A recent study has pinpointed the age at which the human brain begins to age more rapidly, with findings that could lead to new preventative measures for neurodegenerative diseases like Alzheimer’s, Independent reports.
According to the study, the human brain starts to experience accelerated aging at the age of 44, with a peak in deterioration around age 67, followed by a plateau at around 90.
Published in the journal PNAS, the research examined brain function in over 19,300 individuals across four large-scale datasets. The study found that the brain’s communication networks degrade in a nonlinear trajectory, rather than following the previously assumed gradual decline or late-life clinical onset. These transition points, particularly during midlife, are critical to understanding the aging process and could offer key moments for intervention.
Lead author Lilianne Mujica-Parodi, from Stony Brook University, emphasized the importance of identifying the timing and mechanisms of accelerated brain aging.
“Understanding exactly when and how brain aging accelerates gives us strategic time points for intervention,” she said.
The study’s findings could lead to the development of interventions that slow down brain aging, potentially helping to delay the onset of conditions like Alzheimer’s.
One major aspect of the research focused on the metabolic stress experienced by neurons in midlife. During this period, nerve cells function despite being stressed due to a lack of energy, primarily caused by insulin resistance. The study indicates that this metabolic stress, followed by inflammation and changes in blood vessels, marks a critical window before more irreversible damage occurs.
Dr. Mujica-Parodi explained that this period represents a “bend” before a potential “break” in brain function, suggesting that interventions could be most effective during this midlife phase. By providing alternative fuel sources to the brain, such as ketones, it may be possible to restore some of the lost function before damage becomes irreversible.
In their study, researchers also identified two key proteins—GLUT4, an insulin-dependent glucose transporter, and APOE, a known Alzheimer’s risk factor—as playing a role in the aging patterns observed. However, they found that another protein, MCT2, could serve a protective role by enhancing the brain’s ability to utilize ketones, an alternative fuel source that neurons can metabolize without insulin.
To test the potential benefits of metabolic intervention, the researchers administered glucose and ketone supplements to 101 participants across different stages of aging. Their results showed that while glucose had minimal impact, ketones effectively stabilized deteriorating brain networks. The greatest benefits were seen in individuals between the ages of 40 and 59, during the critical metabolic stress period.
These findings open the door to new strategies for preventing neurodegenerative diseases like Alzheimer’s. With dementia cases projected to triple by 2050, the study’s insights could lead to early interventions, potentially before cognitive symptoms appear. Dr. Botond Antal, another author of the study, believes this could represent a paradigm shift in how brain aging is approached, saying:
“Rather than waiting for cognitive symptoms, we can potentially identify people at risk through neurometabolic markers and intervene during this critical window.”
