Broccoli: Health Benefits, Risks & Nutrition Facts

By Jessie Szalay, Live Science Contributor

Your parents knew what was up when they told you to eat your broccoli. This verdant vegetable is a powerhouse of nutrients. It's reputed to benefit digestion, the cardiovascular system and the immune system, and to have anti-inflammatory and even cancer-preventing properties. Plus, broccoli is low in sodium and calories, at about 31 calories per serving. It's also a fat-free vegetable.

Broccoli has an impressive nutritional profile. It is "high in fiber, very high in vitamin C and has potassium, B6 and vitamin A," raved Victoria Jarzabkowski, a nutritionist with the Fitness Institute of Texas at the University of Texas at Austin. "For a nonstarchy vegetable, it has a good amount of protein."

Broccoli is also packed with phytochemicals and antioxidants. Phytochemicals are chemicals in plants that are responsible for color, smell and flavor. Research shows that they have numerous healthful benefits, according to the American Institute for Cancer Research. Phytochemicals in broccoli are good for the immune system. They include glucobrassicin; carotenoids, such as zeaxanthin and beta-carotene; and kaempferol, a flavonoid. 

Antioxidants are chemicals produced by the body or found in fruits, vegetables and grains. "Antioxidants can help find and neutralize free radicals that cause cell damage," Jarzabkowski told Live Science. Free radicals are unstable molecules made during metabolism. The damage they can cause may lead to cancer, according to the National Cancer Institute. 

Broccoli is a good source of lutein, a compound antioxidant, and sulforaphane, which is a very potent antioxidant," Jarzabkowski said.

Broccoli also contains additional nutrients, including some magnesium, phosphorus, a little zinc and iron. 

Here are the nutrition facts for broccoli, according to the U.S. Food and Drug Administration, which regulates food labeling through the National Labeling and Education Act:

Nutrition Facts Serving size: 1 medium stalk (raw) (5.3 oz / 148 g) Calories 45   Calories from Fat 0 *Percent Daily Values (%DV) are based on a 2,000 calorie diet.	Amt per Serving	%DV*		Amt per Serving	%DV*
	Total Fat 0.5g	1%		Total Carbohydrate 8g	3%
	Cholesterol 0mg	0%		Dietary Fiber 3g	12%
	Sodium 80mg	3%		Sugars 2g
	Potassium 460mg	13%		Protein 4g
	Vitamin A	6%		Calcium	6%
	Vitamin C	220%		Iron	6%

Health benefits of broccoli

Diabetes and Autism

For obese individuals with type 2 diabetes, broccoli extract may be what the doctor ordered. Scientists reporting in the June 14, 2017 issue of the journal Science Translational Medicine, found that a compound called sulforaphane in broccoli (and other cruciferous veggies like cabbage and Brussel sprouts) could turn down the activity, or expression, of 50 genes associated with symptoms related to type 2 diabetes. The scientists gave the compound (in the form of a broccoli sprout extract) to 97 individuals with type 2 diabetes over the course of 12 weeks. Though non-obese participants didn't see any effect, the obese individuals saw their fasting blood glucose levels go down a significant 10 percent compared with a control group. The dose, however, is 100 times what is found naturally in broccoli, the researchers reported.

The same compound was also found to improve symptoms related to autism; those who took the extract containing sulforaphane showed improvements in verbal communication and social interactions, researchers reported Oct. 13, 2014 in the journal Proceedings of the National Academy of Sciences. 

Cancer prevention

Probably the most publicized health benefit of broccoli is its possible ability to help prevent cancer. "Broccoli is a cruciferous vegetable, and all vegetables in this group may be protective against some stomach and intestinal cancers," Jarzabkowski said.

The American Cancer Society notes broccoli's isothiocyanates, including sulforaphane and indole-3-carbinol. These chemicals boost detoxifying enzymes and act as antioxidants, reducing oxidative stress. They also may affect estrogen levels, which may help reduce breast cancer risk.

Cholesterol reduction

According to Jarzabkowski, broccoli can help lower cholesterol because the soluble fiber in the vegetable binds with the cholesterol in the blood. This binding makes the cholesterol easier to excrete, and consequently lessens cholesterol levels in the body. 

Detoxification

Phytocheimcals glucoraphanin, gluconasturtiin and glucobrassicin compose a terrific trio in broccoli. Together, they aid all steps of the body's detoxification process, from activation to neutralization and elimination of contaminants. A study published in the journal Proceedings of the National Academy of Sciences of the United States of America found that the sprouts of broccoli may be especially potent in this regard. 

Heart health

In addition to reducing cholesterol, broccoli can aid in heart health by helping to keep blood vessels strong. The sulforaphane in broccoli is also an anti-inflammatory and may be able to prevent or reverse damage to blood vessel linings caused by chronic blood sugar problems. And the vegetable's B-complex vitamins can help regulate or reduce excessive homocysteine, according to the Harvard University School of Public Health. Excess homocysteine, an amino acid that builds up after a person eats red meat, increases the risk of coronary artery disease.

Eye health

"You've probably heard that carrots are good for your eyes, and that's because they contain lutein," Jarzabkowski said. "It's a compound antioxidant that's really good for eye health, and broccoli is also a great way to get it." Another antioxidant in broccoli called zeaxanthin is similarly beneficial. Both chemicals may help protect against macular degeneration, an incurable condition that blurs central vision, and cataracts, a clouding of the eye's lens.

Digestion

Jarzabkowski emphasized broccoli's digestive benefits, which she chalked up mostly to the vegetable's high fiber content. Broccoli has nearly 1 gram of fiber per 10 calories. Fiber helps keep you regular and helps maintain healthy bacteria levels in the intestines.

Broccoli also aids in digestion by helping to keep your stomach lining healthy. The sulforaphane in broccoli helps keep the stomach bacteria Helicobacter pylori from becoming overgrown or clinging too strongly to the stomach wall. A 2009 Johns Hopkins study on mice found that broccoli sprouts are especially good at helping in this way. Mice that were fed broccoli sprouts daily for two months reduced the levels of H. pylori in their stools by more than 40 percent.

Anti-inflammatory benefits

Broccoli is a great anti-inflammatory and may slow down the damage to joints associated with osteoarthritis. A 2013 study at the University of East Anglia found that broccoli's sulforaphane may help people suffering from arthritis because this chemical "blocks the enzymes that cause joint destruction by stopping a key molecule known to cause inflammation."

Broccoli's isothiocyanates and omega-3 fatty acids also help to regulate inflammation. Furthermore, a 2010 study published in the journal Inflammation Researcher suggested that the flavonoid kaempferol lessens the impact of allergens, especially in the intestinal tract, which can reduce chronic inflammation.

Health risks

In general, broccoli is safe to eat, and any side effects are not serious. The most common side effect is gas or bowel irritation, caused by broccoli's high amounts of fiber. "All cruciferous vegetables can make you gassy," Jarzabkowski said. "But the health benefits outweigh the discomfort."

According to The Ohio State University Wexner Medical Center, people taking blood-thinning medications should watch their broccoli intake, since the vegetable's vitamin K content may interfere with the medication's effectiveness. Those with hypothyroidism should also limit their intake of broccoli.

Raw, steamed or boiled: Which is more nutritious?

The way that you prepare broccoli can affect the amount of nutrients you get, and which ones. People looking to broccoli for its anticancer benefits will want to be sure not to cook the vegetable too long. 

A 2007 University of Warwick study found that boiling broccoli can undermine the effects of the food's good, cancer-fighting enzymes. Researchers studied the effects of boiling, steaming, microwave cooking and stir-fry cooking on fresh broccoli, Brussels sprouts, cauliflower and green cabbage.

Boiling led to the biggest losses of cancer-fighting nutrients. Steaming for up to 20 minutes, microwaving for up to three minutes and stir-frying for up to five minutes produced no significant loss of cancer-preventive substances. Raw broccoli maintains all of its nutrients, but it is also more likely to irritate your bowels and cause gas.

Broccoli facts

• Broccoli originated in Italy, where it was developed from wild cabbage and has existed since about sixth century B.C.  
• The Italian name for broccoli is "broccolo," meaning the flowering top of a cabbage. The word comes from the Latin word "brachium," which means branch or arm, a reflection of the vegetable's treelike shape.
• The plant came to France in 1560. Until the early 1700s, broccoli was still not widely known in England and was called "sprout colli-flower" or "Italian asparagus."
• Thomas Jefferson was a fan of broccoli and imported broccoli seeds from Italy, planting them at his home, Monticello, as early as May 1767.
• Another president, George H.W. Bush, was not a fan. He used his distaste for broccoli as a punch line in dozens of speeches. He once said, "I haven't liked it since I was a little kid, and my mother made me eat it. And I'm president of the United States, and I'm not going to eat any more broccoli." In response, broccoli growers sent 10 tons of the vegetable to the White House.
• In 2013, President Barack Obama announced that broccoli was his favorite food.
• California produces 90 percent of the broccoli grown in the United States.
• Vegetables related to broccoli are broccolini, a mix between broccoli and "gai-lin" (Chinese broccoli), and broccoflower, a cross between broccoli and cauliflower.
• The average American eats over 4 lbs. of broccoli a year, according to the U.S. Department of Agriculture.
• The world record for eating broccoli is held by Tom "Broccoli" Landers. It took him just 92 seconds to eat a full pound of the vegetable. His secret: "Just swallow, don't bother to chew."
• The United States is the world's third largest producer of broccoli. China, the top producer, grows over 8 million tons of the vegetable a year.

(Sources: MindBodyGreen.com, Wisconsin Department of Public Instruction)

This article is for informational purposes only, and is not meant to offer medical advice.