Grapefruit is a popular breakfast treat. It is eaten fresh and added to salads. The juice of grapefruit is a delicious breakfast accompaniment and a favorite ingredient in cocktails and punches.  Loaded with a number of nutrients, such vitamin C, beta-carotene and potassium, grapefruit is regarded as a functional food, hence, beneficial for health.  Grapefruit is a unique citrus fruit. It is believed to be the only economically significant citrus fruit that is not indigenous to Southeast Asia. However, this hybrid of sweet orange and pummelo or shaddock cannot be classified as a distinct citrus species. Instead, it is considered as a unique interspecific hybrid.  The cross hybridization of sweet orange and pummelo originated in the Barbados sometime in the mid-1700s. The fruits that hung from the branches in grape-like clusters were for a while dubbed as the forbidden fruits. Later a Jamaican farmer named it the “grapefruit”. From here the French or Spanish settlers carried it to Southern Texas. 
In Florida, the salty soil along the Indian River was ideal for growing citrus trees. The grapefruits that grow in this state are still believed to be the best in America and perhaps in the world. California, Texas, Cuba, Mexico, Brazil, Spain, South Africa, Israel, India and China are other producers of grapefruit.There are two distinct families of grapefruit, fruits that are pale yellow to diamond white in color and those that are pink to ruby red. The antioxidant lycopene gives the pulp its red color. The intensity of the red color is directly proportional to the fruit’s lycopene content. Red grapefruit has a sweeter taste, whereas the flavor of white grapefruit is known to be sharper and clearer. Grapefruit varieties, regardless of their color, are available with and without seeds. The fruits with seeds are known to be more flavorful than the seedless grapefruits. 
Fresh grapefruit is a low calorie fruit. Half of an average pink or red grapefruit, equivalent to 3 ½ ounces or 100 grams, contains 42 calories. It provides 10.7 grams of carbohydrate comprising of 6.9 grams of natural sugar in the form of fructose, sucrose and glucose and 1.6 grams of fiber, and 0.1 gram of fat and 0.8 gram of protein. Grapefruit contains a number of phytochemicals such as lycopene, flavonoids, liminoids and glucarates.  It is especially valued for its vitamin C content. You can get more than your daily value of vitamin C from one serving of grapefruit. By consuming a cup of grapefruit sections you will get 146% of your daily value of vitamin C. A number of health benefits of consuming grapefruits are attributed to its high vitamin C content. This potent antioxidant is good for the skin.  Moreover, grapefruit contains good amount of folic acid and potassium. However, the exact nutritional value depends upon the color of the fruit. For instance, pink and red grapefruits contain larger amount of vitamin A than white grapefruit. 
Benefits Of Grapefruits
There are a number of benefits of including grapefruit in your diet.
1. Reduces Cholesterol
Elevated cholesterol level is one of the leading causes of heart diseases. Grapefruit contains pectin, which is known for its cholesterol-lowering property. Approximately 3.9 percent of the edible portion of the whole fruit comprises of pectin. You will get approximately 7.5 gram of pectin by eating one grapefruit. Studies suggest that consuming 15 grams of grapefruit pectin, which is equivalent to eating about two grapefruits per day, helps in lowering the cholesterol level by 10 percent, thereby causing 20 percent reduction in the risk of heart disease.  In a study, researchers found that regular intake of 100 to 200 ml fresh grapefruit juice daily for 30 days helps in lowering the total cholesterol, LDL cholesterol and triglyceride levels. Furthermore, red grapefruit produced better result than the white variety. Hence, it was deduced from the study that red grapefruit juice works in a dose dependent manner in lowering the lipid level in people suffering from hypercholesterolemia or high blood cholesterol. 
2. Lowers Blood Pressure
Grapefruit is known for its blood pressure reducing effect. In both in-vitro and in-vivo studies, grapefruit juice helped in reducing the diastolic and systolic arterial pressure in hypertensive subjects as well as in subjects with normal blood pressure.  However, hypertension patients on antihypertensive drugs should limit grapefruit intake. Consuming relatively large quantity of grapefruit juice along with antihypertensive drugs increases the bioavailability of the drug, which causes rapid fall in blood pressure level. 
3. Helps In Blood Sugar Management
Grapefruit can be added to the diet of diabetics. It is a good source of fiber. Fiber helps in slowing down glucose absorption. As glucose is gradually released into the bloodstream, it helps in balancing the blood sugar level. Furthermore, the vitamin and mineral rich fruit may improve blood sugar management by reducing insulin resistance that helps in decreasing excess insulin in the blood.  The modest effect of grapefruit on insulin level helps in averting blood sugar fluctuations that stimulate sugar cravings and avoids reduction of energy level. Researchers had found that when half a grapefruit is consumed before each meal, the insulin level stays at a lower level two hours after the meal, which indicates the beneficial effect of grapefruit on insulin resistance.
Furthermore, a study published in the journal Biochemical and Biophysical Communications claims that the flavonoid naringenin present in grapefruit helps in increasing the effectiveness of insulin. It improves glucose uptake and utilization in the muscles. 
4. Good For The Digestive System
Though an acidic food, after digestion grapefruit forms an alkaline residue that helps in neutralizing the acid reactions that occur following intake of acid-forming foods. Eating the fresh pulp of grapefruit juice is known to provide the best result. It helps in keeping the intestines healthy and reduces risk of constipation, dysentery, diarrhea and infections of the digestive tract. It is also believed to be good for the health of the liver. 
Bitter substances present in grapefruit are known to stimulate digestion and are good for the liver.  For people who find lemon too acidic or cannot tolerate orange juice, grapefruit is a good substitute for these citrus fruits. It is best suited for increasing the body’s alkalinity. However, for improving digestion and assimilation of grapefruit, it should not be combined with starches and sweeter fruits. It can be taken with meat and is known to help in digesting meat. 
5. Good For The Heart
The nutrients and chemicals found in grapefruit are known to protect the arteries. Grapefruit pectin is regarded as a cholesterol and blood pressure lowering agent. These properties of grapefruit help in maintaining the healthy function of the cardiovascular system.  Furthermore, grapefruit helps in maintaining the normal viscosity of the blood. Hence, it is considered an excellent food for reducing the risk of heart diseases. It helps in thickening the blood in case it is too thin.  Grapefruit works by normalizing the hematocrit level. The percentage of red blood cells per volume of blood is known as the hematocrit level.
In women, hematocrit level is considered to be normal when it is between 37 and 47%. The normal hematocrit level in men is from 40 to 54%. Anemia lowers the hematocrit level while severe dehydration or high blood viscosity pushes up the hematocrit level. By removing the old red blood cells, the grapefruit flavonoid naringin assists in lowering the hematocrit level. Consuming ½ to 1 grapefruit daily is known to reduce the elevated hematocrit level. 
6. Helps Fight Arthritis
Owing to its high vitamin C and antioxidant bioflavonoid content, grapefruit is believed to be good for people suffering from arthritis. By inhibiting activities of pro-inflammatory substances known as prostaglandins, grapefruit helps in reducing inflammation. Furthermore, it helps in strengthening the cartilages. Regular intake of grapefruit is believed to improve the symptoms of inflammatory arthritis such rheumatoid arthritis. Moreover, it is known to enhance the effectiveness of painkillers by increasing their anti-inflammatory effect.  Laboratory studies have attributed the anti-inflammatory activity of grapefruit to the compound naringin. 
7. Strengthens Immune System
Rich in vitamin C and flavonoids, grapefruit helps in activating the immune system.  Drinking a decoction prepared by boiling unpeeled grapefruit in water is known to relieve sore throat and cold when taken at the early stage of the respiratory infection. Slice an unpeeled grapefruit into four pieces and place it in a pot. Cover the grapefruit sections with water. Bring the water to a boil. Remove the pot from the oven, add a tablespoon of honey and drink the warm decoction. Simmering the grapefruit helps in releasing the vitamin C and flavonoids present between the rind and the fruit. 
8. Helps Lose Weight
Since the 1930s grapefruit diet has been a popular dieting strategy for burning fats and losing weight. The diet that usually lasts of two to three weeks involves eating half a grapefruit with each meal. Though there are different variations of the diet, a common feature of all the grapefruit diets is low carbohydrate intake. Dieters, in some cases, consume fewer than 800 calories per day. However, according to scientists, though grapefruit is a healthy food choice for dieters, it does not entail any magical property for burning fats.  Nevertheless, grapefruit helps in weight loss. Grapefruit is a low calorie food that easily makes you feel full. Therefore, by eating a grapefruit before a meal you are likely to eat less.  In a study, researchers found that overweight people who ate half of a red grapefruit with each meal thrice a day for 6 weeks experienced modest weight loss. Grapefruit caused significant reduction in the waist circumference and systolic blood pressure. The improvement in the lipids and blood pressure levels following grapefruit intake suggests that it is beneficial for obese people. 
9. Maintains Healthy Skin
Grapefruit is an excellent source of vitamin A, which is known to work wonders for the skin. The antioxidant property of the vitamin helps in inhibiting skin damage associated with oxidative stress. It helps in maintaining the healthy moisture level of the skin, thereby combating skin dryness, psoriasis, wrinkles and acne.  Because of its high vitamin C content, grapefruit is good for the acne and psoriasis prone skin. This antioxidant vitamin, by suppressing the free radicals, helps in reducing skin damage and inflammation.  Owing to its skin conditioning and antiseptic properties, grapefruit extract is added to skin care preparations. Grapefruit extract obtained from the juice because of its high vitamin C concentration is considered superior to the extract obtained from the rind of the fruit.  Grapefruit juice helps in toning and brightening the skin, and is usually combined with other skin friendly ingredients and used for skin care. You can make a homemade toner by combining ¼ cup each of grapefruit juice, witch hazel and green tea. With a cotton ball cleanse your face with the homemade toner. It helps in removing the excess oil and dirt. 
Grapefruit juice mixed with honey when applied to the skin helps in reducing age spots and wrinkles. Blend one tablespoon of grapefruit juice with equal quantity of honey. Spread the mixture on your face and leave it on for 10 minutes and then rinse it.  Grapefruit can also be added to face masks. In a food processor grind four teaspoons of organic oatmeal and three teaspoons of chopped organic parsley. Extract the juice of half a large red grapefruit and mix it with the oatmeal and parsley mixture. Mash half of a ripe avocado and mix it with the mixture. Add two tablespoons of manuka honey and blend the ingredients well. If the mixture is too thick, you can make it thinner by adding a teaspoon of water. Apply the face mask to your face and neck. Leave it on for about 15 minutes and then rinse off with warm water. 
10. Anti-cancer Property
Grapefruit contains anti-cancer compounds. The pink and deep red grapefruits contain the carotene lycopene, which is known for its anti-cancer effect. D-limonene, a chemical found in grapefruit, is known to stimulate production of the enzyme glutathione-S-transferase in the liver, which helps in detoxifying toxic compounds, thereby reducing the risk of cancer. The chemical reactions induced by the detoxifying enzyme increases the solubility of toxic substances in the water so that they can be easily flushed out of the body through urine. Furthermore, grapefruit pulp is a source of anti-cancer compounds called glucarates. By assisting in elimination of excess estrogen from the body, they may help in lowering the risk of breast cancer. 
How To Choose And Eat Grapefruit
A juicy grapefruit has a thin skin and feels heavier for its size. The external appearance of the grapefruit, even presence of minor blemishes on the skin, does not affect the quality of the grapefruit. However, avoid consuming a grapefruit that has soft spots. Grapefruits can be stored for a few days at room temperature and is known to last for several weeks when refrigerated. Chilled grapefruits are considered to be tastier.  However, grapefruits are known to be juicier when they are slightly warm. Therefore, if you want to eat the juicier fruit store it at room temperature, otherwise, if you prefer it less juicy refrigerate it. It is always best to eat fresh grapefruits. The fruit is sliced horizontally and the sections of each half are scooped out with the help of a spoon. You can also use a sharp knife or even your hands to separate the rind from the pulp. Eat the fresh grapefruit or juice it. Grapefruit sections can be added to fruit salads and green salads. 
Possible Side Effects Of Grapefruits
Grapefruit is believed to be safe when consumed in normal amounts as food. However, consuming large amounts of grapefruit can cause certain adverse reactions. Drinking large amounts of grapefruit juice may increase the risk of breast or hormone sensitive cancer in women. It may not be suitable for women with hormone sensitive conditions.  It is believed to interact with over 50 drugs. A number of which are used for serious health problems.  Therefore, to avert adverse reactions, consult your physician before taking grapefruit.