ASPARAGUS: HEALTH BENEFITS AND WHAT TO LOOK FOR IN THE STORE
Spring has sprung! The landscape has begun to explode with spring colors from the appearance of crocus, forsythia, daffodils and magnolia trees. Foragers are enjoying collecting the seasonal delicacy of ramps, and gardeners are beaming with excitement as their asparagus spears begin to peek out from the earth.
There are nearly 300 species in the genus asparagus, most of which are used for their medicinal properties rather than culinary uses.1 This article focuses on asparagus officinalis, which is the asparagus commonly used in culinary dishes and comes in three color varieties: green, white, and purple.
Asparagus has been a part world cuisine for at least as far back as the ancient Egyptians.1 It is recommended in multiple recipes from Marcus Gavius Apicius’s De Re Coquinaria, the oldest known book of recipes with the earliest surviving editions dating back to the 9th century C.E.2 Asparagus is believed to be native to the eastern Mediterranean region but is now cultivated worldwide.
Asparagus is a good source of B vitamins (especially folate, B12, and B6), vitamin C, vitamin E, and is an excellent source of vitamin K. The minerals found in asparagus (selenium, phosphorus, calcium, copper, zinc, iron, magnesium, and potassium) are found in the greatest quantities in the upper sections of the spear.1
In addition to the vitamin and mineral content, asparagus is rich in polyphenols, saponins, and sulfur-containing compounds that have antioxidant, anti-inflammatory, antimicrobial, antitumor effects, and support healthy liver function.1,3,4 It is also a good source of fiber, containing both soluble (bulk) and insoluble (prebiotic) forms, supporting healthy digestion and microbiome.
Read more about how a healthy microbiome can improve your mood here
When purchasing asparagus at the grocery store, check that the asparagus spears are stored in a container with a small amount of water in the bottom to keep them hydrated. Also, when examining the asparagus, make sure the spear heads are tight (not beginning to flower) and that the stalks are firm and bright green. At home, store your asparagus in a cup with a small (1 inch) amount of water. If eating soon, you can keep them on your counter but if they will be eaten in a day or two, store them in the refrigerator.
Growing asparagus in a home garden is relatively easy and, if not over harvested, an asparagus bed can last for decades. Many home gardeners process (can) their asparagus, which includes disposing of the lower section of the spear due to its fibrous texture. Not only can this feel wasteful but it also discards a nutrient, antioxidant, and fiber rich part of the vegetable. A study found that microwave blanching at 300 watts for 4 min, rather than water or steam blanching, not only preserved the nutrition content but also cut down processing time. Additionally, the overall texture, nutrient retention, and enzyme inactivation was seen in the butt section of the asparagus as well.5 So, keep those asparagus butts and increase the yield and nutrition of this springs harvest.
Still not sure about asparagus? Try this nutrient dense asparagus soup that incorporates savory flavors.
Roasted Garlic and Asparagus Soup (serves 4) Time: 50 min
4 cups Asparagus (trimmed, cut in half)
10 Garlic (cloves, peeled and cut in half)
1/2 Yellow Onion (cut into thick slices)
1/4 head Cauliflower (cut into florets)
1 tbsp Extra Virgin Olive Oil
1/2 tsp Sea Salt (divided)
2 1/2 cups Vegetable Broth
2 cups Baby Spinach
Directions:
Preheat the oven to 350ºF (176ºC) and line a baking sheet with parchment paper.
Toss the asparagus, garlic, onion and cauliflower with the olive oil and arrange in an even layer on the baking sheet. Season the vegetables with half of the salt then bake for 35 to 40 minutes or until the vegetables have caramelized and the garlic is fork-tender. Flip everything halfway through to prevent burning.
When the vegetables are just about done, heat the vegetable broth in a pot on the stove to a simmer. Add the spinach to the broth and stir to allow it to wilt.
To make the soup, transfer the warmed broth and spinach, the roasted vegetables and the remaining salt to a blender. Blend until smooth and creamy, allowing space for the heat to escape. If the soup is too thick, add more broth until your desired consistency is reached.
Divide between bowls and enjoy!
Refrigerate in an airtight container for up to five days.
Serving Size: One serving is approximately 1 1/4 cups of soup.
Optional:
Add fresh herbs or black pepper to the soup before blending.
Reserve a couple of spears of the roasted asparagus to chop and garnish the soup with.
No Spinach: Use kale instead.
No Blender: Use an immersion hand blender or food processor instead.
References
1. 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. 2019;10(1):17. Published 2019 Dec 25. doi:10.3390/metabo10010017
2. Horgan, J. (2017, November 10). Marcus Gavius Apicius. World History Encyclopedia. Retrieved from https://www.worldhistory.org/Marcus_Gavius_Apicius/
3. Negi JS, Singh P, Joshi GP, Rawat MS, Bisht VK. Chemical constituents of Asparagus. Pharmacogn Rev. 2010;4(8):215-220. doi:10.4103/0973-7847.70921
4. Chan YC, Wu CS, Wu TC, Lin YH, Chang SJ. A Standardized Extract of <i>Asparagus officinalis</i> Stem (ETAS<sup>®</sup>) Ameliorates Cognitive Impairment, Inhibits Amyloid β Deposition via BACE-1 and Normalizes Circadian Rhythm Signaling via MT1 and MT2. Nutrients. 2019 Jul;11(7). DOI: 10.3390/nu11071631.
5. Nguyen TVL, Tran TYN, Lam DT, Bach LG, Nguyen DC. Effects of microwave blanching conditions on the quality of green asparagus (Asparagus officinalis L.) butt segment. Food Sci Nutr. 2019;7(11):3513-3519. Published 2019 Sep 30. doi:10.1002/fsn3.1199