Nutrition

Grapefruit, the antioxidant

Grapefruit, a misunderstood but very beneficial fruit with the tart and bitter taste, is famous for its fat burning abilities and its few calories. Although it is ideal for diets, it should be consumed with caution. This is because scientific research has shown, most recently, that grapefruit juice can significantly affect (and possibly negative) the action of several drugs. Let’s see, however, all in detail.

The origin of grapefruit is “shared” between the islands of Barbados, the West Indies and Asia. It was, initially, came in Europe as a decorative plant, and only in the early 19th century began to be chosen for its fruits. In Greece it is cultivated since the late 60s, but never systematically. Today, we find a small production in the same areas with other citrus fruits, as in Argolis, Laconia, Arta, in Chania, in Etoloakarnania, Ilia and Corinth. The US, the largest consumer in the world, have 41% of world production, while it is systematically cultivated also in China, South Africa, Mexico, Israel, Spain, Australia and Argentina.

Its name, grape-fruit, was given in 1814 in Jamaica, a name which reflects the way it’s arranged when it grows—hanging in clusters just like grapes.

Grapefruit contains large quantities of vitamins A, B and C and minerals such as calcium, manganese, iron, magnesium, potassium and phosphorus. Simultaneously, it has antibacterial properties which soothe peptic ulcers and contribute to the healing process. Grapefruit juice is among the 4 fruit juices with the most powerful antioxidant activity, along with apple, cranberry, and Concord grape juice.

The pink and red grapefruit are rich in lycopene, a carotenoid phytochemical known for its antioxidant action and the prevention of prostate cancer. Studies have shown that the bioflavonoids contained in grapefruit may even prevent the spread of cancer cells in breast cancer cases, sparing the body from harmful estrogen. Naringenin, a flavonoid contained in grapefruit and oranges, helps to restore the damaged DNA in cancer cells, in the case of prostate cancer. In addition, grapefruit contains pectin, a form of soluble fiber, capable of reducing the rates of cholesterol, removing it from the body, and significantly reducing the risk of atherosclerosis.

Moreover, phytochemicals known as limonoid, has proven to help protect against lung cancer, mouth, stomach, colon and skin. The daily consumption of three doses of 175ml, grapefruit juice has been shown to reduce the activity of an enzyme that activates cancer activity contained in cigarette smoke. Another phytochemicals, called glucarate are effective against breast cancer. According to researchers, the best action of red grapefruit is due to the joint action of both components contained phytochemicals and lycopene.

For the prevention and elimination of kidney stones, grapefruit is an excellent choice, as it contains a number of compounds, such as delta-limonene, which contribute to their formation. The grapefruit juice daily consumption reduces urinary pH-level, reducing thereby the risk of stone formation in the kidneys.

A glass of grapefruit juice or half a grapefruit before each meal significantly reduces calorie consumption. The high content of fat-soluble fibers significantly helps us feel satiated for longer hours in the day and contribute to a proper bowel function. Furthermore, the large amount of water containing improves metabolism. Studies have shown that grapefruit provides the feeling of fullness, while constantly keeps blood sugar levels, better regulating appetite.

Pectin contributes to this function, by helping in carbohydrate absorption rate. Results of studies have shown that patients who ate half a grapefruit before each meal for twelve weeks showed lower insulin and glucose levels after every meal, compared with those who didn’t ate grapefruit before a meal.

The high content of grapefruit in vitamin C strengthens protection against infections caused by germs such as parasites, bacteria, viruses etc. Half a grapefruit contains 80% of the recommended amount of vitamin C, which is needed to take our body on a daily basis.

Significant amounts of antioxidants and vitamin A contained in grapefruit, not only moisturize the skin, but prevent diseases, such as acne, psoriasis and dryness.

The juice of the grapefruit, just as apple cider vinegar, is a great solution for those people who suffer from arthritis. Grapefruit has salicylic acid, which cleaves the inorganic calcium inside the body. The accumulation of inorganic calcium in joints causes arthritis.

The antioxidant properties of pink and red grapefruit help to improve your eyesight. The beta-carotene, vitamin A, lycopene, lutein and xanthine containing grapefruit are important components in maintaining eye health.

However, besides the many beneficial properties, grapefruit can affect the ability of our body to metabolize certain drugs and thus, the interactions may be toxic or fatal. There are specific enzymes in the small intestine walls which prevent the absorption of drugs. This means that the body absorbs smaller amounts of the drug compared with what has been consumed. However, the grapefruit can block the activity of this enzyme. This means that the amount of medication in the blood will raise, causing toxic side effects.

According to a study published in the “Canadian Medical Association Journal” (CMAJ), there are many prescription drugs that have serious side effects when mixed with grapefruit. Some of the adverse act parallel intake of drugs and grapefruit are: respiratory failure, gastrointestinal bleeding, renal toxicity, etc.

Indicatively, some of the many drugs that interact with grapefruit, according to the website of the British Health Ministry:

Statins. These are drugs for cholesterol. Grapefruit completely contraindicated for those taking simvastatin, and in large doses can affect those who take atorvastatin.

Cytostatics. They are medicinal products for the treatment of cancer.

Calcium channel blockers. Administered for hypertension and coronary disease. Grapefruit may increase the levels of some of them, if consumed in large amounts. This risk has been observed with amlodipine, felodipine, isradipine, lacidipine to, lercanidipine, nirkardipini, nifedipine, nimodipine and verapamil.

Antihypertensive. The drug aliskiren should not be taken with grapefruit.

For Crohn’s disease. Anyone taking the drug budesonide should not drink or eat grapefruit.

So it is good if you are taking any medication, consult your doctor and pharmacist before consuming grapefruit, to avoid unpleasant situations.

Note: The ideas and information presented in this blog are for informational purposes only and in no case can replace the advice of a specialist in nutrition and health. Before starting any diet or exercise or before adding a special food in your daily intake, you should contact a specialist doctor or dietitian; especially if you suffer from a serious illness.