Sunday, November 23, 2008

Spinach


Spinach — All leafy greens provide folic acid (cuts heart attack risk), vitamins A & C (antioxidants), potassium (helps control blood pressure) and fiber (helps lower cholesterol).
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The 10 Best Foods for Your heart

The World's Healthiest Foods
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Spinach
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Calorie for calorie, leafy green vegetables like spinach with its delicate texture and jade green color provide more nutrients than any other food. Although spinach is available throughout the year, its season runs from March through May and from September through October when it is the freshest, has the best flavor and is most readily available.
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We all know that Popeye made himself super strong by eating spinach, but you may be surprised to learn that he may also have been protecting himself against osteoporosis, heart disease, colon cancer, arthritis, and other diseases at the same time.
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Phytonutrient Flavonoids for Optimal Health.
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Researchers have identified at least 13 different flavonoid compounds in spinach that function as antioxidants and as anti-cancer agents. (Many of these substances fall into a technical category of flavonoids known as methylenedioxyflavonol glucuronides.) The anticancer properties of these spinach flavonoids have been sufficiently impressive to prompt researchers to create specialized spinach extracts that could be used in controlled studies. These spinach extracts have been shown to slow down cell division in stomach cancer cells (gastric adenocarcinomas), and in studies on laboratory animals, to reduce skin cancers (skin papillomas). A study on adult women living in New England in the late 1980s also showed intake of spinach to be inversely related to incidence of breast cancer.
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Spinach Carotenoid Combats Prostate Cancer
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A carotenoid found in spinach and other green leafy vegetables fights human prostate cancer two different ways, according to research published in the the Journal of Nutrition. The carotenoid, called neoxanthin, not only induces prostate cancer cells to self-destruct, but is converted in the intestines into additional compounds, called neochromes, which put prostate cancer cells into a state of stasis, thus preventing their replication.
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Spinach Flavonoid Combats Ovarian Cancer
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Research calculating flavonoid intake in 66,940 women enrolled in the Nurses Health Study between 1984 and 2002 revealed that women whose diets provided the most kaempferol had a 40% reduction in risk of ovarian cancer, compared to women eating the least kaempferol-rich foods. In addition to spinach, foods richest in kaempferol include tea (nonherbal), onions, curly kale, leeks, broccoli, and blueberries.A significant 34% reduction in ovarian cancer risk was also seen in women with the highest intake of the flavone luteolin (found in citrus). Int J Cancer. 2007 Apr 30; Am J Clin Nutr. 2004 May;79(5):727-47.
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Helping You Bone Up
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The vitamin K provided by spinach-almost 200% of the Daily Value in one cup of fresh spinach leaves and over 1000% of the Daily Value in one cup of boiled spinach (which contains about 6 times as much spinach)-is important for maintaining bone health. Vitamin K1 helps prevent excessive activation of osteoclasts, the cells that break down bone. Additionally, friendly bacteria in our intestines convert vitamin K1 into vitamin K2, which activates osteocalcin, the major non-collagen protein in bone. Osteocalcin anchors calcium molecules inside of the bone. Spinach is also an excellent source of other bone-building nutrients including calcium and magnesium.
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Cardiovascular Protection from Spinach
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For atherosclerosis and diabetic heart disease, few foods compare to spinach in their number of helpful nutrients. Spinach is an excellent source of vitamin C and vitamin A, the latter notably through its concentration of beta-carotene. These two nutrients are important antioxidants that work to reduce the amounts of free radicals in the body; vitamin C works as a water-soluble antioxidant and beta-carotene as a fat-soluble one. This water-and-fat-soluble antioxidant team helps to prevent cholesterol from becoming oxidized. Oxidized cholesterol is able to stick to and build up in blood vessel walls, where it can cause blocked arteries, heart attack or stroke. Getting plenty of vitamin C and beta-carotene can help prevent these complications, and a cup of boiled spinach can provide you with 294.8% of the daily value (DV) for vitamin A along with 29.4% of the DV for vitamin C.
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Spinach is also an excellent source of folate. Folate is needed by the body to help convert a potentially dangerous chemical called homocysteine that can lead to heart attack or stroke if levels get too high, into other benign molecules. In addition, spinach is an excellent source of magnesium, a mineral that can help to lower high blood pressure and protect against heart disease as well. A cup of boiled spinach contains 65.6% of the daily value for folate and 39.1% of the daily value for magnesium.In addition to its hefty supply of cardioprotective vitamins and minerals, a study published in the Journal of Agriculture and Food Chemistry has revealed that spinach Rubisco contains four peptides (protein components) that inhibit angiotensin I-converting enzyme-the same enzyme blocked by ACE inhibitor drugs, which are used to lower blood pressure. When given to laboratory animals bred to be hypertensive, spinach produced a blood pressure lowering effect within two to four hours. How much spinach did the animals have to eat to get this beneficial effect? Just 20 to 30 mg of these powerful spinach peptides for each kilogram (2.2 pounds) of their body weight. In human terms, what this suggests is that an entrée-sized spinach salad for lunch or a serving of steamed spinach as part of the evening meal may have a salutary effect on blood pressure two to four hours later.
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Promotes Gastrointestinal Health
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The vitamin C and beta-carotene in spinach help to protect the colon cells from the damaging effects of free radicals. And the folate in spinach helps to prevent DNA damage and mutations in colon cells, even when they are exposed to cancer-causing chemicals. Studies show that people who eat foods high in vitamin C, beta-carotene, and/or folate are at a much lower risk of getting colon cancer than those who don't.
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Anti-Inflammatory Nutrients
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The nutrients in spinach can also help with conditions in which inflammation plays a role. For example, asthma, osteoarthritis, osteoporosis and rheumatoid arthritis are all conditions that involve inflammation. Since beta-carotene, vitamin C and vitamin K all have anti-inflammatory properties, they can be helpful for reducing symptoms in some patients. In addition, the magnesium and riboflavin in spinach, two nutrients of which it is an excellent source, may help to reduce the frequency of migraine attacks in people who suffer from them.
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A Smarter Brain with Spinach
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In animal studies, researchers have found that spinach may help protect the brain from oxidative stress and may reduce the effects of age-related related declines in brain function. Researchers found that feeding aging laboratory animals spinach-rich diets significantly improved both their learning capacity and motor skills.
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Vitamin E-rich Leafy Greens Slow Loss of Mental Function
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Mental performance normally declines with age, but the results of Chicago Health and Aging Project (CHAP) suggest that eating just 3 servings of green leafy, yellow and cruciferous vegetables each day could slow this decline by 40%, suggests a study in the journal Neurology (.Morris MC, Evans DA, et al.) Compared to people who consumed less than one serving of vegetables a day, people who ate at least 2.8 servings of vegetables a day saw their rate of cognitive decline slow by roughly 40%. This decrease is equivalent to about five years of younger age, said lead author Martha Clare Morris, ScD, with Rush University Medical Center in Chicago.The prospective cohort study, funded by the National Institute of Aging, used dietary data from 3,718 participants (62% female, 60% African American, average age 74). Mental function was assessed with four different tests: the East Boston Tests of immediate memory and delayed recall, the Mini-Mental State Examination, and the Symbol Digit Modalities Test, taken at the start of the study and then again after 3 and 6 years.After adjusting the results for potential confounders such as age, sex, race, education, and cardiovascular risk factors, the researchers found that consuming an average of 2.8 vegetable servings each day was associated with a 40% decrease in cognitive decline, compared to those who ate an average of less than one (0.9) serving a day. Of the different types of vegetables, green leafy vegetables had the strongest association, said Dr. Morris. Surprisingly, no relationship was found between fruit consumption and cognitive decline. Morris hypothesizes that this may be due to the fact that vegetables, but not fruits, contain high amounts of vitamin E, which helps lower the risk of cognitive decline. Also, vegetables, but not fruits, are typically consumed with a little fat, such as olive oil or salad dressing, which increases the body's ability to absorb vitamin E. The Rush University researchers plan further research to understand why fruit appears to have little effect and to explore the effects of citrus fruit, specifically, on cognitive decline. Bottomline: If you remember to enjoy at least 3 servings of leafy greens each day, you are much more likely to remember other things as well!
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Better Eyesight from Spinach
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Lutein, a carotenoid protective against eye diseases such as age-related macular degeneration and cataract, is found in green vegetables, especially spinach, as well as kale and broccoli. But egg yolks, although they contain significantly less lutein than spinach, are a much more bioavailable source whose consumption increases lutein concentrations in the blood many-fold higher than spinach,shows a human study published in the Journal of Nutrition.
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Although the mechanism by which egg yolk increases lutein bioavailability is not yet known, it is likely due to the fats (cholesterol and choline) found in egg yolk since lutein, like other carotenoids, is fat-soluble and cannot be absorbed unless fat is also present. To maximally boost your lutein absorption from spinach, we suggest enjoying this vegetable, whether steamed, sautéed or fresh in spinach salad, with a little olive oil and/or a topping of chopped hard-boiled egg to provide your body with some fats to help enhance the bioavailability of this fat-soluble phytonutrient. For a flavorful, quick and easy recipe featuring eggs and spinach, try our Poached Eggs over Spinach and Mushrooms.
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Iron for Energy
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Cooked spinach is an excellent source of iron, a mineral that it particularly important for menstruating women, who are more at risk for iron deficiency. Boosting iron stores with spinach is a good idea, especially because, in comparison to red meat, a well-known source of iron, spinach provides iron for a lot less calories and is totally fat-free. Iron is an integral component of hemoglobin, which transports oxygen from the lungs to all body cells, and is also part of key enzyme systems for energy production and metabolism. And, if you're pregnant or lactating, your needs for iron increase. Growing children and adolescents also have increased needs for iron. In one cup of boiled spinach, you'll be provided with 35.7% of the daily value for iron..
So while spinach probably won't make you super strong the minute you eat it, as it did for Popeye, it will promote your health and vitality in many other ways. It seems like Popeye was pretty smart after all.
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Spinach belongs to the same family (Amaranthaceae-Chenopodiaceae) as chard and beets. It shares a similar taste profile with these two other vegetables-it has the bitterness of beet greens and the slightly salty flavor of chard.
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Popeye popularized spinach, but it's too bad he ate it out of a can. Fresh spinach retains the delicacy of texture and jade green color that is lost when spinach is processed. Raw spinach has a mild, slightly sweet taste that can be refreshing in salads, while its flavor becomes more acidic and robust when it is cooked.
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There are three different types of spinach generally available. Savoy has crisp, creased curly leaves that have a springy texture. Smooth-leaf has flat, unwrinkled, spade-shaped leaves, while semi-savoy is similar in texture to savoy but is not as crinkled in appearance. Baby spinach is great for use in salads owing to its taste and delicate texture. Spinacia oleracea is the scientific name of this leafy vegetable.
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Spinach is thought to have originated in ancient Persia (Iran). Spinach made its way to China in the 7th century when the king of Nepal sent it as a gift to this country. Spinach has a much more recent history in Europe than many other vegetables. It was only brought to that continent in the 11th century, when the Moors introduced it into Spain. In fact, for a while, spinach was known as "the Spanish vegetable" in England.Spinach was the favorite vegetable of Catherine de Medici, a historical figure in the 16th century. When she left her home of Florence, Italy, to marry the king of France, she brought along her own cooks, who could prepare spinach the ways that she especially liked. Since this time, dishes prepared on a bed of spinach are referred to as "a la Florentine."Spinach grows well in temperate climates. Today, the United States and the Netherlands are among the largest commercial producers of spinach.
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Choose spinach that has vibrant deep green leaves and stems with no signs of yellowing. The leaves should look fresh and tender, and not be wilted or bruised. Avoid those that have a slimy coating as this is an indication of decay.
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Store fresh spinach loosely packed in a plastic bag in the refrigerator crisper where it will keep fresh for about five days. Do not wash it before storing as the moisture will cause it to spoil. Avoid storing cooked spinach as it will not keep very well.