Susan Molchan is a regular contributor at HealthNewsReview.org. She is a psychiatrist in the Washington D.C. area and tweets as @SusanMolchan.
There it was again: Another article touting “simple blood tests” together with an alarming headline about Alzheimer’s disease “coming for you.”
I thought I’d missed something in the research news but no, an article in the Nov. 17 Sunday Review of The New York Times focused on ApoE4, a protein in the blood, discovered to be a risk factor for dementia almost 25 years ago.
It’s just one of many risk factors for dementia–and one of over 20 genetic risk factors, albeit the one identified as contributing the highest risk. It’s also a risk factor for heart disease, as well as a subtype of dementia associated with blood vessel disease.
How much more risk, or susceptibility, does it add? You won’t find this information in the article, which was titled “What if you knew Alzheimer’s disease was coming for you? Simple blood tests may soon be able to deliver alarming news about your cognitive health.”
If you’re going to use the phrase “alarming news” in the subtitle, I’d like to know how alarmed I should be.
According to the story, the test is not widely used because “health organizations discourage patients from learning their ApoE genotype,” warning they may not cope well with the news “or will misinterpret the results.”
In reality, doctors don’t use it because it’s not a good predictor of who will get dementia.
One-third to one-half of people who develop Alzheimer’s disease don’t carry ApoE4, and many who do carry it don’t develop dementia. How much risk it adds depends on race, gender, age, and probably a mix of other factors. Furthermore, scientists have done many studies on how people handle the news of their ApoE status, and contrary to what the article says, people handle it quite well.
The story does note that Alzheimer’s disease is actually a multifactorial illness. It also highlights some risk factors besides genetic markers: poor diet, a sedentary lifestyle, inflammation, and exposure to chemicals.
So what is the absolute risk of getting dementia by age 80? The author notes that “25-50% will show signs of Alzheimer’s by the age of 85.” That’s quite a spread. Regardless, most of us will be dead before that (especially men, by age 79, according to life expectancy figures in the U.S.). Most people with dementia are in their 80s, and getting old is the biggest risk factor of all.
Anecdotes can be powerful in giving a human face to medical struggles. That the story would contrast two patients’ polar opposite reactions to testing positive for ApoE4 is noteworthy. Perhaps it reveals just how inappropriately the ApoE4 test is used in counseling patients. In short, these women agonized over lifestyle changes based on a surrogate marker — ApoE4 — that is no guarantee either will develop Alzheimer’s.
Anecdote 1: A 49-year-old woman with poor circulation, blood-sugar swings and generally poor health. So what does she do? She has her genes sequenced, and is “terrified” to find she’s cursed with a double dose of the bad ApoE4. She ends up with a physician who tells her not to bother with her diet or to exercise.
Anecdote 2: A more resourceful woman who — on finding her ‘affliction’ with ApoE4 — is motivated to exercise and watch her diet.
But wouldn’t this be the advice of any doctor, to any patient, at any age? If a blood test helps motivate a patient, great. But the ApoE4 test might convince millions of people they are living with a “‘pre-Alzheimer’s’ condition.” That’s misleading. That’s a bit like saying millions of us could be living with a pre-death condition.
Last year I wrote about news media coverage of Alzheimer’s disease and the focus on finding a drug remedy, to the relative neglect of the importance of lifestyle factors. This despite evidence that the prevalence of dementia is decreasing in the U.S. and Europe (by 44% in the most recent cohort of the Framingham Heart Study).
Although no randomized-controlled trials show one can reduce dementia risk by lifestyle interventions, scientists have made progress toward this goal. For example, in the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment (FINGER), over 1,200 Finns at risk for dementia (determined by factors such as high blood pressure, cholesterol, blood sugar, or poor heart health) participated in a 24-month program of dietary improvements, as well as increased mental and physical activity. Those in the program had considerably higher (25%) global cognitive function by the end of the study period than those in the non-intervention group.
Instead of so much coverage of blood tests and drugs, wouldn’t it be great if more media stories pointed to studies such as FINGER?