Your Body Kept Score Too

The science behind why your body feels like it’s falling apart

This isn’t in your head, and it isn’t weakness. Chronic stress activates the same hormonal stress-response system (the HPA axis) that’s meant to help you survive a short-term threat. When that system stays switched on for months or years instead of minutes, research shows it can loosen the tight junctions in your gut lining — the barrier that normally keeps food particles and bacteria where they belong. Reviews in The Journal of Physiology and Frontiers in Cellular Neuroscience have documented this stress-to-gut-permeability pathway in detail, and a 2023 review in Biological Psychiatry: Global Open Science found the effect specifically in the small intestine, where most food absorption happens.

That matters because a more permeable gut is a gut more prone to reacting to foods it used to tolerate fine — which is one reason food sensitivities so often show up or intensify during and after prolonged stress, not before it.

The connection goes further than digestion. Large cohort studies — including research out of the UK Biobank and Iceland’s SAGA study — have found that women with a history of significant adversity carry measurably higher levels of inflammatory markers, and a higher risk of autoimmune and rheumatic conditions, than women without that history. The landmark ACE Study found that people with two or more adverse childhood experiences had a 70% increased risk of hospitalization for inflammatory conditions and double the risk for rheumatic disease, decades later. Your immune system remembers what your calendar has moved past.

None of this means stress caused any specific condition, or that resolving stress will resolve it. It means the connection between what you lived through and how your body responds now is documented, not imagined — and that’s worth knowing as you make sense of your own symptoms.

What actually helps — grounded in research, not trends

For your nervous system:

• Movement is one of the most consistent, well-studied levers for lowering baseline cortisol over time. A 2025 systematic review and meta-analysis found yoga had the strongest cortisol-lowering effect among exercise types studied, with walking, tai chi, and moderate multicomponent exercise close behind.
• Consistency outperforms intensity. Research on longer exercise interventions shows steady, moderate movement over months does more for baseline stress biology than occasional hard efforts.
• Very intense or prolonged high-intensity training can raise cortisol short-term — useful to know if you’re already running on empty and wondering why a brutal workout left you more wired, not less.

For your gut and your plate:

• If you suspect a food sensitivity, an elimination-and-reintroduction approach done one food at a time (ideally with a registered dietitian or your doctor) is the most reliable way to identify a true trigger — more reliable than any single at-home test.
• Reducing chronic stress load isn’t just an emotional intervention — the research above suggests it may also lower how reactive your gut is in the first place.