| Evidence | Strength of Evidence |
Smoking | 1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1568603/ 2. https://spotlight.kaiserpermanente.org/heavy-smoking-doubles-risk-of-alzheimers-or-vascular-dementia/ | Very Strong |
Obesity | 1. https://www.uclahealth.org/u-magazine/more-obesity-blues | Very Strong |
Stress | 1. https://www.ncbi.nlm.nih.gov/pubmed/1393587 | Very Strong |
Carbon Monoxide | 1. https://www.health.harvard.edu/a_to_z/carbon-monoxide-poisoning-a-to-z | Very Strong |
Heavy Metals | 1. http://sitn.hms.harvard.edu/flash/2016/deadly-biology-lead-exposure/ 2. https://www.harvardmagazine.com/2004/05/mercury-on-the-brain.html | Very Strong |
Repetitive Brain Trauma | 1. http://pnl.bwh.harvard.edu/education/what-is/chronic-traumatic-encephalopathy/ | Very Strong |
Alcohol | 1. https://www.ncbi.nlm.nih.gov/pubmed/22906480 2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5460585/ | Strong |
Dehydration | 1. https://www.ncbi.nlm.nih.gov/pubmed/22855911 | Strong |
Sleep Apnea | 1. https://www.sciencedaily.com/releases/2010/02/100201091638.htm | Strong |
Trans fat | 1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4470692/ 2. https://www.ncbi.nlm.nih.gov/pubmed/12728744 | Moderate |
Sugar | 1. https://www.psychologytoday.com/us/blog/prime-your-gray-cells/201110/why-sugar-high-leads-brain-low 2. https://pubsapp.acs.org/cen/science/87/8720sci1.html | Moderate |
Mold Spores | 1. https://www.sciencenews.org/article/mold-may-mean-bad-news-brain | Moderate |
Blue Light | 1. https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side | Very Weak |