Have you ever heard of a nutrient called luteolin?
It's one of the lesser-known flavonoids, chemical compounds that are found in many vegetables and herbs.
Why am I bringing it up? Jung Han Yoon Park, PhD, a professor of nutrition in South Korea recently led a study that showed luteolin’s ability to stop colon cancer cells in their tracks. This is potentially big news.
Dr. Park told me that she and her colleagues were eager to study luteolin because colon cancer cells—unlike many other cancer cells—are continually exposed to the foods we eat. Previous studies, she said, had showed that luteolin could cause colon cancer cells to die, but no one knew how it did that. She and her colleagues wanted to find out. Additionally, while they wouldn’t expect this to happen, they wanted to make sure that luteolin didn’t also cause normal, healthy intestinal cells to die in the process.
Researchers conducted a petri dish study and created three groups. One group contained human colon cancer cells and luteolin…the second group contained human colon cancer cells alone…and the third group contained noncancerous intestinal epithelial cells from rats (because it’s difficult to culture healthy human intestinal cells) and luteolin.
The researchers were looking to see whether luteolin affected cancerous and noncancerous cells—and more importantly, how. The results were clear after only one day. By counting the number of cells in the dishes, the researchers found that, as expected, human colon cancer cells that were exposed to luteolin stopped multiplying, while human cancer cells that were not exposed to luteolin kept multiplying. And noncancerous intestinal epithelial cells from rats were not adversely affected by luteolin, which was great news.
So how did plain old luteolin—remember, it’s just a natural part of vegetables—have such a large impact on the human colon cancer cells? With more analysis, the researchers discovered that luteolin interfered with an insulin-like growth factor (IGF). Dr. Park told me that the study was so encouraging that within a year or two, researchers are expected to test the effect of luteolin on live animals with colon cancer, probably mice. If that goes well, human tests will quickly follow.
But there's no need to wait for further studies to be done to eat foods containing luteolin, said Dr. Park—especially if you have colon cancer or are at high risk for it. You're probably eating at least a little bit of it already, and there’s no harm in eating more by increasing your intake of certain foods and herbs. Parsley and thyme are unusually rich in luteolin (containing more than 50 milligrams per 100 grams). Foods that have 10 to 50 milligrams per 100 grams include peppermint leaves and rutabagas. And others that have small amounts of luteolin include chives, artichokes, broccoli, carrots, peppers (both hot and sweet), beets, Brussels sprouts, cabbage, cauliflower, lettuce, apple skins, basil, chamomile tea and spinach.
Dr. Park said that taking a luteolin supplement right now isn’t recommended because more studies need to be done to establish a safe dosage.
Researchers don't yet know how much luteolin-rich food one would have to eat for it to be beneficial, but Dr. Park said, don't be shy about it—fill up your plate because you aren’t going to get too much luteolin from food. Because luteolin isn't affected by heat, she said, it doesn't matter whether you eat the vegetables raw or cooked. So serve them up any way you like!
Source: Jung Han Yoon Park, PhD, professor in the department of food, science and nutrition at Hallym University in Chuncheon, South Korea.