Study archive · page 6

A network meta-analysis of 55 randomised trials in 4,603 people with mild cognitive impairment found every exercise modality improved global cognition versus no exercise — multicomponent programmes ranked best overall, mind-body exercise ranked best for memory, and resistance training ranked best for executive function.

⚠What it shows: Network meta-analysis rankings (SUCRA) are indirect comparisons and hypothesis-generating; trials varied widely, and head-to-head studies are needed to confirm which modality is truly best for each cognitive domain.Systematic review · Front Aging Neurosci

When coaches delivered motivational cues during high-intensity intervals, elite footballers rated the same workload as less hard and reported better mood and engagement, while heart rate and lactate were unchanged. Prefrontal oxygenation in the orbitofrontal and frontopolar regions was also lower during the final three bouts.

⚠What it shows: One randomised crossover trial in 22 male elite footballers doing a single 12-bout cycle-ergometer HIIT session; perceptual and brain-imaging outcomes only, no performance outcome, and findings may not transfer to recreational trainees or to women.RCT · Eur J Sport Sci

In a pilot trial with 47 nurses, four laughter yoga sessions delivered online over two weeks significantly improved sleep quality, emotional exhaustion and personal accomplishment, while the same programme delivered face-to-face produced no significant change. Perceived stress did not shift in any group.

⚠What it shows: One small pilot RCT: 47 nurses at a single Turkish public hospital, three groups, only four sessions over two weeks, with outcomes measured immediately afterwards by self-report questionnaires. Perceived stress did not change at all, and why the online format outperformed the in-person one is unexplained — with groups this small the split could be chance.Study · Work

An umbrella review of 17 studies across all the main strands of serotonin research found no consistent evidence that depression is associated with lowered serotonin concentration or activity, including in genetic analyses of 115,257 and 43,165 people. Some evidence was consistent with long-term antidepressant use reducing serotonin concentrations.

⚠What it shows: A systematic umbrella review of existing reviews and meta-analyses searched to December 2020, so it inherits their limitations: quality was variable, many meta-analyses overlapped, prior antidepressant use was not reliably excluded, and no systematic review of tryptophan depletion studies has been done since 2007. It evaluates the low-serotonin hypothesis, not whether antidepressants relieve symptoms.Study · Focus (Am Psychiatr Publ)

A meta-analysis of 14 randomised trials found that purely mental training — no physical component at all — improved older adults' walking speed while they simultaneously performed a cognitive task, but did nothing measurable for ordinary walking speed, functional mobility or balance.

⚠What it shows: Systematic review and meta-analysis of 14 RCTs in older adults; the dual-task gait finding rests on moderate-quality evidence from 376 participants, while the balance estimate was rated very low quality with only 139 participants, and no trial measured falls.Meta-analysis · JMIR Aging

Pooling 10 randomised trials in women with polycystic ovary syndrome, mindfulness-based practices such as yoga and meditation were associated with reductions in BMI, body weight and abdominal circumference, alongside lower total testosterone and less clinical hirsutism. Generic depression and anxiety scores did not shift significantly, but disease-specific quality of life did.

⚠What it shows: Meta-analysis of 10 small RCTs totalling just 356 women with PCOS; the insulin-resistance signal rests on only two studies, interventions and measurement varied, and pooled effects from small trials often shrink on replication.Meta-analysis · Appl Psychol Health Well Being

Pooling 684 observational studies covering 44,979,527 adults, global metabolic syndrome prevalence was estimated at between 19% and 31%, with the highest figures reported in South Asia and in Latin America and the Caribbean. Prevalence did not differ significantly between pre-pandemic and post-pandemic studies.

⚠What it shows: Proportional meta-analysis of 684 observational studies reporting crude prevalence; heterogeneity was substantial, metabolic syndrome definitions and sampling differ between studies, and the socioeconomic correlates come from meta-regression, so they are ecological associations rather than causes.Study · Eur J Cardiovasc Nurs

Pooling four randomised trials in 3613 adults with overweight or obesity but no type 2 diabetes, subcutaneous semaglutide produced 11.85% more weight loss than placebo, while gut side effects and dropouts from side effects were markedly more common.

⚠What it shows: Meta-analysis of only four randomised trials totalling 3613 non-diabetic adults with overweight or obesity; trials were relatively short, so durability of weight loss and long-term safety remain untested, and side effects drove significantly more discontinuation.Meta-analysis · Medicine (Baltimore)

Pooling 34 randomised trials in 2461 adults aged 60 and over with type 2 diabetes, every exercise type beat control for HbA1c, but combined aerobic plus resistance training led the field with a 1.05% reduction and ranked first across glycaemic outcomes. Benefits on HbA1c appeared to start at roughly 520 MET-min per week.

⚠What it shows: Systematic review and Bayesian network meta-analysis of 34 RCTs (2461 participants, mean age 60+); modality rankings rest on indirect comparisons, the 2-hour glucose evidence was sparse, and the dose-response curves need confirmation in purpose-built trials.Meta-analysis · Front Endocrinol (Lausanne)

In a randomised trial of 100 adults with knee osteoarthritis, adding core stability exercises to conventional knee training produced greater improvements in pain, function and mobility over 8 weeks than adding foot-ankle strengthening. Between-group differences exceeded clinically important thresholds for pain and all knee-function subscales.

⚠What it shows: One RCT, n=100 adults aged 40+ with moderate (grade II-III) knee OA, 8 weeks only; the distal structural changes are exploratory and may reflect fluid shifts, not remodelling.RCT · Sci Rep

In a pilot trial with 20 national-level air pistol shooters, 8 weeks of trunk core training on unstable surfaces such as Swiss balls and BOSU balls appeared to improve postural control and shooting precision more than the same training on stable ground. After statistical correction, only 10.5-ring stability and muzzle velocity remained significant, so the rest is exploratory.

⚠What it shows: Pilot RCT, n=20 elite shooters split 10 per group, 8 weeks; most outcomes lost significance after FDR correction, so findings are exploratory and need larger, registered trials.RCT · Sci Rep

In 60 women aged 30-65 with stress or mixed urinary incontinence, six weeks of biofeedback-assisted pelvic floor training improved strength and quality of life in every group, but adding hip rotator strengthening produced the biggest strength gain, a mean difference of 4.44 cm H2O over pelvic floor training alone. Differences between groups in Oxford grading and quality of life were not statistically significant.

⚠What it shows: Single-centre RCT, 60 women aged 30-65 with stress or mixed incontinence and 55 completers, six weeks only; the strength advantage was measured on a perineometer rather than symptom counts, and quality-of-life differences between groups did not reach significance.Study · Int Urogynecol J

Athletes with jumper's knee who added radial pressure wave (shockwave-style) therapy to daily stretching and strengthening gained no statistically significant extra benefit once symptom duration was accounted for. Both groups achieved clinically meaningful improvement over 28 weeks, though the treated group reached that threshold earlier.

⚠What it shows: One open-label RCT of 33 young athletes; the treated group's advantage at 28 weeks lost significance after adjusting for symptom duration, and a modest true effect cannot be ruled out.Study · Transl Sports Med

Across 39 randomised trials totalling 2,481 people with rotator cuff-related shoulder pain, kinesiotape offered at best small, short-term improvements in shoulder function and pain during activity, with uncertain effects on range of motion. The reviewers conclude tape may serve as an adjunct but should not replace education-focused, exercise-based rehabilitation.

⚠What it shows: Systematic review and meta-analysis of 39 RCTs (n=2,481), but the overall certainty of evidence was rated low to very low, so even the small pooled effects are uncertain.Review · Shoulder Elbow

In a double-blind, sham-controlled trial of 60 adults with chronic non-specific low back pain, both high- and low-intensity laser acupuncture added to exercise outperformed sham laser plus exercise on pain, trunk strength, mobility, fatigue and disability. The high-intensity version delivered greater gains in trunk extensor strength and pain relief.

⚠What it shows: One RCT, n=60 split across three groups; a four-week intervention with only a one-month follow-up, and the authors say optimal parameters and long-term effects need further research.Clinical trial · Front Med (Lausanne)

Adding 1,3-butanediol to a carbohydrate drink roughly doubled circulating ketones in male athletes long adapted to a ketogenic diet, but time-trial performance was no better than carbohydrate alone. Lactate, substrate oxidation, oxygen consumption, perceived exertion and heart rate were also unchanged.

⚠What it shows: A counterbalanced crossover trial in just 9 recreationally active men with at least a year of ketogenic adherence; the authors stress this is too small to prove no effect, only that none was detectable here.RCT · Nutrients

In a 14-day randomised trial in under-19 footballers, CoQ10 (300 mg/day) lowered markers of oxidative stress, muscle damage and cortisol more than taurine, while taurine raised the anti-inflammatory marker IL-10 more; both blunted the drop in immune markers. These were blood markers only, with eight players per group.

⚠What it shows: Randomised, double-blind, placebo-controlled but very small: 24 male under-19 soccer players, only 8 per group, 14 days, and outcomes were circulating biomarkers with no performance or recovery measures. The authors call the findings preliminary and pending confirmation in larger trials.RCT · Nutrients

In a 12-week randomised trial of 117 older adults in long-term care, Baduanjin exercise guided by real-time augmented-reality feedback improved frailty more than the same exercise delivered by video or usual care, with extra gains in physical function, daily living ability, nutrition, cognition and mood.

⚠What it shows: One single-blind RCT, n=117 institutionalised older adults in Chongqing, China; 12-week outcomes only, so durability and generalisability beyond long-term care settings are unknown.Study · J Am Med Dir Assoc

Pooling nine randomised trials in 1,385 adults aged 60 and over, exergaming was associated with a lower overall fall rate (incidence rate ratio 0.53) and fewer people falling at least once over 12 months versus usual care (risk ratio 0.75).

⚠What it shows: Meta-analysis of only nine trials with substantial heterogeneity (I²=76%); certainty rated low to moderate, evidence on injurious falls and cost-effectiveness was limited, and the authors say larger trials are needed before routine rollout.Meta-analysis · JMIR Aging

In a 20-patient trial where each person had four comparable skin areas randomised, fractional radiofrequency plus topical tretinoin was the only stretch-mark treatment patients rated significantly better than untreated skin after 20 weeks. A blinded dermatologist saw only a non-significant tendency towards improvement.

⚠What it shows: Small single-centre randomised trial in 20 patients using within-person comparison of four skin areas over 20 weeks; the significant result was patient-reported and unblinded, while the blinded dermatologist and 3D photography found only subtle non-significant tendencies.RCT · Lasers Med Sci

A network meta-analysis of 47 randomised trials in 6230 children and adults found that adding oral antihistamines to eczema treatment cut severity and itch scores by amounts well below what patients would notice as important, and probably did not improve sleep disturbance or flare-ups. First-generation antihistamines probably increase cognitive impairment.

⚠What it shows: Systematic review and network meta-analysis of 47 randomised trials (6230 children and adults, mostly moderate to severe atopic dermatitis); certainty was moderate for the severity, itch and cognitive-impairment findings but only low for sleep and exacerbations, and the trials were largely in more severe disease.Meta-analysis · BMJ

In 31 recreational marathon runners, IL-6 and IL-10 spiked immediately after the race and were back to pre-race levels by 48 h. Habitual intake of the long-chain monounsaturated fat 20:1 was the only dietary fat associated with higher IFN-γ and TNF-α at 48 h.

⚠What it shows: Exploratory observational study in just 31 recreational marathon runners (58.1% female, mean age 38.4 years); habitual fat intake came from a food-frequency questionnaire, dozens of fat–cytokine associations were tested, and the authors themselves call for replication in larger cohorts. Association only, and no health outcome was measured.Study · Nutrients

Overweight and obese female university students doing 75 minutes a week of bodyweight 'exercise snacks' improved weight, body fat, VO2max, blood lipids and jump power over 8 weeks similarly to time-matched HIIT, while rating the sessions as noticeably easier. Only the HIIT group, however, lowered diastolic blood pressure.

⚠What it shows: One 8-week RCT of 30 overweight/obese female university students; the authors themselves call for adequately powered trials, and HIIT retained an edge on diastolic blood pressure.RCT · Front Public Health

In a 50-person pilot trial in people with metabolic syndrome, a 20-day course of "autoprobiotics" — bacteria grown from each patient's own gut Enterococcus strains — reduced obesity measures, lowered glucose and HbA1c and left lower HbA1c and triglycerides than the nutritional mix alone by day 28, alongside larger shifts in gut bacteria.

⚠What it shows: A single 20-day pilot RCT in 50 adults aged 42-63 with metabolic syndrome (26 treated, 24 control) at one Russian centre, with short follow-up to day 28 and many microbiome outcomes reported — and the personalised strains are not an off-the-shelf product.RCT · Nutrients