Lignin

What is lignin?

Lignin is a non-digestible compound made of of phenols (aromatic alcohols) and other molecules ^[1]. It is not a carbohydrate, but is considered an insoluble fiber. It is found in the cell walls of vascular plants and in seeds. Lignin is not digested in the small bowel and is poorly fermented by normal colonic bacteria. It is insoluble in water, but it absorbs water and thus gives bulk to the stool.

Name origin: from the Latin lignum = wood.

Foods High in Lignin

Foods high in lignin include flaxseed, root vegetables (carrots, parsley, horseradish), wheat bran, edible seeds (in berries, tomatoes), vegetables with edible stems (cabbage, broccoli), green beans, peas, peaches, apples, Brazil nuts  ^[2].

Suggested Lignin Effects, but Insufficient Evidence

• Two studies have not shown any significant effect of oral lignin supplements on the bile composition and prevention of bile stones ^[3,4].
• Lignin may prevent the growth of cancer cells in the laboratory, but insufficient human studies have been done to claim that lignin helps in treating cancer ^[5,6].
• Lignin might help to prevent diverticulosis ^[6].