Medical Bulletin 4/November/2022

New research from Edith Cowan University (ECU) has shown one type of muscle contraction is most effective at increasing muscle strength and muscle size -and rather than lifting weights, the emphasis should be on lowering them.

So its a good news for those who struggle to fit a gym workout into their day: you may be able to cut your weights routine in half and still see the same results.

The team, which also included researchers from Niigata University and Nishi Kyushu University in Japan and Brazil's Londrina State University, had groups of people perform three different types of dumbbell curl exercise and measured the results.

It found those who only lowered a weight saw the same improvements as those who raised and lowered weights - despite only performing half the number of repetitions.

Reference:

Professor Ken Nosaka et al,Comparison between concentric‑only, eccentric‑only, and concentric–eccentric resistance training of the elbow flexors for their effects on muscle strength and hypertrophy,European Journal of Applied Physiology, DOI 10.1007/s00421-022-05035-w

COMP360 psilocybin reduces depression symptoms: Phase 2b trial findings

Approximately 100 million people in the world suffer with treatment-resistant depression, which means they have not responded to at least two antidepressant treatments for their major depressive disorder.

A multicentre clinical trial led by COMPASS Pathways across 22 international sites including Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King's College London and South London and Maudsley NHS Foundation Trust has found that a single 25mg dose of COMP360 psilocybin, alongside psychological support, had a significant impact in reducing symptoms of depression in participants with treatment-resistant depression.

The study, published in the New England Journal of Medicine, investigated the change from baseline in the severity of depression, as assessed using the Montgomery-Åsberg Depression Rating Scale, in participants with treatment-resistant depression over the course of 12 weeks following a single dose of COMP360 psilocybin alongside psychological support. Researchers found that participants reported a greater reduction in depression scores three weeks after taking a single 25 mg dose of COMP360 psilocybin compared to those who took the lowest 1 mg dose.

Reference:

Dr James Rucker et al,Single-Dose Psilocybin for a Treatment-Resistant Episode of Major Depression, New England Journal of Medicine, DOI10.1056/NEJMoa2206443

New research explores mechanism behind the role of exercise in protecting against neurodegenerative diseases

A special issue of Brain Plasticity presents new research and insights on neural plasticity and the role of peripheral factors in cognitive health.

Accumulating evidence finds that exercise can improve brain function and delay or prevent the onset of neurodegenerative diseases such as Alzheimer's and Parkinson's disease. While the underlying mechanisms remain unclear, recent research suggests that exercise-induced activation of peripheral systems such as muscle, gut, liver, and adipose tissue may affect neural plasticity.

"At least a dozen peripheral factors have been identified that affect neurotrophin levels, adult neurogenesis, inflammation, synaptic plasticity, and memory function," explained co-Guest Editor and journal Editor-in-Chief Henriette van Praag, PhD, Charles E. Schmidt College of Medicine and Brain Institute, Florida Atlantic University.

Reference:

Jacob M. Haus, Peripheral Factors and Neural Plasticity, Brain Plasticity, DOI 10.3233/BPL-220139

Moderate to heavy drinking linked to higher risk of stroke in young adults, finds study

Young adults who are in their 20s and 30s who were moderate drinkers may be more likely to have a stroke than people who drank low amounts or no alcohol, according to a study published in the November 2, 2022, online issue of Neurology. The risk of stroke increased the more years people reported moderate or heavy drinking.

"The rate of stroke among young adults has been increasing over the last few decades, and stroke in young adults causes death and serious disability," said study author Eue-Keun Choi, MD, PhD, of Seoul National University in the Republic of Korea. "If we could prevent stroke in young adults by reducing alcohol consumption, that could potentially have a substantial impact on the health of individuals and the overall burden of stroke on society."

The study looked at records from a Korean national health database for people in their 20s and 30s who had four annual health exams. They were asked about alcohol consumption each year. They were followed for an average of six years.

Reference:

Eue-Keun Choi et al, Neurology