As a family doctor in Hawaii in the early 2000s, Dr. Cate Shanahan felt a growing disconnect between public health messaging and the problems she was actually seeing in her patients. Amid widespread cheers for the merits of a low-saturated-fat, low-cholesterol diet—what she’d been taught was right—she noticed that with each generation, people were becoming less healthy. She saw grandmothers who were far healthier than their grandchildren.
“This struck me as really bizarre,” said Dr. Shanahan, a biochemist turned physician. “So I started looking into nutrition. I started making connections about what was really going on.” Her research honed in on seed oils, which she’s come to see as “the worst of the worst” when it comes to harming our health. These highly processed oils, which can make up as much as 30 percent of a person’s daily calories, originated as industrial by-products, she explained: “They were never originally designed to be consumed by humans. There’s nothing else in the food supply like them.”

She identified eight harmful oils to avoid, which she calls “the hateful eight”: cottonseed, canola, corn, soy, sunflower, safflower, grapeseed, and rice bran. They damage metabolic health and have been linked to myriad health problems, including obesity, mental health issues, autoimmune disorders, infertility, life-threatening allergies, heart failure, and cancer.
“When people stop using these oils, their lives are changed,” Dr. Shanahan said.
She published her first book, “Deep Nutrition: Why Your Genes Need Traditional Food,” in 2008. Her newest book, published in 2024, is “Dark Calories: How Vegetable Oils Destroy Our Health and How We Can Get It Back.”
In the Pantry
Healthy, flavorful oils, such as avocado, olive, coconut, peanut, and sesame oilOnions and garlic
Dried beans
Wheat berries
Sprouted pumpkin seeds
Dehydrated coconut
Condiments, such as sun-dried tomatoes, mustard, coconut cream, cooking wine, different types of soy sauce
Bone broth concentrate
Canned salmon or sardines
Pepperoncini
Olives
Nuts
Lots of spices

In the Fridge
Raw milk, cream, and whole-milk yogurt from a local farmEmmental, cheddar, and ricotta cheese
Eggs
Nutritional yeast
Higher-quality oils, such as sesame oil
Nuts and seeds, to slow down the oxidation process
Vegetables, such as celery, carrots, mushrooms, arugula, string beans, broccoli, kale
Sauerkraut or kimchi
In the Freezer
Grass-fed or pasture-raised meatsLiver, such as chicken, turkey, or lamb
Sausages
Scallops
Peas and lima beans
Bone broth
