What Is a Radish?
Radishes are root vegetables that belong to the cruciferae or mustard family. Their skins can be red, black, yellow, purple, and pink, and they have a spicy, peppery taste. This taste comes from enzymes that are also in mustard root, horseradish, and wasabi root. Cooking them makes the flavor milder.
Radishes are likely native to Southeast or Central Asia. The Ancient Greeks and Romans also used them for medicine. Several thousand years ago, people began to grow the wild radish, and over time, it spread to new lands. Radishes range in shape from short and round to long and narrow.
Types of Radishes
There are many kinds of radishes. Their main differences are their colors, shapes, and sizes.
Some of the more common types include:
Red. These are round with red skin and white flesh. Cherry Belle and Early Scarlet Globe are two common kinds. Red radishes have a sweet, peppery, and sharp flavor. They're one of the most common types you see in stores, but others, like daikon, are getting more popular.
Daikon. These are native to Japan and China and are a staple in Asian cuisine. They're also known as Japanese radish, Chinese turnip, and mullangi. They are round or cylinder-shaped. Most have white flesh, though some have green. They taste slightly spicy and sweet but are milder than red radishes. There are many varieties, including Minowase, Tama, and Miyashige white.
Watermelon. These white and green radishes with magenta flesh are heirloom daikon radishes. That means they've been grown from seeds saved and passed down over many generations. They have a peppery kick that mellows out if you cook them.
Black radish. These radishes are big and ball-shaped. They have rough, jet-black skin and white flesh. Black radishes have a spicy and earthy flavor that's sharper than most other radishes.
Other radish types
- Pink lady slippers are oblong with pink skin and white flesh. They're very mild, so they're good for many recipes.
- French breakfast kinds are long and pink and taper to a thin white point. They taste light and peppery.
- Easter egg radishes grow in several colors, including red, pink, purple, and white. They taste like red radishes.
- Sakurajima daikon is the largest radish in the world. It's named after the original place it was grown, an area near the Sakurajima volcano in Japan. The minerals from the volcanic ash makes the soil richer, helping to grow these large radishes.
Radish vs. beet
Both grow underground with some leaves sprouting above the earth. But they're quite different. The radish is part of the cabbage family, while the beet is a member of the amaranth family, a group of leafy vegetables and ornamental plants.
Beets are larger than radishes and have a firmer texture. Their taste has been described as sweet and earthy. In fact, you can make sugar from some types of beets. Radishes, on the other hand, are smaller than beets, about the size of golf balls; are crisp and crunchy when raw and have a slightly peppery, sharp taste. Both vegetables can eaten raw or cooked (roots and leaves) and come in many different colors.
Are radishes good for you? Radishes are very low in carbs, which makes them a great option if you're watching your carbohydrate or sugar intake. They also have few calories and a low glycemic index, a measure of how quickly a food causes your blood sugar to rise. And they're rich in several vitamins and minerals:
- Vitamin C
- Vitamin B6
Nutrients per serving
A half-cup serving of fresh, sliced radishes contains:
- Calories: 9
- Protein: 0 grams
- Fat: 0 grams
- Carbohydrates: 2 grams
- Fiber: 0 grams
- Sugar: 0 grams
- Cholesterol: 0 milligrams
- Sodium: 23 milligrams
Radishes contain antioxidants like catechin, pyrogallol, vanillic acid, and other phenolic compounds. Antioxidants are molecules that fight free radicals in your body. Free radical compounds have been linked with many diseases, including cancer. Radishes also have a lot of vitamin C, which protects your cells from damage.
Some likely health benefits include:
Lower risk of diabetes
Radishes have chemical compounds like glucosinolate and isothiocyanate that are thought to help manage your blood sugar levels. Early studies have shown that they might give you energy and lower how much glucose your intestines take in. The vegetable also contains coenzyme Q10, an antioxidant that researchers found helped block the formation of diabetes in animals. We need more research to confirm these results in people.
Many studies have shown that radish leaves have antioxidant properties. These antioxidants seem to help protect you against liver, colon, breast, cervical, prostate and lung cancers. Another study showed that the leaf extract stopped the growth of a certain type of breast cancer cell. But much more research is needed.
Better liver function
These veggies contain special compounds called indole-3-carbinol and 4-methylthio-3-butenyl-isothiocyanate, which help trigger enzymes thought to help your liver get rid of harmful toxins.
Lower risk of heart disease
Nutrients like vitamin C and minerals like calcium and potassium can help control blood pressure, which lowers your risk of heart disease. The giant Sakurajima daikon radish is super-high in trigonelline, which, according to a small study, improves blood vessel function in healthy people. Radishes are also a good source of natural nitrates, which may help improve your blood flow.
Radish leaves might be good for gut health and reducing obesity, according to one study. The leaves also have more fiber than the roots and fiber is good for preventing constipation.
A 2008 study with rats found that fresh radish juice may help to stop stomach ulcers from forming. Another study found that mice fed a high-cholesterol diet and then given radish extracts had lower cholesterol levels.
This vegetable has natural antifungal properties, meaning that it can stop the growth of fungi that cause infections. That's because it contains the antifungal protein RsAFP2.
One study from 2009 suggested that RsAFP2 activated certain proteins in the Candida albicansfungus that caused them to self-destruct. C. albicans is a common fungus in your body that can cause infections like thrush and vaginal yeast infections.
Benefits of Radish Leaves
In the U.S., people tend to throw out radish leaves. But in other countries, like India, the leaves get used in many dishes. Here are some of their health benefits:
They might be the most nutritious part of the plant. Radish leaves have more protein, calcium, ascorbic acid (vitamin C) and antioxidants than the roots.
They may help with Alzheimer’s. In a mouse study, scientists found that the mice treated with erucamide (a compound extracted from radish leaves) performed better on memory tests than mice who hadn’t been given this compound. This suggests that erucamide might protect against memory problems related to Alzheimer's disease by improving how a specific part of the brain works. But further research on humans is needed.
They could guard against anemia. Like other leafy greens, radish leaves contain high levels of iron, which is helpful for everyone, but particularly for people with anemia (low levels of iron in their blood).
They help lower blood pressure. One study found that rats that got the highest dose of an extract made of radish leaves had a noticeable drop in their blood pressure. The extract also caused more sodium and potassium to be pooped out, another sign that it might help with high blood pressure. However, human studies must be conducted to prove the health benefits of lowering blood pressure in people.
Side Effects of Radishes
Radishes are generally safe to eat with few side effects. But here a few to look out for:
- Allergies. Some people may be allergic to radishes, though this is rare. For instance, a Japanese woman developed itching and swollen lips after eating a salad containing raw Japanese radishes.
- Low blood pressure. Since the leaves appear to help lower blood pressure, eating too many of them might make your blood pressure too low if it is currently normal. While it's unclear what constitutes "too many," it's safest to stick to one serving of radishes per day, which the USDA considers a half-cup.
- Dehydration. Since radishes are natural diuretics (foods that lower the fluid in your body, causing you to pee more), eating too many might make you dehydrated.
- Stomach irritation.As with other fruits and vegetables, eating too many radishes or radish leaves may upset your stomach. That's because of the high fiber content.
- Low blood sugar. Since radishes appear to help lower blood sugar, eating too many of them may drop your blood sugar too much if it's a normal level.
How to Eat Radishes
You can find radishes in supermarkets, farmers markets, and specialty grocers. They're mainly a winter and spring vegetable. Here are some easy ways to add radishes to your diet:
- Pickle fresh radishes with white vinegar and spices.
- Add sliced radishes to a fresh salad.
- Top your burger with lettuce and sliced radishes.
- Roast whole radishes with garlic and olive oil.
- Make a simple roasted radish and feta salad.
Kimchi is a traditional Korean dish made by fermenting Napa cabbage and radishes, usually daikon. You also can add other vegetables like cucumbers, carrots, or bok choy.
The greens are low in calories and contain protein, magnesium, and vitamins C and K. To serve them::
- Sauté them in olive oil for a simple side dish.
- Toss them with other greens in a salad.
- Add them to soups, stews, or casseroles.
- Use them in place of basil for pesto sauce.
How to Store Radishes
The best way to keep fresh radishes is to first remove the greens. The tops suck out nutrients and moisture when left on. The greens will keep for 2-3 days in the fridge.
Wash the radishes and store them in a plastic bag with damp paper towels to keep them from drying out. They can stay fresh in the fridge this way for up to 2 weeks. Radishes don't freeze well because of their high water content.
Pickling is a good way to preserve radishes. All you do is boil your canning jars so they're sterile, and fill them with washed and thinly sliced radishes, spices, and hot pickling juice. Seal the lids and let the jars cool overnight. Then store the pickled radishes in a cool, dark spot like your pantry for up to 12 months.
Radishes are root vegetables full of nutrition and low in calories. Though radish health benefits are still being studied, they're thought to lower the risk of heart disease and diabetes and to have anticancer properties. Don't forget about trying the leaves -- they have extra nutrition beyond what's in the roots.
Is it OK to eat radishes every day?
Yes, as long as you don't overdo it.
How many radishes a day should you eat?
Aim for a half-cup of radishes or less.
Are radishes a superfood?
While not a medical or nutrition term, a superfood is usually considered to be a food with a lot of compounds that benefit your health. By that definition, radishes could be considered a superfood, as they are high in vitamins and minerals, low in calories, and have cancer-fighting properties and a low glycemic index.