Former NFL Pro Bowler and Psychologist Julius Thomas, Psy.D., on Why Your Mindset Could Be the Key to a Longer Life

When most people think about living longer, they think about what’s on their plate or how often they hit the gym. But according to Julius Thomas, Psy.D. — a two-time NFL Pro Bowler who went on to become a cognitive scientist and psychologist — that conversation is missing something critical: the state of your mind.

Thomas points to his clinical work with older adults as some of the most telling evidence. Patients with amputations, limited mobility and serious diagnoses were still reporting genuine happiness and satisfaction because they were psychologically healthy. The inverse was equally true: People with no physical illness who were mentally struggling were not enjoying their lives at all.

Stress, Cells and the Body’s Breaking Point

Thomas breaks down chronic stress in refreshingly accessible terms. The human body is made up of trillions of cells designed to respond to stressors — a feature that is useful and even necessary for short-term challenges like a work deadline or a demanding workout. The problem arises when that stress system never turns off.

In modern life, most stressors are psychological: relationship strain, workplace pressure, financial worry. When those stressors are constant, the body’s stress response stays switched on, gradually impairing the cardiovascular, pulmonary and gastrointestinal systems. The downstream effects are visible across virtually every organ system in the body.

The Condition Nobody Is Talking About

The piece of the puzzle Thomas finds most underappreciated is low-grade chronic inflammation — a state of inflammation that exists below the symptom threshold. People feel nothing, yet the process is quietly reshaping their cellular environment and laying the groundwork for cancer, cardiovascular disease, obesity, stroke and potentially neurodegenerative disorders.

The solution, he argues, starts with mindset: learning to manage where you place your attention, how you speak to yourself and which thoughts you engage with. These skills, he says, are not soft add-ons to a wellness routine. They are biological interventions.