Virgin olive oil protects cognitive health through the gut microbiota

 

Virgin olive oil is considered one of the fundamental pillars of the Mediterranean diet and is widely recognised for its cardiovascular and metabolic health benefits. However, its direct influence on the human brain through the digestive system had not been explored in depth. A new study led by researchers from the Human Nutrition Unit at the Universitat Rovira i Virgili (URV), the Pere Virgili Health Research Institute (IISPV) and CIBERobn reveals that extra virgin olive oil may play a decisive role in protecting cognitive function through its effects on the gut microbiota.

‘This is the first prospective study in humans to specifically analyse the role of olive oil in the interaction between gut microbiota and cognitive function,’ explains Jiaqi Ni, first author of the article and researcher at the URV's Department of Biochemistry and Biotechnology. To carry out the study, the research team worked with data from 656 people aged between 55 and 75 who were overweight or obese and had metabolic syndrome—a set of risk factors that increase the likelihood of developing cardiovascular disease. This information was collected over a two-year period as part of the PREDIMED-Plus project and also included data on the participants’ consumption of different types of olive oil (virgin and refined) and the composition of their gut microbiota, as well as a follow-up that sought to identify any changes to their cognitive function.

Improved cognitive function and more diverse microbiota

The results reveal that people who consumed virgin olive oil rather than refined olive oil showed improved cognitive function and greater diversity in their gut microbiota, which is an important marker of intestinal and metabolic health. In contrast, consumption of refined olive oil was associated with less diverse microbiota over time. In addition, the researchers identified a genus of bacteria in the microbiota, known as Adlercreutzia, as a possible indicator of the beneficial association between virgin olive oil consumption and the preservation of cognitive function. The researchers’ findings suggests that some of the benefits for brain function of consuming this type of oil may be due to its impact on the composition of the gut microbiota.

So what is it about extra virgin olive oil that makes it healthier than refined olive oil? The main difference lies in their production processes: the former is obtained exclusively through mechanical procedures, whereas refined olive oil undergoes industrial treatments to remove impurities. The problem is that these treatments also degrade the oil’s natural antioxidants, polyphenols, vitamins and other bioactive compounds that are beneficial to health. Hence Jiaqi Ni’s warning that ‘not all olive oils have benefits for cognitive function’ and that we should aim to consume extra virgin olive oils rather than refined ones.

Quality is as important as quantity

Findings such as these advance our understanding of the mechanisms linking cardiovascular and cognitive health to gut microbiota. Jordi Salas-Salvadó, principal investigator of the study, highlights the importance of olive oil quality as a central component of the Mediterranean diet: ‘This research reinforces the idea that the quality of the fat we consume is as important as the quantity; extra virgin olive oil not only protects the heart, but can also help preserve the brain during ageing.’ The URV professor also points out that the fact that they have identified a microbial profile that plays a role in these benefits ‘paves the way for new nutrition-based prevention strategies to preserve cognitive functions.’

At the same time, researchers Nancy Babio and Stephanie Nishi, co-directors of the study, point out the relevance of the results in the current context of an ageing population: ‘At a time when cases of cognitive decline and dementia are on the rise, our findings drive home the importance of improving diet quality, and in particular prioritising extra virgin olive oil over other refined versions as an effective, simple and accessible strategy for protecting brain health.’

This study was made possible thanks to the leadership of the Human Nutrition Unit of the Department of Biochemistry and Biotechnology at the URV and the participation of institutions such as the Pere Virgili Health Research Institute (IISPV-CERCA) and the CIBER area on the Physiopathology of Obesity and Nutrition (CIBEROBN) of the Carlos III Health Institute. The project also benefited from the collaboration of researchers from the PREDIMED-Plus consortium and international universities such as Wageningen (Netherlands) and Harvard (United States).

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Journal

Microbiome

DOI

10.1186/s40168-025-02306-4 

‘The munchies’ are real and could benefit those with no appetite

Peer-Reviewed Publication

Washington State University

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PULLMAN, Wash. — The urgent onset of “the munchies” after cannabis use isn’t imaginary – it’s a cognitive response that occurs regardless of sex, age, weight or recent food consumption and could offer clues to help people struggling with appetite loss.

Those findings from a collaborative study, conducted by researchers at Washington State University and the University of Calgary, were recently published in the Proceedings of the National Academy of Sciences (PNAS).

“There are a lot of different diseases, conditions and disorders associated with wasting syndromes and lack of appetite, and this study really supports the idea that cannabis can be used medicinally to increase appetite in people who have conditions like HIV, AIDS, or who are on chemotherapy,” said Carrie Cuttler, a WSU psychology professor.

Led in part by Cuttler, who directs The Health and Cognition (THC) Lab at WSU, and College of Veterinary Medicine professor Ryan McLaughlin, the research was conducted in tandem with Calgary researchers Matthew Hill and Catherine Hume, who ran a similar series of studies using a rat model.

The human clinical trial examined 82 volunteer subjects aged 21 to 62 from the greater Pullman, Wash., community. Each participant was randomly selected to vape either 20 or 40 milligrams of cannabis or a cannabis placebo, the latter of which served as the control group.

“The human study found irrespective of body mass index, time of last food consumption, sex or how much cannabis was consumed, human participants who used cannabis during the trial ate significantly more food,” McLaughlin said.

Of all the food options — spanning carbohydrates to protein to fatty snack foods — some appealed more than others.

“Beef jerky was one of the No. 1 things intoxicated people gravitated toward, which I don’t understand. Honestly, I would have thought chocolate, chips, Rice Krispies treats — things like that,” Cuttler said, noting water was also high on the list of desirable items.

The study is significant because, on a subject with little scientific support, it helps highlight the physiological mechanisms responsible for appetite stimulation.

Endogenous cannabinoids, also called endocannabinoids, are naturally produced by the body to regulate mood, memory, pain, immune responses and appetite in order to maintain balance.

“That’s what the natural endocannabinoid system does in the hypothalamus,” McLaughlin said. “But THC hijacks that entire system. So even though you’re not necessarily hungry, THC can stimulate cannabinoid receptors in the brain and make you feel hungry.”

The stimulation of those cannabinoid receptors in the brain is another key finding from the research. Pharmacology studies at the University of Calgary that blocked cannabinoid receptors in the peripheral nervous system in rats didn’t curb appetite, but blocking those same cannabinoid receptors in the brain did.

“That’s what really gives us the opportunity to look at whether this is something brain-mediated or gut-mediated, and this generally shows ‘the munchies’ are mediated by the brain,” McLaughlin said.

Knowing hunger stems from receptors in the brain, researchers hope the study can inform future treatments for people experiencing appetite loss.

“There’s very little documentation of the munchies phenomenon, but this paper really starts to tap into some of the mechanisms that might be responsible,” Cuttler said.

Baduanjinm, a traditional Chinese mind-body practice = brisk walking in lowering blood pressure

 A traditional Chinese mind-body practice that combines slow, structured movement, deep breathing and meditative focus lowered blood pressure as effectively as brisk walking in a large randomized clinical trial published in JACC, the flagship journal of the American College of Cardiology. Blood pressure reductions were seen after three months and sustained for one year.

High blood pressure is one of the leading preventable risk factors for heart disease. Clinical guidelines recommend regular physical activity, yet long-term adherence to exercise programs is challenging for many people, particularly when routines require equipment, dedicated space, gym memberships or ongoing supervision.

Baduanjin is a widely practiced, standardized eight-movement sequence that integrates aerobic, isometric, flexibility and mind–body components. Practiced for centuries and commonly performed in community settings across China, the routine typically takes 10–15 minutes and requires no equipment and only minimal initial instruction, allowing it to be performed in a wide range of settings. Because it is low- to moderate-intensity, it is considered safe and accessible for many adults.

“Given its simplicity, safety and ease at which one can maintain long-term adherence, baduanjin can be implemented as an effective, accessible and scalable lifestyle intervention for individuals trying to reduce their blood pressure,” said Jing Li, MD, PhD, senior author of the study and Director, Department of Preventive Medicine, National Center for Cardiovascular Diseases in Beijing, China.

In the first large, multicenter randomized trial to look at the impact of baduanjin on blood pressure, researchers followed 216 participants across seven communities to determine changes in 24-hour systolic blood pressure from baseline to 12 and 52 weeks. Participants were 40 years old or older and had a systolic blood pressure of 130-139 mm Hg, which according to the ACC/AHA High Blood Pressure Guideline is considered stage 1 hypertension. They were randomly assigned to one of three arms: baduanjin, self-directed exercise alone, or brisk walking for the 52-week intervention.

Compared to self-directed exercise, practicing baduanjin five days a week reduced 24-hour systolic blood pressure approximately 3 mg Hg and office systolic blood pressure by 5 mg Hg at both three months and one year, which is comparable to reductions seen with some first-line medications. Baduanjin showed comparable results and safety profile to brisk walking at one year.

Notably, the benefits were sustained even without ongoing monitoring, a key challenge for many lifestyle interventions that struggle to maintain long-term adherence outside structured programs.

“Baduanjin has been practiced in China for over 800 years, and this study demonstrates how ancient, accessible, low-cost approaches can be validated through high-quality randomized research,” said Harlan M. Krumholz, MD, FACC, Editor-in-Chief of JACC and the Harold H. Hines, Jr Professor at the Yale School of Medicine. “The blood pressure effect size is similar to that seen in landmark drug trials, but achieved without medication, cost or side effects. This makes it highly scalable for community-based prevention, including in resource-limited settings.”

Mindfulness practices found to significantly reduce depression symptoms

 A new study reveals that mindfulness practices may significantly reduce depression symptoms, particularly in people who have experienced early-life adversity, such as childhood abuse and neglect.

Led by Eric Loucks, professor of medicine, epidemiology, and of behavioral and social sciences and director of the Mindfulness Center at Brown, the study enrolled 201 participants, 101 of whom were randomized into the Mindfulness-Based Blood Pressure Reduction Program, while 100 were randomized into an enhanced usual care control, which included home blood-pressure monitors, physician access and health-education materials. Researchers also had a measure of participants’ early-life adversity, particularly their exposure to abuse or neglect.

Loucks and his team followed participants for six months to assess changes in blood pressure, health behaviors and mental health, finding that those in the mindfulness program showed significant improvements in their depression symptoms. Additionally, participants who experienced childhood neglect showed greater improvements in depression symptoms than those who had not. A similar, though less pronounced, trend was observed among people with a history of childhood abuse.

“In this program, that was primarily designed to lower blood pressure while addressing whole-person health, we also saw that mental well-being, particularly around depression symptoms, improved in participants that went through the program,” Loucks said. “The findings suggest that cultivating mindful self-regulation skills–such such as self-awareness, attention control and emotion regulation–may help interrupt maladaptive patterns shaped by past experiences.”

Over the last 15 years, Loucks has been studying social determinants of health such as early-life adversity and its impacts on cardiovascular health, body mass index and blood pressure. “I came to a point where I wanted to not just document it, but do something about it, and I wondered if mindfulness training might help,” he said. “I’d gone through a lot of mindfulness training myself outside of work and started to get trained up in mindfulness programs that are specific to health contexts.”

Loucks began to study the Mindfulness-Based Stress Reduction program, running it through two clinical trials that were funded by the NIH and finding that it reduced blood pressure in both trials. He also wanted to look at the intervention from a whole-person perspective.

“If we look at everyday folks out in the world, those that had exposure to early life adversity, like abuse and neglect, tend to have worse mental health and also worse cardiovascular health,” Loucks said. “Mindfulness interventions help by regulating our emotions better when different challenges come up. For someone who has experienced childhood neglect or abuse, mindfulness training can help us make sense of that and respond skillfully to this moment in time.” 

Loucks discussed this work during a keynote address at the U.S. DOHaD Society this year. “It felt like a coming-home moment to see that this intervention, originally developed to address psychosocial factors that influence health, had even stronger effects among people with early-life adversity, particularly on depression,” he said. “It’s been about a 15-year arc of research that culminated in these findings.”

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Exercise and nutritional drinks can reduce the need for care in dementia

 A simple combination of daily physical exercise and protein-rich nutritional drinks appears to offer significant health benefits for people with dementia. In a new study from Karolinska Institutet, not only did the participants' physical ability improve, but after three months the researchers also saw signs that they were able to manage more everyday tasks themselves. The study is published in the journal Alzheimer's and Dementia.

Older people living in special housing often have an increased risk of malnutrition, muscle weakness, and frailty, which are factors that affect both health and quality of life. The OPEN study has previously shown that the program improves physical function and has positive effects on muscle mass and nutritional status. The new article analyzes retrospectively how the program can be linked to the participants' need for support in everyday life.

A total of 102 people from eight nursing homes in the Stockholm area participated. For twelve weeks, the intervention group was asked to do standing exercises several times a day and drink one to two nutritional drinks with extra protein. Among other things, the researchers monitored how much support the participants needed with tasks such as hygiene, dressing, and moving around.

When the researchers analyzed all the residents together, no clear differences were apparent. However, when the results were broken down by ward type, a different pattern emerged. In the dementia wards, participants who had followed the program had improved their abilities to such an extent that they required less care time compared to the control group.

“One possible explanation is that people in dementia units had better physical conditions for improving their functional ability and were therefore able to do more things themselves after the intervention,” says Anders Wimo, a researcher at the Department of Neurobiology, Care Sciences and Society at Karolinska Institutet.

The researchers also point out that interviews from previous sub-studies indicate that improved function can affect how much support a person needs in different situations. At the same time, they emphasize that the results should be interpreted with some caution, as the analyses are secondary.

“More studies are needed where care time is a primary outcome and where organizational factors, such as staffing levels and work routines, are closely monitored,” says Anders Wimo

Booster jabs reduce the risks of COVID-19 deaths

Booster vaccines reduced the risk of COVID‑19–related hospitalisation and death, according to a new study of over 3 million adults who had the autumn 2022 vaccine in England.  The research led by the universities of Bristol and Oxford, provides further evidence of the effectiveness of booster vaccination against COVID-19.

The study, published in Vaccine today [18 February], also found that this effectiveness was similar for Moderna (BA.1 mRNA-1273) and Pfizer-BioNTech (BA.1 BNT162b2) booster vaccines, but protection declined over time.

Previous work has shown the initial COVID-19 vaccination was effective in reducing the risk of hospitalisation and death due to COVID-19. This latest research, carried out at the National Institute for Health and Care Research (NIHR) Bristol Biomedical Research Centre (BRC), looked at the impact of giving people a booster vaccine.

The team investigated the effectiveness of Moderna and Pfizer-BioNTech booster vaccines administered during the autumn 2022 booster campaign in England for previously vaccinated people age 50 or over. 

The NHS England approved study analysed linked GP and hospital records available within the OpenSAFELY research platform. The team compared 3,464,877 adults eligible for booster vaccination during the autumn 2022 COVID-19 vaccine rollout with the same number of unboosted people.

They matched them with people who were similar in terms of age, date of last COVID-19 vaccine dose, brand of prior vaccination, clinical vulnerability and geographical region. The researchers then followed these people up for nearly a year and tracked hospitalisation and death due to COVID-19.

Across 2.5 million people followed up over a year, the study recorded 14,436 COVID‑19 hospitalisations, 1,152 COVID‑19 deaths, 32,184 non‑COVID‑19 deaths and 52,758 fractures.

The study found boosted individuals had much lower 350‑day risks of COVID‑19 hospitalisation (3.78 vs 6.81 per 1,000) and death (0.29 vs 0.61 per 1,000).  Boosters halved the risks of COVID‑19 hospitalisation and death. Protection waned over time, strongest in the first 70 days. Moderna and Pfizer‑BioNTech boosters performed similarly for COVID‑19 outcomes, though non‑COVID‑19 mortality was slightly higher in the mRNA‑1273 group.

The study also assessed the relationship between booster vaccination and fracture, an outcome not considered likely to be causally related. A small reduction in fracture risk was found for boosted individuals. This suggests that not all confounders (common causes of booster vaccinations and outcomes) were accounted for, but the much smaller effect for fracture is reassuring for the validity of the study’s conclusions.

Dr Paul Madley-Dowd, Research Fellow in Medical Statistics and Health Data Science, and corresponding author at University of Bristol, said: “Our findings reinforce the importance of booster vaccination against COVID-19 among people over 50 years old.

“The study also provides further evidence that COVID-19 booster vaccinations reduced the risk of hospitalisation and death.” 

Adolescent cannabis use linked to doubling risk of psychotic and bipolar disorders

 

 Adolescents who use cannabis could face a significantly higher risk of developing serious psychiatric disorders by young adulthood, according to a large new study published today in JAMA Health Forum. The longitudinal study followed 463,396 adolescents ages 13 to 17 through age 26 and found that past-year cannabis use during adolescence was associated with a significantly higher risk of incident psychotic (doubled), bipolar (doubled), depressive and anxiety disorders. The study was conducted by researchers from Kaiser Permanente, the Public Health Institute’s Getting it Right from the Start, the University of California, San Francisco and the University of Southern California, and was funded by a grant from NIH’s National Institute on Drug Abuse (R01DA0531920).

The study analyzed electronic health record data from routine pediatric visits between 2016 and 2023. Cannabis use preceded psychiatric diagnoses by an average of 1.7 to 2.3 years. The study’s longitudinal design strengthens evidence that adolescent cannabis exposure is a potential risk factor for developing mental illness.

“As cannabis becomes more potent and aggressively marketed, this study indicates that adolescent cannabis use is associated with double the risk of incident psychotic and bipolar disorders, two of the most serious mental health conditions,” said Lynn Silver, M.D., program director of the Getting it Right from the Start, a program of the Public Health Institute, and a study co-author. “The evidence increasingly points to the need for an urgent public health response — one that reduces product potency, prioritizes prevention, limits youth exposure and marketing and treats adolescent cannabis use as a serious health issue, not a benign behavior.”

Cannabis is the most used illicit drug among U.S. adolescents. The Monitoring the Future study shows use rising with grade level — from about 8% in 8th grade to 26% in 12th grade — and according to the 2024 National Survey on Drug Use and Health, more than 10% of all U.S. teens aged 12 to 17 report past-year use. At the same time, average THC levels in California cannabis flower now exceed 20%, far higher than in previous decades, and concentrates can exceed 95% THC.

Unlike many prior studies, the research examined any self-reported past-year cannabis use, with universal screening of teens during standard pediatric care, rather than focusing only on heavy use or cannabis use disorder.

“Even after accounting for prior mental health conditions and other substance use, adolescents who reported cannabis use had a substantially higher risk of developing psychiatric disorders — particularly psychotic and bipolar disorders,” said Kelly Young-Wolff, Ph.D., lead author of the study and senior research scientist at the Kaiser Permanente Division of Research. “This study adds to the growing body of evidence that cannabis use during adolescence could have potentially detrimental, long-term health effects. It’s imperative that parents and their children have accurate, trusted, and evidence-based information about the risks of adolescent cannabis use.”  

 The study also found that cannabis use was more common among adolescents enrolled in Medicaid and those living in more socioeconomically deprived neighborhoods, raising concerns that expanding cannabis commercialization could exacerbate existing mental health disparities.

The Public Health Institute is an independent nonprofit organization that advances wellbeing and health equity with communities around the world. PHI develops research, leadership and partnerships to build strong public health policy, programs, systems and practices. For more information, visit www.phi.org.

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Journal

JAMA Health Forum

DOI

10.1001/jamahealthforum.2025.6839