6 Things You BLAME On Age - No, Age Only Did 2

6 things you blame on age: gray hair, weight gain, stiff knees, bad sleep, memory, and reading glasses. Only 2 are actually aging. Here's which two. The metabolic slowdown you were promised in your 40s never existed — measured energy expenditure is flat from 20 to 63. Knee arthritis has doubled since the mid-20th century in people of the same age and the same weight. And dementia rates at any given age have been falling for decades. Two of these six are genuine aging. The other four moved while human biology stayed exactly where it was. #Aging #GenX #healthafter50 SOURCES Knee arthritis doubled at matched age and weight — Wallace et al., PNAS 2017: https://www.pnas.org/doi/10.1073/pnas.1703856114 (Correction: I say 11% against 5% for knee arthritis. The paper's matched figures are 15% against 8% — the doubling holds, my two numbers didn't). Energy expenditure flat from 20 to 63 — Pontzer et al., Science 2021: https://www.science.org/doi/10.1126/science.abe5017 Portion sizes 1977–1998 — Nielsen & Popkin, JAMA 2003: https://jamanetwork.com/journals/jama/fullarticle/195813 Jobs burn ~140 fewer calories a day — Church et al., PLoS ONE 2011: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0019657 Sleep-disordered breathing, 17% of men 50–70 — Peppard et al., Am J Epidemiol 2013: https://academic.oup.com/aje/article/177/9/1006/145450 Sleep architecture across the lifespan — Ohayon et al., Sleep 2004: https://academic.oup.com/sleep/article/27/7/1255/2696819 Older adults need 7–9 hours — National Institute on Aging: https://www.nia.nih.gov/health/sleep/sleep-and-older-adults Dementia incidence down 13% per decade — Wolters et al., Neurology 2020: https://www.neurology.org/doi/10.1212/WNL.0000000000010022 US dementia prevalence 11.6% → 8.8% — Langa et al., JAMA Internal Medicine 2017: https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2587084 Gray hair and stalled pigment stem cells — Sun et al., Nature 2023: https://www.nature.com/articles/s41586-023-05960-6 IRF4 and when you go gray — Adhikari et al., Nature Communications 2016: https://www.nature.com/articles/ncomms10815 Presbyopia worldwide — Fricke et al., Ophthalmology 2018: https://www.aaojournal.org/article/S0161-6420(17)33797-1/fulltext