Milk’s packaging influences its flavor

New research in the Journal of Dairy Science® demonstrates that paperboard cartons—which are widely used in school meal programs—do not preserve milk freshness as well as other containers

Peer-Reviewed Publication

ELSEVIER

Philadelphia, January 26, 2023 – The dairy industry strives to preserve the quality and safety of milk products while maintaining the freshest possible taste for consumers. To date, the industry has largely focused on packaging milk in light-blocking containers to preserve freshness, but little has been understood about how the packaging itself influences milk flavor. However, a new study in the Journal of Dairy Science®, published by Elsevier, confirms that packaging affects taste—and paperboard cartons do not preserve milk freshness as well as glass and plastic containers.

Lead investigator MaryAnne Drake, PhD, of the North Carolina State University Department of Food, Bioprocessing and Nutrition Sciences, Raleigh, NC, USA, explained that “milk is more susceptible to packaging-related off-flavors than many other beverages because of its mild, delicate taste.” Besides light oxidation, “milk’s taste can be impacted by the exchange of the packaging’s compounds into the milk and by the packaging absorbing food flavors and aromas from the surrounding refrigeration environment.”

To quantify the flavor impacts of packaging, the researchers examined pasteurized whole and skim milk stored in six half pint containers: paperboard cartons, three plastic jugs (made from different plastics), a plastic bag, and glass as a control. The milk was stored in total darkness to control for light oxidation and kept cold at 4°C (39°F).

The samples were tested on the day of first processing, then again at 5, 10, and 15 days after. A trained panel examined the sensory properties of each sample, and the research team conducted a volatile compound analysis to understand how the packaging was intermingling with the milk. Finally, the samples underwent a blind consumer taste test on day 10 to see whether tasters could tell any difference between milk stored in the paperboard carton or the plastic jug compared with milk packaged in glass.

The results showed that package type does influence milk flavor, and skim milk is more susceptible to flavor impacts than whole milk. Of the different packaging types, paperboard cartons and the plastic bag preserved milk freshness the least due to the paperboard’s absorption of milk flavor and the transfer of paperboard flavor into the milk. Milk packaged in paperboard cartons, in fact, showed distinct off-flavors as well as the presence of compounds from the paperboard. The final results show that, while glass remains an ideal container for preserving milk flavor, plastic containers provide additional benefits while also maintaining freshness in the absence of light exposure.

Paperboard cartons are the most widely used packaging type for school meal programs in the United States, so these findings are especially relevant for the consideration of how young children consume and enjoy milk.

“These findings suggest that industry and policymakers might want to consider seeking new package alternatives for milk served during school meals,” said Drake. Over time, the consequences of using milk packaging that contributes significant off-flavors may affect how young children perceive milk in both childhood and adulthood.

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JOURNAL

Journal of Dairy Science

DOI

10.3168/jds.2022-22060 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

The role of packaging on the flavor of fluid milk

FRONT PAGE NEWS ABOVE THE FOLD

Legalizing recreational cannabis does not increase substance abuse, may reduce alcohol-related disorders

A study of 4,000 twins found no relationship between legalization and a wide range of psychological and social problems

Peer-Reviewed Publication

UNIVERSITY OF COLORADO AT BOULDER

Legalizing recreational cannabis at the state level does not increase substance use disorders or use of other illicit drugs among adults and, in fact, may reduce alcohol-related problems, according to new CU Boulder research.

The study of more than 4,000 twins from Colorado and Minnesota also found no link between cannabis legalization and increases in cognitive, psychological, social, relationship or financial problems.

“We really didn’t find any support for a lot of the harms people worry about with legalization,” said lead author Stephanie Zellers, who began the research as a graduate student at CU Boulder’s Institute for Behavioral Genetics (IBG). “From a public health perspective, these results are reassuring.”

For the study, published Jan. 5 in the journal Psychological Medicine, researchers at the University of Minnesota, CU Boulder and the CU Anschutz Medical Campus tapped data from two of the nation’s largest and longest-running twin studies: one housed at IBG and the other at the Minnesota Center for Twin Family Research.

Researchers have followed participants, now aged 24 to 49, since adolescence, collecting data on use of alcohol, tobacco, cannabis (aka “marijuana”), and several illicit drugs, as well as measures of “psychosocial health.”

In 2014, Colorado became one of the first two states in the U.S. to commence legal sales of recreational marijuana. In Minnesota, recreational use of cannabis remains illegal. 

The power of twin studies

By comparing the 40% of twins who live in recreationally legal states to those who live in states where it is still illegal, the researchers set out to get a general sense of the impact of legalization.

In addition, by specifically comparing twin to twin in 240 pairs in which one lives in a state that has legalized and the other in a state that has not, researchers sought to determine what changes, if any, cannabis legalization causes.

“This co-twin design automatically controls for a wide range of variables, including age, social background, early home life and even genetic inheritance” that can influence health outcomes, said John Hewitt, professor of psychology and neuroscience at CU Boulder. “If the association holds up, it provides strong evidence that the environment, in this case legalization, is having an impact.”

In a previous study, the group found that identical twins living in states where cannabis is legal used it about 20% more frequently than their twin in states where it’s illegal.

The logical next question: Does more use mean more problems?

To find out, the team compared survey results looking at 23 measures of "psychosocial distress," including use of alcohol and illicit drugs such as cocaine and heroin, psychotic behavior, financial distress, cognitive problems, unemployment, and relationships at work and at home.

“We included everything we had data on with the goal of getting a well-rounded look at the impacts on the whole person,” said Zellers. “Big picture, there’s not much there.”

Surprisingly, they found no relationship between legalizing cannabis and heightened risk of cannabis use disorder, or cannabis addiction. 

While many critics of legalization have expressed concern that cannabis could serve as a “gateway drug” to other more harmful substances, the researchers found no changes in illicit drug use after legalization.

“For low-level cannabis use, which was the majority of users, in adults, legalization does not appear to increase the risk of substance use disorders,” said co-author Dr. Christian Hopfer, a medical doctor and professor of psychiatry at IBG and CU Anschutz who studies substance abuse disorders.

Twins in states where cannabis is legal did show fewer symptoms of alcohol use disorder: Specifically, they were less likely to engage in risky behavior after drinking, such as driving while intoxicated.

‘No drug is risk-free’

The authors caution that the study did not look at impacts on adolescents and did not look closely at the kinds and dosages of cannabis people were using.

“Our study suggests that we should not be overly concerned about everyday adult use in a legalized environment, but no drug is risk-free,” said Hewitt. “It would be a mistake to dismiss the risks from higher doses of a drug that is relatively safe in small amounts.”

The study found no evidence that legalizing cannabis benefits psychosocial health, either.

Today, 21 states have legalized recreational cannabis. Half the U.S. population lives in a place where it is legal, and several more—including Minnesota—are considering legalization.

Zellers, who recently earned a doctorate from the University of Minnesota, hopes the paper, and more to come, will help inform policy conversations about legalization.

“I would love for us to get past this question of, ‘Is legalization good or bad?’ and move toward more specific questions like, ‘Who is most at risk? Who can benefit the most? And how?’ So that people can make informed choices,” Zellers said. 

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JOURNAL

Psychological Medicine

DOI

10.1017/S0033291722003762 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Recreational cannabis legalization has had limited effects on a wide range of adult psychiatric and psychosocial outcomes

Outlook for the blue economy

Climate modelers add ocean biogeochemistry and fisheries to forecasts of future upwelling using TACC's Frontera supercomputer

Peer-Reviewed Publication

UNIVERSITY OF TEXAS AT AUSTIN, TEXAS ADVANCED COMPUTING CENTER

 

IMAGE: PROJECTED CHANGE (DEFINED AS THE MEAN OVER THE FUTURE PERIOD OF 2071–2100 MINUS THE MEAN OVER THE HISTORICAL PERIOD OF 1991–2020) OF ALONGSHORE WIND STRESS (×10−2 N M−2) SHOWN IN LONGITUDE-LATITUDE PLANE (UPPER) FOR CCS (A), CUS (B), P-CUS (C, D), BUS (E), AND PROJECTED CHANGE OF WIND STRESS CURL (×10−7 N M−3) (MIDDLE) FOR CCS (F), CUS (G), P-CUS (H, I), BUS(J). view more 

CREDIT: CREDIT: CHANG, P., XU, G., KURIAN, J. ET AL.

A handful of hyper-productive fisheries provide sustenance to a billion people and employ tens of millions. These fisheries occur on the eastern edges of the world's oceans — off the West Coast of the U.S., the Canary Islands, Peru, Chile, and Benguela. There, a process called upwelling brings cold water and nutrients to the surface, which in turn supports large numbers of larger sea creatures that humans depend on for sustenance.

A new project led by researchers at Texas A&M University is seeking to understand how changes to the climate and oceans will impact fisheries in the U.S. and around the world.

"We're interested in how climate change is going to alter upwelling and how the sustainability of the future fisheries will be impacted," said Ping Chang, Louis & Elizabeth Scherck Chair in Oceanography at Texas A&M University (TAMU). "It turns out that when we increase the resolution of our climate models, we find that the upwelling simulation becomes much closer to reality."

Funded by the National Science Foundation (NSF), the project aims to develop medium to long-term fishery forecasts, driven by some of the highest-resolution coupled climate forecasts ever run. It is one of the 16 Convergence Accelerator Phase 1 projects that address the ‘Blue Economy' — the sustainable use of ocean resources for economic growth. Convergence projects integrate scholars from different science disciplines.

The TAMU team, led by oceanographer Piers Chapman, includes computational climate modelers, marine biogeochemical modelers, fishery modelers, decision support system experts, and risk communications scholars from academia, federal agencies, and industry.

Chang and Gokhan Danabasoglu at the National Center for Atmospheric Research (NCAR) lead the climate modeling component of the research. They use the Frontera supercomputer at the Texas Advanced Computing Center (TACC) — the fastest academic supercomputer in the U.S. — to power their research.

In the 1990s, marine biologist Andrew Bakun proposed that a warming climate would increase upwelling in the eastern boundary regions. He reasoned that since land is warming faster than the oceans, the temperature gradient between land and ocean would drive a stronger wind, which makes upwelling stronger. However, recent historical data suggests the opposite might in fact be the norm.

"A lot of papers written in the past use coarse resolution models that don't resolve upwelling very well," Chang said. "High resolution models so far predict upwelling in most areas, not increasing. The models are predicting warmer, not colder temperatures in these waters. In Chile and Peru, the warming is quite significant — 2-3ºC warming in the worst case scenario, which is business as usual. That can be bad news for upwelling."

The areas where upwelling occur are quite narrow and localized, but their impact on the marine ecosystem is very large. The eastern Pacific upwelling, for instance, is only about 100 kilometers wide. The climate models used by the Intergovernmental Panel on Climate Change (IPCC) have a resolution of 100 kilometers — and would therefore only produce one data point for the upwelling region, not nearly enough to predict future changes accurately.

On the other hand, the model used by Chang and his colleagues uses a resolution of 10 kilometers in each direction. These are 100 times more resolved than the IPCC models — and require roughly 100 times the compute power.

Chang's study relies on two separate, but related, sets of simulations. The first set involves an ensemble (the same model run with a slightly different starting point to produce a statistically valid result) of high-resolution coupled Earth system models. The second incorporates observed data in the atmosphere to generate realistic ocean states that are then used to initialize the model prediction. Starting from 1982, it will perform five-year retrospective forecasts to determine the skill of the model in forecasting upwelling effects.

"There's a limit to how far out you can make a forecast," Chang said. "Beyond a certain time limit, the model no longer has skill. At five years, our model still shows useful skill."

The team reported their results in Nature's Communications Earth & Environment in January 2023.

The Blue Economy project continues the TAMU-NCAR team's multi-decade effort to upgrade global climate models so they are higher resolution and more physically accurate. The model used by the team was one of a handful of high-resolution Earth system models that were included in the most recent IPCC report and are being explored by an IPCC subcommittee. They represent the future of global climate modeling.

At 10 kilometer resolution, researchers believe it is possible for models to realistically generate extreme weather events like tropical cyclones or atmospheric rivers, as well as more refined predictions of how climate in a specific region will change. However, models at this resolution still cannot resolve clouds, which requires models with a few kilometer resolution and can currently only be integrated for short-term, not climate, timescales.

The effort to capture the Earth system continues to improve.

The TAMU-NCAR project will be one of the first to incorporate biogeochemical models of the ocean and fisheries models into Earth system models at 10 km resolution.

"TACC is unique in providing resources for researchers like us to tackle the fundamental questions of science," Chang said. "Our goal is not routine forecasts. What we want is a better understanding of the Earth system dynamics that are missing in current climate models to make our model and our methods better. Without Frontera, I don't know if we could make simulations like we do. It's critical."

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JOURNAL

Nature

DOI

10.1038/s43247-023-00681-0 

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Uncertain future of sustainable fisheries environment in eastern boundary upwelling zones under climate change

ARTICLE PUBLICATION DATE

23-Jan-2023

Ping Chang, Louis & Elizabeth Scherck Chair in Oceanography, Texas A&M University

CREDIT  TAMU

Frontera, the fastest academic supercomputer in the U.S.

CREDIT   Texas Advanced Computing Center (TACC)

Transcendental Meditation (TM) effective in reducing burnout and depression symptoms in physicians

Peer-Reviewed Publication

MAHARISHI INTERNATIONAL UNIVERSITY

 

IMAGE: THIS FIGURE SHOWS THE WITHIN-GROUP EFFECT SIZES (MEAN CHANGE DIVIDED BY POOLED STANDARD DEVIATION) FOR THE TRANSCENDENTAL MEDITATION GROUP AND THE TREATMENT-AS-USUAL CONTROL GROUP ON BURNOUT, AS MEASURED BY THE MASLACH BURNOUT INVENTORY, AND DEPRESSION SYMPTOMS, AS MEASURED BY THE BECK DEPRESSION INVENTORY-2. BETWEEN-GROUP STATISTICS COMPARING TM TO THE CONTROL GROUP YIELDED SIGNIFICANT DIFFERENCES BETWEEN GROUPS ON BOTH BURNOUT AND DEPRESSION SYMPTOMS (P VALUES <.02). view more 

CREDIT: MAHARISHI INTERNATIONAL UNIVERSITY RESEARCH INSTITUTE

According to a randomized controlled study, published in Journal of Continuing Education in the Health Professions, physicians who practiced the Transcendental Meditation (TM) technique showed significant reductions in both burnout and depression symptoms. Research conducted at Stritch School of Medicine, Loyola University Chicago found that practice of Transcendental Meditation produced large effect sizes in decreasing burnout and depression symptoms in academic physicians; controls exhibited smaller effect sizes. The research was done pre-covid.

Marie Loiselle, PhD, lead author and senior researcher at the Center for Social-Emotional Health at Maharishi International University, stated: “Prior to treatment, the physicians were discouraged by the impact that burnout was having on their work and personal lives. To see both burnout and depression reduced significantly across 1- and 4-month posttests for the Transcendental Meditation group indicates a real possibility for alleviating these symptoms throughout the health profession."

Sanford Nidich, EdD, co-author and director of the Center for Social-Emotional Health, explained that “these findings are consistent with research on Transcendental Meditation recently published in JAMA Network Open and the Journal of the American College of Emergency Physicians showing large within-group effect sizes due to TM on burnout and depression symptoms in healthcare provider groups. The findings are also consistent with research on other populations.”

Forty academic physicians were enrolled in the four-month study, comparing the TM technique to treatment-as-usual controls. TM is described as a simple, effortless technique, practiced for 20 minutes twice a day, sitting with eyes closed. TM allows ordinary thinking processes to become more quiescent, resulting in a unique state of restful alertness. Controls continued with their usual care throughout the duration of the study. The primary outcome was total burnout, using the Maslach Burnout Inventory (MBI). The Beck Depression Inventory (BDI-2) was also used to determine effectiveness of TM on depression symptoms over the same time-period.  

Repeated measures analysis of covariance was used to assess adjusted mean change scores. Significant improvements were found for the TM group compared to controls in total burnout (P=.020) including the MBI dimensions of emotional exhaustion (P=.042) and personal accomplishment (P=.018), and depression (P=.016).  

The following is a sample of responses from semi-structured interviews with TM participants about their experiences:

“I’m more relaxed about things overall, more accepting, calmer, not as revved up by things. I think that is the biggest change.”

“If I am feeling really bothered by the day, I’m able to get over it easier and shift over to focusing on home.”

According to Gregory Gruener, MD, study co-author and Vice Dean for Education, Stritch School of Medicine, Loyola University Chicago: “Longevity in a career that will last 40 to 50 years requires a physician to embrace the ‘long-view’.  While knowledge, skills and attitude are fundamental, Transcendental Meditation provides the clarity of mind and calmness that makes this journey as enjoyable and fulfilling as the destination.”

*

Funding support: This study was supported by grants from Loyola University and other private foundations and individual donors. The article is titled, “Effects of Transcendental Meditation on Academic Physician Burnout and Depression: A Mixed Methods Randomized Controlled Trial.”

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JOURNAL

Journal of Continuing Education in the Health Professions

DOI

10.1097/CEH0000000000000472 

METHOD OF RESEARCH

Randomized controlled/clinical trial

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Effects of transcendental meditation on academic physician burnout and depression: A mixed methods randomized controlled trial

ARTICLE PUBLICATION DATE

26-Jan-2023

Poor literacy linked to worse mental health worldwide, study shows

Peer-Reviewed Publication

UNIVERSITY OF EAST ANGLIA

Peer reviewed - Systematic review - humans

People with poor literacy battle more mental health problems worldwide, according to new research from the University of East Anglia.

A new study published today is the first to look at the global picture of literacy and mental health.

Fourteen percent of the world’s population still has little or no literacy – and the study finds that they are more likely to suffer mental health issues such as loneliness, depression, and anxiety.

The team, from UEA’s Department of Clinical Psychology and Psychological Therapies (CPPT), say their findings disproportionately affect women, who account for two thirds of the world’s illiterate.

Dr Bonnie Teague from UEA’s Norwich Medical School, said: “Despite rising literacy rates over the past 50 years, there are still an estimated 773 million adults globally who can’t read or write. Literacy rates are lower in developing countries and those with a history of conflict, and women are disproportionately affected.

“We know that people with better literacy tend to have better social outcomes in terms of things like finding employment, being paid well, and being able to afford better food and housing. Not being able to read or write holds a person back throughout their life and they often become trapped in poverty or more likely to commit crime.

“We also know that lower literacy is related to poorer health, chronic diseases and shorter life expectancy.

“There has been some research examining the potential association between literacy and mental health but this is the first study looking at the issue on a global scale.”

The team reviewed data from 19 studies that measured both literacy and mental health. These studies took place across nine different countries (USA, China, Nepal, Thailand, Iran, India, Ghana, Pakistan, and Brazil) and involved almost two million participants.

Dr Lucy Hunn completed this systematic review as part of her Doctorate in clinical psychology training at UEA. She said: “We used information relating to mental health and literacy to assess the global reported relationship between these two factors.

“What we found is a significant association between literacy and mental health outcomes across multiple countries.

“People with lower literacy had greater mental health difficulties such as anxiety and depression.

“We can’t say for sure that poor literacy causes poor mental health, but there is a strong association.

“There may be multiple factors impacting on mental health which also impact literacy - such as poverty or living in an area with a history of conflict. However, what the data does show is that even in these places, you still see worse mental health for those without literacy skills.

“This work highlights the importance of mental health services being aware of and supporting literacy,” she added.

Literacy and Mental Health Across the Globe: A Systematic Review is published in the journal Mental Health and Social Inclusion.

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JOURNAL

Mental Health and Social Inclusion

METHOD OF RESEARCH

Systematic review

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Literacy and Mental Health Across the Globe: A Systematic Review

ARTICLE PUBLICATION DATE

27-Jan-2023

KIMM develops the world’s first electrode design for lithium-ion battery that improves smartphone·laptop battery performance

KIMM announces the development of lithium-ion battery with high-performance and reliability using bilayer electrodes,The new battery is expected to improve the performance and lifespan of electric vehicles and other electronic devices

Peer-Reviewed Publication

NATIONAL RESEARCH COUNCIL OF SCIENCE & TECHNOLOGY

 

IMAGE: ELECTRODE (ANODE) WITH A GROOVED, PATTERNED BILAYER STRUCTURE view more 

CREDIT: KOREA INSTITUTE OF MACHINERY AND MATERIALS (KIMM)

KIMM has announced the development of the design and process technology for the world's first battery electrode that significantly improves the performance and stability of batteries used in electronic devices such as smartphones, laptops, and electric vehicles.

A joint research team led by principal researcher Seungmin Hyun of the Department of Nano-Mechanics at the Korea Institute of Machinery and Materials (President Sang-jin Park, hereinafter referred to as KIMM), an institution under the jurisdiction of the Ministry of Science and ICT, and Professor Hoo-jeong Lee of Sungkyunkwan University (President Ji-beom Yoo, hereinafter referred to as SKKU) have developed a new battery technology that uses an electrode (Anode) structure that enhances the reliability and performance of traditional lithium-ion batteries. The results of their research achievement were published in the leading journal Advanced Functional Materials (IF: 19.924)*.

*Publication title: Design Strategies toward High-Performance Hybrid Carbon Bilayer Anode for Improved Ion Transport and Reaction Stability (Publication date: 2022.11.10)

In order to develop a design and process technology that maintains high performance and reliability even when the electrode of the lithium-ion battery is thick, the KIMM-SKKU joint research team formed a bilayered anode. Additionally, the anode is designed with grooves allowing small materials with improved ion conductivity and electrical conductivity to be placed between high-capacity materials

In general, lithium-ion battery electrodes are manufactured by coating and drying a slurry* so that it can be evenly distributed over the entire electrode. As such, it is the uniformity of the slurry that determines the performance of battery. The thicker the electrode, the lower the energy density and uniformity, making it difficult to maintain performance in a high-power environment.

*Slurry: A mixture of solids and liquids. Specifically, this refers to a mixture of active materials that chemically react to generate electrical energy when a battery is discharged, binders that are added for the structural stabilization of electrodes, and conductive materials that are added to improve electric conductivity.

However, with the anode structure of this newly developed battery. Uniform reaction stability can be achieved while maintaining high energy density throughout the electrode, even if the electrode is thick. This is particularly helpful in improving the performance and lifespan of batteries.

Principal researcher Seungmin Hyun stated that this achievement is an efficient method to improve the performance and lifespan of batteries by applying a new design to traditional lithium-ion battery materials and processes. He added that the team will continue to make efforts to apply this new technology to electric vehicles and soft robots that require high energy density in high-power environments, as well as to electronic devices such as commercial smartphones and laptops.

This research study was carried out with the support of the Nano and Material Technology Development Project (No. 2021M3H4A1A02099352) from the Ministry of Science and ICT, and with the support of the Nano-based Omni-TEX Manufacturing Technology Development Project from KIMM.

A Bilayer Electrode battery in pouch form

CREDIT  Korea Institute of Machinery and Materials (KIMM)

###

 

The Korea Institute of Machinery and Materials (KIMM) is a non-profit government-funded research institute under the Ministry of Science and ICT. Since its foundation in 1976, KIMM is contributing to economic growth of the nation by performing R&D on key technologies in machinery and materials, conducting reliability test evaluation, and commercializing the developed products and technologies.

 

This research study was carried out with the support of the Nano and Material Technology Development Project (No. 2021M3H4A1A02099352) from the Ministry of Science and ICT, and with the support of the Nano-based Omni-TEX Manufacturing Technology Development Project from KIMM.

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JOURNAL

Advanced Functional Materials

DOI

10.1002/adfm.202208665 

ARTICLE TITLE

Design strategies toward high-performance hybrid carbon bilayer anode for improved ion transport and reaction stability

New study debunks the assumption that menstrual cycles disqualify women from exercise research

Women are routinely excluded from exercise research; study shows why that's misguided

Peer-Reviewed Publication

BRIGHAM YOUNG UNIVERSITY

Peruse any women’s magazine, and you’ll likely find advice on how to boost workouts. But what many don’t realize is that the research behind most exercise advice is based almost entirely on men. Female subjects are excluded from over 90% of studies on exercise performance and fatigability because hormonal changes during the menstrual cycle were thought to affect exercise capability — which, if true, could muddy the data, making women’s inclusion in the research too complicated.

A new study from Brigham Young University researchers, published in the Journal of Applied Physiology, shows why that assumption is misguided. Analyzing women’s exercise performance across their menstrual cycles, researchers found no variability in endurance thresholds or performance: from workout to workout, women’s performance was just as consistent as men’s.

“Females with regular cycles performed the same between the high-estrogen phase, the high-progesterone phase and during menstruation, when there are low concentrations of both,” said Jessica Linde, who led the study for her BYU Master’s thesis in exercise science. “That information lifts a big barrier. It shows we shouldn’t be excluding women from research based on the idea that their menstrual cycles are going to skew the results.”

In fact, the study demonstrated why it’s crucial to include women in research. While women’s menstrual cycles didn’t affect their exercise, there were key differences between how women’s and men’s endurance played out. For example, women reached exhaustion from muscle fatigue about 18% faster than men, even when adjusting for muscle mass, possibly because women’s bodies may naturally reserve more energy.

“The assumption in exercise research has long been that women are like men, just smaller,” said BYU exercise science professor and co-author Jayson Gifford. “Our study suggests that they’re not, that there are important differences between women’s and men’s exercise. Including more women in research will allow us to fine tune approaches to women’s physiology.”

For the study, seven women and 10 men completed intense cycling sessions, the women at three points during the menstrual cycle confirmed through blood draws and ovulation tests, and the men at 10-day intervals. As participants exercised, researchers measured heart and respiratory rates to assess performance.

“Previous studies have looked at maybe one intensity of exercise in the menstrual cycle, but Jessica was extremely comprehensive and looked at five. It was one of the most thorough studies I’ve seen to date, and the data were extremely convincing,” Gifford said.

Although female participants often told the researchers that their menstrual cycles affected how they were feeling and how well they expected to perform, their measurable results showed “absolutely no change,” the researchers said. While hormones like estrogen are known to influence how well arteries dilate and how blood flows to muscles, those underlying processes “didn’t amount to impaired overall performance.”

Linde and Gifford were careful to note that the study focused only on cycling and included only women without menstrual disorders. More research is needed to determine how irregular menstruation might affect exercise. Learning more about women’s exercise is especially important now that there are more female athletes than ever — Linde, who is now continuing her research as a Ph.D. student at Marquette University, was herself inspired to pursue the research because of her experiences as a Division I athlete in college.

“I had never considered my female physiology impacting my performance until I got injured, and it was brought up,” Linde said. “I think sometimes we just don’t think of these questions. But in the last Olympics, the number of female and male athletes was finally equal. We have so many female athletes and women in general who are exercising and want answers about how they perform, so we need to study them.”

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JOURNAL

Journal of Applied Physiology

DOI

10.1152/japplphysiol.00416.2022 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

The exercise power-duration relationship is equally reproducible in eumenorrheic female and male humans

New study shows snacking on mixed tree nuts may impact cardiovascular risk factors and increase serotonin

New findings From UCLA published in Nutrients in Partnership with The International Tree Nut Council Nutrition Research & Education Foundation

Peer-Reviewed Publication

THE MOTION AGENCY

 

IMAGE: INC NREF LOGO view more 

CREDIT: INC NREF

In a paper[1] published online this week in the journal, Nutrients, researchers found that consuming mixed tree nuts (almonds, Brazil nuts, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios and walnuts) had a positive effect on the metabolism of the essential amino acid, tryptophan, in overweight and obese individuals. Specifically, there was an increase in both cardioprotective tryptophan metabolites and in the neurotransmitter, serotonin.

 

In a previous study[2], researchers at UCLA demonstrated that consuming 1.5 ounces of tree nuts per day (versus pretzels) during 24 weeks of weight loss and weight maintenance, resulted in weight loss, increased satiety, decreased diastolic blood pressure and decreased heart rate. Tryptophan (found in tree nuts) has been indicated as an important factor in cardiovascular disease (CVD). It is metabolized in the gut, producing many bioactive metabolites that are important in immune regulation affecting chronic diseases such as diabetes and CVD. The current study looked at whether tree nut snacks, as part of a hypocaloric diet, could modify the gut microbiome, resulting in increased levels of cardio-protective tryptophan microbial metabolites.

Plasma and stool samples were collected from 95 overweight or obese participants and were evaluated in the current study for tryptophan metabolites and for gut microbiota. “We’ve known for a long time that tree nuts can help decrease CVD risk, and these findings provide some possible explanations,”

Stated lead researcher, Zhaoping Li, MD, PhD, Professor of Medicine and Chief of the Division of Clinical Nutrition at UCLA. “We discovered some new associations between tryptophan metabolites and blood pressure, heart rate, and satiety in overweight/obese subjects, suggesting a broader impact of tryptophan metabolism in overall health, including cardiovascular health.”

Another interesting finding was the significant increase in blood serotonin levels (60.9% and 82.2% increase from baseline at week 12 and 24, respectively) in both the weight loss and weight maintenance phases, in the those who consumed mixed tree nuts. “This is the first time we’ve seen mixed tree nut consumption associated with an increase in serotonin levels in the body,” explained Dr. Li. “While more research is needed, this is exciting since serotonin can have an important impact on mood and overall mental health.”

Research has shown that people get about 25% of their calories each day from snacks and a large proportion come from desserts, sugar-sweetened beverages, sweets and salty snacks.[3] “Replacing just one of those snacks with 1.5 ounces of tree nuts may help improve overall health and reduce the risk for various chronic diseases,” stated Maureen Ternus, M.S., R.D.N, Executive Director of the International Tree Nut Council Nutrition Research & Education Foundation.

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The International Tree Nut Council Nutrition Research & Education Foundation (INC NREF) is a

non-profit, non-governmental organization dedicated to supporting nutrition research and education for consumers and health professionals throughout the world. Members include those associations and organizations that represent the nine tree nuts (almonds, Brazils, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios and walnuts). For more information, please visit our website at www.nuthealth.org.

[1] Yang, J., R. Lee, Z. Schulz, A. Hsu, J. Pai, S. Yang, S.M. Henning, J. Huang, J.P. Jacobs, D. Heber, Z. Li, 2023. Mixed Nuts as Healthy Snacks: Effect on Tryptophan Metabolism and Cardiovascular Risk Factors. Nutrients. 15, 569; https://doi.org/10.3390/nu15030569

[2] Wang, J., S. Wang, S.M., Henning, T. Qin, Y. Pan, J. Yang, J. Huang, C.-H. Tseng, D. Heber, Z. Li., 2021 Mixed tree nut snacks compared to refined carbohydrate snacks resulted in weight loss and increased satiety during both weight loss and weight maintenance: a 24-week randomized controlled trial. Nutrients. 13(5), 1512; https://doi.org/10.3390/nu13051512

[3] Dunford, E.K., B.M. Popkin, 2017. Disparities in snacking trends in US adults over a 35-year period from 1977 to 2012. Nutrients. 9(8), 809; https://doi.org/10.3390/nu9080809.