What Trains Your Immune System? Start with Your Diet

It might surprise you to learn that your immune system is trainable—just like your muscles or your mind. And diet plays a starring role in that training process.

A growing body of research is now revealing just how dynamic and adaptable our immune systems are, shaped by nutrition in ways that go far beyond basic support. Here’s what the science says:

· Gut-first immunity: About 70% of your immune cells reside in your gut. According to recent studies, eating more fiber, fermented foods, and polyphenol-rich plants supports microbial diversity and strengthens immune tolerance.

· Bioactives matter: Compounds like quercetin, EGCG (from green tea), curcumin, and omega-3 fatty acids directly influence how immune cells behave by altering gene expression, inflammation resolution, and cellular “memory.”

· Early nutrition leaves a lasting legacy: Maternal and infant nutrition can leave epigenetic marks on immune genes that influence immune responses for decades—highlighting just how foundational diet really is.

Experts in the field estimate that diet and the microbiome may account for 30–50% of our immune adaptability—more than sleep, stress, or physical activity alone.

It’s a powerful reminder that what we eat isn’t just about calories or nutrients. It’s about messaging. Every bite can shift how your immune system sees the world.

Bottom line?
The immune system is built for learning. Diet is one of its most influential teachers.

Want a deeper dive?
Watch this full-length presentation by Dr. Bland 👉 Watch on YouTube.

Follow these Instagram accounts to plug into all of the latest news and science:

@drjeffreybland I @bigboldhealth I @draustinperlmutter