Lactic Acid Is Not Lactose

Here's one of the all-time most common questions on lactose intolerance, from the British newspaper The Independent.

I do not eat dairy products, but I have heard that sourdough bread contains lactic acid. Could this be the cause?

The doctor writing the column writes a technically correct response, except for one tiny little detail. He doesn't actually answer the question.

The proper answer is that lactic acid is not lactose. It can be made from lactose, but that's not the issue. No byproduct of lactose will cause any distress to those who are lactose intolerant.

In fact, no ingredient in food that starts with "lac" will ever be a problem to those with lactose intolerance. Not lactates, or lactones, or lactylates, or any of the dozen other chemical names that might be encountered. The only "lac" to worry about, ever, is lactose.