Hazel found me at the library in downtown Asheville on a rainy Wednesday in early June, the kind where everyone keeps their voices low because the weather has already set the mood. She'd retired from teaching seventh-grade English in Buncombe County two years before. Soft white braids, reading glasses on a beaded chain, a tote bag full of yellow legal pads. She slid into the chair across from me at one of the long oak tables in the reading room and didn't waste time on hello.
"Eleanor, my sister was diagnosed with Alzheimer's in March. I'm seventy-two. I want to know what I can actually do. Not the magazine articles. Not another supplement nobody can pronounce. What does the real research say?"
I closed the book in my lap. The librarian at the front desk looked over and smiled the way she does at me, which is to say slightly amused that I keep showing up.
What I told Hazel, and what I want to tell you this June during Alzheimer's & Brain Awareness Month, is that the answer is more hopeful than most people realize. And more concrete.
In 2024, the Lancet Commission on dementia prevention updated its landmark report. The headline finding: up to 45 percent of dementia cases worldwide could be prevented or delayed by addressing 14 modifiable risk factors across the lifespan. That number is not from a wellness blog. It is from a peer-reviewed standing commission of dementia researchers (The Lancet, 202401296-0/fulltext)).
Forty-five percent. Almost half. Not all of it within our control after seventy. But more than people think.
The Lancet Commission's 14 Risk Factors
The original 2020 report identified 12. The 2024 update added two: high LDL cholesterol in midlife, and untreated vision loss in later life. Here is the full list, organized roughly by life stage:
Early life: less education (before age 18)
Midlife (45-65): hearing loss, traumatic brain injury, hypertension, alcohol consumption (over 21 units/week), obesity, high LDL cholesterol
Later life (65+): smoking, depression, social isolation, physical inactivity, diabetes, air pollution, untreated vision loss
Hearing loss alone accounts for roughly 7 percent of preventable dementia risk. That makes it the single largest contributor on the list. Surprised me when I first read it. Surprises everyone.
This article is informational, not medical advice. Talk to your doctor before starting or stopping treatments, supplements, or medications.
The Risk Factor Nobody Treats: Hearing Loss
Hazel hears fine. Her sister, the one in memory care now, had untreated hearing loss for almost fifteen years before any of them connected the dots.
Hearing loss is the heaviest hitter on the Lancet's list. The leading theory is straightforward: when the brain works harder to decode muffled sound, it pulls cognitive resources from memory and reasoning. Add in the social withdrawal that often follows. Fewer dinners out. Fewer phone calls. Fewer conversations, because they're exhausting. The brain loses two things at once: stimulation and connection.
The encouraging part is that treatment helps. A 2023 ACHIEVE trial published in The Lancet found that hearing aids slowed cognitive decline by nearly half in older adults already at higher dementia risk.
This month: get your hearing tested. If your last screening was more than two years ago, or never, schedule one. Costco offers free testing. Many audiologists do too. Over-the-counter hearing aids now run $200 to $1,500 versus the older prescription range of $4,000 to $8,000. I wrote more about OTC hearing aids and what actually helps if you want a deeper look.
Education, Hypertension, and the Long Game
Less education before eighteen made the list because cognitive reserve is partially built early. You cannot rewind to 1968. But reserve keeps building across a lifetime. Reading. Learning. Conversation that stretches you. The 2017 ACTIVE study, which I covered in what the science actually says about brain training, found that one type of computerized training — speed-of-processing — cut dementia risk by 29 percent over a ten-year follow-up.
Hypertension quietly sets the table for trouble. Target below 130/80 for most adults sixty-plus. This month: take your blood pressure. Cuffs cost $40 at any pharmacy. High LDL cholesterol works the same way. Plaque is plaque.
Head Injury and the Helmet Conversation
A single moderate-to-severe traumatic brain injury raises lifetime dementia risk by roughly 25 percent. Repeated mild concussions add up too. The damage may show up decades later, which is part of why this risk factor surprises people the first time they read it.
For seniors, the practical concern isn't football. It's falls.
Falls are the leading cause of TBI in adults over sixty-five. I have written before about strength training after seventy, and this is one of the reasons it matters more than people realize. Stronger legs. Better balance. Fewer falls. Fewer head injuries. Less downstream cognitive damage.
Most falls in this age group happen at home, on a familiar floor, in the middle of a familiar day. That is not a comforting fact, but it is a useful one. The risk is closer than people imagine, and the prevention is closer too.
This month: if you bicycle, wear a helmet. Every ride, even the short one to the farmers market. If you have rugs that slide, anchor them or remove them. If you take a medication that makes you dizzy, ask your doctor whether the timing or dose can change. If your bathroom doesn't have a grab bar near the tub, add one. They're $30 at any hardware store and they install in twenty minutes.
Alcohol and the Number That Surprised Me
The Lancet threshold is 21 units per week. A unit is roughly half a standard glass of wine. So somewhere around ten to twelve glasses a week is where the brain starts to register damage.
That is more than I would have guessed in either direction. Not zero. Also not the once-with-dinner habit most people I know in my Seasons of Grace community describe.
This month: track honestly for two weeks. Not to shame yourself. Just to know. Most people are surprised. Some find they're under and stop worrying. Some find they're over and quietly cut back.
Obesity, Diabetes, and What Connects Them
Obesity in midlife and diabetes at any age both drive inflammation and insulin resistance. Two processes increasingly understood to damage the brain over time. Some researchers now informally refer to Alzheimer's as "type 3 diabetes" because of how closely the metabolic pathways overlap. The implication is uncomfortable but useful: what you do for your blood sugar at fifty-five may be doing quiet work for your brain at seventy-five.
The research is messy on weight loss after seventy. Aggressive dieting in older adults can cost lean muscle mass, which creates its own set of problems including increased fall risk and frailty. The clearer prescription is movement. Steady movement. Walking, swimming, gentle weights. Whatever your body will tolerate today, repeated tomorrow.
If you have diabetes, get your A1C below 7 if your doctor agrees that's appropriate for your situation. Some seniors target slightly higher to avoid hypoglycemia, especially those at risk for falls. Ask whether GLP-1 medications might fit your situation. Early data suggests they may have brain-protective effects beyond blood sugar control. Two retired teachers I know in my Seasons of Grace circle started semaglutide last year for diabetes management and both reported, unprompted, that their thinking felt clearer. Anecdote, not evidence. But interesting.
Smoking, Depression, and the Lifeline
Smoking is the easiest one to explain and the hardest one to do. Quitting at any age reduces dementia risk. The brain begins repairing within months.
Depression is harder. It roughly doubles late-life dementia risk, and untreated depression in someone who is also socially isolated is a particular kind of danger I have watched too many times. Therapy works. Medication works. Both together work better than either alone for many people.
If you or someone you love is in crisis, the 988 Suicide & Crisis Lifeline is available twenty-four hours a day. Just dial 988. Free. Confidential. Real people.
Social Isolation: The Quiet Killer
Social isolation may be the factor I've watched do the most damage in my four decades of this work. Loneliness is not just a feeling. It is a measurable physiological stressor that affects sleep, blood pressure, immune function, and the brain itself. The 2023 U.S. Surgeon General's advisory compared the mortality impact of chronic loneliness to smoking fifteen cigarettes a day. Read that sentence twice. Fifteen cigarettes a day. We took smoking seriously as a public health crisis. We have not yet taken loneliness seriously the same way.
During the early months of the pandemic, I called isolated seniors in western North Carolina nearly every day for half a year. I heard what nine days of human silence does to a person. I am still in touch with two of those women. They are why I write what I write.
A senior who has stopped showing up to the things they used to love is sending a signal. Sometimes the signal is grief. Sometimes it's hearing loss. Sometimes it's depression. Sometimes it's all three at once, woven together in a way that's hard to untangle from the outside. The point is: notice. And then ask, gently.
This month: write down three names of people you have not talked to in over a year. Call one of them this week. Text the other two and propose a call. Imperfect. Awkward. Worth it.
For anyone you are worried about, the Alzheimer's Association 24/7 Helpline at 800-272-3900 is staffed every hour. Real humans. Not a phone tree. They can also help you find local support groups for caregivers and people with early diagnoses.
Physical Inactivity, Diabetes, and Air Pollution
The dose for movement is gentler than people fear. Roughly 150 minutes per week of moderate activity, what feels like a brisk walk where you can talk but not sing, produces measurable brain benefits. Resistance training two or three times weekly adds further protection. Tai chi, yoga, water aerobics. They all count. The body and the brain are a single system, and the secrets to brain health as you age almost always come back to this: keep moving, in whatever way your body allows today.
Medicare Advantage plans often include SilverSneakers, which is free fitness center access at thousands of locations nationwide. If you have an Advantage plan and aren't using it, you are leaving the gym membership on the table.
Air pollution is the factor that feels most outside our control. Check your local AQI on a weather app. On bad-air days, walk inside a mall. Keep windows closed. An indoor HEPA air purifier in the bedroom runs roughly $150 and does measurable work overnight.
Untreated Vision Loss
The mechanism mirrors hearing loss. Less visual input, reduced engagement, increased fall risk. Medicare Part B covers an annual diabetic eye exam if you have diabetes, and an annual glaucoma screening if you are at risk. Original Medicare doesn't cover routine exams or glasses. Many Medicare Advantage plans do. Schedule the exam if it's been more than two years.
The Free Cognitive Screening Most Families Don't Know About
I mentioned this in my piece on memory loss versus dementia, and it deserves repeating because most families still don't know.
Medicare covers a brief cognitive screening as part of the free Annual Wellness Visit, bundled into the AWV's own billing codes (G0438 for the initial visit, G0439 for subsequent ones). If that brief screening raises concerns, the doctor can bill a longer follow-up Cognitive Assessment and Care Plan under code G0505 the same day or at a later visit — that is the more thorough work-up, not the initial screen. Zero out-of-pocket cost. The catch is that fewer than half of eligible Medicare beneficiaries actually receive the screening, even though they are entitled to it. Doctors are busy. Visits run short.
So ask. Before the appointment, call the office and say plainly: "I would like a cognitive screening included in the Annual Wellness Visit." Put it in writing if you have to. A baseline today is the most useful thing you can give the version of yourself who walks into a doctor's office five years from now.
If the screening raises questions, Medicare Part B covers a more thorough cognitive assessment and care plan, subject to the 2026 Part B deductible of $283 and 20 percent coinsurance.
What I Told Hazel, and What I'll Tell You
The rain had let up. Hazel had filled three pages of her yellow legal pad. The librarian had brought us each a cup of bad coffee from the staff break room because she's known me too long to pretend otherwise.
I told Hazel the truth. Not all of these factors are equal. Not all of them apply to her. She doesn't smoke. Her hearing is fine. Her education was a master's in literature from UNC-Greensboro in 1976. Her blood pressure runs low. She walks two miles every morning along the French Broad River with a friend named Coretta, who is seventy-eight and has been walking with her since 2018.
The ones she could move on this month: get her cholesterol checked. Schedule her own cognitive baseline at her next wellness visit. Reach out to her sister's caregivers in Charlotte and ask what she could do, not as a panicked sister, but as a steady one.
I also told her this. Forty-five percent prevention is a population statistic. It does not mean any individual person can guarantee they will not develop dementia. Genetics matter. Plain bad luck matters. We do what we can do. Then we keep living anyway.
What I've found is that people who carry this information well do something specific with it. They pick one factor that applies to them and work on that one this season. They don't try to fix all fourteen. They schedule the hearing test, or buy the blood pressure cuff, or call the friend they haven't called.
Hazel finished her coffee. She slid the legal pad into her tote. She thanked me, the way some people do, with both hands and her whole body, and walked out into the wet afternoon.
If you're sitting with this question. If your mother had it, your father has it, your sister was just diagnosed. I want you to hear something. This month is not too late. Sixty-five is not too late. Seventy-two is not too late. The brain is more responsive to change than people raised in the 1950s were ever taught to believe.
Mary Oliver wrote that attention is the beginning of devotion. Pay attention to your hearing. Your blood pressure. The friend you haven't called. The walk you haven't taken. Pay attention this month, on purpose, with love. That is most of the work. The rest will follow.
