Vitamin U isn't a true vitamin, but this compound found in cabbages may still have health benefits. Nutrition Diva explains what vitamin U is, what it does, and how to get it.
I received an email this week from a new listener, who writes:
"I just found your podcast this year and I'm working through the episodes. I'm currently on the episodes from 2010. I've been learning new and interesting ways to eat better and feel fabulous, to borrow your catchphrase. I recently saw a video on vitamin U. Would you do an episode on what it is and why it's good for you?"
After 13 years of the Nutrition Diva podcast, there aren't many nutrients that I haven't mentioned at least once. But I have never talked about vitamin U. Let's set the record straight
What is vitamin U?
Vitamin U is not a true vitamin but rather a sulfur-containing compound found in cabbage and other vegetables in the brassica family. (Its chemical name is s-methylmethionine.) In the 1950s, it was thought to be an effective treatment for peptic ulcers—which is why it was dubbed vitamin U.
Back then, we believed that painful stomach ulcers were caused by stress and spicy foods. Standard treatment was a bland diet and antacids, which helped somewhat. But apparently, not nearly as much as cabbage juice. A handful of studies from this time (including one conducted among inmates at San Quentin prison!) found that drinking raw cabbage juice relieved pain better and healed ulcers more quickly than the usual approach.
Today we know that, while stress and spicy food can certainly exacerbate symptoms if you already have an ulcer, they don't actually cause ulcers. So, what does?
Certain medications can injure the stomach lining and if you're taking one of those medications, that would be the first suspect. But aside from that, ulcers are almost always caused by an infection of h. pylori bacteria. The standard treatment is a course of antibiotics to knock out the bacteria, which is highly effective—not to mention a lot less unpleasant than drinking a quart of raw cabbage juice every day.
We've also learned that long-term use of antacids can have a lot of unintended consequences, including increased risk of osteoporosis and bone fractures, nutrient deficiencies, and intestinal infections. It turns out that maintaining an acidic environment in the stomach plays an important role in our health. So it's just as well that we no longer treat ulcers by chugging milk-of-magnesia.
See also: How to Avoid Acid Reflux
What does vitamin U do?
We still don't know too much about how s-methylmethionine worked to heal ulcers—or whether something else in the cabbage juice may have been part of the effect. And now that we have a highly effective treatment for ulcers, figuring it out hasn't been a research priority. But there are still folks promoting vitamin U as a general tonic for the liver and kidneys, to reduce cholesterol and triglycerides, and even as a cosmetic ingredient.
The evidence to support these benefits is extremely sparse, consisting mostly of test tube and animal studies and a few small, unreplicated or uncontrolled human trials. In my view, there's not nearly enough evidence (let alone safety and dosage information) to recommend taking vitamin U as a dietary supplement. But there's plenty of evidence to support the benefits of eating vegetables from the cabbage family.
What foods contain vitamin U?
Brassicas include all kinds of cabbage, broccoli, Brussels sprouts, and kale. In addition to being rich in s-methylmethione, brassicas are loaded with vitamins A, C, K (which help to build strong bones) and folic acid. Somewhat more unique to the brassica family are the glucosinolates—compounds that protect against cancer. Brassicas contain other sulfur-containing compounds as well, which have a variety of health benefits. You know I don't really believe in superfoods, but if I did, brassicas would be close to the top of the list.
And there are so many ways to enjoy them. You can eat them raw (coleslaw, anyone?), roasted (broccoli and Brussels sprouts are great this way), dried (as in kale chips), sprouted (remember the broccoli-sprout craze a few years back?), or even juiced, if you like. However, I think you get more benefits by eating your vegetables, rather than drinking them.
If you strive to eat five servings of vegetables every day (and I hope you do), try to make sure at least one of those servings is from the brassica family. Here are some of my favorite brassica recipes: