Silymarin is a flavanoid and part of the phytonutrient family, which is a group of compounds found in plants that display antioxidant properties. Silymarin actually consists of three strong antioxidant chemicals called silybin, silidianin and silicristin. Silymarin is most concentrated in the milk thistle plant, where it's extracted from, but it can also be found in some common foods in much smaller amounts. Silymarin is generally considered safe and not toxic if consumed in foods, herbs and spices, but consult with your doctor before taking concentrated extracts of silymarin.
Properties of Silymarin
Silymarin, also called Flavobion or Legalon, is a powerful antioxidant that seems to benefit your liver the most. According to the “Natural Standard Herb & Supplement Reference: Evidence-based Clinical Reviews,” animal studies have shown that silymarin helps repair damaged liver tissue, balances liver enzymes, enhances liver function and has a protective affect on the liver by preventing toxins from penetrating hepatic cell membranes. As such, silymarin is marketed in some countries, particularly the Philippines under the name Liveraide, as an herbal liver supplement. Anecdotal claims suggest that it may help people with some liver diseases, although it is unlikely to be helpful with advanced liver cirrhosis or cancer. Silymarin has also been identified as a potential cancer preventative, especially skin and colon cancers, but more research is required to better understand the mechanisms.
Milk thistle, or Silybum marianum, is the richest source of silymarin. In fact, silymarin is often called milk thistle extract because its seeds contain about 70 percent of the phytonutrient according to the “Encyclopedia of Natural Medicine." Other parts of the milk thistle plant, such as the sprouts and stems, also contain silymarin, but the seeds are the most concentrated form. Milk thistle is indigenous to countries bordering the Mediterranean, where it is still thought of as a medicinal plant. In North America, milk thistle is often regarded as a weed and a target of pesticides. Silymarin is found in most plants of the thistle family.
Wild artichokes are members of the thistle family and also contain decent amounts of silymarin. Silymarin accounts for the antioxidant behavior of artichokes and explains why it is food that can protect against the harmful effects of free radicals. Jerusalem artichokes do not contain silymarin because they are not members of the thistle family, despite their suggestive name.
Turmeric root and coriander seeds and leaves also contain silymarin. Turmeric is often ground into a yellow powder and used as a spice in curry dishes. Coriander leaves, also called cilantro, are a common additive in Thai and Mexican dishes. According to “Medical Herbalism” by David Hoffman, other foods that contain trace amounts of silymarin include dark-skinned grapes, beet greens, black cohosh, peanuts, brewer's yeast and most berries. Silymarin can also be consumed directly as an extract derived from milk thistle seeds.