Guava (Psidium guajava) is a member of the Myrtaceae family, along with myrtle, clove, feijoa, allspice, and eucalyptus. Ranging in size from a chicken’s egg to an apple, the oval fruits have orange flesh beneath skin that varies in color from purplish black to red.

Guava likely originated in Central America. Indigenous people domesticated wild guava trees at least 2,000 years ago. Archaeologists have found guava seeds in food caches in Peru along with beans, corn, and squash. Indigenous Americans cooked guava before it ripened and ate it raw when it was ripe. They boiled the leaves, roots, and bark as a tea and used it to treat diarrhea, dysentery, and gastroenteritis.

Early Spanish explorers began cultivating guava commercially in 1526 in the West Indies, and it spread to the Bahamas and Bermuda. Because the fruits were too delicate to last on ocean voyages, and Europe did not have the climate for growing guava trees, the fruits remained relatively unknown there, but the Spanish and Portuguese transported them from the New World to the East Indies and Guam. Spaniards carried seeds to India, Malaya, and the Philippines. Guava arrived in Hawaii in the 18th century.

Guava was introduced in southern Florida in 1847, and was common over more than half the state by 1886. The Portuguese distributed guava to South Africa during the 19th century. Faan Retief planted the first commercial guava orchard in South Africa in Paarl in 1890. It was adopted as a crop in Asia and Egypt, and it may have traveled from Egypt to Palestine. Guava is also grown in Algeria and on the Mediterranean coast of France. Cooks in India made it into a sauce called chutney, which it made its way to Europe, and became popular in England.

Guava was planted commercially in Hawaii in 1900, and in 1925, the first guava jelly factory opened there. In Florida, the first commercial guava planting was established around 1912 in Palma Sola. During World War II, Cuba harvested 10,000 tons of the wild guava and exported 6,500 tons of guava products. By 1946, just two of the more than two dozen guava jelly manufacturers in Florida were processing a combined 400 bushels of guavas per day. In California, guava trees can only survive in the southern coastal areas where there are no frosts and no intense daytime heat. Even there, the trees will die back if the summers are too cool.

Today, the guava remains a popular shade tree in the tropics and is part of many household gardens. It is common throughout tropical America. In many parts of the world, guava runs wild and forms extensive thickets known in Spanish as guayabales. It overtakes pastures, fields, and roadsides so thoroughly in Hawaii, Malaysia, New Caledonia, Fiji, the U.S. Virgin Islands, Puerto Rico, Cuba, and southern Florida that it is considered as a noxious weed. At the same time, however, wild guavas make up most of the commercial supply. In 1972, Hawaii processed more than 2,500 tons of guavas, and over 90% of those were from wild trees.

Guavas are low in calories, fat, and sodium, but contain several important vitamins, minerals, and antioxidant phytochemicals that can help prevent cancer, slow the aging process, and boost immunity.

Guava can:

1. Lower your risk of heart disease and cancer.  Guavas are an excellent source of vitamin C: 100 grams of fresh fruit provides 228 milligrams, or nearly four times the DV. The outer rind contains much higher levels of vitamin C than central pulp. In fact, guava contains one of the highest vitamin C contents among produce at four times more than oranges. Vitamin C is a potent antioxidant that helps protects your cells from free radical damage that may contribute to the development of heart disease and cancer. It’s also a very good source of , and antioxidant carotenoids like beta-carotene, lutein, cryptoxanthin, and lycopene: 100 grams of pink guava provides 5204 micrograms of lycopene, nearly twice the amount in tomatoes. Lycopene protects your cells from the damaging effects of free radicals, and helps prevent the oxidation of cholesterol, thereby slowing the development of atherosclerosis. Salicylic acid in guavas helps to reduce pain and inflammation, prevent the formation of dangerous blood clots, prolong the life of food, and potentially reduce your risk of colorectal cancer.
2. Promote good eyesight. Guavas are very good sources of vitamin A, and the antioxidant carotenoid lutein, the nutrients best known for preserving and improving eyesight. 
3. Reduce your risk of diabetes. Guavas are a very rich source of soluble fiber, with 5.4 grams per 100 grams of fruit, or about 14% of Daily Value (DV), which makes them a good laxative. In particular, they contain high levels of pectin, a soluble fiber that promotes digestion. They contain about 9 grams of total fiber per cup—more than you’d get in an apple, apricot, banana, and nectarine combined—which helps lower cholesterol, boost immunity and protect your heart. The fiber content helps protect the mucous membranes of your colon by decreasing their exposure time to toxins as well as binding to cancer-causing chemicals. Fiber can also slow down the absorption of sugar in your body, and a high-fiber diet has been linked to a lowered risk of developing type 2 diabetes.
4. Support fertility. Guava also supplies a good amount of folate, which is an essential nutrient for a healthy pregnancy.
5. Stabilize blood pressure. Guavas are a very rich source of potassium, and contain more potassium than bananas by weight. Potassium helps regulate your blood pressure by balancing sodium.
6. Keep your brain healthy. The B-complex vitamins play a vital role in brain function. Besides folate, guavas are rich in pantothenic acid, vitamin B6, niacin, and thiamine. Niacin stimulates brain function and promotes blood flow and vitamin B6 is an important nutrient for brain and nerve function.
7. Help your body use key nutrients. One of the key functions of manganese in your body is activating enzymes, including those responsible for the utilization of some key nutrients such as biotin, thiamine, and vitamin C. Guavas are good sources of manganese. 
8. Relax your nerves and muscles. Eating guavas can help relax your nerves and muscles through its good magnesium content.
9. Build muscle. Guavas provide only 3.5% of your daily calories per 100 grams, but they provide 5% of your DV for protein.
10. Keep your skin healthy. Guavas can also improve your skin through its vitamin E content. Vitamin E helps maintain healthy skin through its antioxidant properties.

Nutrients in 100 Grams of Guava

In the tropics, guavas are available year-round. Red-flesh varieties are richer in nutrition than green apple guavas. They can be picked while green but mature and later allowed to ripen at room temperature.

In the store, buy fresh fruits featuring intact skin without any cuts, bruises, or patches. Placing the fruit wrapped in a paper with a banana or apple will hasten ripening.

Store mature, yet green fruits for two to five weeks between 46°F and 55°F, and relative humidity of 85 to 95 percent. Over-ripened fruits can keep well in the refrigerator for only a few days.

Wash guavas in cold running water in order to remove any dust or insecticide residues. Fresh ripe guavas are best eaten as they are along with skin. Remove any floral remnants (sepals), and then trim either end with a sharp knife. Guava can be cubed or sliced, and are also juiced. Their high pectin content makes them good for jams and jellies. In the tropics, guavas are used in pies, pastries, iced deserts, drinks, salads, and vegetable dishes.