NUTRITIONAL BENEFITS OF GRAPEFRUIT
- Grapefruit is an excellent source of vitamin C, a vitamin that helps to support the immune system. Vitamin C-rich foods like grapefruit may help reduce cold symptoms or severity of cold symptoms; over 20 scientific studies have suggested that vitamin C is a cold-fighter. Vitamin C also prevents the free radical damage that triggers the inflammatory cascade, and is therefore also associated with reduced severity of inflammatory conditions, such as asthma, osteoarthritis, and rheumatoid arthritis. As free radicals can oxidize cholesterol and lead to plaques that may rupture causing heart attacks or stroke, vitamin C is beneficial to promoting cardiovascular health. Owing to the multitude of vitamin C's health benefits, it is not surprising that research has shown that consumption of vegetables and fruits high in this nutrient is associated with a reduced risk of death from all causes including heart disease, stroke and cancer.LYCOPENE
- The rich pink and red colors of grapefruit
are due to lycopene, a carotenoid phytonutrient. Lycopene appears to have anti-tumor activity. Among the common dietary carotenoids, lycopene has the highest capacity to help fight oxygen free radicals, which are compounds that can damage cells. Choosing to regularly eat lycopene-rich foods, such as pink grapefruit, and drink green tea may greatly reduce a the risk of developing prostate cancer.Practical Tips:
~ Get in the habit of drinking green tea
and eating lycopene-rich foods.
~ Take a quart of iced green tea to work and sip throughout the day or take it to the gym to provide prostate protection while replenishing fluids after your workout.
~ Pack a ziploc bag of apricots and almonds in your briefcase or gym bag for a handy snack.
~ Start your breakfast with a half grapefruit or a glass of grapefruit, apricot, papaya or guava juice.
~ Begin lunch or dinner with some spicy tomato juice on the rocks with a twist of lime. Snack on tomato crostini: in the oven, toast whole wheat bread till crusty, then top with tomato sauce, herbs, a little grated cheese, and reheat until the cheese melts.
~ Top whole wheat pasta with olive oil, pine nuts, feta cheese and a rich tomato sauce for lunch or dinner.
~ For a delicious dessert, drizzle a little honey over a half grapefruit and broil for 2 minutes. Serve topped with a fresh mint leaf.JUICE ANTIOXIDANT ACTIVITY
- Not all fruit juices are the same. They differ markedly in the variety of phenolic compounds and antioxidant activity. Concord grapes came out on top with the highest and broadest range of polyphenols and the highest overall antioxidant capacity. (The main components in purple grape juice were flavan-3-ols, anthocyanins, and hydroxycinnamates, together accounting for 93% of the total phenolic content.) Other top scorers were cloudy apple juice, cranberry juice and grapefruit juice. Results for the red grape juice were said to be equal to those for a Beaujolais red wine. Interestingly, however, white grape juice, mainly containing hydroxycinnamates, had the lowest total phenolic content.
Some studies have concluded have indicated that long-term fruit juice consumption can provide protection against Alzheimer's disease and suggest that, since each fruit juice contains its own array of protective phenols, drinking a variety may offer the best protectionLIMONOIDS
- Phytonutrients in grapefruit called limonoids inhibit tumor formation by promoting the formation of glutathione-S-transferase, a detoxifying enzyme. This enzyme sparks a reaction in the liver that helps to make toxic compounds more water soluble for excretion from the body. Pulp of citrus fruits like grapefruit contain glucarates, compounds that may help prevent breast cancer. In animal studies and laboratory tests with human cells, limonoids have been shown to help fight cancers of the mouth, skin, lung, breast, stomach and colon. Now, scientists from the US Agricultural Research Service (ARS) have shown that our bodies can readily absorb and utilize a very long-acting limonoid called limonin that is present is citrus fruits in about the same amount as vitamin C
. In citrus fruits, limonin is present in the form of limonin glucoside, in which limonin is attached to a sugar (glucose) molecule. Our bodies easily digest this compound, cleaving off the sugar and releasing limonin. Limonin's bioavailability and persistence may help explain why citrus limonoids are potent anti-carcinogens that may prevent cancerous cells from proliferating. Other natural anti-carcinogens are available for much less time; for example, the phenols in green tea and chocolate remain active in the body for just 4 to 6 hours.CHOLESTEROL
- Grapefruit contains pectin, a form of soluble fiber that has been shown in animal studies to slow down the progression of atherosclerosis. In one study, animals fed a high-cholesterol diet plus grapefruit pectin had 24% narrowing of their arteries, while animals fed the high-cholesterol diet without grapefruit pectin had 45% narrowing. Both red and blond grapefruits both positively influenced cholesterol levels, but red grapefruit was more than twice as effective, especially in lowering triglycerides. In addition, both grapefruits significantly improved blood levels of protective antioxidants. Red grapefruit's better performance may be due to an as yet unknown antioxidant compound or the synergistic effects of its phytonutrients, including lycopene.KIDNEY STONES
- Want to reduce your risk of calcium oxalate kidney stones? Drink grapefruit juice. A study published in the British Journal of Nutrition found that when women drank ½ to 1 liter of grapefruit, apple or orange juice daily, their urinary pH value and citric acid excretion increased, significantly dropping their risk of forming calcium oxalate stones.COLON CANCER
- Not only are grapefruit rich in vitamin C, but new research presented at the 228th National Meeting of the American Chemical Society provides two more reasons to drink grapefruit juice: protection against lung and colon cancer. In humans, drinking three 6-ounce glasses of grapefruit juice a day was shown to reduce the activity of an enzyme that activates cancer-causing chemicals found in tobacco smoke. In rats whose colons were injected with carcinogens, grapefruit and its isolated active compounds (apigenin, hesperidin, limonin, naringin, naringenin, nobiletin) not only increased the suicide (apoptosis) of cancer cells, but also the production of normal colon cells. Researchers also confirmed that grapefruit may help prevent weight gain by lowering insulin levels.LIVER DETOX
- Grapefruit juice significantly increases the production and activity of liver detoxification enzymes responsible for preparing toxic compounds for elimination from the body. The liver clears out toxins, including carcinogens, using a two step process called Phase I and Phase II detoxification. In the first part of this process, Phase I, enzymes belonging to the cytochrome P450 family, work on the toxin to make it more attractive to enzymes involved in the second part of the process, Phase II. Unfortunately, the action of Phase I enzymes often renders the toxin not only more attractive to Phase II enzymes, but even more dangerous, and some foods contain compounds that only increase the activity of Phase I without also turning up Phase II. Grapefruit increases the activity not only of the Phase I enzyme CYP1A1, but also that of NAD(P)H:quinone reductase 1, a Phase II detoxification enzyme that protects cells against oxidative stress and toxic quinones. The end result: grapefruit works in both Phase I and Phase II to enhance the liver's ability to remove cancer-causing toxins.DNA REPAIR
- Naringenin, a flavonoid concentrated in grapefruit, helps repair damaged DNA in human prostate cancer cells (cell line LNCaP), reports a lab study published in the Journal of Nutritional Biochemistry. The risk of prostate cancer, the most commonly diagnosed cancer in men in the U.S, increases with age since the older we become, the more times our cells have divided and the greater the chance for DNA mutations to occur. DNA repair is one of the body's primary defense mechanisms against the development of cancer since it removes potentially cancer-causing mutations in cells. Naringenin helps restore health to damaged DNA by inducing two enzymes that repair DNA during the replication stage. These enzymes, 8-oxoguanine-DNA glycosylase 1 (hOGG1), and DNA polymerase beta (DNA poly beta), are both involved in the DNA base excision repair (BER) pathway.