Optimal Exercise Dose for Depression in Older Adults: Network Meta-Analysis

What’s the best exercise for depression in older adults?

Walking is the most effective exercise type for alleviating depressive symptoms in older adults, with aerobic exercise showing optimal benefits at approximately 5.5 hours per week of moderate-intensity activity. A systematic review and network meta-analysis of 47 randomized controlled trials with 2,895 participants published in BMC Geriatrics found that walking, aerobic exercise, yoga, qigong, resistance training, and tai chi all significantly improve depression, with walking ranking first in effectiveness.

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How Much Vitamin C Is Enough? Landmark Study Reveals Blood Levels, Dosing, and Urinary Loss

Dr. Kumar’s Take:

This landmark NIH study shows that plasma vitamin C levels rise steeply with low-to-moderate doses, then plateau at higher intakes. Most people reach near-maximal blood levels with just 200 mg daily, and above 400 mg/day, your body starts dumping the extra in urine. For optimal absorption and benefit, aim for 200 mg daily from food or supplements.

Key Takeaways:

✔ Plasma vitamin C increases quickly with doses up to 100 mg/day, then plateaus at higher intakes.
✔ Maximal white blood cell (immune cell) saturation occurs at 100 mg/day; plasma is near-maximal at 200 mg/day.
✔ No vitamin C is lost in urine until about 100 mg/day; after 400 mg/day, most extra is excreted.
✔ High doses above 1000 mg/day may increase urine oxalate and uric acid, with no added benefit.

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A Randomized Controlled Trial of Mindfulness-Based Cognitive Therapy for Major Depressive Disorder in Undergraduate Students: Dose-Response Effect, Inflammatory Markers and BDNF

Introduction

This randomized controlled trial examined the dose-response effect of mindfulness-based cognitive therapy (MBCT) for college students with major depressive disorder (MDD), investigating both clinical outcomes and biological markers including inflammatory cytokines and brain-derived neurotrophic factor (BDNF).

Study Design and Participants

This was a 2-month double-arm randomized controlled trial (RCT) with registration number ChiCTR2100044309. The study recruited 60 undergraduate students with first episode and untreated MDD meeting DSM-5 diagnostic criteria from universities in Kunming, Yunnan, China.

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