Refreshing and delicious grapefruit is rich in phytonutrients like lycopene, vitamin A, and beta-carotene. The fruit is well known as “fruit from the paradise” for its unique health promoting as well as disease preventing properties especially among the health conscious, fitness and enthusiasts. The scientific name is Citrus paradisi. Citrus paradisi is a subtropical citrus tree. Botanically, it belongs to the large Rutaceae family of citrus fruits, in the genus: Citrus, and closely related to oranges.
Grapefruit is an evergreen, medium-sized tree grown for its fruit. It grows up to 15 meters in height and bears numerous yellow-orange fruits in clusters during each season. It is, in fact, a natural hybridization of pomelo and orange. It was first discovered in the forests of Caribbean island, Barbados. Today, it is one of the widely cultivated fruits in the United States, particularly in Florida, California, and the other semi-tropical southern states.
Grapefruit is oblate in shape, ranges in diameter from 3 to 5 inches and can weigh up to 150 g. Characteristically, it has thick, tough skin than that in the oranges. Inside, the fruit is segmented into arils as in other citrus fruits. Its arils are very juicy, acidic, and varying in color depending on the cultivars, which could be white, pink and red of varying sweetness. While some varieties are seedless, there may be up to 50 white, elliptical, pointed seeds about 1/2 inches in length in some.
Grapefruit, with its bitter sweetness, is a popular citrus fruit commonly eaten for breakfast to help start digestion and aid in weight loss. This refreshing fruit could also hold the key to treating conditions such as high cholesterol and type II diabetes. It is found that naringenin, an antioxidant derived from bitter-flavoured grapefruit and other citrus fruits, may cause the liver to break down fat while increasing insulin sensitivity, mimicking the actions of lipid-lowering and anti-diabetic drugs. Naringenin may also protect against liver damage.
Grapefruit is also a good source of vitamins C and A, which help strengthen immune function. It is also a rich source of the soluble fiber, pectin, which helps to lower cholesterol levels. The rich pink and red color of grapefruit is given by lycopene, a phytochemical with powerful antioxidant properties, which helps fight free radical damage in the body. Lycopene, also found in tomatoes, is known for its ability to lower the risk of prostate cancer. Choose fully ripe grapefruit as they have the highest levels of antioxidants.
Grapefruit juice significantly increases the production and activity of liver detoxification enzymes responsible for preparing toxic compounds, including cancer-causing carcinogens, for elimination from the body. Grapefruit also contains phytonutrients called limonoids that have anti-tumour activity. The citric acid present in fresh grapefruit juice also increases alkalinity in the body, which can be useful for treating diseases caused by too much acid. Consuming fruits and vegetables of all kinds has long been associated with a reduced risk of many adverse health conditions. Many studies have suggested that increasing consumption of plant foods like grapefruit decreases the risk of obesity, diabetes, heart disease and overall mortality while promoting a healthy complexion, increased energy, and overall lower weight.
Grapefruit may not be a miracle weight loss food as touted in some previously popular fad diets, but consuming grapefruit as part of a healthy diet may just give you a little boost. Delicious, grapefruit is very low in calories, consists of just 42 calories per 100 g. Nonetheless; it is rich in dietary insoluble fiber pectin, which works as bulk laxative. Dietary fiber helps to protect the colon mucous membrane by decreasing exposure time to toxic substances in the colon as well as binding to cancer-causing chemicals in the colon. Pectin has also been shown to reduce blood cholesterol levels by decreasing re-absorption of cholesterol in the colon.
Further, vitamin A is also required maintaining healthy mucus membranes and skin. Consumption of natural fruits rich in vitamin-A, and flavonoids helps to protect from lung and oral cavity cancers. It is an excellent source of antioxidant vitamin-C; providing about 52 per cent of DRI. Vitamin-C is a powerful natural anti-oxidant and helps the body develop resistance against infectious agents and scavenge harmful free radicals. It, furthermore, is required for the maintenance of healthy connective tissue and aids in early wound healing. It also facilitates dietary iron absorption in the intestine. 100 g of fresh fruit contains about 135 mg of potassium electrolyte. Potassium is an important component of cell and body fluids, helps regulate heart rate and blood pressure through countering sodium effects.
Red varieties of grapefruits are especially rich in powerful flavonoid antioxidant, lycopene. Studies show that lycopene protects skin from dangerous UV rays, and offers protection against prostate cancer. Additionally, it contains moderate levels of B-complex group of vitamins such as folates, riboflavin, pyridoxine, and thiamin in addition to some resourceful minerals such as iron, calcium, copper, and phosphorus.
The fruit contains very good levels of vitamin-A (provides about 1150 IU per 100g), and flavonoid antioxidants such as naringenin, and naringin. Additionally, it is a moderate source of lycopene, beta-carotene, xanthin and lutein. Studies suggest that these compounds have antioxidant properties and are essential for vision. The total antioxidant strength measured in terms of oxygen radical absorbance capacity (ORAC) of grapefruit is 1548 µmol TE/100 g.
As an excellent source of the strong antioxidant vitamin C as well as other antioxidants, grapefruit can help combat the formation of free radicals known to cause cancer. Lycopene intake has been linked with a decreased risk of prostate cancer prevention in several studies and foods high in vitamin C and beta-carotene have been shown to lower the risk of esophageal cancer in particular. Grapefruit, because of its water and fiber content, helps to prevent constipation and promotes regularity for a healthy digestive tract. As one of the most hydrating fruits in the world made up of 91% water (just below watermelon) and full of important electrolytes, grapefruit is a great snack to have on hand to prevent dehydration. The antioxidant vitamin C, when eaten in its natural form (in fresh produce as opposed to supplement form) or applied topically, can help to fight skin damage caused by the sun and pollution, reduce wrinkles and improve overall skin texture. Vitamin C plays a vital role in the formation of collagen, the main support system of skin. Hydration and vitamin A are also crucial for healthy looking skin, both of which grapefruits can provide.
The risks for developing asthma are lower in people who consume a high amount of certain nutrients. One of these nutrients is vitamin C, found in many fruits and vegetables including grapefruit.
The authors are associated with the National Institute of Food Science and Technology, University of Agriculture Faisalabad, Punjab, Pakistan.