📊 Full nutrition facts — per 100g
| Nutrient | Amount | % Daily value | Level |
|---|---|---|---|
| Calories | 20 kcal | 1% | |
| Carbohydrates | 3.9g | 1% | |
| Dietary fibre | 2.1g | 8% | |
| Protein | 2.2g | 4% | |
| GI | ~15 — Near zero | — | |
| Folate | 52µg | 13% | |
| Vitamin K | 41.6µg | 35% | |
| Vitamin C | 5.6mg | 6% | |
| Vitamin B6 | 0.09mg | 6% | |
| Thiamine B1 | 0.14mg | 9% | |
| Inulin (prebiotic) | 2–3g | — | |
| Copper | 0.19mg | 10% |
Based on Australian NRV. Source: FSANZ Australian Food Composition Database.
📈 Glycaemic index (GI)
💊 Key vitamins & minerals
✅ Health benefits
Asparagus contains 2–3g of inulin per 100g — a fructan prebiotic that passes undigested to the colon where it selectively stimulates the growth of Bifidobacterium and Lactobacillus species. Inulin in asparagus has been specifically studied and found to increase beneficial gut bacteria populations, improve bowel transit, reduce constipation and improve gut barrier integrity. Asparagus is one of the richest whole vegetable sources of inulin alongside Jerusalem artichoke, chicory and garlic.
Asparagus provides 41.6µg of vitamin K per 100g — 35% of the daily requirement. Vitamin K1 (phylloquinone) activates osteocalcin, the protein that binds calcium into bone matrix. Regular vitamin K1 intake is associated with higher bone mineral density and reduced fracture risk. Vitamin K also activates matrix Gla protein (MGP), which prevents calcium deposition in arterial walls — a key cardiovascular-protective mechanism. Together these make asparagus one of the most practical everyday vitamin K sources.
Asparagus contains steroidal saponins (asparasaponins I, II, III and others) that are unique to the Asparagus genus. Laboratory studies have demonstrated that asparasaponin I inhibits growth and induces apoptosis in multiple cancer cell lines including breast cancer, colon cancer, liver cancer and leukaemia cells. While these are cell-culture findings and do not directly predict human cancer prevention, the asparasaponins represent a biologically active class of compounds with no other common dietary source — making asparagus nutritionally unique in this respect.
Asparagus provides 52µg of folate per 100g — 13% of the daily requirement — making a 200g serving provide over a quarter of daily folate needs. Folate reduces homocysteine, an independent cardiovascular risk factor that is elevated in folate-deficient states. Folate is also essential for DNA synthesis and repair, neural tube development in pregnancy and red blood cell production. Combined with vitamin K's anti-calcification effects on arteries, asparagus provides a comprehensive cardiovascular nutritional contribution.
⚠️ Who should limit or avoid
Asparagus provides 35% of daily vitamin K per 100g, which is meaningful for people on warfarin anticoagulant therapy. Consistent intake of vitamin K-rich foods is more important than avoidance — sudden large changes in consumption affect INR more than regular moderate intake. People on warfarin should maintain consistent asparagus consumption and inform their anticoagulation team of their regular dietary pattern.
Asparagus is moderately high in purines, which are metabolised to uric acid. In people with gout or hyperuricaemia, regular large servings of asparagus may contribute to uric acid elevation. Asparagus is not in the highest-purine category (organ meats, anchovies) but should be consumed in moderation by people with active gout during flare episodes.
Asparagus contains moderate oxalate levels. People with a history of calcium oxalate kidney stones should not eat asparagus in very large quantities, though normal serving sizes (100–200g) are generally considered acceptable. Drinking adequate water alongside asparagus is advisable.
🛒 How to select & buy asparagus
The tips (head) of asparagus spears are the most perishable part and the best freshness indicator. Fresh asparagus tips should be tightly closed, bright green (or purple for purple varieties), and feel firm. Any opening or spreading of the tip scales indicates age. The cut ends should look moist, not dried or shrivelled. The entire spear should feel firm and snap-crisp, not bend limply.
Thick spears: meatier texture, better for roasting, grilling and as a side dish. Thin spears (pencil asparagus): more tender, better for steaming, stir-frying and eating raw in salads. Nutrition is comparable between thin and thick spears. White asparagus (grown without sunlight): milder, more bitter flavour, lower vitamin content (no chlorophyll synthesis). Purple asparagus: higher in anthocyanins, slightly sweeter. For maximum nutritional value, green asparagus is consistently superior to white.
The woody bottom end of asparagus is tough and unpleasant. The traditional advice is to snap each spear — it naturally breaks at the transition point between tender and woody. This wastes slightly more than cutting, but the snap point is reliable. Alternatively, cut 2–3cm from the bottom as a rough guide. The woody ends can be simmered into asparagus stock for soups rather than discarded. Do not peel asparagus unless using very thick white asparagus.
🧊 Storage tips & shelf life
Treat asparagus like cut flowers: trim the ends, stand upright in a glass or jar with 2–3cm of cold water, loosely cover the tops with a plastic bag and refrigerate. This method keeps asparagus fresh and prevents the tips from drying. Change the water daily. This extends freshness compared to horizontal refrigerator storage.
Blanch in boiling water (thin spears 2 min, thick spears 4 min), immediately cool in ice water, dry thoroughly, freeze spread on a tray, then bag. Frozen asparagus is excellent for stir-fries, frittatas, pastas and soups but will be too soft for eating as a side dish. Do not freeze unblanched — the enzyme activity degrades quality rapidly.
If you do not have space in the fridge, wrap the cut ends in a damp paper towel and keep upright in a cool spot away from sunlight. Asparagus kept this way deteriorates quickly — prioritise eating it within 1–2 days and refrigerate if possible.
📖 About asparagus — complete guide
Asparagus (Asparagus officinalis) is native to the eastern Mediterranean and Asia Minor, where it has been gathered wild and cultivated for over 2,500 years. The ancient Egyptians depicted asparagus as an offering to the gods — bundles appear in tomb paintings from 3000 BCE. Roman agricultural writers including Cato, Pliny and Apicius described cultivation methods and recipes that are recognisable today. The Roman Emperor Augustus Caesar was said to be so fond of asparagus that the phrase 'faster than you can cook asparagus' (velocius quam asparagi coquuntur) became a Latin idiom for speed. Asparagus cultivation spread through medieval Europe via monastery gardens and reached Britain by the 16th century. In France, asparagus culture reached its peak in the 17th century — Louis XIV had asparagus grown under glass year-round in Versailles using heated forcing houses, one of the first examples of greenhouse vegetable production.
The asparagus urine phenomenon is one of the most studied examples of individual genetic variation in food metabolism. After eating asparagus, asparagusic acid (unique to asparagus) is metabolised into several volatile sulphur compounds including methanethiol, dimethyl sulphide and dimethyl disulphide that produce the characteristic pungent smell in urine. However, this only occurs in people who possess the relevant sulphur-metabolising enzymes — approximately 50% of the population. Among those who produce the odorous compounds, there is a second genetic variation: only some people can smell the compounds (those with the relevant olfactory receptor variant). This creates four possible combinations: produce odour/can smell it, produce odour/cannot smell it, do not produce odour/can smell it (nothing to detect), or do not produce odour/cannot smell it. This multi-layer genetic nutritional variation has been studied specifically to understand individual differences in nutrient metabolism and is considered a classic example of nutrigenomics.