Superfood Series: Broccoli

Description

Broccoli has recently become popular as a result of research uncovering high concentrations of the anti-cancer phytonutrient, sulforaphaneBroccoli is a cruciferous vegetable, meaning it belongs to the mustard family along with other green, leafy species such as cauliflower, cabbage, bok choy and brussel sprouts.

Native to the Mediterranean area and Asia Minor, and introduced to England and America in the 1700s, broccoli was originally cultivated in Italy during ancient Roman times (1,2).

It’s name is derived from the Italian plural of broccolo, which means “the flowering crest of a cabbage” (3).

Depending on the variety, of which there are three commonly grown (4), its colour can range from deep sage to dark green and purplish-green (5).

The most popular variety, and the one most popularly sold in Europe and North America, is called Italian Green, or Calabrese, named after the Italian province of Calabria where it first grew (6). Calabrese is a cool season annual crop with large (10 to 20 cm) green heads and thick stalks (7).

The other two main varieties are Sprouting Broccoli, which has a larger number of heads with many thin stalks, and Purple Cauliflower, a type of broccoli sold in southern Italy, Spain, and the United Kingdom with a head shaped like cauliflower, but consisting of tiny flower buds which often, but not always, have a purple cast to the tips (8).

different varieties of broccoli

Nutritional profile

Despite being low in calories, broccoli boasts an impressive nutritional profile and is predominantly an excellent source of quality dietary fibre, vitamins and minerals including Vitamin C, Vitamin K, Folate, Vitamin A, Manganese and Vitamin B6.

Here’s a detailed nutrient breakdown per 100g (1 cup chopped is about 91g) (9).

  • Calories: 34 kcal
  • Protein: 3 grams
  • Carbs: 7 grams
  • Dietary fibre: 3 grams, 10% RDA
  • Vitamin C: 149% of the RDA
  • Vitamin K: 127% of the RDA
  • Folate: 16% of the RDA
  • Vitamin A: 12% of the RDA
  • Manganese: 10% of the RDA
  • Vitamin B6: 9% of the RDA
  • Potassium: 9% of the RDA
  • Phosphorus: 7% of the RDA
  • Riboflavin: 7% of the RDA
  • Calcium: 5% of the RDA
  • Iron: 4% of the RDA

Health Benefits

Broccoli has recently become popular as a result of research uncovering high concentrations of the anti-cancer phytonutrient, sulforaphaneBroccoli earns its stripes as a superfood due to high concentrations of various antioxidants and plant compounds associated with health benefits, such as sulforaphane, indole-3-carbinol, carotenoids, and kaempferol (10).

Here’s a summary of the top health benefits courtesy of the internet’s most reputable sources.

Cancer Prevention

Broccoli has become increasingly popular as a health food following research uncovering high concentrations of the anti-cancer phytonutrient, sulforaphane, which is reportedly the superfood’s most abundant health related compound (11,12).

In fact, it’s not just broccoli which is of interest as all cruciferous vegetables, such as kale, cabbage, and brussels sprouts contain chemical components which may play a role in cancer prevention.

Without getting too technical, these compounds operate at a molecular level by inhibiting mis-regulation of the genes responsible for the growth of abnormal cells (13). Essentially, they activate genes which fight cancer and switch off others which may stimulate the growth of tumours (14).

Recent studies have also provided a much better idea about the amount of broccoli that we need to lower our cancer risk, and the good news is that small helpings have been shown to reap rewards.

At the higher end of the spectrum, some studies suggest an average of 1/2 cup of broccoli per day is needed (15), whilst at the lower end, others have shown that as little as one portion of cruciferous vegetables per week is suffice (16).

Either way, notwithstanding the impressive nutritional profile, the potential for broccoli to fight cancer is a pretty strong reason for you add broccoli to your weekly shopping list.

Reduced risk of Heart Disease and Stroke

Recent studies have shown that sulforaphane may also play a role in preventing atherosclerosis, one of the main contributors to angina, hearts attack and stroke (17).

Atherosclerosis occurs as a result of the build-up of fatty plaques which clog and damage the arteries (18,19).

The high risk arterial areas are those found amongst the bends and branches of our circulatory system where a naturally protective protein in the body, Nrf2, is inactive.

Sulforaphane has been shown to activate Nrf2, thus helping to curb the inflammation and build-up which leads to atherosclerosis (20).

Cholesterol

Cholesterol is used by the liver to produce bile acids, specialised molecules stored in our gall bladder which aid the digestion and absorption of fat.

When we eat fat, bile acids are released into the intestine where the fat is prepared for emulsification and absorption into the body through the interaction with enzymes.

Once they have done their job, bile acids are reabsorbed into the bloodstream and used again (21).

Broccoli’s fibre-related nutrients have the ability to bind with some of the intestine’s bile acids so that they pass through the body rather than getting absorbed along with the fat they have emulsified.

When this happens, our liver needs to replace the lost bile acids by drawing upon our existing supply of cholesterol and, as a result, our cholesterol level drops down, hence why broccoli is potentially has cholesterol reducing benefits.

Recent studies have also shown that the cholesterol-lowering ability of broccoli improves significantly when it is steamed, to a point where it competes with cholesterol-lowering a prescription drugs (22,23).

Eye health

Two of the main carotenoids found in significant concentrations in broccoli, lutein and zeaxanthin, play an important role in the health of the eye (24).

In addition, broccoli contains beta-carotene which is converted to vitamin A, also said to have beneficial effects on eyesight, specifically night blindness (25).

Vitamin D metabolism

The relationship between vitamin D and bone health has been known for many decades, as it is known to help the body absorb calcium (26).

However, recent research has uncovered the importance of vitamin K (specifically vitamin K2) which transports calcium to the bones and away from organs, joints and arteries (27).

Although broccoli is not a good source of vitamin D it is an excellent source of vitamin K meaning it plays a particularly helpful role in optimising vitamin D supplementation (28).

Potential risks

Broccoli is usually perfectly safe, however, it may cause undesirable effects on the thyroid in some people, the risk being seemingly higher if cruciferous vegetables are consumed raw (28).

Fortunately, cooking, and specifically steaming, seems to alleviate these effects.

In addition, high amounts of vitamin K may interact with the blood thinning medication warfarin so individuals taking such medication may wish to consult with a doctor before increasing their broccoli consumption (29).

How to select

  • Choose broccoli with floret clusters that are compact and not bruised: they should be uniformly coloured, either dark green, sage or purple-green, depending upon variety, and with no yellowing.
  • In addition, they should not have any yellow flowers blossoming through as this is a sign of over maturity.
  • The stalk and stems should be firm with no slimy spots appearing either there or on the florets.
  • If leaves are attached, they should be vibrant in color and not wilted.

How to store

  • Place broccoli in a plastic bag, removing as much of the air from the bag as possible.
  • Store in the refrigerator where it will keep for 10 days.
  • Do not wash broccoli before storing because exposure to water encourages spoilage.
  • Partial heads of broccoli should be placed in a well-sealed container or plastic bag and refrigerated.
  • Since the vitamin C content starts to quickly degrade once broccoli has been cut, it is best to use it within a couple of days.
  • Broccoli that has been blanched and then frozen can stay up to a year.
  • Leftover cooked broccoli should be placed in tightly covered container and stored in the refrigerator where it will keep for a few days.

Tips for Preparing

  • Rinse broccoli under cold running water and cut florets into quarters for quick and even cooking.
  • Be sure to enjoy the stems and leaves of broccoli; they provide a good balance of flavors.
  • Peel the broccoli stem and cut the stem into 1/2″ slices
  • To get unique health benefits from broccoli, let it sit for several minutes before cooking.

Steaming: The Healthiest Way of Cooking Broccoli

Our cooking method of choice for broccoli is steaming as it has been shown to do a better job of preserving nutrients than other cooking methods.

Option 1 – Use an electric steamer

Steaming broccoli is the best cooking method and an electric steamer can save time as you can cook different food types in one go.Investing in an electric steamer makes a lot of sense for anyone looking to lose weight as you can easily prepare meals and steam vegetables together with meat and fish which saves loads of time. You can pick an electric steamer for less than $30 on Amazon so it’s excellent value.

Option 2 – Steamer pot or steamer pot insert

Steamer pots are easily the quickest for steaming vegetablesAt a similar price-point to an electric steamer, you could pick up a steamer pot and for even less you could get a steamer insert to use in your current pots. The advantage of using a pot over an electric steamer is that your broccoli will be ready in about 5 minutes as opposed to the electric alternative which takes about 20 mins to cook properly. To use a steamer pot, fill the bottom of a steamer pot with 2 inches of water. While waiting for the water to come to a rapid boil prepare broccoli florets and stems. Steam for about 5 minutes maximum. 

Sources for this article

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