Lectins are plant defence proteins that stick to gut-lining sugars, and a raw bean's lectin will latch on and cause trouble ¹. Heat unfolds the protein: boil a kidney bean ten minutes and toxic activity drops hundreds- to thousand-fold ¹². Canning and pressure cooking run hotter still, so the lectins in food you eat have almost always been cooked to death.

The toxicology is settled; the autoimmune claim isn't. As few as four or five raw or undercooked red kidney beans start vomiting within one to three hours, with no recorded deaths ³. The separate idea, that cooked dietary lectins slip through the gut and seed autoimmune disease, has been on the table since 2000 ⁴. In the quarter-century since, no human trial has shown that cutting lectins improves rheumatoid arthritis, thyroiditis, diabetes, or any autoimmune endpoint ⁵. The popular "70% of patients improve" figure traces to one author's clinical impression ⁵.

The diet drops the foods most tied to survival. Cutting lectins means cutting all beans, lentils, whole grains, tomatoes, peppers, potatoes and peanuts — most of a Mediterranean plate. Three servings of whole grains a day track with a 22% lower risk of dying from any cause ⁶. Legumes are the single strongest dietary predictor of survival in older adults, beating fish, meat and vegetables ⁷. Low whole-grain and legume intake rank among the largest food-based mortality drivers worldwide ⁸.

Three rules cover the entire real risk in a normal kitchen.

If you've been restricting, here's what comes back.

• First weeks: digestion settles as fibre intake roughly doubles; afternoon energy steadies on slower carbohydrate.
• Socially: eating out stops being a tax — the menu opens back up, and meals stop routing through your food rules.
• Decades: the re-added food groups are the ones most tied to longer life ⁹. You won't feel a 22% mortality drop on a Tuesday. You'll statistically get more Tuesdays.