Cognitive Risk Factors
Evidence-based research summaries on every known risk factor for cognitive decline and dementia. Understand what the science says about your risk — and which factors you can actively manage.
These guides are for educational purposes only. Consult a healthcare professional if you have concerns about your cognitive health.
Non-modifiable Risk Factors
Risk factors you cannot change — but can monitor and factor into your management strategy.
How a Family History of Alzheimer's Affects Your Cognitive Health
A first-degree relative with Alzheimer's disease increases your lifetime risk. Here is what the evidence says about how large that increase is, which lifestyle factors modify it, and why monitoring your cognitive baseline matters.
How a Family History of Dementia Affects Your Cognitive Health
Dementia runs in families — through both shared genes and shared environments. Here is what the evidence says about your risk and what meaningfully changes the odds.
How the APOE4 Gene Affects Your Cognitive Health
APOE4 is the largest known genetic risk factor for late-onset Alzheimer's disease. Here is a clear-eyed look at what carrying this variant actually means — and does not mean.
How a Previous Head Injury Affects Your Cognitive Health
Head injury — from a single moderate traumatic brain injury to repeated concussions — is a recognized risk factor for cognitive change later in life. Here is what the evidence says.
How Being Over 50 Affects Your Cognitive Health
Age is the largest risk factor for dementia, but the 50s are when lifestyle interventions have the greatest impact on long-term trajectory. Here is what the evidence says.
How Aging Past 65 Affects Your Cognitive Health
Age is the single most significant risk factor for dementia, but most people over 65 will not develop it. Here is what the evidence says about what changes with age, what does not, and how to monitor your own trajectory.
How a History of Traumatic Brain Injury Affects Your Cognitive Health
Moderate and severe traumatic brain injuries carry a documented increased risk of later cognitive decline. Here is what the research says, how risk varies by injury severity, and what monitoring can offer.
How a History of Concussions Affects Your Cognitive Health
A single concussion carries modest long-term risk, but multiple concussions over a lifetime are a meaningful cognitive risk factor. Here is what the research says and what you can do with this information.
How a Family History of Down Syndrome Affects Your Cognitive Health
People with a sibling who has Down syndrome have a modestly elevated risk of Alzheimer's disease. Here is why this genetic link exists and what it means for your cognitive monitoring.
How Female Sex Affects Cognitive Health and Dementia Risk
Women represent nearly two-thirds of all people with Alzheimer's disease. Longer lifespan explains part of this — but not all of it. Here is what the research actually says.
Vascular Risk Factors
Cardiovascular and metabolic conditions that directly affect brain blood supply and health.
How High Blood Pressure Affects Your Cognitive Health
Hypertension is one of the most powerful modifiable risk factors for cognitive decline and dementia. Here is the evidence — and what treating it can do for your brain.
How Type 2 Diabetes Affects Your Cognitive Health
Type 2 diabetes increases dementia risk by up to 65%. Here is why — and what optimal diabetes management means for your brain.
How High Cholesterol Affects Your Cognitive Health
Midlife elevated cholesterol — particularly LDL cholesterol — is a modifiable risk factor for Alzheimer's disease and vascular dementia. Here is what the evidence shows.
How Obesity Affects Your Cognitive Health
Midlife obesity increases dementia risk through multiple mechanisms. Here is what the evidence shows about body weight and your brain — and what reducing that risk requires.
How Cardiovascular Disease Affects Your Cognitive Health
What is good for the heart is good for the brain — and what damages the heart damages the brain. Here is the evidence linking cardiovascular disease and cognitive health.
How Metabolic Syndrome Affects Your Cognitive Health
Metabolic syndrome is not just a cardiovascular problem. The cluster of high blood pressure, abdominal obesity, insulin resistance, and dyslipidemia is one of the more modifiable drivers of cognitive aging.
How Atrial Fibrillation Affects Your Cognitive Health
Atrial fibrillation is not just a heart rhythm problem. It is one of the most consistently documented vascular drivers of cognitive decline — even in people who have never had a stroke.
How a History of Stroke Affects Your Cognitive Health
Stroke is one of the most powerful risk factors for dementia. Even strokes that appear to fully resolve leave lasting effects on the cerebrovascular architecture that underlies cognitive function.
Lifestyle Risk Factors
Modifiable behaviors and conditions with the strongest evidence for dementia risk reduction.
How Sleep Apnea Affects Your Cognitive Health
Sleep apnea causes repeated nighttime oxygen drops that impair brain maintenance, memory consolidation, and long-term cognitive health. Here is what the research shows — and why treatment matters.
How Poor Sleep Quality Affects Your Cognitive Health
Sleep is not passive recovery — it is when the brain performs critical maintenance. Chronic poor sleep disrupts processes essential for long-term cognitive health. Here is the evidence.
How a Sedentary Lifestyle Affects Your Cognitive Health
Physical inactivity is among the most powerful modifiable risk factors for cognitive decline and dementia. Here is what the evidence says — and what kind of exercise actually helps.
How Social Isolation Affects Your Cognitive Health
Social isolation is an increasingly recognized risk factor for cognitive decline. Here is the neuroscience behind why human connection matters for brain health.
How Hearing Loss Affects Your Cognitive Health
Hearing loss is one of the single largest modifiable risk factors for dementia — yet it is frequently untreated. Here is the evidence for why your ears matter for your brain.
How Untreated Depression Affects Your Cognitive Health
Depression affects brain structure, impairs cognitive function, and increases long-term dementia risk. Here is what the evidence shows — and why treating depression is also treating your brain.
How Chronic Stress Affects Your Cognitive Health
Sustained psychological stress has measurable effects on brain structure and function. Here is what the neuroscience says about stress, the hippocampus, and long-term cognitive health.
How Smoking Affects Your Cognitive Health
Smoking is a significant and underappreciated cognitive risk factor — not just a cardiovascular one. Here is what the evidence shows about smoking, the brain, and what cessation can do.
How Excessive Alcohol Affects Your Cognitive Health
Heavy alcohol consumption is a recognized, significant, and largely reversible risk factor for cognitive decline. Here is what the neuroscience says.
How Chronic Anxiety Affects Your Cognitive Health
Chronic anxiety is not just an emotional experience — it has documented effects on brain structure and function. Here is what the research shows about anxiety and long-term cognitive health.
How Chronic Insomnia Affects Your Cognitive Health
Chronic insomnia does more than make you tired. Persistent sleep difficulty is one of the more actionable risk factors for accelerated cognitive aging and dementia.
Environmental Risk Factors
Occupational, hormonal, and environmental exposures that affect cognitive health.
How Long COVID Brain Fog Affects Your Cognitive Health
Post-COVID cognitive symptoms are real, measurable, and affect a meaningful proportion of those infected. Here is what the research currently shows.
How Menopause Affects Your Cognitive Health
The cognitive changes of menopause are not imagined — they are documented in research. Here is what happens to the brain during this transition and what you can do.
How Thyroid Disorders Affect Your Cognitive Health
Thyroid dysfunction is one of the most common and most treatable causes of cognitive symptoms in adults over 40. Here is what you need to know.
How Vitamin Deficiencies Affect Your Cognitive Health
Several vitamin deficiencies — particularly B12, vitamin D, and folate — cause measurable cognitive impairment that is largely reversible with treatment. Here is what to know.
How Air Pollution Exposure Affects Your Cognitive Health
Air pollution is an emerging and significant environmental risk factor for cognitive decline. Here is what the research shows about fine particulate matter and your brain.
How Shift Work Affects Your Cognitive Health
Long-term shift work is associated with chronic circadian disruption and cumulative sleep debt — both of which have documented effects on cognitive function and long-term brain health.
How Chemotherapy Affects Your Cognitive Health
Post-chemotherapy cognitive impairment — widely known as 'chemo brain' — affects a significant proportion of cancer survivors. Here is what the research shows about why it happens and what to expect.
How a History of Contact Sports Affects Your Cognitive Health
Contact sports involving repeated head impacts — football, boxing, hockey, rugby — are associated with elevated cognitive risk later in life. Here is what the evidence says and what is still uncertain.
How Military Service and Blast Exposure Affect Your Cognitive Health
Combat veterans face elevated rates of traumatic brain injury from blast exposure and other mechanisms that carry meaningful long-term cognitive risk. Here is what the evidence says.
How Perimenopause Affects Your Cognitive Health
Cognitive changes during perimenopause — brain fog, word-finding difficulty, memory lapses — are real and documented. Understanding the difference between hormonally-driven symptoms and early pathology matters.
Know your risk. Track your baseline.
Understanding your risk factors is step one. Step two is building the personal data record that lets you detect change early — before it becomes clinically obvious.
Free to start. No account required. Not a diagnostic tool.