Tag: Research

Mind-body practices lower blood sugar levels in people with type 2 diabetes

Published September 30, 2022

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Mind-body practices lower blood sugar levels in people with type 2 diabetes

New research from the Keck School of Medicine of USC reveals mind-body practices are highly effective at reducing blood sugar levels in people with type 2 diabetes
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Mind-body practices such as yoga and meditation are increasingly popular tools for promoting health and combating diseases, including type 2 diabetes. Approximately 66% of Americans with type 2 diabetes use mind-body practices and many do so because they believe it helps control their blood sugar. Until now, however, whether mind-practices can reduce blood glucose levels has never been rigorously quantified.
According to new research conducted by a team from the Keck School of Medicine of USC, published recently in the Journal of Integrative and Complementary Medicine, some mind-body practices can be nearly as effective as commonly prescribed drugs at reducing blood glucose levels in people with type 2 diabetes.
“The most surprising finding was the magnitude of the benefit these practices provide,” said Fatimata Sanogo, a PhD student in the Department of Population and Public Health Sciences and lead author of the study. “We expected there to be a benefit, but never anticipated it would be this large.”
All practices achieve significant reductions in blood sugar levels
The team analyzed data from randomized controlled trials conducted across the globe between 1993 and 2022. They found 28 trials in which people with type 2 diabetes began a mind-body practice in addition to receiving medication and compared their results with people who only received medication to reduce their blood sugar levels.
This study, the first to analyze a range of mind-body practices including meditation, qigong, yoga and mindfulness-based stress reduction and their effect on blood glucose levels, revealed that all mind-body practices led to significant reductions in blood sugar levels.
Taken as a whole, the mind-body practices averaged a .84% reduction in hemoglobin A1c, a measure of the average blood glucose level for the past 3 months. Yoga, the most-studied modality, provided the largest benefit, about a 1% reduction in hemoglobin A1c. The authors noted that a 1% reduction is particularly notable because metformin, the most prescribed diabetes drug, reduces hemoglobin A1c in people with type 2 diabetes by 1.1% on average.
“What is important about this study is that the effect is very strong and that it is on top of the standard of care,” said Richard M. Watanabe, PhD, professor of population and public health sciences and physiology and neuroscience at the Keck School of Medicine, noting that the research revealed that mind-body practices helped participants achieve reductions in blood glucose levels on top of the reductions they were getting from medication.

A potential new tool for clinicians

The research suggests that mind-body practices could be used as a both as a complementary nonpharmacological treatment for people with type 2 diabetes and possibly as a preventive measure as well.
New effective methods for keeping type 2 diabetes under control are needed, since only about half of people with type 2 diabetes succeed at reducing their blood sugar levels to the target level of 7% hemoglobin A1c. At the same time, the number of Americans who are pre-diabetic has grown to about one-third in recent decades.
The studies came from different countries, further suggesting that mind-body practices could benefit people with type 2 diabetes worldwide.

“This could be an important tool for many people because type 2 diabetes is a major chronic health problem and we are not doing a good enough job at controlling it,” said Sanogo. “Although this study does not address it as a preventive measure, it does suggest it could help people who are pre-diabetic reduce their risk for future type 2 diabetes.”

About the study

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Exposure to air pollution worsens COVID-19 outcomes, even among the fully vaccinated

Published September 30, 2022

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COVID-19 is a respiratory illness, so it’s not surprising that exposure to poor air quality worsens patient outcomes. But how does air pollution affect people who are vaccinated?

To answer that question, a team of researchers analyzed data from more than 50,000 COVID-19 patients across Southern California. By comparing publicly available air quality monitoring data with deidentified patient medical records, they first established that regardless of air pollution exposure, vaccines go a long way in reducing COVID-19 hospitalizations.

“Fully vaccinated people had almost 90% reduced risk of COVID hospitalization, and even partially vaccinated people had about 50% less risk,” said Zhanghua Chen, PhD, assistant professor of population and public health sciences at the Keck School of Medicine of USC and co-first author of the study.

But air pollutants–in particular fine particles (PM2.5) and nitrogen dioxide (NO2)–are still harmful. Even among people who were vaccinated, exposure to those two pollutants over the short or long term increased the risk of hospitalization up to 30%.

“Among vaccinated people, the detrimental effect of air pollution exposure is a little smaller, compared to people who were not vaccinated,” Chen said. “But that difference is not statistically significant.”

The study was just published in the American Journal of Respiratory and Critical Care Medicine. The research builds on the team’s earlier findings, which helped establish the link between air pollution exposure and COVID-19 severity.

“These findings are important because they show that, while COVID-19 vaccines are successful at reducing the risk of hospitalization, people who are vaccinated and exposed to polluted air are still at increased risk for worse outcomes than vaccinated people not exposed to air pollution,” said corresponding author Anny Xiang, PhD, MS, a senior research scientist at Kaiser Permanente Southern California’s (KPSC) Department of Research & Evaluation.

Short-term and long-term exposures

The researchers analyzed medical records, which were deidentified to protect patient privacy, from KPSC patients. Across the health care network, 50,010 patients, ages 12 and up, were diagnosed with COVID-19 in July or August of 2021, when the Delta variant was circulating and many people had been vaccinated.

Then, the researchers calculated estimated air pollution exposure levels for each participant based on residential addresses. They looked at average PM2.5, NO2, and ozone (O3) levels during the one-month and one-year periods before each patient received a COVID-19 diagnosis.

“We investigated both long-term and short-term air pollution exposure, which may influence COVID-19 severity through different mechanisms,” said Chen.

Over the long term, pollution is linked to increases in cardiovascular and lung diseases, which are in turn linked to more severe COVID-19 symptoms. In the short term, air pollution exposure may worsen inflammation in the lungs and could even alter the immune response to the virus.

Chen, Xiang, and their colleagues found that among 30,912 people who were unvaccinated, high short-term PM2.5 exposure increased the risk of COVID-19 hospitalizations by 13%, while long-term exposure increased the risk by 24%. For NO2, short-term exposure raised hospitalization risk by 14% and long-term exposure raised the risk by 22%. The pollutant O3 was not significantly associated with COVID-19 hospitalizations.

For those who were partially or fully vaccinated, the hospitalization risks related to air pollution exposure were slightly lower–but the difference was not statistically significant.

Using data from medical records and neighborhood-level databases, the researchers were able to control for the effects of vaccination status, age, sex, race/ethnicity, health insurance status, body mass index, smoking history, health comorbidities, education level, income level and population density.

Improving indoor air quality

The findings suggest that in order to reduce severe cases of COVID-19, we need to improve air quality. This spring, the Biden Administration launched the Clean Air in Buildings Challenge, an effort to install high-efficiency particulate absorbing (HEPA) filters in schools and other public buildings.

Chen recently received funding to conduct clinical trials of HEPA filters to determine whether they reduce the risk of diabetes and cardiovascular disease. Her team will also continue their collaboration with KPSC to study the direct impacts of indoor air purifiers on COVID-19 patients.

About this study

In addition to Chen and Xiang, the study’s other authors are Brian Z. Huang and Frank D. Gilliland of the Department of Preventive Medicine, Keck School of Medicine of USC; Margo A. Sidell, Ting Chow and Mayra P. Martinez of the Department of Research & Evaluation, Kaiser Permanente Southern California; and Fred Lurmann of Sonoma Technology, Inc.

This work was supported by the National Institute of Environmental Health Sciences at the National Institutes of Health [3R01ES029963-01] and the Keck School of Medicine of USC’s Department of Preventive Medicine COVID-19 Pandemic Research Center (CPRC).

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Can school choice lead to segregation?

Published September 30, 2022

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New Study: Can School Choice Lead to Segregation?

Research by USC Marshall professor Kalinda Ukanwa suggests an unintended consequence of open school choice.
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Although school choice is often touted as a strategy to desegregate schools, a new study led by Assistant Professor of Marketing Kalinda Ukanwa shows it may in fact drive segregation.

The paper – co-authored with Aziza C. Jones of University of Wisconsin-Madison and Broderick L. Turner Jr., of Virginia Tech – was recently published in the Proceedings of the National Academy of Sciences (PNAS). It examines how parents’ preferences on factors such as school ratings and commute times influence the racial makeup of schools.

“We found that school choice increases racial segregation even when parents do not factor racial demographics into their choice because racial groups have different priorities when it comes to school characteristics,” said Ukanwa.

To determine the effect of school choice at scale, Ukanwa and her research partners modeled school choice as an open market. The authors presented more than 1,600 Black and White parents with a set of fictional school choices intended to uncover underlying market segment preferences for characteristics including a school’s performance rating, teachers’ experience, income, racial demographics, and commute time.

Impacts of unmitigated school choice
Even when the authors controlled for an “own-race preference,” the model found that the fictional schools presented became more segregated because White parents and Black parents had differing priorities when selecting their ideal school.

For example, the authors found that school performance ratings in particular signal a school’s potential to alter a child’s socioeconomic status. As such, Black parents were more willing to forgo other school attributes such as short commutes or teacher experience, for higher-rated schools. Meanwhile, White parents placed greater value on short commutes. Both groups, however, valued teacher experience.

The study shows that even if parents do not intentionally seek schools where students are of their race, unmitigated school choice among these market segments can increase segregation because these groups are seeking schools that have different attributes.

The study’s model revealed that for every 3% of households that exercise school choice, an additional 564,000 U.S. children would need to leave their schools to offset the racial divide.

Read the full study here.

Accounting for Parental Preferences
The study’s authors recommended that schools take the preferences of racial groups into consideration when marketing schools to help prevent increased segregation.

“If you simply expand school choice without first addressing some of these underlying differences in parents’ preferences, we’ll see increasingly segregated schools,” said Ukanwa. “But this can be mitigated by taking preferences into account. Schools aiming to increase integration could speak to unique preferences by marketing attributes such as convenience in getting to school, or the resources associated with performance such as advanced placement courses or pre-college programs.”

About the Study
The researchers first conducted a series of experiments where parents rated the attributes they consider most important in a school, with consideration for their race and other demographic information. They then created a computer model that ran a scenario of how such preferences would play out in a district that had seven schools with a combined 4,000 students. The model reflected residential segregation that currently exists in U.S. neighborhoods.

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How L.A.’s culinary roots lie in its Mexican tradition

Published September 30, 2022

Sarah Portnoy’s labs are scattered all over the city of Los Angeles and beyond. You can also find her at loncheras (food trucks) and in the back of the house at any number of Mexican restaurants.

Portnoy, a teaching professor of Spanish at the USC Dornsife College of Letters, Arts and Sciences, has traveled to Cuba, Spain and Mexico over the past quarter century, expanding her worldview of Latino culture and migration through a culinary lens.

As USC celebrates Latinx Heritage Month, LA Plaza de Cultura y Artes in downtown Los Angeles is featuring Portnoy’s curated exhibit, Abuelita’s Kitchen: Mexican Food Stories, which explores traditional recipes, kitchen artifacts and oral histories. Her documentary of the same name was screened Thursday at the USC Fisher Museum of Art. We talked with her about her work.

What’s the relationship between food and migration?

People have always migrated and crossed national borders. As they migrate, they take their traditional cuisine with them. Those dishes, like the culture itself, adapt and change in a new environment — in this case, the Mexican and Mexican American communities of Southern California.

Chefs and home cooks adapted their dishes to the ingredients available in the United States and to the American appetite for large plates of food with the creation of the “combo plate.” This evolution is part of the invention of a mass-produced version of Mexican food for the U.S. market, one that succeeded in establishing “Mexican” restaurants across the country.

Mexican cuisine is hardly the only one to have been transformed by other cultures. Transculturation — Fernando Ortiz’s term for the merging and converging of cultures — has historically taken place between colonizer and colonized. It is present in many cuisines. Italian dishes such as pizza and spaghetti with tomato sauce are inextricably linked to the tomato, yet tomatoes did not make their way from Mesoamerica to Europe until the 16th century.

How is the Latino population of Los Angeles different compared with populations elsewhere?

Unlike older, more established East Coast cities, L.A. was once part of Spain and later Mexico — it is a very Mexican city and increasingly a very Central American one, too. It is a city that the border crossed after Mexico lost the Mexican American War in the mid 19th century [and Mexico’s northern border moved south of L.A.], but it kept that Mexican feel — the streets in downtown once had names in Spanish. Not only is it a city defined by its Mexican and Latino history, but more recently its Korean, Japanese, Jewish and Chinese [cultures], and much more.

How does Los Angeles culture influence L.A. cuisine?

Well, first of all, its sheer proximity to Mexico and history of Mexican immigration — on a good day you can be in Tijuana in a few hours.

Trends can come from the bottom up. How often have you seen street tacos on the menu at a high-end restaurant for $25?.

Sarah Portnoy, Abuelita’s Kitchen

Secondly, it’s a young city — after the Transcontinental Railroad (1876-1900), it had only 100,000 residents. The city only exploded in population in the first few decades of the 20th century. So, unlike people in more established cities such as New York, Paris and London, among Angelenos there is a lack of culinary hierarchy. Angelenos are more open to new trends — and trends can come from the bottom up. How often have you seen street tacos on the menu at a high-end restaurant for $25? There are about 12,000 sidewalk vendors in L.A., and food trucks are part of the culture.

Diabetes is prevalent in the Latino community. How do you square that with a celebration of foods that are not always healthful? Can that be part of the conversation?

While Mexican American cuisine such as Tex-Mex and Cal-Mex can be considered unhealthful — often loaded with sour cream and cheddar cheese — Indigenous Mexican cuisine is based on ingredients grown together in the milpa farming system: beans, squash and corn. Corn is the main ingredient in all Mexican cuisine.

It is only with the Spanish conquest and the imposition of European culture that Mesoamerican cuisine adopted the use of animal products such as pork and beef and dairy. Traditional Mexican cuisine is incredibly healthful. Little dairy is used in most dishes, a vegetable soup is usually served at the beginning of every meal, and comida (lunch) is the main meal and includes soup, a main dish that almost always has vegetables, and tortillas.

In fact, diabetes and obesity only became an epidemic in Mexico in the past 25 years, largely as a result of globalization, as fast food and sodas became widely accessible and soda became cheaper to drink than water.

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Dad brain is real: Study reveals men’s brains change after baby arrives

Published September 29, 2022

Psychologist Darby Saxbe leads the Center for the Changing Family and a research effort to explore how parents change biologicially and neurobiologically in response to their babies — all at the USC Dornsife College of Letters, Arts and Sciences.

Saxbe, an associate professor, recently had a study published in the journal Cerebral Cortex and found evidence that men develop a sort of “dad brain” after their baby is born, somewhat like how mothers’ brains change in response to their newborns. She discussed why studying these changes in parents is important and what she hopes to tackle next.

Why are you studying these changes in the parents’ brains? What do you hope to understand?

Parenting is incredibly important for society and public health, but also understudied from a neurobiological perspective. We’re hoping our research can inform public policies like paid family leave and other initiatives that support new parents.

What is neuroplasticity and what does it usually signify? Why would it change when one becomes a parent?

We’re still learning about neuroplasticity, but there is evidence that the brain changes and grows when we develop a new skill, like learning a musical instrument, or during developmental windows like early childhood and adolescence. Becoming a parent entails changes to your lifestyle and your biology and requires new skills like being able to empathize with a nonverbal infant, so it makes sense — but has not been proven — that the brain would be particularly plastic during the transition to parenthood as well.

What is the “parental caregiving brain network”? Does this exist for mothers, too?

Yes — it does exist for mothers — this refers to areas of the brain that have been shown to be involved in parenting or caregiving (and pregnancy and lactation) in both human and animal studies.

The study shows that you found changes in the default mode network. What is this network and what do these changes mean for men who are new fathers? What does it mean for their partners?

The default mode network refers to the regions of the brain that “light up” when the brain is at rest (not doing a particularly cognitive task). These regions are thought to be involved in mentalizing about other people’s thoughts and feelings. The fact that we found changes in that part of the brain both for fathers and mothers suggests that there is some remodeling of the social brain taking place.

You note that these changes are occurring in the cortex. What is the cortex responsible for, particularly as it relates to parenting?

The cortex is the latest-evolving part of the brain that is involved in attention, planning, and executive functioning and is more unique to humans. The subcortical regions (below the cortex) are the more basic brain structures that you see in animals, involved in reward, threat, and salience detection. In moms we see both subcortical and cortical changes … in dads we just saw cortical changes. It’s too soon to speculate with such a small sample but it might suggest more higher-order processing involved in fatherhood specifically.

Noted in here, too, is that volumes in the men’s visual network decreased. Do you have any hypotheses on the reasons that would drive changes in the visual system?

We’re not sure, although it may be that visual cues are particularly important for orienting to offspring and understanding their needs, given that infants are non-verbal.

Based on your results, what do you want to explore next?

We plan to study individual differences in fathers’ brain changes that are associated with hormones and parenting.

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Next-generation liquid biopsy detects nano-sized signs of breast cancer in early-stage patients

Published September 28, 2022

A USC-led team of scientists has found indications that a special blood test called a liquid biopsy could determine whether a patient has breast cancer at its early stage and if that cancer is unlikely to return.

The high-definition comprehensive liquid biopsies are conducted using a standard blood draw from the arm of a patient in a doctor’s office. Once in the laboratory, the sample is examined for signs of cancer.

The study demonstrating the liquid biopsy results for early breast cancer detection was published on Sept. 27 in Nature’s npj Breast Cancer journal. The work was a collaboration between USC, Billings Clinic, Duke University, Epic Sciences and the USC Norris Comprehensive Cancer Center. The results raise hopes that one day doctors could detect breast cancer in patients with a simple blood draw.

The researchers at the USC Michelson Convergent Science Institute in Cancer (CSI-Cancer) are cautiously optimistic about their findings. They are eager to test and see whether the results will be proven in larger clinical trials to demonstrate the benefit of the method for patients everywhere.

It’s an amazing opportunity to change how early breast cancer detection is being done with a simple blood draw.

Peter Kuhn, USC’s CSI-Cancer

“It’s an amazing opportunity to change how early breast cancer detection is being done with a simple blood draw, but it’s only a research outcome at this point and we still need to demonstrate clinical benefit,” said Peter Kuhn, a USC cancer physicist who directs CSI-Cancer.

Breast cancer is the most prevalent form of cancer in the world, affecting 1 in 8 women over their lifetime.

Since 1976 when the American Cancer Society endorsed mammography X-rays, the technique — along with a tissue biopsy — has become the standard way for doctors to check patients for breast cancer.

Breast cancer detection: Mammography isn’t 100% accurate

But mammography is not 100% accurate and its detection can be impeded by healthy dense tissue. Mammography’s sensitivity to breast cancer is about 87%, according to the Breast Cancer Surveillance Consortium. And for some women, mammograms are not accessible, especially those living in poor isolated communities that have no clinics or hospitals. Other women simply do not get a regular mammogram.

But a tissue biopsy also is not a foolproof method. Although it can reveal information about the tumor, it has limitations. Doctors can sample only a small area and may fail to capture the full extent of the tumor. A tissue biopsy is also invasive and painful.

Combined, the drawbacks for diagnosis with mammograms and tissue biopsies mean some patients are not diagnosed until the cancer has grown and spread. New methodologies such as CSI-Cancer’s liquid biopsy can bring a complementary toolset into clinical practice.

For the study, Kuhn and his team worked with 100 breast cancer patients — some early and some late stage — and 40 patients without breast cancer from April 2013 through January 2017. The work was conducted at clinical sites including at the USC Norris cancer center at the Keck School of Medicine of USC; the Billings Clinic in Montana; the Duke University Cancer Institute in Durham, N.C.; and the City of Hope Comprehensive Cancer Center in Duarte.

The team tested a theory that the high-definition liquid biopsy could detect multiple cancer biomarkers, including the so-called “oncosomes” — nano-sized, membraned cargo carriers that enrich the body’s environment for cancer growth. These oncosomes are secreted by cancer cells as the group has shown previously.

“The news here is that we found the vast majority of early-stage breast cancer patients have these oncosomes at very robust levels,” said Kuhn, a Dean’s Professor at the USC Dornsife College of Letters, Arts and Sciences and cancer physicist. “They’re about 5-10 microns in diameter, about the size of a cell. We first identified these large vesicles in prostate cancer about a year-and-a-half ago and showed that they are related to the cancer. They are hiding in plain sight.”

A future diagnostic tool for breast cancer detection?

If further studies produce similar results, it could mean that the next generation high-definition liquid biopsy may become a diagnostic tool for early breast cancer detection and other cancers, he said. The test also could inform patients who have been treated for cancer that they will most likely remain cancer-free.

“Typically, I’m the bearer of bad news. I say, ‘You have cancer in your blood,'” Kuhn said. “But a test like this could give hope that if there is a sign of cancer, we can find it very early and improve treatment and survival.”

Kuhn’s co-authors included from USC: Sonia Maryam Setayesh, Olivia Hart, Amin Naghdloo and Nikki Higa, Anand Kolatkar, as well as Nicholas Matsumoto, Rafael Nevarez, James B. Hicks, Jeremy Mason, Stephanie N. Shishido at USC Michelson. Other researchers were Jorge Nieva and Janice Lu of the USC Norris Center at Keck Medicine of USC, Shelley Hwang of Duke University School of Medicine, Kathy Wilkinson and Michael Kidd of Billings Clinic, as well as Amanda Anderson of Epic Sciences in San Diego.

The study was funded by grants from Breast Cancer Research Foundation; USC Norris Comprehensive Cancer Center; the National Cancer Institute; National Institutes of Health; Kalayil and Leela Chacko, Fellowship; Winnie and James Hart Endowed Fellowship; USC Dornsife Student Opportunities for Academic Research Fellowship; Vassiliadis Research Fund; Vicky Joseph Research Fund; Hart Family Research Fund; The Hsieh Family Foundation; Sandy Borden Thielicke; Jennifer B. and Gregory A. Ezring; Rochika and Kenny Dewan; Andy Perlman; Neil and Anjini Desai; Mamak and Mahmood Razavi Research Fund; Susan Pekarovics; Anila P. Bhagavatula; Giorgio De Santis; Thuy Thanh Truong; Cheryl Faillace; Wayne R. Green Fund; Armstrong McDonald Foundation; Ms. Margaret Turney Hulter Funds; Suzanne B. Borden Fund; and Mr. and Mrs. Stanley A. Mayer Fund.

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Low-calorie sugar substitute consumption during adolescence appears to impair memory later in life

Published September 28, 2022

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Scientists using laboratory models find that eating FDA-approved levels of saccharin, ACE-K and stevia early in life may result in several changes to the body, including brain regions involved in memory and reward-motivated behavior.

By Darrin S. Joy – September 28, 2022

Diet soft drinks often use low-calorie sugar substitutes such as stevia and acesulfame potassium, or Ace-K. (Image Source: iStock.)
Diet soft drinks often use low-calorie sugar substitutes such as stevia and acesulfame potassium, or Ace-K. (Image Source: iStock.)
A high-sugar diet early in life has been shown to harm brain function, but what about low-calorie sugar substitutes? A new study reveals they may take a heavy toll on the developing brain and gut.

The News: In a study published Sept. 13 online in the journal JCI Insight, scientists at the USC Dornsife College of Letters, Arts and Sciences show that adolescent rats that consumed the low-calorie sweeteners saccharin, ACE-K and stevia exhibited long-term impairments in memory.

The findings align with those from earlier studies in which the researchers show that adolescent rats that consume sugar suffer lingering memory impairment.
Consuming low-calorie sweeteners also affected metabolic signaling in the body, which can lead to diabetes and other metabolism-related diseases.
Rats that consumed low-calorie sweeteners as adolescents were less willing to work for sugar as adults, but they consumed more sugar if it was freely available, another factor that might affect the likelihood of developing metabolic disease.
Why It Matters: Advice on what to eat and when to eat it varies widely. Findings from studies like this can help consumers and clinicians make healthier choices throughout the lifespan, say the researchers.

“While our findings do not necessarily indicate that someone should not consume low-calorie sweeteners in general, they do highlight that habitual low-calorie sweetener consumption during early life may have unintended, long-lasting impacts,” said Scott Kanoski, associate professor of biological sciences at USC Dornsife.

What It Means for Humans: While most studies of low-calorie sweeteners focus on one substance and use amounts far exceeding the norm, the researchers made sure the study was in line with real-life conditions for people.

Sweeteners tested include saccharin, acesulfame potassium (ACE-K) and stevia — which are commonly used in sweetened foods.
The amount of sweetener consumed fell within FDA-approved guidelines for humans.
In Their Words:

“Research using rodent models and low-calorie sweeteners has typically involved consumption levels that far exceed the FDA ‘acceptable daily intake’ (ADI) levels and used only a single sweetener. To design our research to be more applicable to humans, we kept consumption levels within the ADI and used multiple low-calorie sweeteners to determine if effects were specific to a given sweetener or general across sweeteners.”

— Lindsey Schier, Gabilan Assistant Professor of Biological Sciences at USC Dornsife

The Experiment: To determine the effect of low-calorie sweetener consumption on memory, the researchers used methods that test object recognition and spatial recognition.

Rats were provided water sweetened with either stevia, ACE-K or saccharin or plain water, along with their normal food.
After a month, the rats’ memory was tested using two different methods — one tests if they remember an object they’ve seen before and the other is a maze.
In the end, rats consuming sweetener were less likely to remember an object or the path through the maze than those that drank only plain water.

What Else?

The scientists also found other effects among the rats after they consumed sweeteners.

They had fewer receptors on their tongues that detect sweet taste.
The biological mechanism in their intestines that transports glucose into the blood was altered.
Their brains had changed, specifically in regions associated with memory control and reward-motivated behavior.
What’s Next?

Kanoski and Schier say the findings reveal more questions worth exploring, including:

How do sweetener substitutes cause a reduction in sweet taste receptors and how does that affect later dietary behavior?
What does the change in the nutrient transport in the gut mean for health?
What biological mechanisms link sweetener consumption with the changes to the brain?
The researchers say they intend to explore ways to reverse the long-lasting effects of adolescent low-calorie sweetener consumption and to study how it influences food choices and preferences later in life.

About the Study

In addition to Schier and Kanoski, authors on the study include Linda Tsan, Sandrine Chometton, Anna Hayes, Molly Klug, Lana Bridi and Rae Lan of USC Dornsife; Yanning Zuo and Xia Yang of UCLA; Shan Sun and Anthony Fodor of the University of North Carolina at Charlotte; and Emily Noble of the University of Georgia.

The study was supported by National Institute of Diabetes and Digestive and Kidney Diseases grants DK123423 and DK104363; the National Institute on Deafness and Other Communication Disorders grant R01 DC018562; and National Science Foundation Graduate Research Fellowship DGE-1842487.

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Fasting-mimicking diet reduces signs of dementia in mice

Published September 27, 2022

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Fasting-Mimicking Diet Reduces Signs of Dementia in Mice

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Fasting-Mimicking Diet Reduces Signs of Dementia in Mice

Short cycles of a low-calorie diet that replicates fasting appeared to reduce inflammation and delay cognitive decline in mouse models of Alzheimer’s disease; initial data indicates diet’s safety in Alzheimer’s patients.
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Cycles of a diet that mimics fasting appear to reduce signs of Alzheimer’s in mice genetically engineered to develop the illness, according to a new USC Leonard Davis School of Gerontology-led study.

The study appeared in Cell Reports on Sept. 27.

The researchers, led by Professor Valter Longo in collaboration with Professors Christian Pike and Pinchas Cohen, found that mice that had undergone several cycles of the fasting-mimicking diet showed less Alzheimer’s pathology. The researchers found lower levels of two major hallmarks of the disease: amyloid beta – the primary driver of plaque buildup in the brain – and hyperphosphorylated tau protein, which forms tangles in the brain. They also found that brain inflammation lessened and better performance on cognitive tests compared to the mice that were fed a standard diet.

The fasting-mimicking diet (FMD) is high in unsaturated fats and low in overall calories, protein, and carbohydrates and is designed to mimic the effects of a water-only fast while still providing necessary nutrients. Previous research led by Longo has indicated that brief, periodic FMD cycles are associated with a range of beneficial effects, including the promotion of stem cell regeneration, lessening of chemotherapy side effects, and lowering risk factors for cancer, diabetes, heart disease and other age-related diseases in mice and humans.

Promising results in mouse models of Alzheimer’s
Alongside healthy mice, the team investigated two mouse models of Alzheimer’s, E4FAD and 3xTg. During the study, mice were fed the fasting-mimicking diet for 4 or 5 days twice per month and were allowed to eat normally between FMD cycles. In a long-term experiment to see the effects in aged mice, 3xTg mice were placed on the diet for 30 cycles in 15 months. Shorter-term experiments in both 3xTg and E4FAD mice ranged from a single FMD cycle to 12 cycles in 6 months.

In both models, mice who underwent FMD cycles showed promising reductions in amyloid beta – which form the sticky, disruptive plaques in the brain – and tau pathology compared to mice eating a standard diet. The FMD mice also showed lower levels of brain inflammation, including a reduction in the number of active microglia, the immune cells that seek and destroy pathogens and damaged cells in the brain. In addition, mice on the diet demonstrated a lower level of oxidative stress, which plays a role in Alzheimer’s pathology by damaging neurons and contributing to the accumulation of amyloid in the brain. The study specifically pointed to the free radical “superoxide” as a central culprit in the damage occurring in these Alzheimer’s mouse models, Longo explained.

Outwardly, mice of both Alzheimer’s models who underwent the FMD showed less cognitive decline than their standard diet counterparts. Cognitive behavior, including exploration and performance within mazes, was tested in young mice before the dietary regimen began and again after several months of either a standard diet or twice-monthly FMD cycles. The Alzheimer’s mice given the FMD significantly outperformed the Alzheimer’s mice given standard diets and in some instances performed similarly to the non-Alzheimer’s-prone control mice, indicating that cognitive decline had been significantly slowed.

The FMD cycles appeared effective in reversing a range of pathology markers but also cognitive defects in two of the major mouse models for Alzheimer’s disease. Longo said that the results are promising.

Small clinical study explores feasibility for humans
In addition to the study in mice, Longo and colleagues also included data from a small Phase 1 clinical trial of the fasting-mimicking diet in human patients diagnosed with mild cognitive impairment or mild Alzheimer’s disease. Forty such patients who were otherwise healthy and had family support were randomized to either a once-monthly, 5-day fasting-mimicking diet or a 5-day period in which lunch or dinner was replaced with a meal based on pasta or rice.

Initial data indicates that the FMD is safe and feasible for patients with mild impairment or early Alzheimer’s disease. Further tests in the ongoing clinical trial will measure cognitive performance, inflammation and more, Longo said.

Other early trials of the diet published by Longo and colleagues have indicated other benefits of a monthly cycle, such as a loss of fat mass without loss of muscle mass and improved cardiometabolic risk factors, especially in overweight or obese people.

Notably, in a recently published clinical trial in which Longo was a co-author, FMD cycles were associated with disease regression in diabetes patients. Diabetes nearly doubles the risk of developing Alzheimer’s disease, per the Alzheimer’s Association.

Other authors included co-first authors Priya Rangan, Fleur Lobo and Edoardo Parrella of USC; Terri-Leigh Stephen, Christian J. Pike, Pinchas Cohen, Kyle Xia, Katelynn Tran, Brandon Ann, and Dolly Chowdhury of USC; Anna Laura Cremonini, Luca Tagliafico, Angelica Persia, Irene Caffa, Fiammetta Monacelli, Patrizio Odetti, Tommaso Bonfiglio, and Alessio Nencioni of the University of Genoa, Italy; Nicolas Rochette, Marco Morselli, and Matteo Pellegrini of UCLA; Mary Jo LaDu of the University of Illinois at Chicago; and Martina Pigliautile, Virginia Boccardi, and Patrizia Mecocci of the University of Perugia, Italy.

The study was funded in part by National Institutes of Health/National Institute on Aging grants AG20642, AG025135, and P01 AG034906 to Longo; AG058068 to Pike; the NIA T32 training grant AG052374 to Rangan; and the PE-2016-02362694 and PE-2016-02363073 grants by the Italian Ministry of Health to Odetti, Mecocci, Monacelli, and Longo. The LaDu lab is funded by NIH (NIA) R01 AG056472, R01 AG057008, UH2/3 NS10012, R56 AG058655, 1R44 AG060826, institutional funds from the College of Medicine at the University of Illinois, Chicago, and generous philanthropic contributions.

Longo is the founder of and has an ownership interest in L-Nutra; the company’s food products are used in studies of the fasting-mimicking diet. Longo’s interest in L-Nutra was disclosed and managed per USC’s conflict-of-interest policies. USC has an ownership interest in L-Nutra and the potential to receive royalty payments from L-Nutra. USC’s financial interest in the company has been disclosed and managed under USC’s institutional conflict-of-interest policies.

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Disadvantaged workers face more challenges in retirement, too

Published September 27, 2022

REDIRECT 7902 Christian Hetrick
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Study: Disadvantaged workers face more challenges come retirement
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As Healthy Aging Month comes to a close, research from Price School associate professor Emma Aguila documents the varied work pathways of America’s increasingly diverse older workforce.

Highlights:

? Workers with limited job opportunities face more obstacles in retirement – perpetuating inequities among demographic groups
? Various disparities, along with other inequities such as health and education, perpetuate income inequality come retirement
? Employer-sponsored pension plans cover about two-thirds of white workers, but just over one-third of Latino workers

American workers with limited job opportunities during their working years face obstacles in retirement too, perpetuating inequities among demographic groups. That’s according to research conducted by Emma Aguila, a USC Price School associate professor and expert on the economics of aging.

Aguila’s research, which was reported in a recent study for the National Academy of Sciences, Engineering and Medicine, sheds light on some of the challenges many older Americans face in planning for retirement or seeking to work longer into their lives.

As Healthy Aging Month comes to a close, the study documents the varied work pathways of America’s increasingly diverse older workforce. Disadvantaged older workers are more likely to be forced into involuntary retirement due to job loss or disability, for example. They may take on informal gigs that don’t contribute to the Social Security system, such as nannying. Hispanic and Black Americans in mid-skilled jobs have been particularly affected by automation, as well.

Additionally, historically disadvantaged groups are less likely to have control over where, when and how much they work at older ages.

Despite the growing diversity of the aging workforce, much of the existing research on older workers has focused on the experiences of economically and socially advantaged groups, the study concluded.

“I think we’ve been analyzing the population as if they all behave the same, like they all have full-time jobs and they follow this career path and then they retire,” Aguila said. “But I think what we really need to consider is the heterogeneity across the population.”

Take pensions, for example. Employer-sponsored plans covered about two-thirds (64.6%) of non-Hispanic white workers, 55.7% of Black workers, and just over one-third (38.4%) of Hispanic workers, Aguila reported.

Occupational segregation

Those differences can be explained in large part by occupational segregation. Whites are more likely to work at larger firms that provide pensions, while Blacks are more likely employed in the public sector, which often offers pensions, too. Hispanics, by contrast, are more likely to work at smaller firms or part time – jobs that are less likely to include employer-sponsored retirement plans.

Disparities like this, along with other inequities such as health and education, further perpetuate income inequality come retirement. “The more advantaged workers, they not only have Social Security, but they will have other sources of income” like savings or pensions, Aguila noted. “So the inequality continues.”

The National Academy tapped Aguila to analyze existing data and research on vulnerable older workers, as part of a broader report published in May examining the aging American workforce. She reported that there is not enough literature on the experience of these populations, limiting insight into how inequality in retirement and work opportunities affects older adults.

Aguila recommended that future research take a “life course perspective” on inequity in work and retirement. Gathering such data would require following people over time to better understand inequalities in later adulthood. Doing so is necessary because the causes of unequal work and retirement pathways begin long before age 50, she explained.

Pandemic effect
Aguila conducted her research just as the COVID-19 pandemic swept the country, putting older adults at heightened risk of serious illness or death, while prompting employers to lay off workers or send them home to work remotely. In many ways, the pandemic and the ensuing turmoil in the job market underscore the issues Aguila studied.

Still, she said it’s too early to know whether the pandemic exacerbated the problems she highlighted in her study.

“More research will come out,” Aguila said of the pandemic’s impact on older workers. “We will be able to understand better whether these issues were exacerbated.”

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Women still less likely to be hired, promoted, mentored or even have their research cited

Published September 26, 2022

REDIRECT https://viterbischool.usc.edu/news/2022/09/breaking-the-glass-ceiling-in-science-by-looking-at-citations/

Breaking the Glass Ceiling in Science by Looking at Citations
Julia Cohen | September 26, 2022
USC’s Information Sciences Institute researchers used artificial intelligence to study gender disparities in science.

 

PHOTO CREDIT: SVETAZI / ISTOCK

It’s 2022 and women in science are still less likely than their male peers to be hired and promoted. Women are less likely to be mentored by eminent faculty, they publish in less prestigious journals, have fewer collaborators, are underrepresented among journal reviewers and editors, and their papers receive fewer citations.

How. Is this. Happening?!

USC’s Information Sciences Institute (ISI) Principal Scientist Kristina Lerman and her team used AI to look for answers to this question. The resulting paper has been published in the prestigious, peer-reviewed, multi-disciplinary science journal Proceedings of the National Academy of Sciences (PNAS) on September 26, 2022.

As a woman in science herself, Lerman knows the world she works in, but even she was shocked by statistics she recently learned: only two percent of Nobel Prize winners in physics have been women (until a few years ago that was one percent) and those numbers are similar across many scientific fields. Lerman said, “only seven percent of Nobel Prize winners in chemistry have been women! Women have been working in chemistry for such a long time, so how is that? We were curious about this discrepancy.”

Right Data, Right Time

Lerman had the right dataset for the problem. Since 2019, she and her team had been working on a large project that used AI to predict the reproducibility of research papers. Funded by DARPA (the Defense Advanced Research Projects Agency), the ISI team used AI to analyze many aspects of scientific papers, including the citations, to predict reproducibility. They published the paper “Assessing Scientific Research Papers with Knowledge Graphs” at ACM SIGIR 22 (the Association for Computing Machinery’s Special Interest Group on Information Retrieval) in July 2022, describing their novel method and promising findings.

To do this reproducibility research, Lerman’s team gathered a huge amount of data on academic papers. Her co-author Jay Pujara, director of the Center on Knowledge Graphs at ISI said, “We collected this very large citation graph – the network of papers, authors, citations, references, collaborations, author institutions, where they publish, etc.” They turned this data into a vast knowledge graph (a “knowledge graph” is a representation of a network of real-world entities that illustrates the relationships between them).

The team looked at the shapes or “structures” that arose in the knowledge graph. They wondered if there was some kind of natural phenomenon causing the different structures in the citation networks. Additionally, they wanted to make sure that the data used in their reproducibility predictions was not being impacted by biases in the data. Pujara said, “Kristina [Lerman] had the idea to look at covariates like gender or prestige.” And with that idea, the team of researchers set out to see if there was a difference in a network based on whether the author was a man or a woman, as well as if they were at a top ranked university or a lower ranked university.

The Who, What and Why of Citations

Before we go any further, a little info on how citation in scientific research works. There are typically three reasons an author might cite another author’s paper. First, as background – in order to understand their paper, an author will cite other papers that give the background information needed. Second, to explain a method – if an author used a method that’s similar, a version of, or comparable to a method from another paper they will cite the paper that explains that method. And third, results – an author will explain their results, but might cite other papers that studied that same thing but got different results.

Gleaning Information from Citations

“Trying to study the citation network for every researcher out there is really hard, so why don’t we pick the cream of the crop?” said Pujara. The team looked at scientists elected to the US National Academy of Sciences (NAS), one of the oldest and most prominent professional science organizations. New members of NAS are elected by current members based on a distinguished record of scientific achievement meaning, in theory, they’ve all reached the same echelon of recognition. The ISI team looked at 766 NAS researchers, 120 of whom were women, hypothesizing that complex gender differences would be visible within this group of elite scientists.

Their hypothesis proved correct.

They constructed citation networks that captured the structure of peer recognition for each NAS member. These structures differed significantly between male and female NAS members. Women’s networks were much more tightly clustered, indicating that a female scientist must be more socially embedded and have a stronger support network than her male counterparts. The differences were systemic enough to allow the gender of the member to be accurately classified based on their citation network alone.

Lerman said, “We could write an AI algorithm that would just look at the citation networks and predict whether this was the citation network of a woman or a man. This was pretty shocking and disappointing to us.”

As a control study, the team also looked at the covariate of prestige. NAS members affiliated with less prestigious institutions are a minority in NAS, similar to women. Lerman said, “we would have imagined that maybe women’s citation networks would look like those of members from non-prestigious universities.” But that was not the case. They did not observe any disparities due to the prestige of a member’s institutional affiliation.

Conclusion: based on a scientist’s citation network alone, gender can accurately be determined, but the prestige of the university that scientist is affiliated with cannot. This suggests that gender continues to influence career success in science, according to the ISI team.

How to Stop Being So Short-Cited

Why is this happening? Pujara said, “We don’t know. It could be because there’s some aspect of gender that changes collaborative behavior. Or it might be something about society that shapes researchers and their paths based on social biases. So we don’t actually know the answer to that. What we know is that there’s a difference.”

The real question is: how can we change it? How can we make science a less hostile climate for women, remove the barriers to opportunities for women, and create an environment that allows women to rise to the top of their fields?

The ISI team hopes that, moving forward, their methods and results can help. To start, this study could be used to help researchers understand what their networks look like. Additionally, it could be used as a way for policymakers to understand if programs aiming to improve gender equity in science are working.

Finally, and importantly, we can learn from those differences in the citation structures between men and women. “For a woman to be recognized, she has to be well-embedded and have a strong support network,” Lerman said. “Mentoring young women and telling them they really have to build those networks of social support, and be very intentional about them” seems to be one way to change the shape of these structures… and the shape of science.

This work was supported, in part, by the Defense Advanced Research Projects Agency (contract W911NF192027) and the Air Force Office of Scientific Research (contract FA9550-17-1-0327).

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