In 2008, family physician and biochemist Cate Shanahan self-published the book Deep Nutrition: Why Your Genes Need Traditional Food. Several years before, the now Morrison-based doctor had fallen ill, to the point of not being able to walk for two years, and decided to research diets as a possible solution to her health problems. Her resulting book extolled the benefits of fresh fruits and vegetables; sprouted and fermented foods; meat on the bone; and organ meat—a regimen that resembles the now-trendy Paleolithic diet. (In contrast to paleo, dairy is included in Shanahan’s recommendations.)

On January 3, more than nine years after her book was first released, Shanahan has issued a revised edition full of new chapters, more evidence to support her claims, and responses to common queries readers had asked her over the last decade. “A lot of students now don’t even have a home ec class,” she says. “They don’t learn to cook; they learn to microwave. We just want people to understand the depth to which this stuff matters, so they cannot just know it but feel like it’s important at this guttural level.” Here, we’ve pulled out the five most important things to learn from Shanahan’s updated guide to what she calls “the human diet.”

1. Canola oil can damage your brain.

Canola oil is often marketed as heart-healthy and full of omega-3 fats. Yet the molecular bonds holding the substance together are fragile and susceptible to heat. Every time you throw some canola oil in a frying pan, you’re actually transforming it from a good fat into a trans fat. Those trans fats can do everything from damaging appetite centers in your gray matter to changing the structure of your DNA.

2. Vegetarians and vegans in particular should eat fermented and sprouted foods.

Yes, kombucha really does have appeal beyond its hipster roots. “When the first version of our book came out, nobody was talking about the microbiome,” Shanahan says. “Now everyone’s talking about it. That’s one of the reasons we updated Deep Nutrition.” Although fermented and sprouted foods can help improve the diversity of anyone’s microbiome, non-meat eaters—whose diets are often lacking in protein—can especially benefit from the enzymes or microbes in, say, yogurt or sourdough bread converting sugars into nutrients for their own cells. Without sugar in the way, our bodies can better absorb the protein in the plants we eat.

3. Gluten is not necessarily bad for you.

Gluten is simply one of the wheat plant’s proteins. It’s not inherently harmful, but the human body can produce antibodies in response to any protein. That’s more likely to happen with gluten because it’s frequently added to processed foods (when incorporated into dough, it helps to trap air and create crunchy or fluffy textures), which also include negative substances like vegetable oils that cause inflammation. And historically, inflammation served as a warning to the body that an infection or poison was present, triggering the creation of antibodies. This is just one question Shanahan answers in the updated book that readers have frequently asked, now compiled together in an easy-to-read FAQ chapter.

4. The Los Angeles Lakers healed ankle sprains faster by drinking bone broth.

Shanahan serves as the director of the Lakers’ PRO Nutrition Program, a position she took on after first publishing the first iteration of Deep Nutrition. Throughout the updated edition, she slips in advice and information she gave the team, like how bone broth (more commonly known as stock) can improve the health of skin, nails, hair, and joints by building collagen in those tissues.

5. How to change your diet.

The first edition of Deep Nutrition didn’t include specific meal plans, making it harder for readers to implement Shanahan’s tips. Now she’s included extensive templates for breakfast, lunch, and dinner, plus shopping lists and recipes, from sauerkraut to the more adventurous liver and onions.

Follow assistant editor Mary Clare Fischer on Twitter at @mc_fischer.