Doctor's simple 'hack' for better sleep and a stronger immune system

A highly-regarded medical expert has shared what he is calling the "ultimate biohack", and it's a practice that is both free and fairly simple to introduce into our day-to-day lives. Dr Mark Hyman is a doctor, speaker, author, and podcast host.

He also regularly shares health tips and tricks with his millions of Instagram followers. In a new update on Thursday, November 28, Dr Hyman took a moment to acknowledge that it is Thanksgiving in the USA.

He said: "What are you grateful for today? This Thanksgiving, remember that gratitude is more than just a nice tradition—it’s a physiological superpower.

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"Gratitude activates the vagus nerve, the key communicator between your brain and gut. This nerve stimulates digestion by promoting the release of digestive enzymes and regulating gut motility. It reduces cortisol (stress hormone) levels, which can otherwise impair proper digestion and nutrient absorption.

"A calm, grateful state shifts your body into ‘rest and digest’ mode, optimizing your digestive system for the feast ahead. Gratitude doesn’t just feel good—it helps your body function better."

He also explained, in text within the post's image, that being grateful "reduces stress, improves sleep, strengthens your immune system, and aids digestion", adding: "A grateful heart is essential for health".