Eating vegetables with every meal, or as a snack in between, is a powerful strategy to stay healthy. You'll want to count cruciferous vegetables among those you eat regularly, as they're low in cost and high in disease-fighting nutrients.
Among them, isothiocyanates, a cancer-fighting compound, works by turning on cancer-fighting genes and turning off others that feed the disease. It's found in broccoli, arguably the most well-known cruciferous vegetable, but it's also found in other members of this vegetable family as well.
This is good news, particularly, if you loathe broccoli, as there are plenty of other, equally beneficial, options. Cruciferous vegetables include the following (plus others):
Did You Know?
- Cancer-fighting phenethyl isothiocyanate (PEITC) is naturally produced when you chew cruciferous vegetables
- PEITC killed 75 percent of human cervical cancer stem cells within 24 hours of exposure
- Watercress is a particularly concentrated source of PEITC
Watercress and Broccoli May Reduce Cancer Recurrence and Spread
Part of the cancer-fighting powers of cruciferous vegetables comes from an enzyme called phenethyl isothiocyanate (PEITC). PEITC is naturally produced when you chew cruciferous veggies, such as broccoli or watercress.
When researchers exposed human cervical cancer stem cells to PEITC, 75 percent of them died within 24 hours.1 This is important, as cancer stem cells may continue to live in your body even after a tumor has been eliminated. Though they make up less than 5 percent of a tumor, they can trigger a tumor to regenerate or spread cancer throughout your body. The study's lead author, Moul Dey of South Dakota State University's health and nutritional sciences department, noted:2
"These [cancer stem] cells are frequently resistant to conventional therapies… [and] are very difficult to detect in a tumor. It's like finding a needle in a haystack."
Regularly eating a diet rich in cruciferous vegetables, particularly watercress, might provide some extra protection against such cells. Results were found even with lower concentrations of PEITC, and the researchers noted "consuming just a few ounces will give you the concentrations" used in the study.3
Past studies by Dey and colleagues have also found low concentrations of PEITC dramatically prevent the spread of cancer in mouse lung tissue.4 South Dakota State University reported:5
"Based on information from scientific literature, the concentrations of PEITC that Dey and her team typically use in their research—5 to 15 micromolars—may be achieved through diets rich in certain types of cruciferous vegetables, particularly land cress and watercress."
Watercress Stands Out Among Other Cruciferous Vegetables
We often hear about the health benefits of broccoli, but watercress deserves at least as much fanfare – if not more. It may actually be the most nutrient-dense vegetable out there, scoring higher on nutrient density scores than both broccoli and sunflower sprouts.
Based on 17 nutrients— including potassium, fiber, protein, calcium, iron, thiamin, riboflavin, niacin, folate, zinc, and vitamins A, B6, B12, C, D, E, and K— watercress scored a perfect 100 in a study titled, "Defining Powerhouse Fruits and Vegetables: A Nutrient Density Approach."6
Watercress, which is a close cousin to mustard greens, cabbage, and arugula, can be eaten as a salad green, steamed as a vegetable, added to soups and sandwiches or, my favorite, sprouted.
This plant has such a strong history of healing prowess that Hippocrates is said to have located the first hospital on the island of Kos close to a stream so that fresh watercress could be harvested for patients (watercress grows in water). Greek soldiers also reportedly ate it as a health tonic prior to going into battle.7
In a more recent study, people who ate about 1.5 cups of fresh watercress daily for eight weeks had a 10 percent reduction in triglyceride levels and a significant increase in lutein and beta-carotene, by 100 percent and 33 percent, respectively.8
Further, the watercress diet lead to significant reductions in DNA damage to blood cells, with researchers concluding "consumption of watercress can be linked to a reduced risk of cancer via decreased damage to DNA and possible modulation of antioxidant status by increasing carotenoid concentrations."
In addition, research presented at the annual meeting of the American Association for Cancer Research found that PEITC in watercress and other cruciferous vegetables is highly effective for suppressing the growth of human prostate cancer cells at concentrations achievable through dietary intake of cruciferous vegetables.9 Prior research also found that watercress had a beneficial impact on human colon cancer cells, helping to prevent:10
- Initiation, the DNA damage that triggers cancer cell development
- Proliferation, or uncontrolled growth of cancer cells
- Metastasis, the spread of cancer cells
Eating a Variety of Cruciferous Vegetables Is Important
It's important to eat a variety of cruciferous vegetables, as each will contain a different composition of nutrients and cancer-fighting compounds. According to the Linus Pauling Institute:11
"Cruciferous vegetables, such as bok choy, broccoli, Brussels sprouts, cabbage, cauliflower, horseradish, kale, kohlrabi, mustard, radish, rutabaga, turnip, and watercress, are rich sources of glucosinolate precursors of isothiocyanates. Unlike some other phytochemicals, glucosinolates are present in relatively high concentrations in commonly consumed portions of cruciferous vegetables.
For example ½ cup of raw broccoli might provide more than 25 mg of total glucosinolates… Some cruciferous vegetables are better sources of specific glucosinolates (and isothiocyanates) than others."
This table from the Linus Pauling Institute lists vegetables that are good sources of various forms of isothiocyanates:12
|Allyl Isothiocyanate (AITC)
||Broccoli, Brussels sprouts, cabbage, horseradish, mustard, radish
|Benzyl Isothiocyanate (BITC)
||Cabbage, garden cress, Indian cress
||Broccoli, Brussels sprouts, cabbage
So eating watercress is a particularly good source of PEITC, while broccoli (and broccoli sprouts) provide meaningful levels of sulforaphane. Like PEITC, sulforaphane has also been shown to kill cancer stem cells, which slows tumor growth. This sulfur compound also normalizes DNA methylation, which plays a role in a number of diseases, including hypertension, kidney function, gut health, and cancer.
Sulforaphane also increases enzymes in your liver that help destroy cancer-causing chemicals you may consume or be exposed to in your environment. This compound has even been called "one of the most powerful anticarcinogens found in food."13
While you can get meaningful amounts of PEITC and sulforaphane from eating mature broccoli, watercress, and more, which will also provide you with synergistic phytochemicals, it may be difficult to eat enough of such vegetables to consistently reach therapeutic doses.
Sprouts Offer a Concentrated Source of Cancer-Fighting Nutrients
One alternative is to eat broccoli sprouts. Fresh broccoli sprouts are FAR more potent than whole broccoli, allowing you to eat far less in terms of quantity. For example, tests have revealed that three-day-old broccoli sprouts consistently contain anywhere from 10-100 times the amount of glucoraphanin -- the precursor to sulforaphane -- found in mature broccoli.14
Perhaps better still, research showed broccoli sprouts enhanced the absorption of sulforaphane when consumed along with a broccoli powder, and broccoli sprouts alone had the highest absorption rate of all (74 percent).15
So if you want to have your own ready supply of cancer-fighting nutrients, learn to grow sprouts. Growing your own sprouts is quite easy, and you don't need a whole lot of space either; they can even be grown indoors. My Sprout Doctor Starter Kit comes with what I consider to be three of the best sprouts to grow – sunflower, broccoli, and pea shoots. When grown in soil, you can harvest your sprouts in about a week, and a pound of seeds will probably produce over 10 pounds of sprouts.
Sunflower shoots will give you the most volume for your effort and, in my opinion, have the best taste. In one 10x10 tray, you can harvest between one and two pounds of sunflower sprouts, which will last you about three days. You can store them in the fridge for about a week. Broccoli sprouts look and taste similar to alfalfa sprouts, which most people like. They're perfect for adding to salads, either in addition to or in lieu of salad greens, and sandwiches and are especially tasty in combination with fresh avocado.
You can also add them to your vegetable juice or smoothies. I've partnered with a company in a small town in Vermont that develops, breeds, and grows their own seeds, and is an industry leader in seed safety for sprouts and shoots. All of my seeds are non-GMO, certified organic, and packed with nutrition. My starter kit makes it easy to grow your own sprouts in the comfort of your home, whenever you want. It provides everything you need, so all you have to do is grow and enjoy your sprouts.
Watercress and Broccoli Salad with Cranberries
Watercress has a slight peppery flavor and a pleasant crunchy texture that works well paired with a variety of flavors. The salad below, which makes six side-dish-sized servings, is one delicious way to give watercress a try. As a bonus, it also includes broccoli florets, for even more cancer-fighting power. As posted by Epicurious:16
Watercress and Broccoli Salad Recipe
- 4 cups broccoli florets (from about 1 1/2 pounds broccoli)
- 1/4 cup red wine vinegar
- 1/4 cup honey
- 1 garlic clove, minced
- 3/4 cup thinly sliced red onion
- 6 tablespoons dried sweetened cranberries (optional)
- 2 bunches watercress, thick stems trimmed (about 5 cups)
- Steam broccoli until crisp-tender, about 4 minutes. Rinse under cold water; drain.
- Whisk vinegar, honey, and garlic in large bowl to blend. Season to taste with salt and pepper. Add red onion and cranberries to dressing. Let stand until onion softens slightly, about 30 minutes.
- Add broccoli and watercress to onion mixture and toss to coat. Sprinkle with pepper. Divide salad among plates.
Sources and References