QUESTION: I am vegan and use coconut, soy and almond milk and yogurt to substitute for animal-based products. I read about an additive, carrageenan, that can cause stomach problems. What is it and should it be avoided?

ANSWER: Carrageenan comes from a red seaweed or algae that is found near Ireland.

The seaweed has been used for hundreds of years to make a sort of pudding, and an extract made from it is now a common food additive. It’s used to give products a thick, creamy texture, so it’s popular in organic products to replace gelatin, which is animal-based.

There is concern about its safety, because some studies indicate that it may cause intestinal inflammation and could be associated with tumors.

Note the use of the words “may” and “could be.” The findings aren’t definitive. It’s been suggested that the effects have been observed in lab rats given large amounts, more than humans would commonly consume.

The Food and Drug Administration and the U.S. National Organic Standards Board currently allow carrageenan as a food additive, although the organic board doesn’t allow it in organic infant formula. The World Health Organization also concluded it’s safe but recommends not using it in formula.

Some companies are removing it from processed foods and others continue to use it.

Should you avoid it? It’s hard to say. Some sources suggest it’s better to consume a little carrageenan if that allows you to continue to use dairy substitutes like soy milk because the known advantage outweighs the unknown risk. But if you have a history of intestinal disease, you should be cautious.