Bok choy is a variety of Chinese white cabbage that falls into the cruciferous vegetable category along with kale, Brussels sprouts, and broccoli.
Also called pak choi, it’s part of the Brassica genus of plants and is native to China. In fact, within China, it’s the most widely-eaten brassica vegetable. However, people consume it worldwide.
You may be aware that cruciferous vegetables can be a key part of a healthy diet. However, you might be wondering what exactly bok choy has to offer.
This article discusses the health benefits and potential downsides to eating bok choy and suggests a few ways to incorporate it into your diet.
Bok choy nutrition facts
Similar to other leafy greens and cruciferous vegetables, bok choy is full of health-promoting nutrients, including a wide array of vitamins and minerals.
One cup (70 grams) of shredded bok choy has the following nutritional profile:
- Calories: 9
- Protein: 1 gram
- Total fat: 0 grams
- Total carbs: 1.5 grams
- Total sugar: 1 gram
- Fiber: 1 gram
- Calcium: 6% of your daily need
- Iron: 3% of your daily need
- Magnesium: 3% of your daily need
- Phosphorus: 2% of your daily need
- Potassium: 4% of your daily need
- Zinc: 1% of your daily need
- Manganese: 5% of your daily need
- Selenium: 1% of your daily need
- Vitamin C: 35% of your daily need
- Folate: 12% of your daily need
- Vitamin A: 17% of your daily need
- Vitamin K: 27% of your daily need
Bok choy is an especially good source of vitamins C and K. It also contains some fiber, a critical nutrient found only in plant foods. Fiber supports digestive health and helps reduce the risk of many chronic diseases.
Summary: Bok choy contains a wide variety of vitamins and minerals. It’s particularly high in vitamins C and K. It also offers some fiber, an important nutrient for overall health.
Health benefits of bok choy
Many of the health benefits that bok choy offers have to do with its micronutrient content.
Bok choy is also rich in antioxidants, which are compounds that protect your cells from oxidative damage that can lead to inflammation and various chronic diseases. Vitamin C is one of the many antioxidants in bok choy.
Bok choy may have anticancer properties
Scientists have studied the cruciferous vegetable family for its potential anti-cancer benefits. These effects appear to come from their sulfur-containing compounds, called glucosinolates, and their breakdown products, called isothiocyanates.
One study found that eating bok choy at least once per week was associated with a significantly lower risk of oral, esophageal, colorectal, breast, and kidney cancers, compared with never or occasionally consuming bok choy.
Additionally, bok choy is a rich source of the mineral selenium, which may also have anti-cancer benefits.
In one analysis of studies, researchers found that high selenium exposure, indicated by levels in the blood or toenails, was related to a lower risk of cancers of the breast, lungs, esophagus, stomach, and prostate.
Another analysis of studies concluded that a high intake of cruciferous vegetables, like bok choy, was associated with a lower risk of stomach cancer.
Bok choy may support thyroid function
The selenium in bok choy is beneficial for proper functioning thyroid glands. These glands are located at the front base of your neck and play a critical role in metabolism and growth.
One study found that having a low level of selenium in the bloodstream was associated with thyroid conditions, such as hypothyroidism, autoimmune thyroiditis, and enlarged thyroid also called goiter.
One study found that taking selenium supplements also helped manage these conditions.
Bok choy may support bone health
Several minerals in bok choy work to maintain bone health. These include calcium, phosphorus, zinc, magnesium, and vitamin K.
Zinc and iron play a role in collagen synthesis and vitamin D metabolism. Collagen is a type of protein that forms a matrix in your joints and skeletal system, helping maintain bone structure and strength.
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Studies have found that reduced levels of these minerals are associated with collagen reduction and an increased risk of osteoporosis, a disease in which bones soften and become prone to fracture.
Bok choy may promote heart health
Bok choy contains the minerals potassium, magnesium, and calcium, which work to help naturally regulate your blood pressure.
Having unmanaged high blood pressure can be a risk factor for developing heart disease.
Bok choy is also a good source of folate and vitamin B6. Studies have found these may prevent the buildup of homocysteine. This compound can damage blood vessels and increase the risk of heart disease and stroke if it accumulates.
Summary: Bok choy is rich in vitamins, minerals, and antioxidants that may offer benefits for thyroid function and heart and bone health. They may even have anti-cancer properties.
Potential side effects of bok choy
While bok choy offers several health benefits, it may also come with downsides for some people when consumed in large amounts.
In their raw, uncooked form, cruciferous vegetables contain an enzyme called myrosinase that breaks down the glucosinolates that these vegetables also contain.
Some of the breakdown products of glucosinolates may inhibit your body from absorbing iodine, which is critical for thyroid function.
In one case study, an older woman was hospitalized in intensive care for severe hypothyroidism and related coma. She had been eating 14–21 cups (1,000–1,500 grams) of raw bok choy daily for several months.
Though this effect may seem severe, keep in mind this is a single, extreme case. This effect may only be a concern if you eat an unusually large amount of raw cruciferous vegetables over an extended period.
One review notes that there is little research on the potential thyroid-inhibiting effect of bok choy. However, the researchers state that typical serving sizes of bok choy probably do not impair thyroid function.
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Furthermore, cooking bok choy deactivates the enzyme myrosinase, so thyroid inhibition isn’t a concern with cooked bok choy.
Additionally, because bok choy is a rich source of vitamin K, you may not want to consume it in larger amounts if you take blood-thinning medication.
Significant changes in your vitamin K intake can interfere with the effectiveness of these medications. This is because vitamin K plays a role in blood clotting.
A 1-cup (70-gram) serving of loosely packed, chopped bok choy provides about 27% of your daily vitamin K needs.
If you are taking blood clotting medications, such as warfarin, you can ask your healthcare provider how much bok choy is safe to consume.
Summary: One case study suggests that eating bok choy raw in very large amounts may interfere with thyroid function, but this is probably not a concern with typical serving sizes. If you take blood-thinning medication, you may want to watch your intake.
How to incorporate bok choy into your diet
People often cook bok choy in stir-fries and soups, particularly in Asian cuisine.
You can consume all parts of the bok choy plant, including its white stems and green leaves.
Here are some ideas for how to prepare and eat bok choy:
- Chop it and sauté it with olive oil, garlic, and ginger as a side dish or to top a grain like rice or quinoa.
- Dice it and add it to an Asian-inspired soup recipe.
- Shred it and toss it with other vegetables to make a raw salad.
- Chop it and cook in a pan with bell peppers, carrots, broccoli, and water chestnuts to make a stir-fry.
- Slice lengthwise, drizzle with olive oil and salt, and roast in the oven.
- Use in place of lettuce or other leafy greens on a sandwich.
- Dice it finely and add it to fried rice.
There are plenty of ways to try adding bok choy to your diet.
Summary: You can consume bok choy raw, roasted, or cooked on the stovetop in a soup, stir-fry, or fried rice dish. You can incorporate bok choy into your diet in Asian dishes and many other ways.
Bok choy is a cruciferous, leafy green vegetable native to China. People often use it in Asian cuisine.
It offers a wide variety of vitamins and minerals, as well antioxidants and fiber that are good for your health. Bok choy may be beneficial for heart health, bone health, and thyroid function. It may even have anti-cancer properties.
You may want to eat it in the cooked form to reduce your intake of myrosinase, a compound that could interfere with iodine absorption. That said, this may only be an issue if you consume bok choy raw in large amounts. Eating bok choy in typical serving sizes is generally not a concern.
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Bok choy is also high in vitamin K, so you may want to eat less or avoid it if you take blood-thinning medications. If you are concerned about this, ask your healthcare provider for guidance.
You can use bok choy in several ways, such as raw in a salad, cooked in soup, or added to a stir-fry or fried rice dish.