even participants who had not cooked for a long time took to the kitchen without much prompting—they seemed to be in their element,” says Fitzsimmons, who has retired from teaching. “And some of the very low-functioning participants surprised us: After making butter, they independently spread it on bread. This may not sound like much, but these older adults had been fed by staff for more than a year. After participating in the program for a few weeks, they were able to eat finger foods independently. They also started communicating more, especially with cooking partners, recalling fondly what they cooked and telling family members what they had accomplished.”

Encouraging people with dementia to cook comes with safety hazards: sharp tools, open flames, spills, forgetting to turn off burners or ovens, and other risks. That’s why therapeutic cooking programs—and any attempt to reproduce them at home—must include supervision and must match cooking chores to people’s level of functioning. More complex tasks might include making shopping lists and cutting stems off strawberries. Simpler tasks would be stirring ingredients in a bowl, shaking a sealed container of ingredients, wiping surfaces, clearing a table, and drying dishes.

While the benefits of staying active and socially engaged and eating a healthy diet are increasingly clear, the science behind the recommendations is still evolving. “We don’t know for certain what particular mechanisms are at work to bring about these benefits,” says Dr. Madison. “Every person is unique. The complex relationships between our own biology and genetic expression, environment, and diet make research in neurodegenerative diseases particularly challenging.”

As for Wolfert, she worked with Thelin and “Team Renegade” to review and test recipes, plan photo shoots, and participate as fully as possible in the publication of Unforgettable. “When we were shooting recipes for the book, Paula tasted every dish we prepared,” says Thelin. “More often than not, she would insist she could not remember anything about the dishes. But we learned to roll with it, to cherish the unpredictable moments when memories would shake loose, such as the time I prepared cassoulet for her and she vividly recalled and described watching a French housewife prepare cassoulet for her 50 years earlier.” But as with everyone diagnosed with cognitive impairment, Wolfert’s future remains uncertain.

“While the inevitable progression of Paula’s Alzheimer’s dementia has made cooking challenging for her, I’ve been endlessly amazed by how she has found fresh inspiration in new passions, including taking to exercise well into her seventies,” Thelin says. “It’s quite something how the diagnosis has, in surprising ways, widened her world through the memory cafe and in her work with the Alzheimer’s Association.”

Source: Brain & Life

Drinking 1% Milk Instead of 2% Milk Accounts for 4.5 years of Less Aging in Adults

Todd Hollingshead wrote . . . . . . . . .

A new study shows drinking low-fat milk — both nonfat and 1% milk — is significantly associated with less aging in adults.

Research on 5,834 U.S. adults by Brigham Young University exercise science professor Larry Tucker, Ph.D., found people who drink low-fat (1% and skim) milk experience several years less biological aging than those who drink high-fat (2% and whole) milk.

“It was surprising how strong the difference was,” Tucker said. “If you’re going to drink high-fat milk, you should be aware that doing so is predictive of or related to some significant consequences.”

Tucker investigated the relationship between telomere length and both milk intake frequency (daily drinkers vs. weekly drinkers or less) and milk fat content consumed (whole vs. 2% vs. 1% vs. skim). Telomeres are the nucleotide endcaps of human chromosomes. They act like a biological clock and they’re extremely correlated with age; each time a cell replicates, humans lose a tiny bit of the endcaps. Therefore, the older people get, the shorter their telomeres.

And, apparently, the more high-fat milk people drink, the shorter their telomeres are, according to the new BYU study, published in Oxidative Medicine and Cellular Longevity. The study revealed that for every 1% increase in milk fat consumed (drinking 2% vs. 1% milk), telomeres were 69 base pairs shorter in the adults studied, which translated into more than four years in additional biological aging. When Tucker analyzed the extremes of milk drinkers, adults who consumed whole milk had telomeres that were a striking 145 base pairs shorter than non-fat milk drinkers.

Nearly half of the people in the study consumed milk daily and another quarter consumed milk at least weekly. Just under a third of the adults reported consuming full-fat (whole) milk and another 30 percent reported drinking 2% milk. Meanwhile, 10% consumed 1% milk and another 17% drank nonfat milk. About 13% did not drink any cow milk.

“Milk is probably the most controversial food in our country,” Tucker said. “If someone asked me to put together a presentation on the value of drinking milk, I could put together a 1-hour presentation that would knock your socks off. You’d think, ‘Whoa, everybody should be drinking more milk.’ If someone said do the opposite, I could also do that. At the very least, the findings of this study are definitely worth pondering. Maybe there’s something here that requires a little more attention.”

Somewhat surprisingly, he also found that milk abstainers had shorter telomeres than adults who consumed low-fat milk.

Tucker said the study findings provide support for the current Dietary Guidelines for Americans (2015-2020), which encourage adults to consume low-fat milk, both nonfat and 1% milk, and not high-fat milk, as part of a healthy diet.

“It’s not a bad thing to drink milk,” Tucker said. “You should just be more aware of what type of milk you are drinking.”

Source: Brigham Young University

Scientists Develop Superbug-resistant, Self-cleaning Plastic Wrap

Amy Woodyatt wrote . . . . . . . . .

Researchers have developed a self-cleaning plastic wrap that repels bacteria — and could be used to prevent the transfer of antibiotic resistant superbugs, and other forms of dangerous bacteria.

A team of scientists from Canada’s McMaster University used a combination of nano-scale surface engineering and chemistry to develop a plastic surface — a treated form of transparent wrap — which repels all kinds of bacteria.

The coating, inspired by water-resistant lotus leaves, is textured with microscopic “wrinkles” that block out external molecules and are chemically treated, meaning that water, blood or bacteria bounce away when they come into contact with the surface.

The plastic covering can be shrink wrapped onto surfaces that are considered common breeding grounds for bacteria like MRSA — such as door handles, railings and IV stands.

“We developed the wrap to address the major threat that is posed by multi-drug resistant bacteria,” Leyla Soleymani, an engineering physicist who co-led the research, published Friday in the journal ACS Nano, told CNN.

“Given the limited treatment options for these bugs, it is key to reduce their spread from one person to another,” she added.

According to data from the US Centers for Disease Control and Prevention, more than 2.8 million antibiotic-resistant infections occur in the United States every year, and more than 35,000 people die as a result of these drug-resistant infections.

The researchers believe the new material could also be used to package food, and could stop the spread of bacteria such as E.coli, salmonella and listeria from raw meats and foods.

Some 20% of all drug-resistant infections come from the food we eat, according to the CDC.

“We’re structurally tuning that plastic,” Soleymani said in a statement. “This material gives us something that can be applied to all kinds of things,” she added.

The surface, the researchers say, is durable, flexible and inexpensive to make.

They tested the material using MRSA and Pseudomonas — considered the most dangerous forms of antibiotic-resistant bacteria — using electron microscope images to confirm that virtually no bacteria could transfer to the surface.

“We can see this technology being used in all kinds of institutional and domestic settings,” Tohid Didar, who co-led the research, said. “As the world confronts the crisis of anti-microbial resistance, we hope it will become an important part of the anti-bacterial toolbox,” he said.

Source: CNN