Study archive · page 5

A meta-analysis of 14 randomised trials (763 women across reproductive stages) found that adding protein, amino acids or creatine to exercise produced no significant improvement in skeletal muscle mass, appendicular lean mass, fat-free mass, bone mineral content or bone mineral density; only bench press (g = 0.279) and handgrip strength (g = 0.412) improved significantly, with no increase in adverse events.

⚠What it shows: Pooled from just 14 RCTs totalling 763 women, lumping together whole proteins, amino acids and creatine monohydrate — very different compounds — so heterogeneity is high and the null may hide effects of specific supplements. The authors note that trials were mostly shorter than 12 months and lacked site-specific bone measurements, and no head-to-head comparisons exist.Meta-analysis · Int J Med Sci

A Cochrane review of five randomised trials (305 women) found very low quality evidence that continuous oestrogen delivered by patch or implant plus progestogen produced a small to moderate improvement in overall premenstrual syndrome symptom scores (SMD -0.34), while one small crossover trial suggested luteal-phase oral oestrogen was ineffective and might aggravate symptoms.

⚠What it shows: Only five RCTs and 305 women in total, with Cochrane rating every comparison very low quality because of attrition bias, imprecision and heterogeneity; the oral luteal-phase finding rests on a single crossover trial of 11 women. No included trial looked beyond 2-8 months, so long-term risks such as endometrial or breast cancer were never assessed.Meta-analysis · Cochrane Database Syst Rev

A systematic review and meta-analysis of 11 randomised trials in women with genitourinary syndrome of menopause found that fractional CO2 laser was associated with improved sexual function, including less pain during sexual activity (standardised mean difference 0.51), and better urinary function including less leakage and urinary frequency (standardised mean difference 0.51), but not with improved vaginal epithelium quality.

⚠What it shows: Eleven RCTs pooled, but with mixed comparators — sham laser, topical hormonal treatment or a lubricant gel — and only short-term outcomes, so durability is unknown. The authors themselves state the clinical significance of the changes is unclear, and women with any history of cancer or prior laser treatment were excluded.Meta-analysis · Obstet Gynecol

A systematic review of 75 articles graded the evidence as good for a positive effect of oral contraceptives on bone density in perimenopausal women, fair in premenopausal women with hypothalamic oligo- or amenorrhoea, and only limited in healthy premenopausal women; the ideal formulation and duration remain undetermined.

⚠What it shows: A narrative systematic review of 75 articles appraised with Oxford levels of evidence rather than a pooled meta-analysis, and now nearly two decades old; the strongest rating applied to perimenopausal women, while evidence in healthy premenopausal women was rated limited, and the authors call for larger randomised trials.Systematic review · Br J Sports Med

A meta-analysis of 14 randomised trials in 2,101 perinatal women found digital health interventions significantly increased daily step counts and light physical activity (by 13.04 min/day), but did not significantly shift moderate-to-vigorous activity or sedentary time.

⚠What it shows: Meta-analysis of 14 RCTs (n=2,101); the step-count effect reached significance only after excluding outliers via sensitivity analysis, and evidence quality was rated moderate for steps and low for light activity.Meta-analysis · Front Public Health

In a post hoc analysis of a six-month randomised trial in 93 cognitively healthy women aged 20-67, post-menopausal women assigned to aerobic exercise four days a week improved more on executive function than those assigned to stretching and toning, and more than pre-menopausal women.

⚠What it shows: Secondary post hoc analysis of one randomised trial, not what it was designed to test: 93 cognitively healthy women aged 20-67 (43% post-menopausal), of whom 76 completed, leaving small subgroups and a real chance of a spurious interaction.Study · J Alzheimers Dis

In a meta-analysis of 4 randomised trials covering 566 adults with type 2 diabetes in primary care, continuous glucose monitoring cut HbA1c by 0.46% at 6-8 months and 0.33% at 12-14 months versus usual care, and improved device satisfaction — but quality of life did not change.

⚠What it shows: Meta-analysis of only 4 multisite RCTs (n=566) in primary care settings; CGM types were mixed (real-time, retrospective and intermittently scanned), and quality of life showed no improvement.Meta-analysis · Sci Diabetes Self Manag Care

In a meta-analysis of 12 interventional studies with 177 adults with type 2 diabetes, high-intensity interval training lowered 24-hour mean glucose, post-meal glucose and time spent in hyperglycaemia compared with no exercise, and outperformed moderate-intensity continuous training on 24-hour mean glucose and hyperglycaemic time. Effects on glycaemic variability (mean amplitude of glycemic excursions) remained uncertain.

⚠What it shows: Systematic review and meta-analysis, but only 12 studies and 177 participants in total, all adults with type 2 diabetes; GRADE certainty was rated very low to low because of methodological limitations and heterogeneity between trials.Meta-analysis · Front Endocrinol (Lausanne)

Six months of the 5:2 diet was associated with weight loss of -6.3% in overweight or obese adults with type 2 diabetes and -5.0% in those without, alongside improvements in waist circumference, blood pressure, HDL and LDL cholesterol and adiponectin. HDL and adiponectin improvements were still present at the 12-month follow-up in both groups.

⚠What it shows: Secondary analysis of a non-randomised six-month controlled trial: 97 recruited, 93 completed and 82 returned at 12 months, and everyone followed the same 5:2 diet with no non-fasting comparison arm, so the changes cannot be separated from weight loss.Clinical trial · Int J Mol Sci

In a randomised trial of 57 adults aged 45-60 with type 2 diabetes-associated dyslipidaemia and BMI above 25, a 12-week programme combining aerobic, resistance and flexibility exercise significantly reduced BMI, waist circumference and waist-to-hip ratio and improved quality-of-life scores, with greater benefits than a control group that continued routine activity and walking.

⚠What it shows: One single-centre randomised trial, 57 adults aged 45-60 with type 2 diabetes and dyslipidaemia, 12 weeks only; the abstract reports body composition and self-reported quality of life but no blood lipid or glucose outcomes, and the control group simply carried on walking.Study · Cureus

In a 12-week randomised trial, 23 resistance-trained adults bulking on a 16:8 time-restricted eating schedule gained similar fat-free mass, muscle mass and 1RM strength to controls, but significantly less body weight and fat mass. The time-restricted group ate fewer calories, protein and carbohydrate than prescribed, so the smaller fat gain reflects intake falling short of the target surplus rather than meal timing itself.

⚠What it shows: Small 12-week RCT in 23 healthy resistance-trained individuals, with body composition measured by single-frequency bioelectrical impedance; the eating-window group failed to hit the prescribed energy surplus, so the fat-mass difference is confounded by lower intake.Study · J Nutr

In a 24-week randomised trial of 120 overweight or obese adults with type 2 diabetes, calorie-carbohydrate restriction with or without time-restricted eating significantly reduced hunger and increased satiety compared with control, with no significant difference between the two intervention groups. Binge eating scale scores and objective binge episodes did not differ significantly between any of the groups at any time point.

⚠What it shows: One 24-week randomised trial with 120 adults with type 2 diabetes, 40 per group; appetite was rated on subjective scales, participants were not selected for high baseline binge eating scores, and binge outcomes did not move.Study · Appetite

In a 12-week multicentre randomised trial, adding early, late or self-selected 8-hour time-restricted eating to Mediterranean diet-based usual care reduced MRI-measured hepatic fat within each group, but none of the timings beat usual care or each other, and liver markers and faecal microbiota showed no between-group differences. Larger liver fat reductions tracked with baseline steatosis and with achieving ≥5% weight loss, which more people managed on time-restricted eating than on usual care (41-44% vs 16%).

⚠What it shows: One 12-week randomised trial in adults with overweight or obesity (arms of 49, 49, 52 and 47); the study was not powered for secondary outcomes such as liver markers and microbiota, and follow-up ended at 12 weeks.Study · JHEP Rep

A meta-analysis of 25 randomised trials in 2,078 healthy older adults found exergaming — training with active video games — improved muscle strength and balance versus conventional therapies, with the biggest mobility gains when training ran at three or more sessions per week.

⚠What it shows: Meta-analysis of 25 RCTs (n=2,078, at least 80% female, mean age 71.5 years); effects varied by console, game type and training dosage across numerous subgroup analyses, and generalisability to older men is limited.Meta-analysis · Exp Gerontol

Hill sprints are prized for building leg strength and speed, but a meta-analysis of 13 randomised trials found no significant pooled effect of uphill running on knee strength, jump performance or aerobic capacity. Narrative evidence still hinted at better running economy, repeated sprint ability and lactate clearance.

⚠What it shows: Meta-analysis of 13 RCTs but only 7 could be pooled, total n=308, with varied protocols and comparators; the authors rate the overall certainty of evidence as low.Meta-analysis · Medicine (Baltimore)

In a triple-blind trial of 60 first-time mothers, a daily 700 mg fenugreek seed extract capsule taken from the first postpartum week until day 60 was associated with better self-reported sleep quality than placebo at days 30 and 60. The two groups' sleep scores already differed significantly before treatment started, so the analysis had to be adjusted for that gap.

⚠What it shows: One small trial, n=60 first-time mothers attending health centres in Sabzevar, Iran; the groups differed significantly on sleep scores at baseline (p=0.009), sleep was measured only by self-report questionnaire, and the authors themselves call for objective sleep measurement.Study · Matern Health Neonatol Perinatol

In a three-arm randomised trial of 66 regional and national track and field athletes, written and verbal sleep hygiene advice both significantly improved Sleep Hygiene Index scores compared with a control group, but ten days of actigraphy showed no significant change in objective sleep parameters. The only hint of benefit was a non-significant increase in total sleep time driven by earlier bedtimes.

⚠What it shows: One RCT in 66 track and field athletes over a ten-day intervention; the only significant improvement was a self-reported questionnaire score, six objective actigraphy measures did not shift, and the total sleep time trend was not statistically significant.Study · J Sports Med Phys Fitness

A 12-week programme combining physical exercise with internet-delivered CBT improved six-minute walk distance by 81.6 m more than control in 80 adults with mild-to-moderate depression, exceeding the accepted threshold for a clinically meaningful change. None of nine endocannabinoid biomarkers, including anandamide and 2-AG, shifted more in the intervention group than in controls.

⚠What it shows: Single randomised trial, 80 adults with mild-to-moderate depression, 12 weeks plus an 8-week follow-up; the primary analysis was on completers, muscular fitness outcomes were exploratory and non-significant, and depression symptom change is not reported in this abstract.Study · Eur Arch Psychiatry Clin Neurosci

In a three-arm randomised trial of 122 UK undergraduates, five consecutive days of digital attachment security priming or mindfulness practice both produced significant longer-term improvements in stress, insomnia, emotion regulation and academic dropout intention compared with a waitlist control. Attachment priming produced the most consistent and substantial benefits across the follow-up points.

⚠What it shows: One randomised trial in 122 UK undergraduate students, compared against a waitlist rather than an active placebo, all outcomes self-reported and follow-up ending at four weeks; effect sizes were not given in the abstract.RCT · Appl Psychol Health Well Being

A critical review with meta-analysis found that vitamin D's apparent protection against acute respiratory infections was confined to small trials: the summary odds ratio was 0.69 in trials of 25 to fewer than 248 patients but 0.98 in trials of 248 to 16,000 patients (interaction p = 0.0001), with strong evidence of publication bias.

⚠What it shows: A meta-analysis of previously published randomised trials, not new experimental data; the acute respiratory infection trials were re-analysed from an earlier pooled dataset, and the analysis splits trials by size, which can be confounded by differences in populations, doses and outcome definitions. It shows the benefit signal is fragile, not that vitamin D is useless for people who are deficient.Meta-analysis · PLoS One

Across two accelerometry cohorts of adults with both diabetes and hypertension — 4,294 in UK Biobank and 530 in NHANES — higher peak 30-minute activity intensity was associated with lower all-cause mortality (hazard ratio 0.43 and 0.57 respectively), while total daily activity volume was associated with mortality in UK Biobank (HR 0.66) but attenuated to non-significance in NHANES (HR 0.95).

⚠What it shows: Observational analysis of two population cohorts with wrist accelerometry — 4,294 and 530 adults who had both diabetes and hypertension, with 731 and 123 deaths — so these are associations, not proof that harder activity extends life; reverse causation from existing illness and residual confounding cannot be excluded.Study · Acta Diabetol

A meta-analysis of 24 studies (1,972 participants, 71.46% female) found that low-intensity physical activity — Baduanjin, tai chi, walking and general activity — significantly reduced knee osteoarthritis pain (d = -0.65) and stiffness (d = -0.71) and improved physical function (d = -0.58) in middle-aged and older adults.

⚠What it shows: Pooled from 24 trials of mixed quality (assessed with the Cochrane risk-of-bias tool) in middle-aged and older adults with knee osteoarthritis, mostly women; exercise trials cannot blind participants, so effect sizes for self-reported pain may be flattered, and the review does not establish which modality is best.Meta-analysis · J Aging Phys Act

Pooled across 22 randomised trials, text-message interventions improved medication adherence and reduced systolic blood pressure by 6.12 mmHg and diastolic by 2.66 mmHg, but produced no significant improvement in BMI, LDL, HDL, total cholesterol or HbA1c.

⚠What it shows: Meta-analysis of 22 randomised trials, but heterogeneity between studies was extreme for the blood-pressure outcomes (I² of 96% for systolic and 85% for diastolic), populations varied widely, and long-term effects were not established.Meta-analysis · BMC Public Health

Across 17 prospective cohorts of East Asian men, light drinking (up to 20 g/day) was associated with a lower risk of ischaemic stroke (RR 0.85) and lower all-cause mortality (RR 0.83), while intake above 60 g/day was associated with markedly higher haemorrhagic stroke (RR 1.74) and death from any cause (RR 1.32). The relationship was dose-dependent, with risk rising as intake climbed.

⚠What it shows: Meta-analysis of 17 prospective cohort studies, but entirely observational and restricted to East Asian men (cohorts ranged from 1322 to 108,461 subjects); data on women were too limited to include. Associations cannot establish cause, and residual confounding can flatter apparent benefits at low intakes.Meta-analysis · Zhonghua Yi Xue Za Zhi