Aging is no easy feat—it involves a lot of acceptance, preparation, and adaptation. According to a new study by the Proceedings of the National Academy of Sciences (PNAS), scientists have pinpointed the exact age when our brains begin to decline the fastest; and since age-related cognitive decline follows a specific progression, knowing how it works can help you have some say in the matter. “Understanding the key drivers of brain aging is essential for effective prevention and treatment of neurodegenerative diseases,” the study says. Read on to learn more about the study’s findings, along with ways to delay cognitive declines as you age.

Cognitive Aging Starts in Our 40s

Brain aging typically starts when our midlife does—around age 40. Previous research has continued to suggest that our brain networks go through significant changes starting in our late 40s, which can sometimes lead to destabilizing and desynchronizing effects, the study notes. As a result, our midlife lifestyle choices are crucial between ages 40 to 60. Similarly, if lifestyle habits aren’t where you’d like them to be, ages 40 to 60 are critical for intervention. Additionally, the metabolic stress period—aka, an imbalanced homeostasis—typically lasts from ages 40 to 59, making it an essential period for midlife intervention (if needed).

Three Key Ages

Using four data sets from the Mayo Clinic Study of Aging, researchers were able to identify three major transition points in aging: at 43.7 years, when the onset of metabolic destabilization begins. At 66.7 years, when the most rapid destabilization takes place. At 89.7 years, when destabilization reaches its plateau. Insulin resistance can also play a significant role in how these transitional points play out and increase destabilization; if you struggle with insulin-related conditions, it’s best to regulate and manage symptoms as you age.

How to Curb Age-Related Cognitive Decline

Ultimately, metabolic stress is the key instigator of age-related cognitive decline. It can be caused by a variety of lifestyle habits—nutrient deficiencies, physical inactivity, and chronic stress are just a few major factors that can determine how metabolic stress plays out. As we age (including right now!), it’s important to be aware of what we eat, how we treat our bodies, and effective mechanisms for dealing with stress in our lives. Because while aging is an inevitable part of life, healthy lifestyle choices can make the process more manageable.