The World's Healthiest Foods
Romaine lettuce

Not all lettuce is created equal, but if you start your meal with a salad made of romaine lettuce you will be sure to add not only a variety of textures and flavors to your meal but an enormous amount of nutritional value. Most of the domestic harvest of romaine lettuce and other salad greens comes from California and are available throughout the year.

Lettuce is synonymous with salads as they are predominantly made from crispy green lettuce leaves. Most varieties of lettuce exude small amounts of a white, milky liquid when their leaves are broken. This “milk” gives lettuce its slightly bitter flavor and its scientific name, Lactuca sativa derived from the Latin word for milk.

 


Health Benefits

Want to maximize the health benefits of your salads? Start with romaine lettuce for a salad guaranteed to be packed with nutrients. And the vitamins and minerals found in romaine lettuce are especially good for the prevention or alleviation of many common health complaints.

Due to its extremely low calorie content and high water volume, romaine lettuce - while often overlooked in the nutrition world - is actually a very nutritious food. Based on its nutrient density, our food ranking system qualified it as an excellent source of vitamin A (in the form of beta-carotene), folate, vitamin C, manganese and chromium. Romaine lettuce also emerged from our ranking system as a very good source of dietary fiber.

Salad Days Keep Your Heart Young

Romaine's vitamin C and beta-carotene content make it a heart-healthy green. Vitamin C and beta-carotene work together to prevent the oxidation of cholesterol. When cholesterol becomes oxidized, it becomes sticky and starts to build up in the artery walls forming plaques. If these plaques become too large, they can block off blood flow or break, causing a clot that triggers a heart attack or stroke. The fiber in Romaine lettuce adds another plus in its column of heart-healthy effects. In the colon, fiber binds to bile salts and removes them from the body. This forces the body to make more bile, which is helpful because it must break down cholesterol to do so. This is just one way in which fiber is able to lower high cholesterol levels.

Equally beneficial to heart health is Romaine's folic acid content. This B vitamin is needed by the body to convert a damaging chemical called homocysteine into other, benign substances. If not converted, homocysteine can directly damage blood vessels, thus greatly increasing the risk of heart attack and stroke. In addition, romaine lettuce is a very good source of potassium, which has been shown in numerous studies to be useful in lowering high blood pressure, another risk factor for heart disease. With its folic acid, vitamin C, beta-carotene, potassium, and fiber content, romaine lettuce can significantly contribute to a heart-healthy diet.

Description

The words lettuce and salad are practically interchangeable since most salads are made predominantly with the green crispy leaves of lettuce. Most varieties of lettuce exude small amounts of a white, milky liquid when their leaves are broken. This “milk” gives lettuce its slightly bitter flavor and its scientific name, Lactuca sativa since Lactuca is derived from the Latin word for milk.

Lettuce can be classified into various categories with the most common being:

  • Romaine: Also known as Cos, this variety of head forming lettuce has deep green, long leaves with a crisp texture and deep taste.
  • Crisphead: With green leaves on the outside and whitish ones on the inside, this variety of head lettuce has a crisp texture and a watery, mild taste. The best known variety of crisphead lettuce is iceberg.
  • Butterhead: These types of lettuce feature tender large leaves that form a loosely arranged head that is easily separated from the stem, a sweet flavor and a soft texture. The best known varieties of Butterhead lettuce include Boston and Bibb.
  • Leaf: Featuring broad, curly leaf varieties that are green and/or red, the leaf lettuces offer a delicate taste and a mildly crispy texture. Best known varieties of leaf lettuce include green leaf and red leaf.

While vegetables such as arugula, watercress and mizuna are not technically lettuce, these greens are often used interchangeably with lettuces in salads.

History

Native to the eastern Mediterranean region and western Asia, lettuce has a long and distinguished history. With depictions appearing in ancient Egyptian tombs, the cultivation of lettuce is thought to date back to at least 4,500 BC. The ancient Greeks and Romans held lettuce in high regard both as a food and for its therapeutic medicinal properties.

In China, where lettuce has been growing since the 5th century, lettuce represents good luck. It is served on birthdays, New Year’s Day and other special occasions. Christopher Columbus introduced varieties of lettuce to North America during his second voyage in 1493. Lettuce was first planted in California, the lettuce capital of the United States, by the Spanish missionaries in the 17th century. Its popularity across the US did not become widespread until centuries later with the development of refrigeration and railway transportation.

How to Select and Store

How to Enjoy

For some of our favorite recipes, click Recipes.

Tips for Preparing Lettuce:

To clean lettuce, first remove the outer leaves and with one slice cut off the tips of the lettuce which tend to be bitter. Chop the remaining lettuce to the desired size and discard the bottom root portion. Rinse and pat dry or use a salad spinner if you have one available to remove the excess water.

Wash greens such as arugula and watercress like you would spinach. Trim their roots and separate the leaves, placing them in a large bowl of tepid water and swishing them around with your hands. This will allow any sand to become dislodged. Remove the leaves from the water, empty the bowl, refill with clean water and repeat this process until no dirt remains in the water (usually two or three times will do the trick). Make sure your leaves are spun or patted dry before adding dressing so as not to dilute flavor.

A Few Quick Serving Ideas:

Give sandwiches extra crunch (and nutrients) by garnishing with lettuce leaves.

When it comes to salads, the only limitation is your imagination. Be creative-use a variety of different lettuce types and add your favorite foods. Whether they’re vegetables, fruits, seeds, nuts, whole grains, whole wheat croutons, soy products, meats or cheeses, most every food goes well with lettuce.

For an interactive meal that is both unusual and fun, arrange nuts, diced vegetables, chicken and/or baked tofu and romaine lettuce leaves on a large plate. Everyone then has the chance to make their own lettuce pockets by placing their favorite fillings in a lettuce leaf and making a breadless sandwich wrap.

Safety

Romaine Lettuce and Pesticide Residues

Even though pesticides are present in food at very small trace levels, their negative impact on health is well documented. The liver’s ability to process other toxins, the cells’ ability to produce energy, and the nerves’ ability to send messages can all be compromised by pesticide exposure. Since lettuce is among the 20 foods on which pesticide residues have been most frequently found, individuals wanting to avoid these health risks may want to avoid consumption of lettuce unless grown organically.

Nutritional Profile

Introduction to Food Rating System Chart

The following chart shows the nutrients for which this food is either an excellent, very good or good source. Next to the nutrient name you will find the following information: the amount of the nutrient that is included in the noted serving of this food; the %Daily Value (DV) that that amount represents (similar to other information presented in the website, this DV is calculated for 25-50 year old healthy woman); the nutrient density rating; and, the food's World's Healthiest Foods Rating. Underneath the chart is a table that summarizes how the ratings were devised. For more detailed information on our Food and Recipe Rating System, please click here.

 

Lettuce, Romaine
2.00 cup
15.68 calories
Nutrient Amount DV
(%)
Nutrient
Density
World's Healthiest
Foods Rating
vitamin A 2912.00 IU 58.2 66.9 excellent
vitamin C 26.88 mg 44.8 51.4 excellent
folate 151.98 mcg 38.0 43.6 excellent
manganese 0.71 mg 35.5 40.8 excellent
chromium 15.68 mcg 13.1 15.0 excellent
potassium 324.80 mg 9.3 10.7 very good
molybdenum 6.72 mcg 9.0 10.3 very good
dietary fiber 1.90 g 7.6 8.7 very good
vitamin B1 (thiamin) 0.11 mg 7.3 8.4 very good
iron 1.23 mg 6.8 7.8 very good
vitamin B2 (riboflavin) 0.11 mg 6.5 7.4 very good
phosphorus 50.40 mg 5.0 5.8 very good
calcium 40.32 mg 4.0 4.6 good
protein 1.81 g 3.6 4.2 good
omega 3 fatty acids 0.08 g 3.2 3.7 good
tryptophan 0.01 g 3.1 3.6 good
vitamin B3 (niacin) 0.56 mg 2.8 3.2 good
vitamin B6 (pyridoxine) 0.05 mg 2.5 2.9 good
World's Healthiest
Foods Rating
Rule
excellent DV>=75% OR Density>=7.6 AND DV>=10%
very good DV>=50% OR Density>=3.4 AND DV>=5%
good DV>=25% OR Density>=1.5 AND DV>=2.5%

References

  • Bazzano LA, He J, Odgen LG et al. Dietary intake of folate and risk of stroke in US men and women:NHANES I Epidemiologic Follow-up Study. Stroke 2002 May;33(5):1183-9.
  • Ensminger AH, Ensminger, ME, Kondale JE, Robson JRK. Foods & Nutriton Encyclopedia. Pegus Press, Clovis, California.
  • Ensminger AH, Esminger M. K. J. e. al. Food for Health: A Nutrition Encyclopedia. Clovis, California: Pegus Press; 1986.
  • Fortin, Francois, Editorial Director. The Visual Foods Encyclopedia. Macmillan, New York.
  • Wood, Rebecca. The Whole Foods Encyclopedia. New York, NY: Prentice-Hall Press; 1988.

This page was updated on: 2004-11-20 19:08:12
© 2002 The George Mateljan Foundation