In days gone by there were a few slimming diets that discovered around taking grapesfruits before each meal? What was the logic in this? Back in 1971 researchers discovered a natural compound called hydroxycitric acid (HCA) and how it could inhibit the production of cholesterol and fat.
The food we eat is extremely well broken down into glucose which is used as energy. The rest is stored as glycogen in the muscles and liver. Once the body's glycogen store is full the rest is converted and stored into cholesterol and fat by an enzyme called ATP-citrase lyase. Hydroxycitric acid (HCA) appears to inhibit this last stage, reducing the amount that is converted and stored. It has been estimated that this could be as much as 40%!
It is thought that as more glycogen is kept at optimum levels, this in turn signals to the brain that energy levels are not running low and this will decrease cravings. There is a fruit that is used widely in Asia and it too contains hydroxycitric acid it is brindle berry, used extensively in Asian cooking. It is used as a flavoring instead of tamarind or lemon.
The grapefruit tree can grow to a height of about 30 feet, and is part of the citrus family. The fruit's skin may be either completely yellow or yellow with a pinkish hue. The pulp of the fruit may be yellow, pinkish, or reddish. It can be more or less sharp-tasting, sometimes a little bitter, acidic, sweet, and fragrant. The United States is the largest producer of grapefruit, accounting for over 40% of the world's production and approximately 60% of the grapesfruits are used for the manufacture juice and canned grapefruit, while the rest is sold fresh. Choose grapefruits that are heavy for their size, quite firm, with tight and shiny skin. Avoid fruits that are too soft with dull-colored skin.
Typically grapefruits are 90% water, contain Vitamin C, beta-carotene, iron, calcium, copper, magnesium zinc, bioflavonoids and other plant chemicals that protect against cancer and heart disease. Grapefruits are low in calories and high in compounds that encourage detoxification and cleansing.
Recent studies indicate that grapefruits contain substances that are useful in preventing several diseases. Pink and red grapefruits contain more beta-carotene but they are also high in lycopene found in tomatoes, an antioxidant that appears to lower the risk of prostate cancer. This is good news, as tomatoes can cause pain and inflammation in many people to arthritic type conditions.
Other protective plant chemicals found in grapefruits include phenolic acid, which inhibits the formation of cancer-causing nitrosamines, limonoids, terpenes, and monoterpenes, which induces the production of enzymes that help prevent cancer; and bioflavonoids, which inhibit the action of hormones that promote tumor growth.
Some people with rheumatoid arthritis, lupus, and other inflammatory disorders find that eating grapefruit (any color) daily seems to alleviate their symptoms. This is thought to stem from plant chemicals that block prostaglandins, substances that cause inflammation.
The other interesting thing researchers discovered about grapefruit was about the essential oil of grapefruit. We all know aromas / smells can affect our appetite – encouraging it or curbing it. Several trials with people have shown that that inhaling grapefruit essential oil over time helped to cur their appetite and they generally ate less.
Another interesting, but very important fact is the interactions with drugs / medicines. There are some serious interactions with many commonly prescribed pharmaceutical medicines. Grapefruit inhibits a special enzyme in the intestines that is responsible for the natural breakdown and absorption of many medications. When the action of this enzyme is blocked, the blood levels of these medications increase, which can lead to toxic side-effects or over load.
Research has suggested that flavonoids and / or furanocoumarin compounds found in grapefruit are the substances that act to block the enzyme in the intestines that normally metabolizes these medications. It has been noted that the interaction with grapefruit compounds can lead to unpredictable or even hazardous levels of certain drugs. Medications that have been implicated are statins (for lowering cholesterol), anti-histamines, calcium channel blockers (for blood pressure), immune suppressants, and psychiatric medication. If in doubt avoid grapefruit or talk to you doctor.