Beans, Lentils And Uric Acid: What The Old Lists Got Wrong

Look at any list of foods to avoid for uric acid and you'll find beans and lentils on it, somewhere between the organ meat and the sardines.

They shouldn't be there. The reason they are is a mistake made sixty years ago that nobody has gotten around to correcting, and it's cost a lot of people the cheapest protein in the store.

How they ended up on the list

Here's how it happened. For most of the twentieth century, dietary advice for uric acid worked off a single idea: purines in food become uric acid in the body, so avoid foods with purines. Someone made a table, flagged everything above a certain number per hundred grams, and beans, lentils, peas, spinach, asparagus, mushrooms and cauliflower all landed on the same page as organ meat.

What the research actually found

In 2004, researchers published a study in the New England Journal of Medicine that followed 47,150 men for twelve years. They tracked what people ate and who developed gout, and they did something the old lists never did: they separated purines from animals from purines from plants.

Meat tracked with higher risk. Seafood tracked with higher risk. The purine-rich vegetables, beans and lentils among them, showed no significant association at all, either as a group or one by one.

The researchers' own conclusion was that purine restriction may apply to animal sources but not to plant ones. A separate study following tens of thousands of adults in Singapore found the same thing for soy and legumes.

Why plants behave differently

Two things seem to be going on.

The first is that plant purines are less available to your body. The same number on a chart doesn't translate into the same amount of uric acid once it's been through you.

The second is that vegetables and legumes are alkaline-forming, and an alkaline environment is the one your kidneys clear uric acid in most easily. So a food can carry purines and still leave you better off than the food it replaced.

What that looks like at dinner

You don't have to become a vegetarian, and this isn't an argument for giving up meat. It's an argument for having somewhere to put the meals you're not eating steak.

A pot of beans on the stove. Dried beans cost almost nothing, and a pot of them with an onion, a bay leaf and some salt will feed you for three days.

Lentil soup. Lentils don't need soaking, they cook in half an hour, and they turn into a meal with nothing but carrots, celery and whatever stock is in the cupboard.

Chili with half the meat. If the family expects chili, make it with half the beef and twice the beans. Nobody complains, and it's the easiest swap on this page.

One practical note: if you're not used to eating many beans, go gradually. Your digestion adjusts over a couple of weeks, and rinsing canned beans well helps.