Researchers have especially observed a link with “prospective” memory: that which allows us not to forget what we had planned to do. An interesting avenue, but which does not allow us to predict Alzheimer’s disease or to know, on an individual scale, how our brain will age.
What if the problem isn’t age, but how quickly we age?
At 45, forgetting to take a medication or suddenly realizing that you missed an appointment can give rise to a nagging worry: is it simply fatigue, a busy life… or a sign that something is changing in the brain?
A team from Pennsylvania State University looked into this question by following adults for around ten years. His study, published in September 2026 in The Journals of Gerontology: Series Ainvolves 232 participants from the large American MIDUS study.
The researchers didn’t just measure their biological age. They mainly sought to determine how quickly their bodies seemed to age. To do this, they analyzed blood samples taken between 2004 and 2009 using three measures of epigenetic aging. Among them,
DunedinPACEa ‘clock’ based on chemical changes to DNA, estimates the rate at which a person ages biologically.
David M. Almeida, lead author of the study, sums up the difference with a telling image:
“Biological aging basically means that your body appears older than your birth date suggests. We see this thanks to the chemical modifications of our DNA, which constitute a sort of molecular register of the aging of the organism. Many of these tests are like a car’s odometer: they show your age and the extent of changes associated with aging. In this study, the most relevant measure turned out to be an indicator of the speed of aging in our 40s and 50s“.
And it is precisely this speed which seems to have counted.
The signal appears especially between 40 and 49 years old
Around ten years after the blood samples, between 2017 and 2019, the participants were interviewed eight times by telephone on their daily forgetfulness. Researchers distinguished two forms of memory failure.
- The first is said retrospective : forgetting the name of someone you know or information you already knew;
- The second is prospective : forgetting to do something you had planned, such as taking treatment or going to an appointment.
On average, participants reported approximately two prospective omissions per week and retrospective forgetting a little less than every other day.
However, the results show an important difference: the measures corresponding to biological “age” were not associated with forgetting. On the other hand, in people whose biological aging was more rapid, the risk of experiencing a
prospective forgetting was 18% higher on a given day. Over the course of a month, this represents approximately
five more days with an oversight.
The phenomenon was particularly visible among participants aged 40 to 49 years oldwhich brings to the fore what researchers describe as a possible period of vulnerability in midlife.
A period which is not insignificant. “In midlife, people have a lot of responsibilities: at work, in their social life, with their children and their parents. Rapid aging occurring during this period of life may have a specific link to later memory problems“, recalls David M. Almeida.
A forgotten medication does not have the same weight as a pair of keys
This distinction between the different omissions is essential. Looking for your keys for ten minutes is annoying. Regularly forgetting a treatment or a medical appointment can have concrete consequences on your health.
The researchers also point out that frequent prospective forgetting has been associated, in previous work by other teams at Penn State, with a greater later risk of certain dementias, notably Alzheimer’s disease.
However, this does not mean that participants in this study will develop dementia.
The study shows an association between the speed of biological aging and certain forgetfulness, not a cause and effect relationship. DunedinPACE also remains primarily a
search tool. The sample is relatively small and memory problems were reported by the participants themselves. Many factors can also influence memory in midlife, from sleep to circulatory problems, stress or certain health difficulties.
For David M. Almeida, the issue is therefore less about being alarmed at the first forgetting than about don’t wait to talk about it when a change becomes unusual or bothersome :
“Don’t hesitate to talk to your doctor about memory changes you might experience in your 40s or 50s; this could constitute an early warning system.”
Because at 40 or 45 years old, an isolated memory lapse is not necessarily worrying. On the other hand, when forgetfulness becomes frequent, interferes with daily life or seems to take hold, it is worth mentioning.
And this is perhaps the most interesting message of this study: cognitive health does not begin to be monitored in old age. Midlife could be a period where certain changes are already perceptible — and where it is still possible to act on many factors likely to sustainably preserve quality of life.