Test, Don't Guess: The Lab Tests That Matter Most for Men Over 50
The blood tests that matter most after 50 — PSA, testosterone, vitamin D, A1C and cholesterol — explained in plain English, plus how to order them online.
OPA Nutrition Blog
Supplement & Wellness Guides
Plain-English guides to CoQ10, magnesium, gut health, sleep, blood sugar and more: what the research says and how to choose the right supplement.
169 articles
Sleep and Aging: Why Sleep Changes as You Get Older and What Helps
A plain-English guide to sleep and aging: how sleep changes after midlife, how much older adults need, what the research says about sleep and longevity, the habits that help, and what to check on a sleep supplement label.
Biological Age Tests and Epigenetic Clocks: What They Can and Can't Tell You
A plain-English guide to biological age: how it differs from chronological age, how epigenetic clocks from Horvath to DunedinPACE work, how accurate consumer tests are, where AI fits, and what the CALERIE trial found.
How to Read a Supplement Facts Label (With a Real OPA Example)
A line-by-line guide to the Supplement Facts panel: serving size, servings per container, amount per serving, plant part, %DV, "Daily Value not established" and other ingredients, using the real OPA Resveratrol 600 mg label as the worked example.
Healthspan vs Lifespan: What 'Healthy Aging' Actually Means
A plain-English guide to healthspan and lifespan: how each is defined and measured, how big the gap is in the US and worldwide, the 12 hallmarks of aging, and what official guidance says actually helps.
Sirtuins Explained: The Longevity Proteins Everyone Talks About
A plain-English guide to sirtuins: what SIRT1 to SIRT7 do, how NAD+ fits in, where the resveratrol story went wrong, and what has actually been shown in people.
Vitamin B12: Benefits Research, Dosage, Forms, Safety and Interactions
What vitamin B12 does, how much you need by life stage, the best food sources, how the four forms compare, and what research says about popular claims.
CoQ10: Ubiquinone vs Ubiquinol, Research, Dosage and Safety
Ubiquinone vs ubiquinol: how the two CoQ10 forms differ, what absorption studies found, doses used in research, food sources and safety notes.
Saw Palmetto: Research, Dosage, Safety and Interactions
Saw palmetto explained: extract forms, how it is thought to work, what large trials found, the 320 mg dose studied, safety and interactions.
Quercetin: Benefits Research, Forms, Dosage, Safety and Interactions
What quercetin is, which forms absorb best, what human trials actually measured, doses used in studies, and the safety and interaction facts to know.
Resveratrol: Benefits Research, Dosage, Safety and Interactions
What resveratrol is, trans vs cis forms, why so little reaches the blood, what human trials measured, the doses studied and its safety and interactions.
Turmeric and Curcumin: Benefits Research, Dosage, Safety and Interactions
Turmeric vs curcumin, absorption forms like black pepper, what joint trials measured, doses studied, and the liver and drug-interaction safety facts.