Asparagus is an excellent ingredient for multiple dishes and a must-add to every healthy diet. With a unique flavour, packed with plenty of nutrients and health benefits, the global market for asparagus is predicted to grow significantly in the next few years.1
What is asparagus?
Asparagus is a perennial plant, which means it can be planted once and survive for several years. It is classified into the following types:
- Green asparagus
- White asparagus
- Purple asparagus
- Purple-green asparagus
- Purple-blue asparagus
- Pink asparagus
Green asparagus dominates the world’s market as the most popular type. It is harvested above ground and is exposed to light, which gives it a strong flavour, unlike white asparagus, which is harvested underground with no access to light.2
Asparagus contains chemicals known as bioactive compounds that provide many health benefits. The bioactive compounds in asparagus are:
- Polyphenols – these are chemicals produced by plants (phytochemicals) with many health benefits such as antioxidant, anti-inflammatory, and anti-cancer effects. They mainly include flavonoids and anthocyanins (plant pigments)2
- Phytoestrogens – these are plant compounds that resemble oestrogen that promote bone health and are used to treat menstrual and menopausal disorders3,4
- Steroidal saponins – these are phytochemicals that have anti-cancer, anti-fungal, and lipid-lowering effects. They are also responsible for the bitter taste of asparagus1,2
Green asparagus contains more of these beneficial compounds compared to purple and white asparagus, most likely due to the differences in light exposure. The tips of asparagus spears (especially young ones) should be included in healthy diets as they have the highest concentration of antioxidants, which help fight diseases.5,6
Health benefits of asparagus
Incorporating asparagus in your diet could lead to a number of long-term health benefits. Consuming asparagus regularly may:
- Improve heart health – it lowers the risk of high blood pressure, strokes, and heart diseases because it contains folic acid, B vitamins, and vitamin K, and is low in fat content2,7
- Reduce likelihood of developing diabetes – clinical trials have shown that asparagus lowers blood sugar levels, increases insulin secretion, decreases insulin insensitivity, and improves pancreatic β-cell function2,7,8
- Lower cholesterol – it reduces dyslipidaemia (high cholesterol) and prevents associated conditions such as atherosclerosis, heart disease, obesity, metabolic syndrome, and kidney disorders2,7,8
- Reduce likelihood of developing cancer – it is a potential anti-cancer agent since clinical trials on cells have demonstrated that it inhibits the growth or kills the cancer cells of colon, prostate, breast, and pancreatic cancer2
- Improve bone health – it strengthens bones and reduces the risk of fracture and osteoporosis by promoting bone formation, increasing bone mass, and preventing bone loss4,9
- Encourage weight loss – it helps with losing weight because not only is it low in calories, but it also contains dietary fibres, which makes you feel more full by delaying gastric emptying and bulking up your diet
- Improve digestive health – it promotes gut health by improving the gut microbiome and helping digestion. It also prevents constipation, stomach ulcers, dyspepsia (indigestion), and diarrhoea7
- Strengthen the immune system – its anti-inflammatory nutrients modulate the immune system to fight against infections by increasing antibody production and mobilising immune cells during an immune response7
- Reduce the likelihood of menstrual and menopausal disorders – it can treat severe menopausal symptoms and menstrual problems such as dysmenorrhea, irregular bleeding, and PMS7
- Strengthen reproductive health – it contributes to a healthy and safe pregnancy due to its folate content that helps the baby’s development and prevents birth defects. Asparagus also contains a substance known as galactagogue that increases milk supply while nursing7,8
- Destroy harmful microorganisms – its extracts can inhibit the growth of many species of fungi, bacteria, and single-celled organisms (protozoa) that are harmful to the body3
- Improve kidney health – it may remove excess salt and water from the body the same way as certain medicines known as diuretics. Since high sodium intake is a risk factor for high blood pressure, strokes, and heart attacks, eating asparagus can prevent these diseases3
Other health benefits of asparagus in humans include relieving stress, insomnia, and epilepsy.2 Animal studies show that it also improves mental health due to its anti-anxiety, anti-depressant, and anti-amnesic effects, with other promising results in improving health in the liver, central nervous system, kidneys, and tissues of animals. However, clinical trials still need to be conducted in humans to properly test its effectiveness.5,6
What nutrients are in asparagus?
Asparagus contains many different nutrients. Its main properties include dietary fibre, vitamins, and minerals.
Dietary fibre promotes gut health, lowers blood sugar and cholesterol levels, helps with weight loss, and is an antioxidant.2
Asparagus is rich in B vitamins which lowers blood pressure and reduces the risk of atherosclerosis and heart disease. Vitamin B12 is also essential for making DNA and maintaining energy levels. Otherwise, asparagus contains vitamins A, C, E, and K. While vitamin K promotes bone health, the others neutralise free radicals.
100 g of raw asparagus contains the following vitamins:1
- 0.143 mg vitamin B1 (thiamine)
- 0.141 mg vitamin B2 (riboflavin)
- 0.978 mg vitamin B3 (niacin)
- 0.274 mg vitamin B5 (pantothenic acid)
- 0.091 mg vitamin B6
- 52 µg (micrograms) vitamin B9 (folate/folic acid)
- Trace quantities of vitamin B12
- 5.6 mg vitamin C (ascorbic acid)
- 1.13 mg vitamin E (alpha-tocopherol)
- 38 µg (micrograms) vitamin A
- 41.6 µg (micrograms) vitamin K
Asparagus contains the following essential minerals: calcium, copper, iron, magnesium, manganese, potassium, selenium, sodium, phosphorous, and zinc. They are present in large amounts at the tips of asparagus spears.1
Ways to include asparagus in your diet
Asparagus is an excellent addition to healthy diets since it is a low-calorie vegetable packed with vitamins and antioxidants. It can be eaten raw, boiled, steamed, baked, fried, roasted, grilled, or microwaved. You can buy asparagus fresh, canned, or frozen, and can even prepare it blended into a drink, vinegar, or yoghurt.2
When cooking asparagus spears, remember:
- To wash them thoroughly under water before cooking
- Cooked asparagus should be bright green and tender-crisp
- Overcooking them causes loss of vitamins and flavour
- Microwave on high power for 4-7 minutes
Its bitter, savoury flavour pairs well with many foods including poultry, fish, and cheese. It can be served raw in salads, as a snack with dipping sauce, or cooked in casseroles. It also pairs well with a variety of herbs and seasonings.
When shopping, fresh asparagus will look bright green with closed and compact tips. If asparagus has gone bad, it will look shrivelled and soft. Since asparagus goes out of date quickly, cook it the same day to prevent it from spoiling and losing flavour. You can also opt for short-term storage by covering it with moisture-proof wrapping, refrigerating it, and using it within two to three days.
Long-term storage involves blanching, packaging, and freezing the spears at 0°C or lower for up to a year. After washing the spears before storage, pat them completely dry since moisture promotes bacterial growth.
How much is enough?
The NHS counts having 80g of asparagus daily (5 spears of fresh asparagus/7 spears of canned asparagus) as one portion of an adult’s 5 a day. However, you can eat more as it’s a nutrient-rich food with plenty of health benefits.
It is high in folic acid compared to other vegetables. A 150g serving of asparagus gives us 60% of the recommended daily folate dose, while a 180g serving ensures adequate daily dietary mineral intake.1
Although asparagus is generally considered safe, it has a few side effects:
- Strong-smelling urine: if your pee smells after eating asparagus, the odour can last up to fourteen hours after consumption
- Asparagus allergy: asparagus can trigger allergic reactions and induce the following food allergy symptoms in people with: anaphylaxis, oral allergy syndrome, rhinitis, conjunctivitis, occupational contact dermatitis, contact urticaria, rhinoconjunctivitis, asthma, and eczema (seasonal)
- Potential teratogenic effects: animal studies have revealed that the root extracts of a species of asparagus known as Asparagus racemosus cause birth defects. Human trials are therefore needed to evaluate its safety5
Asparagus is rich in dietary fibre, vitamins, minerals, and antioxidants. It is therefore an excellent vegetable with many health benefits including improving gut and bone health, helping with weight loss and pregnancy, and preventing and treating heart disease, cancer, and infections. It can be easily incorporated into our diets as it is used in a variety of cuisines and can be prepared using different cooking methods.
Despite the many health benefits of asparagus, you may experience a few side effects such as strong-smelling urine and allergic reactions. Overall, however, it is a great addition to our diets as it offers many long-term benefits when consumed regularly.
- Pegiou E, Mumm R, Acharya P, De Vos RCH, Hall RD. Green and white asparagus (Asparagus officinalis): a source of developmental, chemical and urinary intrigue. Metabolites [Internet]. 2019 Dec 25 [cited 2023 Mar 3];10(1):17. Available from: https://www.mdpi.com/2218-1989/10/1/17
- Guo Q, Wang N, Liu H, Li Z, Lu L, Wang C. The bioactive compounds and biological functions of Asparagus officinalis L. – A review. Journal of Functional Foods [Internet]. 2020 Feb [cited 2023 Mar 3];65:103727. Available from: https://linkinghub.elsevier.com/retrieve/pii/S1756464619306516
- Sharma A, Sharma DN. A comprehensive review of the pharmacological actions of Asparagus racemosus [Internet]. Am. J. Pharm. Tech. Res. 2017 Dec [cited 2023 Mar 3];7(1). Available from: https://www.researchgate.net/publication/313797510_A_Comprehensive_Review_of_the_Pharmacological_Actions_of_Asparagus_Racemosus
- Gujarathi, Jasmine & Gujarathi, Ritesh. Minimizing risk of Postmenopausal Osteoporosis through Shatavari - A clinical study [Internet]. Res. 2013 Jan [cited 2023 Mar 3]; World Journal of Pharmaceutical Research. 2. 260-265. Available from: https://www.researchgate.net/publication/234044858_Minimizing_risk_of_Postmenopausal_Osteoporosis_through_Shatavari_-_A_clinical_study
- Kobus-Cisowska J, Szymanowska D, Szczepaniak OM, Gramza-Michałowska A, Kmiecik D, Kulczyński B, et al. Composition of polyphenols of asparagus spears (Asparagus officinalis) and their antioxidant potential. Cienc Rural [Internet]. 2019 [cited 2023 Mar 3];49(4):e20180863. Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782019000400751&tlng=en
- Slatnar A, Mikulic-Petkovsek M, Stampar F, Veberic R, Horvat J, Jakse M, et al. Game of Tones: sugars, organic acids, and phenolics in green and purple asparagus (Asparagus officinalis L.) cultivars. Turk J Agric For [Internet]. 2018 [cited 2023 Mar 3];42:55–66. Available from: https://journals.tubitak.gov.tr/agriculture/vol42/iss1/7
- Shaha P, Bellankimath A. Pharmacological profile of asparagus racemosus: a review. IntJCurrMicrobiolAppSci [Internet]. 2017 Nov 20 [cited 2023 Mar 3];6(11):1215–23. Available from: https://www.ijcmas.com/abstractview.php?ID=5064&vol=6-11-2017&SNo=144
- Nishimura M, Ohkawara T, Kagami-Katsuyama H, Sato H, Nishihira J. Improvement of blood pressure, glucose metabolism, and lipid profile by the intake of powdered asparagus (蘆筍 Lú Sǔn) bottom-stems and cladophylls. Journal of Traditional and Complementary Medicine [Internet]. 2013 Oct [cited 2023 Mar 3];3(4):250–5. Available from: https://linkinghub.elsevier.com/retrieve/pii/S2225411016302000
- Iqbal M, Bibi Y, Iqbal Raja N, Ejaz M, Hussain M, Yasmeen F, et al. Review on therapeutic and pharmaceutically important medicinal plant asparagus officinalis l. J Plant Biochem Physiol [Internet]. 2017 [cited 2023 Mar 3];05(01). Available from: https://www.esciencecentral.org/journals/review-on-therapeutic-and-pharmaceutically-important-medicinal-plantasparagus-officinalis-2329-9029-1000180.php?aid=85301