If you’re health-focused and looking for ways to add disease-preventing vegetables to your diet, you may be hearing a lot about cruciferous vegetables (pronounced 'croo-sif-er-us'). But what exactly are cruciferous vegetables and which plants belong in this health-boosting category? Let’s talk about this fascinating group of healthy veggies.
What are cruciferous vegetables?
Cruciferous veggies are vegetables in the plant family Brassicaceae. The old name for Brassicaceae is Cruciferae, which means ‘cross-bearing’ and refers to the fact that many of these plants have 4-petaled flowers in the shape of a cross. Brassicaceae is a huge plant family with thousands species, but most cruciferous veggies fall into the genus Brassica.
Cruciferous veggies have been a subject of health research since the early 1970s, when several researchers found that these plants contained glucosinolates (prounced 'gloo-koh-sin-oh-lates'). Glucosinolates are the precursors to an important group of disease-preventing (and possibly therapeutic) compounds called isothiocyanates (pronounced 'iso-thyo-siyah-nates'). We’ll get into the health benefits a little further down in the blog.
Interested in learning more? Check out 15 benefits of our favorite broccoli-based isothiocyanate, sulforaphane.
Believe it or not, most of the common cruciferous vegetables that you probably eat every day are actually a single species! Let’s talk about that a little more.
Cruciferous vegetables representative species
Brassica oleracea has been selectively-bred by humans for hundreds of years and now makes up a large variety of different plant cultivars. Cultivars are simply plants that have been cultivated in a certain way to form different types of plants.
Brassica oleracea has at least thirteen economically-important cultivars such as cabbage, Brussels sprouts, cauliflower, bok choy and the superfood kale. Have you already eaten a cruciferous veggie today without knowing it? Lots of common vegetables are actually crucifers, including broccoli, which is the most-commonly eaten vegetable in the United States.
However, there are some less common vegetables that are also cruciferous vegetables, such as Ethiopian mustard, romanesco, and the trending superfood maca.
Cruciferous vegetables list
If you’ve been searching the internet for a complete list of cruciferous veggies, look no further. While there are hundreds of regional cultivars around the world, we think this is the most complete online list you’ll find. Click on the links to see what each veggie looks like so that you can recognize it at the grocery store or farmer’s market!
- Arugula (rocket)
- Black mustard seeds
- Bok choy
- Broccoli romanesco
- Brussel sprout
- Cabbage (Red, Chinese, savoy, etc.)
- Canola (rapeseed)
- Choy sum (flowering cabbage)
- Gai lan (Chinese broccoli)
- Collard greens
- Ethiopian mustard
- Field pepperweed
- Garden cress
- Gai choi (head mustard)
- Kale (curly, dinosaur, etc.)
- Land cress
- Mustard (seeds and greens)
- Rapini (broccoli rabe)
- Rutabaga (swede)
- Siberian kale
- Stock (cut flower; leaves and stems not edible)
- Thale cress (Arabidopsis)
- Turnip (root and greens)
- White mustard seeds
- Wild arugula (rucola)
- Wild broccoli (uncultivated Brassica oleracea)
Cruciferous vegetables and cancer
Cancer is a disease that causes uncontrolled cell growth. It is hard to treat because doctors must design ways to target cancerous cells without harming non-cancerous cells...but the cells themselves are the same.
Foods with sulforaphane
Many researchers are studying alternative methods to preventing and treating cancer. Cruciferous vegetables are studied as possible anti-cancer foods because they contain compounds called glucosinolates (pronounced 'gloo-koh-sin-oh-lates').
Glucosinolates contain sulfur and are converted into a bunch of biologically active compounds that reduce inflammation, increase antioxidants, and inhibit cancer cells. One of these compounds is sulforaphane. Researchers suggest that bioactive compounds such as isothiocyanates (for example, sulforaphane) may alter early cancer cell development and slow down carcinogenesis.
There have been many human clinical trials on cruciferous vegetables’ effect on cancer. While past studies have found mixed results, several recent studies have shown very strong correlations between eating lots of crucifers and reduced cancers.
For instance, a 2019 study found that eating raw cruciferous veggies was associated with a lower risk of stomach cancer. Interestingly, this one study found that certain types of crucifers (cabbage and cauliflower, for instance) were associated with less cancer, and also found that women who ate lots of cruciferous vegetables had a lower cancer risk than men.
While there is still plenty of work to be done on unraveling whether cruciferous vegetables can prevent cancer, the research shows promise as a natural method for cancer prevention and therapy.
Cruciferous vegetables and the thyroid
The thyroid is a butterfly-shaped gland in your neck. It’s incredibly important because it secretes hormones that affect bodily functions as diverse as metabolism, internal body temperature, growth, and brain development in children. Sometimes the thyroid can produce too many or too few hormones, which causes problems throughout the body.
One of the biggest risks to thyroid health is thyroid cancer. Some researchers thought that cruciferous vegetables caused thyroid cancer and this has been a persistent myth in nutrition medicine.
However studies later showed that only eating high amounts while iodine deficient is associated with increased cancer risk. This is because the bioactive compounds in crucifers beat out iodine molecules for uptake in the thyroid gland, causing iodine deficiency. Currently, only radiation and iodine deficiency are known to increase the risk of thyroid cancer, and eating lots of vegetables is shown to reduce the risk of many cancers.
Cruciferous vegetables and estrogen
Estrogens are hormones that help to develop and maintain ‘female’ characteristics in the body, such as breasts, wider hips, and regulation of menstruation. But it also helps form bones, clot blood, maintain skin, hair, mucus membranes, muscles, and can even affect mood.
Unregulated levels of estrogen can cause many problems. In many studies, having higher levels of estrogen is associated with higher risk of breast cancer. Cruciferous vegetables contain a compound called indole-3-carbinol, which, when digested, becomes diindolylmethane (DIM).
DIM is shown to decrease carcinogenesis and cancer cell growth in many animal models. Interestingly, DIM is currently being researched as a way to regulate estrogen metabolism (in other words, stop the body from producing too much potent estrogen) in order to reduce the risk of thyroid and breast cancer. While there are many more clinical trials on indole-3-carbinol (the precursor to diindolylmethane) than DIM, researchers are investigating whether DIM might be a beneficial supplement for post-menopausal women to prevent cancer.
Cruciferous vegetables and weight loss
Cruciferous vegetables are just that–vegetables. If you increase the number of cruciferous vegetables in your diet while decreasing Standard American Diet (SAD) foods (fried foods, sugar-laden foods, high-fat dairy, red meat, and alcohol) it’s likely you will lose weight.
However, the benefits of cruciferous vegetables go further. Several studies have shown that cruciferous veggies contain compounds that activate the Nrf2 pathway. Nrf2 is a gene that encodes for proteins that help to combat oxidative stress in your body–in other words they’re super powerful antioxidants.
Unfortunately, nearly half of Americans are obese and obesity is a potent trigger for systemic inflammation. Activating Nrf2 through natural processes such as eating lots of cruciferous veggies may reduce this inflammation.
One study showed a significant decrease in inflammatory cytokines (a molecule that promotes inflammation) and toxic oxygen molecules. In a study in mice given a high-fat diet, indole-3-carbinol reduced body weight and fat accumulation and improved glucose regulation.
Cruciferous vegetables and bloating
In addition to healthy compounds like isothiocyanates and diindolylmethane, cruciferous veggies contain a trisaccharide (complex sugar molecule) called raffinose. Raffinose is difficult to digest and can cause bloating and gas.
Most information regarding cruciferous vegetables and bloating is anecdotal...in other words, not based on scientific research. However, people have reported that gradually introducing cruciferous vegetables into your diet causes less bloating.
Cruciferous vegetables and blood thinners
If you’re on an anticoagulant (blood-thinning) drug such as warfarin to avoid blood clots, your doctor has probably told you to avoid cruciferous vegetables.
That’s because decades of research has shown that vegetables high in vitamin K (phylloquinone) cause blood-thinners to work less effectively. That’s because vitamin K has an important function as a blood coagulant, so it’s doing the opposite action of drugs like warfarin.
One study showed how a diet rich in just one vegetable–Brussels sprouts–caused a marked decrease in warfarin in the body, probably contributing to less anticoagulation.
However, studies show that eating lots of vegetables (including cruciferous vegetables) is good for maintaining cardiovascular health. So if you’re not on a blood-thinning drug and have been specifically told by your doctor to avoid cruciferous vegetables, make sure to eat your veggies!
Broccoli - our favorite cruciferous vegetable!
Like any food, beverage, or supplement, moderation is key. For most people, eating plenty of veggies–including cruciferous veggies–is a great way to maintain good health and may be preventative against a multitude of diseases including cancer.
If you want to get more green veggies in your life but don’t have time to cook them or regulate your serving sizes, try simply adding a teaspoon serving of our new Broccoli Booster to your favorite smoothie (that’s over 300 broccoli microgreens)! That way, you can add cruciferous veggies to your diet and keep track of your servings. Or sneak a little more micronutrient power into your morning tea with our Microtea superfood tea blends.
Carly Anderson Stewart, MSc | Head of Biology and Education