Have you ever been told to eat at least 5 vegetables per day? Although almost everyone knows this, not all of us accomplish it and from those who do, many get tired of eating the same vegetables over and over. However, there are more than a thousand vegetables with many different properties and flavours and just by increasing your knowledge about the different options available, you will learn how to make your diets not only healthier but also less boring and repetitive.1 Leeks are a great example of this. Have you ever thought about introducing them to your diet? There are many reasons why leeks are an awesome option to include within your daily vegetables, and if you want to learn about them, this article is exactly what you were looking for.
About leeks
Leeks (Allium porrum) are vegetables related to onions that have a mildly sweet flavour similar to other allium vegetables such as chives, shallot, garlic, and onions. Although they are root vegetables like onions, they are longer and practically do not form a bulb. These vegetables are originally from the Mediterranean countries and the Middle East but are widely used worldwide. In Europe, fresh leeks are mainly used as a complement to potatoes or to dishes such as stews and as the main ingredient of foods such as leek juice and leek soups, like vichyssoise, which is a leek and potato soup. Apart from this, popular ways of cooking leeks also include steaming and frying them with butter or olive oil (e.g. butter sautéed leeks).2
Health benefits of leeks
Cancer risk reduction
Leeks have different components that make them really beneficial for our health. First of all, they contain flavonoid kaempferol, which is an antioxidant found in different fruits and vegetables, such as strawberries and broccoli.3 The consumption of vegetables with flavonoid kaempferol, such as leeks, seems to be useful for preventing the development of chronic diseases, especially cancer, as this compound inhibits cancer cell growth. Although its effectivity as a treatment for cancer is debatable, flavonoid kaempferol does exert a protective effect against cancer development and moreover, it might be possible to increase its bioavailability using nanotechnology, making it more likely to be possible to use it as an agent to reduce the risk of developing cancer.4
Heart health
Apart from this, flavonoid kaempferol is also beneficial for our cardiovascular system. Indeed, apart from having anticancer properties, this compound is anti-inflammatory and anti-hypertensive. In this way, flavonoid kaempferol can, first of all, be useful to combat chronic inflammation, which can lead to the development of cardiovascular disease, which is the leading cause of death globally, and diabetes. Secondly, this component of leeks can also be helpful in reducing blood pressure, which is one of the main risk factors for cardiovascular disease. Apart from this, as leeks have potent antioxidant properties, they can prevent the oxidation of low-density lipoproteins, also referred to as “bad” cholesterol. By doing this, they can reduce the risk of atherosclerosis, in which the blood vessels, specifically the arteries, become narrowed due to the buildup of cholesterol and other substances.5
Vitamin A and B6 benefits: boost your immune system
Leeks are also rich in vitamin A and B6. Vitamin A is beneficial mainly for vision and the immune system,6 but it also has antioxidant properties that protect the cells against the effect of free radicals, which are molecules linked to the development of heart diseases and cancer that can derive, for example, from exposure to tobacco smoke.7 By its side, vitamin B6 also has many health benefits. Indeed, this vitamin is essential for the nervous and immune systems and for the normal development of the brain. Furthermore, it is known that vitamin B6 deficiency can cause anaemia, depression, and the weakening of the immune system, and therefore, consumption of leeks might also help to prevent these.8
Blood clotting and bone health
Leeks are also a good source of vitamin K and manganese. These compounds seem to help heal wounds faster by stimulating blood clotting and have, among others, anticancer and bone-forming properties. Thanks to this last property, consuming leeks might be helpful to decrease your risk of fractures and osteoporosis, which is a health condition with a very high incidence, especially in women, that causes more than 8.9 million fractures each year.9
Antimicrobial activity
Lastly, leeks are also known to be effective in treating infectious diseases thanks to their antimicrobial activity. This activity results from the allicin, a sulfur compound that leeks, as other Allium species such as garlic contain. Allicin has been shown to exert antimicrobial activity against bacteria and has been suggested to inhibit their biofilm formation of, which is the main cause of antibiotic resistance, which endangers the efficacy of these medications.10
Nutritional facts
Apart from having as many health benefits, leeks are a really good source of water and dietary fibre, specifically soluble fibre, which might help to promote weight loss, and are low in calories and fats. In this way, 100g of leeks contain approximately the following amounts of nutrients:11
- Water: 83 g
- Energy: 61 kcal/255 kJ
- Fiber: 2 g
- Fats: 0.3 g
- Proteins: 1.5 g
- Carbohydrate: 14.2 g
- Calcium: 59 mg
- Potassium: 180 mg
- Manganese: 0.48 mg
- Vitamin B6: 0.23 mg
- Vitamin A: 83 µg
- Vitamin K: 47 µg
- Folic acid: 0 µg (assumed zero)
Side effects and other concerns
In terms of the side effects, the consumption of leeks is generally safe even in big quantities, although, as with any food, moderation is recommended. For example, eating leeks in massive quantities, which implies eating too much fibre, might cause abdominal bloating, intestinal gas, and cramps, and excessive consumption of vitamin A might increase the risk of osteoporosis, although for this to happen, you would have to eat approximately 2 kg of leeks each day over many years.6,12 Apart from this, it is highlightable that, as with any vegetable, leeks should be washed under running water thoroughly as this reduces the risk of consuming harmful bacteria and parasites such as E.coli. In fact, in 2011, there was an E.coli outbreak in the UK, and according to the Health Protection Agency, leeks and potatoes were the main culprits. However, as stated, this could probably have been avoided if these vegetables had been adequately washed before consuming them.13
Summary
If you are thinking about which new vegetables to introduce to your foods, leeks are a really good and safe option. Not only are they easy and fast to cook, but they also are helpful for losing weight and have many different health benefits, such as decreasing the risk of osteoporosis, heart disease, and cancer. Furthermore, although they have been linked to the outbreak of E.coli that took place some years ago, their consumption is really safe as long as they are washed under running water and they do not have major side effects. With all this, it is a no-brainer that leeks are an excellent option to include among your daily vegetables, and with no doubt, you will not regret it.
References
- Meldrum G, Padulosi S, Lochetti G, Robitaille R, Diulgheroff S. Issues and prospects for the sustainable use and conservation of cultivated vegetable diversity for more nutrition-sensitive agriculture. Agriculture. 2018 Jul 9;8(7):112.
- Encyclopedia Britannica. Leek [Internet]. Britannica. 2023 [cited 2023 May 22]. Available from: https://www.britannica.com/plant/leek
- Blythman J, Sykes R. Why leeks are good for you [Internet]. The Guardian. 2014 [cited 2023 May 23]. Available from: https://www.theguardian.com/lifeandstyle/2014/jan/27/why-leeks-are-good-for-you
- Chen AY, Chen YC. A review of the dietary flavonoid, kaempferol on human health and cancer chemoprevention. Food chemistry. 2013 Jun 15;138(4):2099-107.
- Ciumărnean L, Milaciu MV, Runcan O, Vesa ȘC, Răchișan AL, Negrean V, Perné MG, Donca VI, Alexescu TG, Para I, Dogaru G. The effects of flavonoids in cardiovascular diseases. Molecules. 2020 Sep 21;25(18):4320.
- NHS. Vitamin A [Internet]. NHS. 2020 [cited 2023 May 25]. Available from: https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-a/
- MayoClinic. Vitamin A [Internet]. Mayo Clinic. 2020 [cited 2023 May 25]. Available from: https://www.mayoclinic.org/drugs-supplements-vitamin-a/art-20365945
- MayoClinic. Vitamin B6 [Internet]. Mayo Clinic. 2021 [cited 2023 May 24]. Available from: https://www.mayoclinic.org/drugs-supplements-vitamin-b6/art-20363468
- DiNicolantonio JJ, Bhutani J, O'Keefe JH. The health benefits of vitamin K. Open heart. 2015 Oct 1;2(1):e000300.
- Lemma E, Yusuf Z, Desta M, Seyida S, Idris M, Mengistu S, Teneshu J. Physicochemical Properties and Biological Activities of Garlic (Allium sativum L.) Bulb and Leek (Allium ampeloprasum L. var. Porrum) Leaf Oil Extracts. The Scientific World Journal. 2022 Apr 26;2022.
- US Department of Agriculture. Leeks, (bulb and lower-leaf portion), raw [Internet]. US Department of Agriculture. 2019 [cited 2023 May 24]. Available from: https://fdc.nal.usda.gov/fdc-app.html#/food-details/169246/nutrients
- MayoClinic. Dietary fiber: Essential for a healthy diet [Internet]. Mayo Clinic. 2022 [cited 2023 May 23]. Available from: https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/fiber/art-20043983