Lettuce


Lettuce is the type of a vegetable that just about all plant breeders like to meddle with, hence the seemingly endless varieties! Ranging in colour anywhere from crispy green to crimson red, the flavours and nutritional values of the different varieties also vary greatly. Lettuce belongs to the Asteraceae family with the scientific name Lactuca sativa. With small annual plants, the leaves of Lactuca sativa excrete milk like liquid (sap) upon cutting. The name lactuca (lac meaning milk) is derived from Latin.  Lettuce can be grouped into seven basic types with numerous sub-varieties in each. They are distinguished from one another based on formation of their heads and leaves. The leaf varieties tend to be a little bitter, but loaded with antioxidants. The main lettuce types are as follows:

Loose-leaf lettuces are generally multi-coloured, delicate with well flavoured leaves, and are a fast growing variety. They form loose open heads which makes it convenient to harvest just a few leaves or the whole head according to needs.

Butterhead lettuces are another group with open loose leaves and have a buttery texture. This variety is more popular in Europe.

Romaine (Cos) are upright, tall, and have open heads with deep green coloured leaves. The leaves carry a stronger flavour compared to the loose-leaf variety, and contain a prominent crunchy midrib that travels all the way to the tip of the leaf.

Buttercrunch lettuces are a cross between romaine and the butterhead varieties. The head has a more upright stature than romaine, with hardly any leaves touching the ground. This group is better able to withstand the cold weather than butterhead, with leaves that defy rotting.

Batavian Lettuces have crunchy, thick leaves. The leaves of Batavian Lettuces can tolerate heat better than all other varieties.

Heading lettuces curl their leaves inward forming heads similar to those of cabbages. These are the basic iceberg lettuces valued for their ability to resist disease and heat. They have a solid watery crunch and very little flavour or nutritional value.

Chinese lettuces are strong flavoured with rather stiff, long, non-head forming leaves. They are valued not only for their leaves but the stalks as well. They are slightly bitter in taste, but do well in soups and stir-fries.

History of Lettuce

Egyptians started the cultivation of lettuce from a weed at least 4500 BC, the seeds of which were used to produce oil. Depictions of lettuce can be seen in Egyptian tombs. The Egyptians used lettuce as fertility medicine. It spread to the Greeks and Romans, and both cultures valued it highly, both as a food and for its medicinal properties. The Romans named it ‘lactuca’, which eventually lead to the English ‘lettuce’.

Several varieties of lettuce were known by 50 AD, and it was frequently named in medieval writings. From the 16th to 18th centuries, many additional varieties were developed in Europe. In the medieval era, it was believed that lettuce possessed medicinal qualities, and was prescribed for a number of diseases. It was used to cure appetite loss, blood pressure irregularity, as a tonic for the digestive system, and to limit sexual urges. Dried lettuce latex was prescribed as a cure for insomnia, as nasal drops, as an antispasmodic, and a sedative.

Lettuce had been grown in China as early as the 5th century. To the Chinese, lettuce represents good luck and is served on special occasions like birthdays, weddings and New Year’s Day, etc. Christopher Columbus is credited with introducing lettuce to North America in 1493 during his second voyage. By the nineteenth century, the use of lettuce had spread to the rest of world. Today this leaf vegetable can be found in literally every corner of the planet.

Health Benefits of the Lettuce

Regular consumption of lettuce is believed to have numerous health benefits. It has dietary fibre and Omega fatty acids, both of which are important for general health. The roughage helps to enhance bulk in the intestines, thereby improving peristalsis and eliminating constipation and other stomach problems.

Additionally, the high folate content is good for maintaining cardiovascular health and for putting off arteriosclerosis and stroke. Minerals like potassium, phosphorus, and manganese, destroy free radicals which damage cells, improve immune system function, and offer protection against viral infections. The iron in lettuce aids in the transport of oxygen for cell growth and blood distribution within the body. This makes lettuce the ideal food for anaemic patients. It is also helpful for insomniacs as it contains substances that induce sleep.

It is said that the regular consumption of lettuce juice helps to improve the rate of fertility, raises sperm count, and also helps with erectile dysfunction and early ejaculation issues. Furthermore, it is believed to put a stop to habitual miscarriages and has an effect on progesterone release, something which is liable for lactation in mothers who are breast feeding.

Nutritional Value

Of the different varieties of lettuce available in the market, the three types that are most favoured include, leaf, head, and romaine (cos). Other types also have varying kinds and amounts of nutrients. The Romaine lettuce is considered the most nutrient rich among all the varieties, while iceberg lettuce has the least nutritional value.

Iceberg lettuce has almost no cholesterol and very little fat. It is abundant in dietary fibre and folate, has some fatty acids, and trace amounts of omega fatty acids. It has lower amounts of vitamin C, A, iron, potassium, phosphorous, zinc, sodium, magnesium, manganese, calcium and amino acids than its dark green leaved cousins.

Romaine lettuce is a good source of Vitamins B6, E, A, K, and C. It supplies some dietary fibre through its ribs and spine, carbohydrates, and protein. Additionally, it contains the minerals, calcium, iron, magnesium, phosphorous, potassium, sodium, zinc (along with thiamin), riboflavin, niacin, and folate. It also naturally concentrates and absorbs lithium.

How to Use Lettuce

The best lettuce is purchased fresh and should have, crisp leaves that are devoid of dark or slimy spots. The best way to use lettuce is to ensure it is garden fresh, discard any tarnished leaves, chop to desired size, and throw away the lower stem. Wash the leaves under cold running water and then let soak in salt water for approximately ½ an hour to get rid of sand and any parasite worms and eggs. Finally pat dry before use.

Some serving ideas:

  • Fresh, uncooked lettuce may be used in sandwiches, burgers, salads or spring rolls.
  • It may be stir fried, stewed, and supplement noodles or fried rice.
  • It can be combined with seafood, green beans, and peas.

Traditional Use Methods

Traditionally, the Romans consumed their lettuce with an oil and vinegar dressing, while the lettuce with smaller leaves was just eaten raw.  During the reign of Domitian (81 – 96 AD), the concept of serving lettuce before a meal started. In Europe, after the Roman rule, the tradition of poaching lettuce continued, especially with the romaine variety.

Little Lettuce Enfolds

This is a really nice alternative to the typical family meal. It is not only nutritious, but also something that kids really enjoy. It allows you to make alterations according to your tastes. In the recipe below I am using chicken, but there is no reason why you can substitute this with beef, tuna, or turkey.

Ingredients:

  • ½ pound of ground chicken
  • ½ cup of water chestnuts, chopped
  • ½ cup of mushrooms, chopped
  • 1 small carrot, chopped
  • 1½ tablespoon of soy sauce
  • ½ tablespoon of oyster sauce
  • ½ teaspoon of ginger
  • Salt and pepper to taste
  • 1-2 cloves of garlic, crushed
  • ½ tablespoon of olive oil
  • Iceberg lettuce, separated leaves

Directions:

In a small bowl, combine soy sauce, oyster sauce, and ginger, then place aside.

Heat olive oil over a medium heat in a large skillet. Add the chicken and stir-fry, breaking it up while cooking. When about half cooked, add the vegetables to the chicken, along with chestnuts and the sauce mixture. Continue to cook until most of the liquid disappears. Season with salt and pepper to taste (the sauce mixture is fairly salty, so take care with the salt!).

For serving; spoon the meat mixture onto the middle of the lettuce leaf, and wrap the lettuce around it making a cylindrical shaped rod.

Clinical Trials

As reported in the “Journal of Young Investigators” back in August 2007, The University of Central Florida cultivated genetically modified lettuce that has the potential to treat insulin dependent diabetics. The lettuce was able to cure diabetes in mice, but human trials are still inconclusive. The special genetically altered lettuce manufactures insulin that is housed in the plant’s chloroplast cells, and is not damaged by the stomach's acid. The intestinal bacteria helps to release the insulin which then makes its way into the bloodstream to remove excessive glucose.

Wild lettuce has shown to have benefits for anxiety and anxiety related disorders. Some subjective evidence suggests that lettuce may relieve insomnia, a key anxiety disorder. The “Journal of Clinical Sleep Medicine” published a clinical review in 2005 of the use of lettuce for insomnia. The lactucin, a component of wild lettuce, generated pain-eliminating and sedative like effects, according to another study published in the September 2006 issue of “Journal of Ethno pharmacology”.

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About Andy Williams

In a processed food culture, simply eating may not be enough. Andy Williams, B.SC., Ph.D. is a scientist with a strong interest in Juicing and how it can supply the body with the nutrients it needs to thrive in modern society. You can subscribe to his free daily paper called Juicing The Rainbow and follow him on Facebook orTwitter. You can also follow me on Google +

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