Sorrel, common sorrel or spinach dock goes by the scientific name Rumex acetosa and is a green, leafy vegetable, culinary herb, invasive weed and medicinal plant of sorts. It is from the same family as buckwheat, rhubarb and patience dock and boasts a nutritional profile similar to that of most green leaf vegetables. Sorrel leaves are an important source of vitamins A, C and K, iron, magnesium and manganese, dietary fiber as well as provide small amounts of B vitamins, phosphorus and potassium. The leaf vegetable is especially recommended for its purgative effects, promoting digestive detoxification, boosts immunity and is reportedly good for skin and hair health.
What does sorrel look like? Sorrel is a perennial, green, leafy plant native to Europe and parts of Africa and Asia. It can reach heights of 50-60 cm, has long taproots and medium-sized green leaves with meaty, green stems. The leaves look similar to arrows: they have an overall elongated, narrow shape, slightly larger at the base with the bottom lobes slightly directed downwards. Mature leaves can reach 10-15 cm in length and are usually a medium, green color. Smaller leaves are often a lighter green color and more tender which makes them more palatable. The entire plant can be green or have bright, purple-red leaves at the top, in which case it looks similar in appearance to other dock plants of the same family, notably patience dock (see article on Properties and Benefits of Patience Dock). There are also sorrel varieties with red-veined leaves throughout.
What does sorrel taste like? While all plant parts above the ground are edible and used for therapeutic purposes, many people only eat the leaves. This is because sorrel stems have a meaty, but thick texture which results in them often being discarded. The leaves can be eaten both raw and cooked. Raw sorrel leaves have a sour, sharp taste with faint lemony, grassy flavors. The taste of the raw leaves is comparable to that of extremely sour kiwifruit. The larger and more mature the leaves, the stronger their taste. Smaller leaves are more tender and have a less pronounced tart flavor. It is not uncommon for sorrel leaves to be damaged and present with holes starting from the margins of the leaf as they serve as a food source for several hundred thousand butterfly species.
How to use sorrel. The leaves can be eaten raw, but since they are a source of oxalic acid which can cause kidney damage when ingested in large amounts, it is best to cook sorrel, especially if you have kidney problems. At the same time, know that cooking the leaves destroys their vitamin C. The leaves can be blanched, stewed, fried and generally cooked like any other leafy green vegetable. Common recipes include sorrel puree soup and sour soup with egg. The leaves can be added to sandwiches, rice, pasta, lentils, beans and chickpeas dishes or used as pizza topping, in pastries or omelettes (see eggs page for information on various egg varieties). They can are wonderful stewed and eaten with hard-boiled eggs and fresh tomatoes or used in juicing to replace other greens, but moderation is in order considering it is a significant source of oxalic acid.
How to choose sorrel. When choosing sorrel, look for smaller leaves which are more tender. A paler color also indicates a milder taste, while larger, darker leaves will have a stronger taste and a slightly tougher texture. Avoid leaves with holes in them, yellow or brown discoloration as well as wilted leaves. Once harvested, sorrel has a short shelf life of a maximum of 3-4 days. The leaves are best eaten as soon as possible after being picked and should be kept in the refrigerator unwashed until ready to be eaten. They are best consumed in 1-2 days and should always be washed prior to consumption to avoid heavy metals contamination, bacteria or parasites. Also, avoid picking sorrel from the side of the road, former industrial areas or anywhere where there is or was a high level of pollution.
What is sorrel good for? In addition to an above average content of minerals and vitamins, sorrel leaves are a good source of dietary fiber and antioxidants as well as provide small amounts of protein. Here are the top 5 nutrition facts and benefits of the leafy green:
1) Strong depurative properties. Sorrel and other Rumex species are known to have strong purgative effects and contribute to detoxifying the bowels and kidneys (so both a laxative and a diuretic). The laxative effect is attributed to a good fiber content, estimated at around 2.9 g of dietary fiber per 100 g of leaves and makes the plant a good food for relieving constipation. The diuretic action is credited to good amounts of potassium which helps maintain fluid balance in the body and reverse water retention. Rumex plants, sorrel included, are estimated to have an average of 390 mg of potassium per 100 g, which amounts to about 8.3% of the recommended daily intake.
However, there are voices that credit the depurative effects of sorrel to its content of oxalic acid. Oxalic acid is essentially a toxin found in all green leafy plants and other vegetables from garlic and carrots to Brussel sprouts, potatoes and eggplants. It is believed by some that the depurative effects of eating sorrel are generated as a response to the ingestion of too much oxalic acid from the leaves.
2) Rich source of iron. Sorrel is a source of non-heme iron, a type of dietary iron specific to plant foods and is estimated to contain around 2.4 g of iron for every 100 g of leaves (around 13.3% of the recommended daily intake). In the presence of vitamin C, also found in the leaves, non-heme iron is well absorbed and helps make red blood cells and contributes to energy metabolism. Eating sorrel is believed to combat muscle weakness fatigue, boost energy levels and restore vitality. However, remember that cooking the leaves causes them to lose most of their vitamin C, if not all, so including other vitamin C rich foods in your diet is important for iron absorption.
3) Good for eyesight and skin. Green leafy vegetables like spinach, kale, turnip greens or docks, which includes sorrel, are generally important sources of pro-vitamin A antioxidant carotenoids like beta-carotene. Carotenoids are essentially pigments with antioxidant effects and some of them are converted into vitamin A into the body, providing benefits such as better eyesight, anti-acne effects and healthier skin.
4) Immune-boosting properties. Sorrel is estimated to provide around 25% of the recommended vitamin A intake from antioxidants (200 mcg/100 g). Vitamin A is especially important for mucous membranes like the nose and throat lining, but also lungs and gastrointestinal lining and essentially keeps them healthy. Since these mucous membranes are what stand between us and the outside world, they represent one of the first lines of defense of our immune system, preventing infection and disease. The high vitamin A content is believed to be one of the main reasons why sorrel preparations are found useful for treating nose and throat inflammation and as an adjuvant therapy for treating respiratory infections.
Moreover, the sour taste is indicative of the presence of generous amounts of vitamin C, a strong antioxidant and anti-inflammatory nutrient with immune-boosting properties. Among others, vitamin C is used by immune system cells to carry out their activity in the fight against infections and disease. Dock plants like sorrel are estimated to have around 58 mg of vitamin C per 100 g.
5) Rich in potassium and magnesium. Research on the nutrition of Rumex species shows dock plants in general are good sources of potassium and magnesium, providing an estimate of 390 mg of potassium and 103 mg of magnesium for 100 g of leaves. The two dietary minerals support muscle health, heart included, and regulate blood pressure, with benefits for the cardiovascular system.
6) Contains vitamin K. Like all green, leafy vegetables, sorrel too is an important source of vitamin K. In addition to anti-inflammatory properties, vitamin K aids in blood coagulation and helps prevent hemorrhaging. Benefits include reducing frequent nosebleeds and easy bruising. However, if you are receiving treatment for blood clots, green leafy vegetables like sorrel are not good for you as the vitamin K they contain may interact with and reduce the effects of anticoagulant medication.
7) Sorrel benefits for hair and others. Sorrel is consider to hold benefits for hair. Indeed, it contains vitamins B1, B2, B3, B6 and B9 and small amounts of protein (approximately 2 g/100 g) which can help repair damaged hair and strengthen it. But in order to produce visible effects, both a good diet and hair treatments are needed, so eating sorrel is not enough to have strong, beautiful hair. Sorrel tea for hair is also not a reliable remedy and is often confused with tea made from a hibiscus species called roselle (Hibiscus sabdariffa), also commonly known as Jamaican sorrel. Other sorrel vitamins and minerals include manganese, phosphorus, zinc and calcium.
Sorrel side effects may include the following:
1) Kidney problems. Because of a high content of oxalic acid, eating too much sorrel can cause toxic effects and affect primarily the kidneys, causing kidney stones and kidney failure. The vegetable is best avoided by children, the elderly and anyone with kidney problems.
2) Blood clots. Sorrel has high amounts of vitamin K which promotes blood clots. While to a healthy person it’s safe to eat in moderate amounts, anyone with a predisposition to blood clots or an anticoagulants should avoid sorrel and other leafy green vegetables.
3) Miscarriage. Sorrel in pregnancy is especially dangerous because of the plant’s strong purgative properties which may create stomach upset and increase the risk for a miscarriage, especially in early pregnancy.
4) Birth defects. Oxalic acid in sorrel is believed to hold the potential to cause birth defects, which is why it’s recommended to avoid eating excessive amounts of any green leaf vegetable during pregnancy.