Rachel Whitehall, student dietitian, Glasgow Caledonian University.

Broccoli is one of those foods that usually springs to mind when you reminisce about your parents telling you to eat your greens as a child, well it turns out they had very good reason to! Broccoli may not be at the top of everybody’s shopping list but truth is, this vegetable is a powerhouse of nutrients, which really you want to have on your dinner plate more often.

Broccoli belongs to the brassica family, also commonly known as cruciferous vegetables, alongside some of its cousins, cauliflower, cabbage, kale and turnip, which are known particularly for their beneficial health effects and are sometimes referred to as ‘superfoods’. However, the term ‘superfoods’ is more of a marketing ploy used by manufacturers to promote their products. Although diet plays a vital role in our health, too much focus on individual foods may encourage unhealthy eating habits. Therefore, we should be aiming to consume a wide range of fruits, vegetables and wholegrains to promote a healthy, balanced diet. 1

However, there is no denying that eating Broccoli will provide you with a rich source of vitamins, minerals, dietary fibre, phytochemicals and anti-oxidants, all of which have fantastic health-promoting and potential disease-preventing properties.

Although broccoli is available year round, its peak season is between July and October. 2 When purchasing broccoli, look for florets with bright green heads and preferably compact, clusters of broccoli florets. Also, avoid any florets with yellowish tinges as this is a sign it’s no longer the desirable texture you want, although it could still be used in soups. To store the veggie at home and keep it in optimum condition until eating, you want to keep the broccoli cold so either keep it in a cool, dark place or pop it in the fridge within its plastic wrapping. Remember all parts of the broccoli can be eaten even the stems, just make sure to wash it before eating. 3

Macronutrients

As you can see in Table 1, a medium portion of boiled broccoli is approximately 85g, which will count towards one of your five a day.

Table 1 – Nutritional composition of a medium portion of boiled broccoli and the equivalent RNI4

Nutrient Amount per medium 85g (boiled) Recommended Nutrient Intake (RNI) of nutrient/per day
Children

Aged 2-5 years

Children

Aged 5-11 years

Teens

11-16 years

 

Adults

 

Energy (kcals) 24
Carbohydrate (g) 2.4
Of which sugars (g) 1.4
Total Fat (g) 0.4
Protein (g) 2.8
Fibre (NSP) (g) 2 15 20 25 30
Vitamin A (µg) 26.4 400 400-500 600-700 600

(Women)

 

700

(Men)

Vitamin C

(mg)

37.4 25-30 30 35 40
Calcium (mg) 29.8 350-450 450-550 800

(Girls)

 

1000mg (Boys)

700

 

* Lactation +550

Iron (mg) 0.5 6.1-6.9 6.1 – 8.7 14.8 (Girls)

11.3 (Boys)

14.8

(Women)

 

8.7

(Men)

 

8.7

(+50 years)

 

It is clear that broccoli is a fantastic low-calorie food to include in your meals regularly, particularly if you are trying to watch your weight, as it is also contains very minimal traces of saturated fat and cholesterol. Broccoli is also a good source of protein, making it a great option for vegetarians. Although it is an incomplete protein source, as it doesn’t contain sufficient amounts of the eight essential amino acids, it could easily be paired with whole grains such as brown rice, barley or quinoa or nuts to supplement any of the missing amino acids.

Broccoli is also a good source of dietary fibre, with a medium boiled portion of the vegetable containing around 2 grams. Fibre comes in two forms –insoluble and soluble, and most vegetables contain a combination of both. Insoluble fibre remains unchanged all the way to the colon, giving bulk to stools and making them soft so they can move along with ease. Soluble fibre on the other hand, dissolves in water and forms into a gel in the gut and helps slow digestion, lower cholesterol and blood glucose levels. 5 A lack of fibre in the diet can lead to symptoms of constipation and can make a trip to the bathroom uncomfortable and even painful. However, fibre isn’t just important for a smooth-running bathroom break! Research indicates that diets rich in fibre are associated with reduced risk of cardiovascular disease, type-2 diabetes and bowel cancers, whereas, conversely diets low in fibre are associated with poor digestive health. 6 Recent, compelling research has suggested that individuals consuming a low-fibre diet have increased cortisol levels, indicating a heightened stress response within the body, which is strongly linked to anxiety and depression. 7 The UK Government recently revised their guidance on Dietary Fibre recommendations in 2015. The average population recommendation for adults has now increased to 30 grams per day, however the reality is adults are consuming much less than this at 60% (18g) of what it should. 6 Including broccoli in your meals regularly will help increase your dietary fibre intake, although it is best to increase fibre gradually in your diet rather than all at once.

Micronutrients

Broccoli is a good source of Vitamin A, a fat-soluble vitamin which our bodies store in our fat tissues and liver. Vitamin A plays an important role in maintaining healthy vision, promoting a healthy immune system, reproduction and cellular communication. It also plays a vital role in promoting cell growth and differentiation, playing a crucial role in the normal functioning and maintenance of the heart, lungs, kidneys and other organs.8 Consumption of Vitamin A at very high levels is toxic, and consequently recommended intakes have been put in place as seen in Table 1. Although, it is unlikely that you will exceed your requirements through diet alone, pregnant women should be aware of their intake as high levels can be harmful to the unborn baby. If you are pregnant avoid liver products and pate, because they are very high in Vitamin A, and for the general population if you take a multi-vitamin containing Vitamin A, make sure your daily intake from diet and supplements does not exceed 1.5mg to protect bone health. 8

Broccoli packs a punch of Vitamin C, with one medium boiled portion of the vegetable providing around 37.4 mg of the nutrient.  Equivalent to around 94% of the daily, recommended nutrient intake (RNI) for adults. 4 Vitamin C is a water-soluble vitamin, and as our bodies are unable to store these vitamins, it is important to make sure we are receiving adequate amounts from the foods we eat. Vitamin C, also known as ascorbic acid, is essential for the growth and regeneration of body tissues, as well as the synthesis of collagen, an important protein that helps give our skin strength and elasticity. Vitamin C also plays an important role in the maintenance of healthy bones and teeth and is a powerful anti-oxidant, protecting the body from damage caused by harmful molecules called free radicals. 8

Broccoli is also a fantastic source of Vitamin K, a fat-soluble vitamin that our bodies store in our fat tissues and liver. Vitamin K takes its name from the German word for blood clotting (koagulation), and perhaps is one of the main functions Vitamin K is best known for. The clotting process in the human body is very complex, requiring at least 12 proteins before the process can be initiated, of which four proteins require Vitamin K to become activated. Although some people may hear the words blood clot and think of its negative associations, in fact blood clotting is extremely important to stop bleeding due to accidental cuts or punctures to our skin. Moreover, there is growing interest that Vitamin K plays an important role in maintaining bone health. Vitamin K helps to seal calcium into the bones to increase bone density and strength, reducing the risk of fractures and in the long-term, osteoporosis.  It is thought that by helping to seal calcium into the bones, it prevents the risk of calcium accumulating in the lining of our arteries and other tissues, therefore reducing the risk of cardiovascular disease. 8 A journal review in 2016 suggested that increasing dietary consumption of foods rich in Vitamin K such as broccoli, promotes bone health through optimising bone strength and reducing fracture risk.9

Minerals

Moreover, broccoli is an excellent food to eat regularly to increase levels of several essential minerals we need from our diet such as Calcium, Iron, Magnesium, Manganese and Potassium. Iron is an essential mineral, which is required for the production of red blood cells, which carry oxygen around the body. A lack of iron in the diet can lead to feeling a lack of energy and tiredness alongside shortness of breath. Dark, green leafy vegetables such as broccoli are all good sources of Calcium particularly, for those who do not consume dairy. The main role of calcium is to support bone growth and structure, as well as playing an important role in maintaining heart health. As you age you have a greater risk of bone loss, and so ensuring adequate calcium intakes is crucial for reducing the risk of osteoporosis and fractures in later life.  10

Phytochemicals

As mentioned earlier, cauliflower belongs to the cruciferous family of vegetables, which have been the subject of increasing health-related research due to their rich nutrient profile. Cruciferous vegetables contain a group of natural phytochemicals known as glucosinolates, which are sulphur-containing compounds and are responsible for the strong aroma of cauliflower. Currently ongoing research is investigating whether cruciferous vegetables may reduce the risk of certain cancers; however further investigations are required to be certain of their role in cancer prevention. Although in general, higher consumption of vegetables is associated with a lower-risk of all cause mortality, particularly cardiovascular disease. 11

 

References

[1] NHS UK (2015) What are superfoods? [online] [Viewed on 24/02/2017] Available from: http://www.nhs.uk/Livewell/superfoods/Pages/what-are-superfoods.aspx

[2] Vegetarian Society (2016), Seasonal UK Grown produce. Available from: https://www.vegsoc.org/page.aspx?pid=525 Accessed on 06.02.2017

[3] Epicurious (2017) How to buy, store, and yes, eat your broccoli. [online] [Viewed on 23/02/2017] Available from: http://www.epicurious.com/ingredients/how-to-buy-store-and-eat-your-broccoli-article

[4] McCance, R.A., Widdowson, E.M., Royal Society of Chemistry. Information Services, Public Health England, Institute of Food Research & Great Britain. Ministry of Agriculture, Fisheries and Food (2015), McCance and Widdowson’s the composition of foods, 7th summary edn, Royal Society of Chemistry.

[5] BDA (2016) Fibre Food fact sheet [online] [Viewed on 25/02/2017] Available from: https://www.bda.uk.com/foodfacts/fibrefoodfactsheet.pdf

[6] SACN (Scientific Advisory Committee on Nutrition) (2015) Carbohydrates and Health. [online] [Viewed on 07/02/2017] Available at: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/445503/SACN_Carbohydrates_and_Health.pdf

[7] Schmidt, K., Cowen, P.J., Harmer, C.J., Tzortzis, G., Errington, S. & Burnet, P.W.J. (2015) “Prebiotic intake reduces the waking cortisol response and alters emotional bias in healthy volunteers”, Psychopharmacology, vol. 232, no. 10, pp. 1793-1801.

[8] British Nutrition Foundation (2017) Vitamin A, K & C [viewed on 17/02/2017] Available from: https://www.nutrition.org.uk/nutritionscience/nutrients-food-and-ingredients/vitamins.html?limit=1&start=5

[9] O’Keefe, J.H., Bergman, N., Carrera-Bastos, P., Fontes-Villalba, M., DiNicolantonio, J.J. & Cordain, L. 2016, “Nutritional strategies for skeletal and cardiovascular health: hard bones, soft arteries, rather than vice versa”, Open heart, vol. 3, no. 1, pp. e000325.

[10] British Nutrition Foundation (2017) Minerals and Trace Elements [online] [Viewed on 23/02/2017] Available from: https://www.nutrition.org.uk/nutritionscience/nutrients-food-and-ingredients/minerals-and-trace-elements.html

[11] Wang, X., Ouyang, Y., Liu, J., Zhu, M., Zhao, G., Bao, W. & Hu, F.B. 2014, Fruit and vegetable consumption and mortality from all causes, cardiovascular disease, and cancer: systematic review and dose-response meta-analysis of prospective cohort studies, BMJ (Clinical research ed.), vol. 349, pp. g4490.