What is Romaine Lettuce?
Romaine or cos lettuce is a variety of lettuce that grows in a tall head of sturdy dark green leaves with firm ribs down their centers. Unlike most lettuces, it is tolerant of heat. In North America, romaine is sold as whole heads or as “hearts” that have had the outer leaves removed and are often packaged together.
Romaine lettuce is a type of salad lettuce. It comes from the same plant family as other types of lettuce.
The name “romaine” suggests that the lettuce might have originated in Rome. It also grows well in the Mediterranean climate.
Romaine lettuce leaves are long and taper toward the root of the lettuce. The upper part of the leaves is a deeper green color and more flimsy than the lower leaves.
Toward the bottom of the lettuce, the leaves become sturdier and have thick, white ribs that contain a slightly bitter fluid. This gives romaine lettuce its distinctive taste.
The amount of this bitter fluid increases farther down the stalk. Some people throw away the thickest part of the leaves to avoid this bitterness.
Romaine lettuce is an underrated veggie and doesn’t get the accolade, especially when compared to its dark leafy cousins, kale, and spinach. Experts say romaine lettuce is actually loaded with important vitamins and minerals. In fact, romaine ranked even higher than kale, collard greens, and arugula thanks to its impressive nutritional profile. So, if you love to eat romaine lettuce just indulge in it.
“Romaine lettuce can be a wonderfully healthy addition to a balanced diet,” says Kylie Ivanir, MS. RD, Clinical Research Coordinator at Columbia University Medical Center, New York, New York, United States.
“This sturdy lettuce is packed with nutrients and can be added to salads, sandwiches, and smoothies. Plus, it’s a low-calorie food that naturally contains high levels of fiber, varying vitamins and minerals, carotenoids, and phenolic compounds that are important for overall health.”
What is Romaine lettuce used for?
Known for its mild flavor and crisp texture, it has sturdy leaves that make it more tolerant to heat than other lettuce varieties. It is most commonly used as salad greens, although it can also be grilled and sautéed. In recent years, romaine has become a grilling staple along with other vegetables.
Romaine lettuce is more than just a tasty leaf that adds color and crunch to a salad. It also provides vitamins, minerals, and fiber. For example, one 70 gram salad serving of romaine lettuce contains:
- 65.4 g of water
- 13.3 kilo calories
- 1 g of protein
- 2.7 g of carbohydrate
- 2.2 g of fiber
- 43.4 milligrams (mg) of calcium
- 0.6 mg of iron14 mg of magnesium
- 24.5 mg of phosphorus
- 229 mg of potassium
- 17.5 mg of sodium
- 90.3 micrograms (mcg) of folate
- 194 mcg of vitamin A
- 8.1 mg of vitamin C
- 2,320 mcg of beta-carotene
- 147 mcg of vitamin K
And within a single head of lettuce, the darker outer leaves, which are exposed to more sunlight, are more nutritious than the paler inner ones. Specifically, darker green lettuce leaves are likely to be significantly higher in beta carotene, folate, vitamins C and K, calcium, magnesium, potassium, and iron.
The nutrients in romaine lettuce provide multiple health benefits:
- Vitamin C helps support the immune system, is high in antioxidants, and helps keep bones and teeth strong.
- Calcium is necessary for the building and maintenance of bones, muscle function, nerve function, and blood clotting.
- Vitamin K is also necessary for blood clotting. It works together with calcium to prevent bone mineral loss and fractures due to osteoporosis.
- Vitamin A (from beta carotene) is a vital nutrient, necessary for health. An antioxidant, vitamin A supports cell growth and reproductive health. It also helps to maintain the heart, kidneys, and lungs. Vitamin A also supports the eyes.
- Folate is a B vitamin, which supports cell division, the production of DNA, and genetic material. Folate deficiency in pregnant women can lead to complications with pregnancy, including premature birth, low birth weight, or the birth defect spina bifida.
- Phosphorus works with calcium to build strong bones and teeth.
- Magnesium helps enzymes function and relaxes the muscles in your body. It works with calcium to build tissue.
- Potassium is an electrolyte that helps your heartbeat regularly. It supports nerve function and helps your muscles contract normally. Potassium also helps your cells to move, and utilize, nutrients efficiently. It minimizes the negative impact of sodium (salt) on the body.
Possible health benefits
Romaine lettuce is suitable for people who wish to lose weight, due to its high nutrient density and low-calorie content. However, it can be a tasty and healthful addition to any meal and eating plan. The nutrients and minerals it contains can provide benefits to anyone who regularly eats it. Here are some possible health benefits of Romain lettuce in the sections below.
Romaine lettuce is a good source of vitamins C and A, which are antioxidants. These play a key role in balancing and maintaining many systems in the body.
The body naturally produces unstable molecules called free radicals during metabolism. Environmental exposures also cause the body to take in free radicals.
However, if too many free radicals build up in the body, it can cause a condition known as oxidative stress. Cell damage can result, and this can lead to health problems.
The body can eliminate free radicals naturally, but it may have difficulty eliminating all of them. Antioxidants in foods appear to boost the body’s ability to do this.
Examples of conditions in which free radicals may play a role include:
- cardiovascular disease
- Alzheimer’s disease
- Parkinson’s disease
- age-related macular degeneration
The antioxidant content of romaine lettuce may help support a person’s immune system and protect against various health concerns.
2. May boost your immunity.
Romaine lettuce helps to ward off that seasonal cold. This leafy vegetable packs a ton of valuable vitamins and minerals that can keep you from getting sick. For example, just 1 cup contains about 11.3 milligrams of vitamin C or 19% of your daily value—which is noteworthy given the crucial role this vitamin plays in your immune system.
“Vitamin C is an essential immune-boosting nutrient, keeping your skin strong to keep out pathogens as well as increasing the effectiveness of immune cells in the body as they work to kill microbes that intend to make us sick,” explains Kelsey Lorencz, RDN from Graciously Nourished.
According to Kylie Ivanir, RD, vitamin C is also involved in wound healing and is essential for the growth and repair of body tissues, the formation of collagen, and the absorption of iron.
3. Regularity of your bowel movements.
You’re highly unlikely to deal with constipation after you eat romaine lettuce. That’s because as Kelsey Lorencz, RDN from Graciously Nourished, points out, romaine is relatively high in fiber.
“Most of this fiber is insoluble fiber, which helps add bulk to stool and keeps things moving more regularly,” she says.
“In the colon, fiber binds to bile salts and removes them from the body,” she says. “This forces the body to make more bile, which is helpful because it must break down cholesterol to do so.”
4. Good source of hydration needs.
Drinking water isn’t the only way to hydrate your body—you can also get plenty of water through certain foods, including romaine lettuce. In fact, romaine lettuce is almost 95% water. According to Brad Dieter, a NASM-certified nutrition coach and research scientist, a 2-cup serving of romaine are equivalent to drinking half a glass of water.
Looking to up your water intake even further? Top that romaine salad with some other hydrating vegetables, like cucumber, carrots, radishes, and tomatoes.
Staying hydrated has a number of health rewards. Not only does it help to prevent infections, keep your organs functioning properly, and keep your joints lubricated, but it can also help to improve your mood and sleep quality.
5. Helps you lose weight.
Romaine lettuce is basically a dieter’s dream: A 1-cup serving only has 15 calories and 2.8 grams of carbs, but 1.8 grams of satiating fiber.
“As a dietitian, I regularly include lettuce at my lunch meal to add bulk without adding a lot of calories,” says Mary Wirtz, an RD and nutritional consultant at Mom Loves Best. “It keeps me more full and less apt to crave other high-calorie foods.”
Trista Best, an RD at Balance One Supplements, adds that since romaine takes up a lot of space in your stomach, it can activate your “stretch receptors”—and when this happens, you end up feeling satisfied based on the density of the food rather than the caloric content.
6. Potassium, sodium, and the cardiovascular system
Romaine lettuce is also rich in the heart-healthy mineral potassium.
Sodium and potassium are electrolytes. The body needs both sodium and potassium to maintain healthy levels of bodily fluids and circulating blood. Experts recommend consuming more potassium than sodium, as too much sodium can give rise to heart problems.
The Dietary Guidelines for Americans 2015–2020 recommend that adults consume around 4,700 mg of potassium and no more than 2,300 mg of sodium each day.
Romaine lettuce provides both sodium and potassium in healthful proportions.
Loading up on romaine can do wonders for your ticker, according to Galvin. When cholesterol becomes oxidized, it starts to build up in the artery walls forming plaque—but fortunately, the vitamin C and beta-carotene in romaine lettuce work together to prevent the oxidation of cholesterol.
Folate in Romaine lettuce
Additionally, Galvin notes that the folate in romaine can help to lower levels of a damaging chemical called homocysteine in your body.
“If not converted, homocysteine can directly damage blood vessels, thus greatly increasing the risk of heart attack and stroke,” she explains.
Lastly, romaine is an excellent source of potassium, which Mary Wirtz, an RD and nutritional consultant at Mom Loves Best.
says is linked to decreased risk of high blood pressure and stroke.
7. Heart and circulatory health
The high levels of potassium within romaine lettuce can help maintain cardiovascular health.
In addition, the antioxidant vitamins A and C in the lettuce may help prevent cholesterol from building up and forming plaque in the arteries.
The folate in romaine lettuce may also help prevent serious heart complications. It does this by breaking down the chemical homocysteine so that the body can remove it.
A 2015 review suggests that people with a folate deficiency face a higher risk of having too much homocysteine in the blood. Homocysteine may contribute to heart conditions.
Romaine lettuce is a good source of folate, which can help keep this chemical in check.
It also contains some fiber, which plays a key role in maintaining healthy cholesterol levels.
8. Your eyes will love you.
While kale may offer more vitamin C, Brad Dieter, a NASM-certified nutrition coach, and research scientist says that romaine actually has twice the amount of vitamin A. 1 cup contains approximately 80% of your daily recommended value for this particular nutrient.
“Vitamin A is incredibly important for vision and ensuring we maintain an adequate intake of Vitamin A can help reduce the risk of age-related declines in vision and eye diseases,” he says.
Jay Cowin, registered nutritionist, and director of formulations at ASYSTEM, adds that eating a diet rich in Vitamin A can help prevent eye conditions such as cataracts and vision loss.
By the way, according to the American Optometric Association, higher intakes of vitamin C are associated with a lower risk of cataracts.
Vitamin A helps protect eye health. The vitamin A in romaine lettuce might help prevent eye conditions such as cataracts as people get older.
Also, according to the National Institutes of Health (NIH), beta-carotene may help prevent a condition called macular degeneration. This is one of the leading causes of vision loss due to aging.
Many plants, including romaine lettuce, provide beta-carotene. This may make it a good option for people wishing to boost eye health.
9. Helps to strengthen your bones.
“Romaine contains various nutrients that are important for health, such as calcium and vitamin K,” says Ivanir. “Calcium and vitamin K are critical for maintaining strong, healthy bones, preventing bone mineral loss and potential fractures.”
Research has shown that vitamin K can not only increase bone mineral density in osteoporotic people but also reduce fracture rates. There’s also evidence that even low doses of vitamin K can improve bone density when it’s ingested alongside vitamin D.
Luckily, just 1 cup of romaine has 53% of your RDA for vitamin K. If you want to fully reap the bone health benefits of vitamin K, you might combine your romaine lettuce with another food rich in vitamin D, such as sockeye salmon, eggs, cooked shiitake mushrooms, or canned white albacore tuna.
10. Cancer prevention
The antioxidants and folate within romaine lettuce might help protect the body from cancer.
The NIH (National Institute of Health) states that folate that occurs naturally in food may help decrease the risk of several forms of cancer.
Possible health risks
Romaine lettuce can be a healthful part of a varied diet, but some people have expressed concern that salad greens may carry toxins. For example, contamination can occur if farmers grow their produce in contaminated soil or irrigate it with contaminated water.
Some suggest that improper farming practices may increase the risk of romaine lettuce being contaminated with bacteria, such as Salmonella or Escherichia coli.
Following an E. coli outbreak in 2018, the Food and Drug Administration (FDA) noted that a key reason for this was the watering of plants using contaminated water.
2. Heavy metals
Another health concern is the absorption of heavy metals from the soil. One study, from 2013, found that romaine lettuce can pull heavy metals from the soil. These heavy metals may then transfer to the body of the person who eats them, which could pose a health risk.
Also, a 2016 study measured levels of heavy metals — including lead, cadmium, chromium, and mercury — in 5,785 vegetables grown in China. The team found the highest amounts of cadmium and lead in romaine lettuce, among other vegetables. They expressed concern that this could affect people’s health.
Using only organic or homegrown lettuce can help a person reduce this risk. Romaine lettuce seeds are available for purchase online. Thank you so much.
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Romaine lettuce can be a healthful part of a balanced diet and can provide even more health benefits if a person eats it regularly.
Romaine’s long, crisp leaves are popular for Caesar salads. It’s high in folate, potassium, antioxidants, and vitamins A and K.
The combination of a low-calorie content and high nutritional value make this leafy green an excellent, healthful staple.
Please share your comments below:
- Do you eat Romaine lettuce? If so, how do you prepare it?
- Would you prefer Romaine lettuce to other leafy vegetables?
- What health benefit do you derive from eating Romaine Lettuce?
Information on this site is not intended to diagnose, treat, cure, or prevent any disease. We encourage you to do your own research. Seek the advice of a medical professional before making any changes to your lifestyle or diet.
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