Lettuce vs. Arugula — Health Impact and Nutrition Comparison

Calories

Arugula and lettuce are both considered low-calorie vegetables, with arugula having a slightly higher calorie count per 100 grams than lettuce. A 100g serving of arugula contains 25 calories; meanwhile, the same serving of lettuce contains 15 calories. 

Protein and Fats

Arugula contains slightly more protein than lettuce. Per 100 grams of arugula, you receive about 2.58 grams of protein, while for the same serving of lettuce, you receive 1.35g of protein.

Arugula and lettuce are low in fat content, although arugula contains 0.51 grams more fat than lettuce per 100 grams of serving. The primary type of fat found in these greens is polyunsaturated fatty acids.

Both arugula and spinach contain no cholesterol. 

Carbohydrates

Arugula and lettuce are low-carb vegetables. However, arugula contains slightly more carbohydrates than lettuce, with the majority of the carbohydrates in lettuce consisting of dietary fiber, while in arugula, they are primarily sugars containing glucose and fructose.

Nitrates

Nitrates found in green leafy vegetables (unlike the nitrates found in processed meat) are known to provide various health benefits, including improved cardiovascular outcomes (3). 

Although both lettuce and arugula contain high amounts of nitrates, according to a report published by the European Food Safety Authority, arugula contains around 3 times more nitrates than lettuce (4). However, it is important to note that the amount of nitrates may vary depending on various environmental factors, including humidity, temperature, water content, and more (5).  

Flavonoids

Flavonoids have been studied to reveal anti-inflammatory and antioxidant properties (6, 7). Whereas there is a general consensus that the major flavonols in both lettuce and arugula are quercetin and kaempferol, there is limited research available on the comparisons of their exact content. 

Carotenoids

Research has also found a link between carotenoids, including carotenes and xanthophylls, and protective cardiovascular, anti-cancer, and anti-obesity effects (7). Per 100 grams, lettuce contains 4440μg β-carotene, which is around 3 times more than arugula (1420μg). 

Glucosinolates

Glucosinolates, sulfur-containing phytochemicals, have been associated with anti-cancer properties and protective cardiovascular effects (8). While they are abundantly present in arugula, research indicates no detection of glucosinolates in lettuce (6, 9).

Moreover, the hydrolysis products of glucosinolates, called isothiocyanates, have also been widely studied in arugula. For example, a type of isothiocyanate called erucin has been linked with anti-cancer properties (10).

Cardiovascular Health

Various meta-analyses have identified several studies that explained positive cardiovascular outcomes through the high concentrations of magnesium, potassium, nitrates, dietary fiber, and phytochemicals found in vegetables (12). Arugula is slightly a better source of magnesium (per 100g, there is 47 mg in arugula, 13 mg in lettuce) and potassium (per 100g, there is 369 mg in arugula, 194 mg in lettuce) than lettuce. They both contain different amounts of phytochemicals, which may also be linked to cardiovascular outcomes.

Arugula and lettuce are also known to have a positive cardiovascular impact because of their high nitrate contents, although arugula contains 3 times more nitrates than lettuce (4). The Danish Diet, Cancer, and Health Study, which involved over 53,150 participants that were followed for 23 years, found that higher consumption of foods with high nitrate content was associated with lower blood pressure levels and reduced risks of cardiovascular disease, including heart disease, heart failure, and stroke (13). 

Diabetes

As stated above, both arugula and lettuce have low glycemic values, which means their consumption has little effect on blood sugar levels. 

Moreover, the nutritional composition and the various phytochemicals found in arugula and lettuce help to further reduce the risk of diabetes. One study has found that arugula and its fatty acid-rich fraction have exhibited anti-diabetic activities, and thus, they may have potential in type 2 diabetes treatment (14). On the other hand, the phytochemicals lactucaxanthin and polyphenols found in lettuce were found to exhibit anti-diabetic properties in another study (15). 

Cancer

Consumption of arugula and lettuce has been associated with a lower risk of certain types of cancer, including breast, colorectal, lung, and liver cancers. Some studies have linked this association to the prevalence of phytochemicals, specifically, erucin in arugula and β-carotene and ascorbic acid in lettuce (10, 16, 17, 18, 19).

Neurological Health

Arugula and lettuce are also known to provide neuroprotective effects. In lettuce, this has been studied to be linked with the ethyl acetate portion and the glycoside B found in it (7). Another study has revealed the neuroprotective effects of Eruca sativa (arugula) seed extract on NSC-34 motor neurons (20).

Bone Health

Consumption of foods with high amounts of Vitamin K and Calcium has been linked to better bone health outcomes (21). As discussed above, both lettuce and arugula are rich in these nutrients, although arugula contains 4 times more Calcium, while lettuce contains slightly more Vitamin K. Research also linked positive bone health outcomes to antioxidants found in lettuce and arugula.   

Medication Interactions

Green leafy vegetables, such as lettuce and arugula, contain high Vitamin K content (per 100 grams, there is 126 µg of Vitamin K in lettuce and 109 µg in arugula). As a result, the consumption of these foods among those who are taking anticoagulation medication, such as warfarin, should be controlled (22). The National Institute of Health recommends consuming the same amount of Vitamin K daily for those taking anticoagulants to reduce the risk of bleeding or blood clots (23).

Food Contamination

Although the consumption of lettuce and arugula provides many health benefits, it is important to note that they are, just like many other fresh vegetables, prone to contamination due to the prevalence of germs. To reduce your chances of contamination, make sure to always wash the vegetables. 

One of the most common contaminants associated with lettuce and arugula includes Escherichia coli (E. coli) bacteria. E. coli outbreaks are associated with symptoms that include diarrhea, abdominal cramps, and more (24). Follow your local health authorities for information on E. coli outbreaks.