Asparagus: Nutrition Facts, Health Benefits, and Why It Belongs on Your Plate

Asparagus is one of those vegetables that has earned its place on fine dining menus and everyday dinner plates alike — not just for its distinctive flavor and elegant appearance, but for a genuinely impressive nutritional profile at just 22 calories per 100g. It’s one of the richest vegetable sources of folate, a good source of Vitamin K, a source of prebiotic fiber, and the vegetable that gave its name to the amino acid asparagine, first isolated from asparagus juice.

For a vegetable with fewer calories than most drinks, asparagus delivers a remarkable concentration of vitamins, minerals, and other beneficial compounds that make it a valuable addition to any diet.

Asparagus Nutrition Facts (per 100g, cooked)

USDA’s figures for asparagus, boiled and drained.

Raw vs Cooked Asparagus (per 100g)

Raw and cooked asparagus are broadly similar — cooking mainly affects the water-soluble vitamins, folate and Vitamin C, some of which leach into cooking water:

Raw figures are from USDA’s newer Foundation Foods analysis of green asparagus; * raw Vitamin K is from USDA’s older SR Legacy data, since the Foundation entry doesn’t include it. The raw and cooked figures come from different samples and analyses, so small differences — such as in protein — reflect natural variation as much as cooking. The newer raw analysis found much more folate (183µg) than USDA’s older raw figure (52µg), which helps explain why cooked asparagus once appeared to have more folate than raw.

Vitamins in Asparagus (per 100g, cooked)

Standout: Asparagus is one of the best vegetable sources of folate (Vitamin B9) — 37% of the daily value per 100g cooked. Folate is essential for DNA synthesis and cell division, red and white blood cell formation, and — critically — the development of the baby’s neural tube in the first weeks of pregnancy. Asparagus is also a good source of Vitamin K (42% DV per 100g), needed for blood clotting and bone health, and provides useful thiamine (13% DV), riboflavin (11% DV), and Vitamin E (10% DV).

Minerals in Asparagus (per 100g, cooked)

Standout: Asparagus isn’t a mineral powerhouse in absolute terms, but its copper is notable — 19% of the daily value per 100g. Copper is often overlooked but is essential for iron metabolism, collagen formation, energy production, and antioxidant defense through superoxide dismutase (SOD). Asparagus also provides selenium (11% DV), and some potassium and manganese, at very low calorie cost.

Health Benefits of Asparagus

An Excellent Folate Source

Asparagus is one of the most concentrated vegetable sources of folate — which makes it particularly valuable for several groups:

Pregnancy: Low folate in the first weeks of pregnancy significantly increases the risk of neural tube defects such as spina bifida and anencephaly. This critical period often comes before a woman knows she’s pregnant, which is why folate matters for all women who could become pregnant. Folate-rich foods like asparagus help, but health authorities also recommend a folic acid supplement for anyone who may become pregnant, because food alone often doesn’t provide enough.

Homocysteine: Folate, along with Vitamins B6 and B12, helps keep levels of homocysteine — an amino acid linked with cardiovascular disease when elevated — in check. However, trials that lowered homocysteine with B vitamin supplements haven’t clearly reduced heart attacks, so folate’s heart benefit is best seen as part of an overall healthy diet.

DNA synthesis and cell division: Folate is essential for making new DNA — particularly important during periods of rapid growth such as pregnancy, infancy, and adolescence, and for ongoing red and white blood cell production throughout life.

Mood and brain health: Low folate status has been consistently associated with depression in research. Folate is involved in the pathways that produce several neurotransmitters, so adequate intake supports normal brain function.

Prebiotic Fiber: Inulin

Asparagus contains inulin, a type of prebiotic fiber that feeds beneficial gut bacteria rather than being digested by the body itself. Asparagus is a useful source — one of the better ones among commonly eaten vegetables — though foods such as chicory root, Jerusalem artichokes, garlic, and onions contain considerably more.

When inulin reaches the colon, beneficial bacteria — particularly Bifidobacterium species — ferment it and produce short-chain fatty acids (SCFAs) such as butyrate, which:

• Nourish the cells lining the colon
• Have anti-inflammatory effects in the gut
• Help maintain the gut barrier
• Help regulate immune function

Eating a variety of prebiotic-rich foods like asparagus is a good way to support a diverse, healthy gut microbiome.

The bloating note: For some people, asparagus causes temporary bloating and gas — a direct result of gut bacteria fermenting its inulin. For most people this settles as the gut adapts, so starting with smaller portions and increasing gradually helps. People with irritable bowel syndrome (IBS) may find asparagus is one of the foods worth limiting, since inulin is a type of FODMAP.

Vitamin K and Bone Health

At 42% of the daily value per 100g cooked, asparagus is a good source of Vitamin K.

Bone health: Vitamin K activates osteocalcin, a protein that helps bind calcium into bone. Low Vitamin K intake has been associated with lower bone density and higher fracture risk in observational studies.

Arterial health: Vitamin K activates matrix Gla protein (MGP), which helps prevent calcium from building up in artery walls. Higher Vitamin K intake has been linked with less arterial calcification in some studies, though the evidence is strongest for Vitamin K2 from animal and fermented foods rather than the K1 in vegetables.

Blood clotting: Vitamin K is essential for making several clotting factors in the liver — without it, the blood can’t clot properly.

Note for people on warfarin: Vitamin K interacts with warfarin, a blood-thinning medication. People taking warfarin shouldn’t suddenly change how much asparagus or other Vitamin K-rich food they eat without talking to their doctor — keeping Vitamin K intake consistent matters more than the absolute amount.

Antioxidant Compounds

Asparagus contains a range of antioxidant compounds that work in different ways:

Glutathione — asparagus is one of the richest food sources of glutathione, a key antioxidant made by the body. How much glutathione from food is absorbed intact is debated — much of it is broken down during digestion — but its building blocks can be used by the body to make its own.

Rutin — a flavonoid with antioxidant and anti-inflammatory properties in laboratory studies, which has been studied for its effects on blood vessel health.

Quercetin — another flavonoid with well-documented anti-inflammatory effects in laboratory research.

Saponins — compounds that have shown cholesterol-lowering and other potential effects in laboratory and animal studies.

Vitamin E and beta-carotene — asparagus provides 10% DV of Vitamin E, and beta-carotene that contributes 6% DV of Vitamin A per 100g — both fat-soluble antioxidants.

A Traditional Diuretic

Asparagus has long been used in traditional medicine as a mild diuretic, and some people notice they urinate more after eating it. Its high water content and potassium may contribute. However, there’s little clinical evidence that eating asparagus has a meaningful diuretic effect in people, so it shouldn’t be relied on to manage fluid retention or blood pressure.

Heart Health

Asparagus fits well into a heart-healthy diet:

Folate helps keep homocysteine in check as part of a healthy diet.

Potassium (224mg per 100g) helps counter sodium’s effect on blood pressure.

Fiber and a range of plant compounds contribute to the well-established heart benefits of vegetable-rich diets.

Low sodium — 14mg per 100g cooked without salt makes asparagus a good fit for low-sodium eating.

Blood Sugar Friendly

With just 4.1g of carbohydrate per 100g, about half of it fiber, asparagus has a minimal effect on blood sugar. Laboratory and animal studies have suggested that asparagus extracts may influence insulin secretion, but this hasn’t been shown in people eating normal amounts.

For people managing blood sugar, following a ketogenic diet, or simply wanting steady energy, asparagus is one of the most blood-sugar-friendly vegetables available — providing substantial nutrition with very little carbohydrate.

Weight Management

At just 22 calories per 100g, asparagus is one of the most calorie-efficient nutrient-dense foods available:

Very low calorie density — large portions add very few calories.

More protein than many vegetables — 2.4g per 100g cooked, which contributes a little to fullness.

Fiber — 2.0g per 100g supports digestive regularity and fullness.

Prebiotic content — a healthy gut microbiome is increasingly linked with appetite regulation and body weight, though research is still developing.

Asparagus for Athletes and Active People

Asparagus is a surprisingly valuable vegetable for anyone training regularly:

Folate for red blood cell production — folate is essential for producing healthy red blood cells, which carry oxygen to working muscles and support aerobic performance and recovery.

Copper for energy production — asparagus provides 19% of daily copper per 100g. Copper is part of cytochrome c oxidase, the final enzyme in the chain that produces cellular energy (ATP) in the mitochondria.

Antioxidant support — intense exercise increases free radical production. Asparagus’s Vitamin E, glutathione, and plant compounds contribute to the antioxidant-rich diet that supports recovery.

Vitamin K for bone health — training places repeated stress on bones, and adequate Vitamin K, alongside calcium, Vitamin D, and protein, supports healthy bones.

A light, nutrient-dense side — asparagus adds volume, fiber, and micronutrients to protein-focused meals for very few calories, which is useful during cutting phases.

Plant compounds for recovery — asparagus’s quercetin, rutin, and saponins contribute to the overall anti-inflammatory pattern of vegetable-rich diets that support training and recovery.

The Famous Asparagus Urine Effect

This is probably the most searched question about asparagus — and it deserves a clear, honest answer.

Many people notice a distinctive, sulfurous smell in their urine soon after eating asparagus — sometimes within 15–30 minutes. It comes from asparagusic acid, a sulfur compound found in asparagus, which the body breaks down into several volatile sulfur compounds, including methanethiol and dimethyl sulfide, that are excreted in urine.

The interesting twist: not everyone can smell it. In a large 2016 study of nearly 7,000 people, about 60% said they couldn’t detect the smell, and this “asparagus anosmia” was linked to genetic variations near genes for smell receptors. People may also differ in how much of the smelly compounds they produce. So the debate over whether asparagus “makes your urine smell” is really a mix of differences in both producing and smelling the odor.

Asparagusic acid is essentially unique to asparagus, and the effect is completely harmless — just an interesting metabolic quirk of one of nature’s most nutritious vegetables.

Raw vs. Cooked Asparagus: Which Is Better?

Raw asparagus — retains the most Vitamin C and folate, and has a firmer, crunchier texture. Thin, tender spears can be shaved into salads or served with dips.

Lightly steamed or blanched — one of the best cooking methods for keeping nutrients. Brief cooking (3–5 minutes) keeps most of the Vitamin K and B vitamins, and may make beta-carotene easier to absorb.

Roasted — brings out natural sweetness through caramelization. Some water-soluble vitamins are reduced, but fat-soluble vitamins (A, E, and K) are well retained and better absorbed with the cooking oil.

Boiled — loses the most water-soluble nutrients, as folate and Vitamin C leach into the cooking water. If you boil asparagus, keep it brief, or use the cooking water in soups or sauces.

General recommendation: steam or roast asparagus to keep the most nutrients, and avoid prolonged boiling — the color, texture, and nutritional value all suffer.

Asparagus vs. Other Green Vegetables

How does asparagus compare with other popular green vegetables, all cooked the same way?

Asparagus stands out for folate — level with spinach and well ahead of broccoli and Brussels sprouts — at the lowest calorie count in the group. It contains far less Vitamin K than spinach, broccoli, or Brussels sprouts, and much less Vitamin C than broccoli or Brussels sprouts, but it brings its own strengths: inulin, glutathione, and a distinctive flavor that makes it easy to enjoy.

How to Select and Store Asparagus

Selecting: choose firm, straight spears with tightly closed, compact tips. Avoid limp, wrinkled, or woody spears, and check that the cut ends look fresh rather than dried out. Thick spears aren’t necessarily tougher — thickness depends mainly on the age and variety of the plant, not quality.

Storing: asparagus deteriorates quickly after harvest. Stand the spears upright in a glass or jar with an inch of cold water — like cut flowers — loosely covered with a plastic bag in the refrigerator, and use within a few days. Alternatively, wrap the cut ends in a damp paper towel.

Freezing: blanch asparagus for 2–3 minutes in boiling water, plunge it into ice water to stop the cooking, drain, and freeze in a single layer before transferring to bags. Frozen asparagus keeps most of its nutritional value and works well in cooked dishes, though not in salads.

Practical Ways to Include Asparagus in Your Diet

Roasted with olive oil — the simplest and one of the most delicious preparations. Toss spears in olive oil, season with salt and pepper, and roast at 200°C for 12–15 minutes until tender with slightly crispy tips. The olive oil also helps you absorb the fat-soluble Vitamins A, E, and K.

Steamed as a side — a few minutes of steaming preserves color, texture, and nutrients. Serve alongside any protein for a complete, nutritious meal.

In omelettes and frittatas — chopped asparagus with eggs is an excellent combination, pairing the eggs’ complete protein and choline with asparagus’s folate, Vitamin K, and fiber.

In pasta dishes — briefly blanched asparagus works beautifully in pasta primavera, carbonara, or simple garlic and olive oil dishes.

In salads (raw or blanched) — shaved raw asparagus with lemon, Parmesan, and olive oil is a classic Italian preparation that keeps all the water-soluble vitamins.

As a soup — asparagus blended with onion, garlic, and stock keeps the vitamins that leach into the liquid and concentrates asparagus’s distinctive flavor.

Grilled — grilled asparagus alongside a steak or fish is a classic combination for good reason: the char adds flavor, and the asparagus adds folate, Vitamin K, and fiber to the meal.

Potential Considerations

Warfarin interaction — as discussed above, Vitamin K can affect warfarin dosing. People on warfarin should keep their Vitamin K intake consistent rather than suddenly eating much more or less asparagus.

Gout — asparagus contains moderate amounts of purines, which the body breaks down into uric acid. However, large studies have found that purine-rich vegetables, unlike meat and seafood, aren’t linked with a higher risk of gout or gout attacks, so most people with gout don’t need to avoid asparagus.

Bloating and digestive discomfort — the inulin in asparagus is fermented in the colon, which can cause gas and bloating in some people, especially those with irritable bowel syndrome (IBS) or small intestinal bacterial overgrowth (SIBO). Starting with small portions helps most people adapt, and people following a low-FODMAP diet may need to limit it.

Allergies — asparagus allergy is rare but does exist, and skin reactions have been reported in people who handle raw asparagus frequently, such as farm and kitchen workers.

Nutrient data: USDA FoodData Central, SR Legacy — asparagus, cooked, boiled, drained (FDC ID 168390). Raw asparagus: Foundation Foods (FDC ID 2710823), with Vitamin K and the older raw folate figure from SR Legacy (FDC ID 168389). Comparisons from SR Legacy: broccoli (FDC ID 169967), spinach (FDC ID 168463), and Brussels sprouts (FDC ID 169971), all boiled, drained, without salt. % Daily Values use the FDA’s current Daily Values.