Pleasant, delicate sweet flavored leeks are cylindrical leafy stalks obtained from the onion-family plant, in the Allium genus. They are biennial, tall, slender herbs with long cylindrical stem composed of concentric layers of overlapping leaves. They are commonly employed as vegetables in many parts of Europe, America, and Asia.
Leek requires well-drained, fertile soil to flourish. In general, it is cultivated as annual crop in many parts of Europe and Asia. Planting can be done by either sowing seeds or transplanting seedlings that take about 100-120 days to harvest.
In general, leeks are planted in deep trenches to deprive them exposure to sunlight which otherwise would turn stems green (chlorophyll pigmentation) due to photosynthesis. As the plant grows in height, the trench is filled gradually by pulling surrounding earth to create a mound around the stalk. This method is employed in order to obtain long, white, blanched stalks instead of green, pungent ones.
- Leeks contain many noteworthy flavonoid anti-oxidants, minerals, and vitamins that have proven health benefits.
- Leeks are moderately low in calories. 100 g fresh stalks carry 61 calories. Further, their elongated stalks provide good amounts of soluble and insoluble fiber.
- Though leeks contain proportionately less thio-sulfinites than that in garlic, they still possess significant amounts of these anti-oxidants such as diallyl disulfide, diallyl trisulfide and allyl propyl disulfide. The compounds convert to Allicin by enzymatic reaction when the leek-stalk was subjected to crushing, cutting, etc. The total measured anti-oxidant strength (ORAC value) of 100 g leek is 490 TE (Trolex Equivalents).
- Laboratory studies show that Allicin reduces cholesterol formation by inhibiting the HMG-CoA reductase enzyme in the liver cells. Further, it also found to have anti-bacterial, anti-viral and anti-fungal activities.
- Additionally, Allicin reduces blood vessel stiffness by facilitating nitric oxide (NO) release in the vessel wall, and, thereby bring a reduction in the total blood pressure. It also blocks platelet clot formation and has fibrinolytic action (clot-breaking) in the blood vessels. Thus, Allicin helps decrease an overall risk of coronary artery disease (CAD), peripheral vascular diseases (PVD), and stroke.
- Leeks are a great source of vitamins that are essential for optimum health. Their leafy stems indeed contain several vital vitamins such as pyridoxine, folic acid, niacin, riboflavin, and thiamin in healthy proportions. 100 g fresh stalks provide 64 µg of folates. Folic acid is essential for DNA synthesis and cell division. Their adequate levels in the diet during pregnancy can help prevent neural tube defects in the newborn babies.
- Additionally, leeks are one of the good sources of vitamin-A (1667 IU or 55% of RDA per 100 g) and other flavonoid phenolic anti-oxidants such as carotenes, xanthin, and lutein. They also have some other essential vitamins such as vitamin C, K, and vitamin E. Vitamin C helps the human body develop resistance against infectious agents and scavenge harmful, pro-inflammatory free radicals.
- Further, its stalks hold small amounts of minerals such as potassium, iron, calcium, magnesium, manganese, zinc, and selenium.