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10 Health Benefits of Broccoli

Last updated: January 16, 2019

Health Benefits of Broccoli

Broccoli is a healthy cruciferous vegetable that is packed with a number of nutrients and other bioactive compounds.

Because of its nutritional value and high concentration of phytochemicals, broccoli may help reduce the risk of several diseases, including cancer, cardiovascular diseases, respiratory conditions such as asthma, and osteoporosis. It may also help reduce chronic inflammation, lower blood sugar levels, aid in weight loss, and boost the health of your skin and eyes.

Here's a detailed look at 10 health benefits of broccoli:

1. Eating Broccoli May Increase the Nutritional Value of Your Diet

Broccoli packs a nutritional punch for only 34 calories per 100 grams. It is an excellent source of vitamins C and K, with 100 grams of raw broccoli providing 89 milligrams (149% DV) of vitamin C and 102 milligrams (127% DV) of vitamin K. It also contains appreciable amounts of dietary fiber, vitamin B6, folate, potassium, manganese and carotenoids like lutein and zeaxanthin (1).

Eating a diet rich in foods that are low in calories and high in nutrients can help your body meet its daily nutritional needs and prevent nutrient deficiencies, while keeping your weight within a healthy range.

2. Raw Broccoli is a Rich Source of a Cancer-Fighting Compound

Broccoli has been touted as an anti-cancer food, largely because of its high concentration of a glucosinolate called glucoraphanin. While glucoraphanin itself has limited health benefits, an enzyme called myrosinase can convert glucoraphanin into sulforaphane.

Sulforaphane has been extensively researched for its potential anti-cancer effects, and there is now a compelling body of evidence that sulforaphane may help prevent cancer through multiple mechanisms.

For example, studies show that sulforaphane can induce phase II enzymes which are involved in the elimination of mutagens, trigger apoptosis (programmed cell death), induce cell cycle arrest, and inhibit NF-κB, a protein complex that is involved in the initiation, development and spread of cancer within the body. (2).

What's more, newer research indicates that sulforaphane may also work by influencing cellular genetics. A study led by Laura Beaver from the Oregon State University found that sulforaphane can influence the expression of long non-coding RNAs, or lncRNAs, which play a critical role in triggering cells to become malignant and spread (3).

It is worth noting, though, that high temperatures destroy myrosinase, the enzyme that is needed to turn the glucoraphanin in broccoli into sulforaphane, and human studies comparing raw broccoli with cooked broccoli confirm that raw broccoli provides significantly more sulforaphane than its cooked counterpart (4).

So, if you are looking to increase your sulforaphane intake, it is best to eat you broccoli raw or cook it gently. According to the University of Illinois researcher Dr. Elizabeth Jeffery, the best way to cook broccoli, if you want to protect the sulforaphane, is to steam it lightly about 3 or 4 minutes, until it is tough-tender (5).

3. Eating Broccoli May Provide Cardiovascular Benefits

Diets that are rich in vegetables, particularly cruciferous vegetables like broccoli, have been associated with a lower risk of atherosclerosis in older women. Atherosclerosis – or hardening and narrowing of the arteries – is an underlying cause of cardiovascular disease and one of the most common medical conditions in the elderly.

In a study published in the Journal of the American Heart Association in 2018, more than 950 Australian women aged 70 and older were asked to complete a food frequency questionnaire measuring their consumption of different types of vegetables.

Sonograms were used to measure the thickness of the participants' carotid artery walls. Carotid arteries are blood vessels that supplying blood to the neck, face and brain.

The researchers found that those who ate more vegetables had thinner carotid artery walls. The beneficial effects of cruciferous vegetables, a group that includes broccoli, appeared to be particularly strong. (6)

However, because of its observational nature, this study cannot establish any definite causal relationships. "Still, dietary guidelines should highlight the importance of increasing consumption of cruciferous vegetables for protection from vascular disease," said Lauren Blekkenhorst, the lead author of the study and a then-PhD candidate at the University of Western Australia (7).

4. Broccoli May Aid in Weight Loss

There is also some evidence suggesting that broccoli might help you lose weight. Not only does broccoli provide only about 30 calories per 100 grams, it also has a low glycemic load and a high fiber content (1).

An intriguing study published in the journal PLOS Medicine found that eating high-fiber, low glycemic load vegetables was associated with greater weight loss, compared with eating lower fiber, higher glycemic vegetables. The positive association was particularly strong for cruciferous vegetables, like broccoli, and green leafy vegetables.

What's more, broccoli contains glucobrassicin which acts as a precursor to indole-3-carbinol (I3C). In an animal study published in the journal Nutrition, I3C resulted in weight loss and reduced fat accumulation in obese mice who were fed a high-fat diet (8). Another animal study, published in The Journal of Nutritional Biochemistry, had similar findings (9).

Researchers believe the apparent weight loss effects of I3C may involve multiple mechanisms, including preventing undifferentiated cells from turning into fat cells, reducing inflammation, and stimulating thermogenesis, a metabolic process during which the body burns more calories to produce heat (9).

5. May Help Lower Blood Sugar Levels in Some People

As broccoli has a glycemic index (GI) value of only 13, eating broccoli should not cause drastic spikes in your blood sugar levels (10). But there are also a number of other reasons why broccoli is a great choice for people with diabetes.

For one, broccoli is an excellent source of vitamin C, and according to a study published in the journal Nutrients, people with type 2 diabetes or prediabetes may have greater vitamin C requirements due to oxidative stress and chronic inflammation caused by abnormal blood sugar levels (11). Another study found that high doses (but not lower doses) of supplemental vitamin C decreased blood sugar levels in people with type 2 diabetes (12).

In addition, obese people with dysregulated type 2 diabetes have been found to benefit from high-sulforaphane supplements made from broccoli sprouts which, along with broccoli, are among the best natural sources of sulforaphane.

6. Sulforaphane Provided by Broccoli May Promote Respiratory Health

Sulforaphane, the breakdown product of the glucoraphanin present in broccoli, may also help improve respiratory health. A study led by Dr. Marc Riedl from the David Geffen School of Medicine at UCLA found that sulforaphane may help protect against respiratory inflammation that causes conditions like asthma, allergic rhinitis, and chronic obstructive pulmonary disease.

For this study, which was published in the journal Clinical Immunology, Dr. Riedl's team used broccoli sprouts, which are the richest natural source of sulforaphane (13, 14).

The beneficial effects of sulforaphane appeared to be linked to its effect on antioxidant enzymes. "We found a two- to three-fold increase in antioxidant enzymes in the nasal airway cells of study participants who had eaten a preparation of broccoli sprouts," Dr. Riedl said in a news release (14).

This could mean that foods that provide sulforaphane, such as broccoli, may provide protection against free radicals. Produced by things like air pollution and tobacco smoke, free radicals can cause oxidative tissue damage, which leads to inflammation and respiratory conditions like asthma.

In addition, the high concentration of vitamin C in broccoli may offer some interesting benefits related to respiratory health: according to several studies, vitamin C may provide protection against some types of asthma, including exercise-induced asthma.

7. Broccoli May Be Good for Your Skin

Eating broccoli is a great way to give your skin a health boost, not least because it's loaded with vitamin C. This well-researched nutrient is important for skin health because of its antioxidant properties and its role in collagen synthesis, and observational studies have associated diets rich in vitamin C with better skin appearance, with significant decreases in skin wrinkling (15).

In addition, broccoli contains coenzyme Q10, a fat-soluble compound that is well-known for its antioxidant properties (16). Coenzyme Q10 is commonly added to cosmetics because of its purported anti-aging benefits, but this interesting compound might also help treat your skin from the inside out: a double-blind, placebo-controlled study published in the journal BioFactors found that oral coenzyme Q10 supplements reduced seasonal deterioration of viscoelasticity as well as some visible signs of ageing, such as wrinkles (17).

8. Eating Broccoli May Help Improve Eye Health

Cataracts and age-related macular degeneration (AMD) are common causes of visual impairment and blindness in developed countries. The good news that eating right can help protect your vision, and carotenoids such as lutein and zeaxanthin have been found to be particularly beneficial for people who want to lower their risk of developing eye or vision problems.

Indeed, one study found that while several carotenoid-rich foods were inversely associated with AMD, a high intake of collard greens or spinach – which are among the most concentrated sources of lutein and zeaxanthin – was associated with a particularly low risk for AMD (18).

In addition, lutein helps protect the eye from damage caused by the sun's ultraviolet rays and blue light emitted by smartphones, laptops and other similar electronic devices. In fact, the evidence for lutein as an eye health protecting nutrient is so convincing that ophthalmologist Robert Abel, M.D., has called lutein "nature's sunglasses" in his groundbreaking book, The Eye Care Revolution.

While broccoli does not contain as much lutein and zeaxanthin as collards and spinach, it is still a very good source of these eye health protecting nutrients.

Plus, broccoli ranks low on the glycemic index, which might confer some additional benefits. In the Eye Care Revolution, Dr. Abel recommends paying attention to the glycemic index of foods because people who consume unusually high glycemic foods have been found to have a higher risk of both cataracts and AMD.

9. Broccoli Has Anti-Inflammatory Properties

Chronic, low-grade inflammation has been linked to a variety of diseases and conditions including rheumatoid arthritis, heart disease, inflammatory skin conditions such as psoriasis and eczema, Crohn's disease, and irritable bowel syndrome.

The good news is that chronic inflammation can be reduced or even resolved with a diet that emphasizes anti-inflammatory foods and limits the intake of unhealthy pro-inflammatory foods.

Many great anti-inflammatory diet books are filled with recipes featuring broccoli, and broccoli and other cruciferous vegetables have been shown to reduce some (but not all) markers of systemic inflammation in humans.

The apparent anti-inflammatory properties of broccoli may be due to a number of factors, including the low GI of broccoli and its high content of glucosinolates.

Broccoli also has a high ratio of omega-3 to omega-6 fatty acids, and as you may know, omega-3 fatty acids are thought to be anti-inflammatory, while omega-6 fatty acids tend to be inflammatory (see The Optimal Omega 6 to 3 Ratio). However, as the overall fat content of broccoli is very low, eating a serving of broccoli won't make a great contribution to your omega-3 intake (1).

10. Broccoli is Rich in Nutrients That Protect Bones

According to the National Osteoporosis Foundation, approximately 54 million Americans have osteoporosis, or low bone density which puts them at higher risk for developing osteoporosis. What's more, studies suggest that approximately one in two women and up to one in four men aged 50 or older will break a bone due to osteoporosis in their lifetime. (19)

Luckily, switching to a healthy diet can be very effective at reducing your risk of developing osteoporosis or breaking a bone, and many green vegetables, including broccoli, are packed with nutrients that are known to be good for your bones.

Vitamin K is one of the most important, yet often overlooked bone-strengthening nutrients – and broccoli is loaded with it.

Studies have associated a low intake of vitamin K with low bone density and an increased risk of osteoporosis, while a high intake of vitamin K has been associated with high bone density and a lower risk of osteoporosis (20).

Another vitamin that is good for your bones is vitamin C, and eating broccoli is a great way to keep up your vitamin C levels. Vitamin C is involved in bone development and is critical for the production of collagen, which is an important building block of bones, cartilage, and other structures. (21)

What's more, while broccoli does not compare to kale in terms of calcium content, it does contain a decent amount of this bone- and teeth- strengthening mineral (1, 22).

Book You May Like

Anti-Inflammatory Lifestyle

Written by Dr. Walter C. Willett, MD, DrPH, who has led the Department of Nutrition at the Harvard T.H. Chan School of Public Health for over twenty years, "Eat, Drink, and Be Healthy" draws on cutting-edge nutrition research to explain what the USDA dietary guidelines have gotten wrong — and how you can eat right. In this eye-opening book, the world-renowned researcher and bestselling author explains, among other things, how to choose foods with the best types of carbohydrates, fats, and proteins, and why keeping your weight in check is crucial for a long, healthy life.