Donna Jackson Nakazawa is a favorite nonfiction author of mine. Her book, The Autoimmune Epidemic was one of the first books I read after being diagnosed with Rheumatoid Arthritis 10 years ago. And I’ve devoured every one she’s written since.

The Angel and the Assassin: The Tiny Brain Cell That Changed the Course of Medicine is her latest, and publishes in January 2020. It introduces a component of our brains called microglia to the general public. Microglia are cells in the body that don’t get much attention even though scientists are aware of them. But, as Nakazawa explains, some ground-breaking scientists are now intensely researching microglia.

And what they’re learning is stunning. In it’s simplest form, studying microglia proves that brain, mind, and body are intimately tied together. This seems obvious, but medicine and science don’t treat them as connected. Instead, we focus on the barriers between them. And we assume that the immune system doesn’t exist in the brain, just because we don’t see the same elements as we see in the body.

But Nakazawa explains that this is all old science. Now we know that physical trauma affects the brain, and thus, affects everything about mood, cognition, and brain function. This trauma could be as common as a concussion, all the way up to complicated and traumatic brain injuries.

In addition, diseases that affect the body’s immune system are also likely to affect the brain—a relatively new concept called neuroimmune function. This also changes the way we’ll treat diseases like depression, bipolar disorder, and Alzheimer’s in the future.

Ultimately, the fields of neuroscience, genetics, psychology, psychiatry, medicine, and immunology are all more closely connected than ever.

My conclusions

First, I’m not explaining this as eloquently as Nakazawa does. The science is complex and multi-layered. And yet, she walks readers through the information step by step. The way she integrates stories of real-life patients makes the clinical and research details come to life. Having examples makes everything easier to absorb, and along the way you cheer for the people searching for solutions.

Which leads me to my next point. I particularly like that Nakazawa doesn’t stop at discussing the science. She helps readers understand if and how they can bring these cutting edge concepts into their own lives. Part way through, I was definitely searching online to find specific neuroimmune-related services in my area.

It’s not common to find a book with innovative information that is also so readable. I never felt talked down to, despite my lack of scientific education. Nakazawa is a patient who writes for patients, not researchers. She’s the advocate you’ve always wanted, and by writing books, she helps many more patients than she could do individually.

Read this if you like learning more about how your body, especially your brain, works. You’ll see how the science of microglia is already changing what we know about our brains. Definitely recommended for people with neurological, autoimmune, and mental health conditions of all kinds (and the people in their lives).

Pair with either of Norman Doidge’s books about neuroplasticity. If you’d like a shorter option, pair with The Beautiful Brain by Hana Walker-Brown (an Audible Original). This one’s about concussions. I’d also pair this with The Ghost in My Brain or Brain on Fire, which are memoirs about neurological journeys.


Many thanks to NetGalley, Random House Publishing Group, Ballantine Books, and the author for the opportunity to read the digital ARC in exchange for this honest review.

Why I Read About Brains

You can see that I’m fascinated by the brain. It’s because mine has been dysfunctional for quite some time. I have three neurological conditions, which means I’ve had two brain surgeries. Thankfully, the results have been mostly very positive. But I still think our brains our fascinating, and plan to keep learning more.