Friday, September 12, 2008

The World's Healthiest Foods

Bananas

Wonderfully sweet with firm and creamy flesh, bananas come prepackaged in their own yellow jackets and are available for harvest throughout the year.

The banana plant grows 10 to 26 feet and belongs to the same family as the lily and the orchid. The cluster of fruits contain anywhere from 50 to 150 bananas with individual fruits grouped in bunches, known as "hands," containing 10 to 25 bananas.



This chart graphically details the %DV that a serving of Bananas provides for each of the nutrients of which it is a good, very good, or excellent source according to our Food Rating System. Additional information about the amount of these nutrients provided by Bananas can be found in the Food Rating System Chart. A link that takes you to the In-Depth Nutritional Profile for Bananas, featuring information over 80 nutrients, can be found under the Food Rating System Chart.

Health Benefits

Creamy, rich, and sweet, bananas are a favorite food for everyone from infants to elders. Sports enthusiasts appreciate the potassium-power delivered by this high energy fruit.

Cardiovascular Protection from Potassium and Fiber

Bananas are one of our best sources of potassium, an essential mineral for maintaining normal blood pressure and heart function. Since the average banana contains a whopping 467 mg of potassium and only 1 mg of sodium, a banana a day may help to prevent high blood pressure and protect against atherosclerosis.

The effectiveness of potassium-rich foods such as bananas in lowering blood pressure has been demonstrated by a number of studies. For example, researchers tracked over 40,000 American male health professionals over four years to determine the effects of diet on blood pressure. Men who ate diets higher in potassium-rich foods, as well as foods high in magnesium and cereal fiber, had a substantially reduced risk of stroke.

A study published in the Archives of Internal Medicine also confirms that eating high fiber foods, such as bananas, helps prevent heart disease. Almost 10,000 American adults participated in this study and were followed for 19 years. People eating the most fiber, 21 grams per day, had 12% less coronary heart disease (CHD) and 11% less cardiovascular disease (CVD) compared to those eating the least, 5 grams daily. Those eating the most water-soluble dietary fiber fared even better with a 15% reduction in risk of CHD and a 10% risk reduction in CVD.

In addition to these cardiovascular benefits, the potassium found in bananas may also help to promote bone health. Potassium may counteract the increased urinary calcium loss caused by the high-salt diets typical of most Americans, thus helping to prevent bones from thinning out at a fast rate.

Soothing Protection from Ulcers

Bananas have long been recognized for their antacid effects that protect against stomach ulcers and ulcer damage. In one study, a simple mixture of banana and milk significantly suppressed acid secretion. In an animal study, researchers found that fresh bananas protected the animals' stomachs from wounds.

Bananas work their protective magic in two ways: First, substances in bananas help activate the cells that compose the stomach lining, so they produce a thicker protective mucus barrier against stomach acids. Second, other compounds in bananas called protease inhibitors help eliminate bacteria in the stomach that have been pinpointed as a primary cause of stomach ulcers.

Improving Elimination

Bananas are a smart move if you suffer from elimination problems. A bout of diarrhea can quickly deplete your body of important electrolytes. Bananas can replenish your stores of potassium, one of the most important electrolytes, which helps regulate heart function as well as fluid balance.

In addition, bananas contain pectin, a soluble fiber (called a hydrocolloid) that can help normalize movement through the digestive tract and ease constipation. Bananas also contain resistant starch, but this amount varies depending on their degree of ripeness. In their lesser ripe stages, bananas score as low as 30 on the glycemic index (below 50 would be considered low). In their riper stages, this number usually rises to a moderate level in the 60's. All of the above features help place banana in a more favorable digestive light than might otherwise be expected for a sugary fruit.

Protect Your Eyesight

Your mother may have told you carrots would keep your eyes bright as a child, but as an adult, it looks like fruit is even more important for keeping your sight. Data reported in a study published in the Archives of Ophthalmology indicates that eating 3 or more servings of fruit per day may lower your risk of age-related macular degeneration (ARMD), the primary cause of vision loss in older adults, by 36%, compared to persons who consume less than 1.5 servings of fruit daily.

In this study, which involved over over 100,000 women and men, researchers evaluated the effect of study participants' consumption of fruits; vegetables; the antioxidant vitamins A, C, and E; and carotenoids on the development of early ARMD or neovascular ARMD, a more severe form of the illness associated with vision loss. Food intake information was collected periodically for up to 18 years for women and 12 years for men.

While, surprisingly, intakes of vegetables, antioxidant vitamins and carotenoids were not strongly related to incidence of either form of ARMD, fruit intake was definitely protective against the severe form of this vision-destroying disease.

Three servings of fruit may sound like a lot to eat each day, but by simply tossing a banana into your morning smoothie or slicing it over your cereal, topping off a cup of yogurt or green salad with a half cup of berries, and snacking on an apple, plum, nectarine or pear, you've reached this goal.

Build Better Bones with Bananas

Build better bones by eating bananas? Yes, enjoying bananas frequently as part of your healthy way of eating can help improve your body's ability to absorb calcium via several mechanisms.

Bananas are an exceptionally rich source of fructooligosaccharide, a compound called a prebiotic because it nourishes probiotic (friendly) bacteria in the colon. These beneficial bacteria produce vitamins and digestive enzymes that improve our ability to absorb nutrients, plus compounds that protect us against unfriendly microorganisms. When fructooligosaccharides are fermented by these friendly bacteria, not only do numbers of probiotic bacteria increase, but so does the body's ability to absorb calcium. In addition, gastrointestinal transit time is lessened, decreasing the risk of colon cancer.

Green bananas contain indigestible (to humans) short chain fatty acids (SCFAs) that are a favorite food of the cells that make up the lining of the intestines. When these cells are well-nourished and healthy, the body's ability to absorb nutrients such as calcium can increase dramatically.

Research published in Digestive Diseases and Sciences underscores just how much bananas can improve nutrient absorption. In this study, 57 male babies (5-12 months) with persistent diarrhea of at least 14 days duration were given a week's treatment with a rice-based diet containing either green banana, apple pectin or the rice diet alone. Treatment with both green banana and apple pectin resulted in a 50% reduction in stool weights, indicating that the babies were absorbing significantly more nutrients.

Also, to check how well their intestines were able to absorb nutrients, the babies were given a drink containing lactulose and mannitol. Lactulose is a compound that should be absorbed, while mannitol is one that should not be. When the intestines are too permeable, a condition clinicians call "leaky gut," too little lactulose and too much mannitol are absorbed. After just one week of being given the green banana-rice diet, the babies' were absorbing much more lactulose and little mannitol, showing that their intestines were now functioning properly.

Some banana cultivars are also rich in provitamin A carotenoids, which have been shown to protect against chronic disease, including certain cancers, cardiovascular disease, and diabetes. How to identify which bananas contain the most carotenoids? Check the color of their edible flesh. Bananas whose flesh is more golden contain the most carotenoids.

Promote Kidney Health through Regular and Moderated Intake

About 190,000 cases of kidney cancer are diagnosed each year. Risk factors include smoking, high blood pressure, obesity, and exposure to toxic chemicals such as asbestos and cadmium.

Dietary factors can be related to kidney disease in a preventive way. Research published in the International Journal of Cancer suggests that regular, moderated consumption of whole fruits and vegetables, especially bananas, can be protective. The results of this large population based prospective study (13.4 years) of 61,000 women aged 40-76, show that women eating more than 75 servings of fruits and vegetables per month (which translates into 2.5 per day) cut their risk of kidney cancer 40%. Among the fruits, bananas were especially protective. Women eating bananas four to six times a week halved their risk of developing the disease compared to those who did not eat this fruit.

Salads, eaten at least once a day, were associated with a 40% decreased risk. Among vegetables, frequent consumption of root vegetables and white cabbage offered the most protection, providing a 50-65% decrease in risk.

The conclusion drawn by the researchers: routine and moderated consumption of fruits and vegetables, especially bananas, cabbage and root vegetables, may reduce risk of kidney cancer. Why these foods? Bananas and many root vegetables contain especially high amounts of antioxidant phenolic compounds. Cabbage is rich in sulfur compounds necessary for efficient and effective detoxification of potential carcinogens. This mixture of phytonutrients may have been particularly helpful in protecting kidney function.

The benefits of regular and moderated fruit intake need to be contrasted, however, with the increased risks that stem from very high consumption of fruit juices. In several studies examining diet and renal (kidney) cancer, very high consumption of fruit juices is associated with increased cancer risk. Since most fruit juice consumption involves highly processed fruits and stands in sharp contrast to consumption of whole, natural foods, this finding is not surprising. The reasons for avoiding high intake of fruit juice are not limited to increased risk of kidney disease, but also to problems involved with excessive sugar intake and excessive calorie intake from non-whole foods. Moderate amounts of fruit juice - especially juice containing as much of the whole fruit as possible, for example, pulp or skin - are still recommended, since these limited amounts in a balanced diet appear to be protective against kidney cancer.

Description

Bananas are elliptically shaped fruits "prepackaged" by Nature, featuring a firm, creamy flesh gift-wrapped inside a thick inedible peel. The banana plant grows 10 to 26 feet in height and belongs to the family Musaceae. Banana fruits grow in clusters of 50 to 150, with individual fruits grouped in bunches, known as "hands," of 10 to 25 bananas.

Bananas abound in hundreds of edible varieties that fall under two distinct species: the sweet banana (Musa sapienta, Musa nana) and the plantain banana (Musa paradisiacal). Sweet bananas vary in size and color.

While we are accustomed to thinking of sweet bananas as having yellow skins, they can also feature red, pink, purple and black tones when ripe. Their flavor and texture range with some varieties being sweet while others have starchier characteristics. In the United States, the most familiar varieties are Big Michael, Martinique and Cavendish. Plantain bananas are usually cooked and considered more like a vegetable due to their starchier qualities; they have a higher beta-carotene concentration than most sweet bananas.

History

Bananas are thought to have originated in Malaysia around 4,000 years ago. From there, they spread throughout the Philippines and India, where in 327 B.C. Alexander the Great's army recorded them being grown.

Bananas were introduced to Africa by Arabian traders and discovered there in 1482 A.D. by Portuguese explorers who took them to the Americas, the place where the majority of bananas are now produced.

Bananas were not brought to the United States for sale in markets until the latter part of the 19th century and were initially only enjoyed by people in the seacoast towns where the banana schooners docked; because of the fruit's fragility, they were unable to be transported far.

Since the development of refrigeration and rapid transport in the 20th century, bananas have become widely available. Today, bananas grow in most tropical and subtropical regions with the main commercial producers including Costa Rica, Mexico, Ecuador and Brazil.

How to Select and Store

Since bananas are picked off the tree while they're still green, it's not unusual to see them this color in the store. Base your choice of bananas depending upon when you want to consume them. Bananas with more green coloration will take longer to ripen than those more yellow in hue and/or with brown spots.

Bananas should be firm, but not too hard, bright in appearance, and free from bruises or other injuries. Their stems and tips should be intact. The size of the banana does not affect its quality, so simply choose the size that best meets your needs.

While bananas look resilient, they're actually very fragile and care should be taken in their storage. They should be left to ripen at room temperature and should not be subjected to overly hot or cold temperatures. Unripe bananas should not be placed in the refrigerator as this will interrupt the ripening process to such an extent that it will not be able to resume even if the bananas are returned to room temperature.

If you need to hasten the ripening process, you can place bananas in a paper bag or wrap them in newspaper, adding an apple to accelerate the process. Ripe bananas that will not be consumed for a few days can be placed in the refrigerator. While their peel may darken, the flesh will not be affected. For maximum flavor when consuming refrigerated bananas, remove them from the refrigerator and allow them to come back to room temperature.

For the most antioxidants, eat fully ripened fruit:

Research conducted at the University of Innsbruck in Austria suggests that as fruits fully ripen, almost to the point of spoilage, their antioxidant levels actually increase.

Key to the process is the change in color that occurs as fruits ripen, a similar process to that seen in the fall when leaves turn from green to red to yellow to brown— a color change caused by the breakdown and disappearance of chlorophyll, which gives leaves and fruits their green color.

Until now, no one really knew what happened to chlorophyll during this process, but lead researcher, Bernard Kräutler, and his team, working together with botanists over the past several years, has identified the first decomposition products in leaves: colorless, polar NCCs (nonfluorescing chlorophyll catabolytes), that contain four pyrrole rings - like chlorophyll and heme.

After examining apples and pears, the scientists discovered that NCCs replace the chlorophyll not only in the leaves of fruit trees, but in their very ripe fruits, especially in the peel and flesh immediately below it.

"When chlorophyll is released from its protein complexes in the decomposition process, it has a phototoxic effect: when irradiated with light, it absorbs energy and can transfer it to other substances. For example, it can transform oxygen into a highly reactive, destructive form," report the researchers. However, NCCs have just the opposite effect. Extremely powerful antioxidants, they play an important protective role for the plant, and when consumed as part of the human diet, NCCs deliver the same potent antioxidant protection within our bodies. Angew Chem Int Ed Engl. 2007 Nov 19;46(45):8699-8702.

Bananas can also be frozen and will keep for about 2 months. Either purée them before freezing or simply remove the peel and wrap the bananas in plastic wrap. To prevent discoloration, add some lemon juice before freezing.

How to Enjoy

In addition to being eaten raw, bananas are a wonderful addition to a variety of recipes from salads to baked goods.

A few quick serving ideas:

A peanut butter and banana sandwich drizzled with honey is an all-time favorite comfort food for children and adults alike.

Add chopped bananas, walnuts and maple syrup to oatmeal or porridge.

Try our Tropical Breakfast Risotto in the Recipe File

Safety

Bananas and Latex Allergy

Like avocados and chestnuts, bananas and plantain contain substances called chitinases that are associated with the latex-fruit allergy syndrome. There is strong evidence of the cross-reaction between latex and these foods. If you have a latex allergy, you may very likely be allergic to these foods as well. Processing the fruit with ethylene gas increases these enzymes; organic produce not treated with gas will have fewer allergy-causing compounds. In addition, cooking the food may deactivate the enzymes.

Nutritional Profile

Bananas are a very good source of vitamin B6 and a good source of vitamin C, potassium, dietary fiber, and manganese.

For an in-depth nutritional profile click here: Banana.

In-Depth Nutritional Profile

In addition to the nutrients highlighted in our ratings chart, an in-depth nutritional profile for Bananas is also available. This profile includes information on a full array of nutrients, including carbohydrates, sugar, soluble and insoluble fiber, sodium, vitamins, minerals, fatty acids, amino acids and more.

Introduction to Food Rating System Chart

In order to better help you identify foods that feature a high concentration of nutrients for the calories they contain, we created a Food Rating System. This system allows us to highlight the foods that are especially rich in particular nutrients. The following chart shows the nutrients for which this food is either an excellent, very good, or good source (below the chart you will find a table that explains these qualifications). If a nutrient is not listed in the chart, it does not necessarily mean that the food doesn't contain it. It simply means that the nutrient is not provided in a sufficient amount or concentration to meet our rating criteria. (To view this food's in-depth nutritional profile that includes values for dozens of nutrients - not just the ones rated as excellent, very good, or good - please use the link below the chart.) To read this chart accurately, you'll need to glance up in the top left corner where you will find the name of the food and the serving size we used to calculate the food's nutrient composition. This serving size will tell you how much of the food you need to eat to obtain the amount of nutrients found in the chart. Now, returning to the chart itself, you can look next to the nutrient name in order to find the nutrient amount it offers, the percent Daily Value (DV%) that this amount represents, the nutrient density that we calculated for this food and nutrient, and the rating we established in our rating system. For most of our nutrient ratings, we adopted the government standards for food labeling that are found in the U.S. Food and Drug Administration's "Reference Values for Nutrition Labeling." Read more background information and details of our rating system.

Banana
1.00 each
118.00 grams
108.56 calories

Nutrient

Amount

DV
(%)

Nutrient
Density

World's Healthiest
Foods Rating

vitamin B6 (pyridoxine)

0.68 mg

34.0

5.6

very good

vitamin C

10.74 mg

17.9

3.0

good

potassium

467.28 mg

13.4

2.2

good

dietary fiber

2.83 g

11.3

1.9

good

manganese

0.18 mg

9.0

1.5

good

World's Healthiest
Foods Rating

Rule

excellent

DV>=75%

OR

Density>=7.6

AND

DV>=10%

very good

DV>=50%

OR

Density>=3.4

AND

DV>=5%

good

DV>=25%

OR

Density>=1.5

AND

DV>=2.5%

In-Depth Nutritional Profile for Bananas

Thursday, September 4, 2008

The World's Healthiest foods

Carrots


Easy to pack and perfect as crudités for that favorite dip, the crunchy texture and sweet taste of carrots is popular among both adults and children. Although they are shipped around the country from California throughout the year, locally grown carrots are in season in the summer and fall when they are the freshest and most flavorful.

The carrot has a thick, fleshy, deeply colored root, which grows underground, and feathery green leaves that emerge above ground. It is known scientifically as Daucus carota, a name that can be traced back to ancient Roman writings of the 3rd century. Carrots belong to the Umbelliferae family along with parsnips, fennel caraway, cumin and dill which all have the umbrella-like flower clusters that characterize this family of plants.



Food Chart
This chart graphically details the %DV that a serving of Carrots provides for each of the nutrients of which it is a good, very good, or excellent source according to our Food Rating System. Additional information about the amount of these nutrients provided by Carrots can be found in the Food Rating System Chart. A link that takes you to the In-Depth Nutritional Profile for Carrots, featuring information over 80 nutrients, can be found under the Food Rating System Chart.

Health Benefits

Carrots are an excellent source of antioxidant compounds, and the richest vegetable source of the pro-vitamin A carotenes. Carrots' antioxidant compounds help protect against cardiovascular disease and cancer and also promote good vision, especially night vision.

Carotenoids and Heart Disease

When six epidemiological studies that looked at the association of diets high in carotenoids and heart disease were reviewed, the research demonstrated that high-carotenoid diets are associated with a reduced risk of heart disease. In one study that examined the diets of 1,300 elderly persons in Massachusetts, those who had at least one serving of carrots and/or squash each day had a 60% reduction in their risk of heart attacks compared to those who ate less than one serving of these carotenoid-rich foods per day.

Better Vision

Beta-carotene helps to protect vision, especially night vision. After beta-carotene is converted to vitamin A in the liver, it travels to the retina where it is transformed into rhodopsin, a purple pigment that is necessary for night-vision. Plus beta-carotene's powerful antioxidant actions help provide protection against macular degeneration and the development of senile cataracts, the leading cause of blindness in the elderly.

Carotenoids and Optimal Health

Carrots are by far one of the richest source of carotenoids-just one cup provides 16,679 IUs of beta-carotene and 3,432 REs (retinol equivalents), or roughly 686.3% the RDA for vitamin A. High carotenoid intake has been linked with a 20% decrease in postmenopausal breast cancer and an up to 50% decrease in the incidence of cancers of the bladder, cervix, prostate, colon, larynx, and esophagus. Extensive human studies suggest that a diet including as little as one carrot per day could conceivably cut the rate of lung cancer in half. Remember the study in which heavy long-term cigarette smokers were given synthetic beta-carotene, and it did not appear to prevent them from developing lung cancer? Well, not only is synthetic beta-carotene not biochemically identical to the real stuff found in carrots, but scientists now think that carrots' protective effects are the result of a team effort among several substances abundant in carrots, including alpha-carotene-another, less publicized carotenoid. A recent National Cancer Institute study found lung cancer occurence was higher in men whose diets did not supply a healthy intake of alpha-carotene.

Carotenoids and Blood Sugar

Intake of foods such as carrots that are rich in carotenoids may be beneficial to blood sugar regulation. Research has suggested that physiological levels, as well as dietary intake, of carotenoids may be inversely associated with insulin resistance and high blood sugar levels.

Falcarinol in Carrots Promote Colon Health

Although best known for their high content of beta carotene, carrots also contain a phytonutrient called falcarinol that may be responsible for the recognized epidemiological association between frequently eating carrots and a reduced risk of cancers.

Falcarinol provides protection against colon cancer, suggests a study published in the Journal of Agricultural and Food Chemistry. Three groups of laboratory animals in whom precancerous colon lesions (aberrant crypt foci) had been chemically-induced were fed a standard diet, one supplemented with freeze-dried carrots naturally containing falcarinol, or one supplemented with an extract of falcarinol. After 18 weeks, precancerous lesions in the animals given diets containing carrots or falcarinol were much smaller than those in the control animals, and far fewer of the lesions had grown in size or progressed to become tumors.

Promote Lung Health

If you or someone you love is a smoker, or if you are frequently exposed to secondhand smoke, then making vitamin A-rich foods, such as carrots, part of your healthy way of eating may save your life, suggests research conducted at Kansas State University.

While studying the relationship between vitamin A, lung inflammation, and emphysema, Richard Baybutt, associate professor of nutrition at Kansas State, made a surprising discovery: a common carcinogen in cigarette smoke, benzo(a)pyrene, induces vitamin A deficiency.

Baybutt's earlier research had shown that laboratory animals fed a vitamin A-deficient diet developed emphysema. His latest animal studies indicate that not only does the benzo(a)pyrene in cigarette smoke cause vitamin A deficiency, but that a diet rich in vitamin A can help counter this effect, thus greatly reducing emphysema.

Baybutt believes vitamin A's protective effects may help explain why some smokers do not develop emphysema. "There are a lot of people who live to be 90 years old and are smokers," he said. "Why? Probably because of their diet…The implications are that those who start smoking at an early age are more likely to become vitamin A deficient and develop complications associated with cancer and emphysema. And if they have a poor diet, forget it." If you or someone you love smokes, or if your work necessitates exposure to second hand smoke, protect yourself by making sure the World's Healthiest Foods rich in vitamin A (carrot's beta-carotene is converted in the body into vitamin A) are a daily part of your healthy way of eating.

Description

Carrots? The favorite food of Bugs Bunny hardly needs a description for they are well known and loved by even the youngest children in many countries. Carrots benefits are legendary. Bet your mother told you that eating carrots would keep your eyesight bright.

While we usually associate carrots with the color orange, in fact, carrots grow in a host of other colors including white, yellow, red, or purple, the latter being the color of the original variety. The carrot is a plant with a thick, fleshy, deeply colored root, which grows underground, and feathery green leaves that emerge above ground. It is known scientifically as Daucus carota, a name that can be traced back to ancient Roman writings of the 3rd century.

Carrots belong to the Umbelliferae family, named after the umbrella like flower clusters that plants in this family produce. As such, carrots are related to parsnips, fennel caraway, cumin and dill. There are over 100 different varieties that vary in size and color. Carrots can be as small as two inches or as long as three feet, ranging in diameter from one-half of an inch to over two inches. Carrot roots have a crunchy texture and a sweet and minty aromatic taste, while the greens are fresh tasting and slightly bitter.

History

The carrot can trace its ancestry back thousands of years, originally having been cultivated in central Asian and Middle Eastern countries. These original carrots looked different from those that we are accustomed to today, featuring deep purple coloring, ranging from lavender to deep eggplant. This coloration was a reflection of the anthocyanin phytonutrient pigments these carrots had. In pre-Hellenic times, a yellow-rooted carrot variety appeared in Afghanistan and was further cultivated and developed into an earlier version of the carrot we known today. Both types of carrots spread throughout the Mediterranean region and were adopted by the ancient Greeks and Romans for their medicinal use.

It seems that carrots did not become a popular vegetable in Europe until the Renaissance. This was probably related to the fact that the early varieties had a tough and fibrous texture. Centuries later, beginning in the 17th century, agriculturists in Europe started cultivating different varieties of carrots, developing an orange-colored carrot that had a more pleasing texture than its predecessor. Europeans favored the growing of this one over the purple variety, which was and still is widely grown in other areas of the world, including southern Asia and North Africa. Carrots were subsequently introduced into the North American colonies. Owing to its heightened popularity, in the early 1800s, the carrot became the first vegetable to be canned. Today, the United States, France, England, Poland, China and Japan are among the largest producers of carrots.

How to Select and Store

Carrot roots should be firm, smooth, relatively straight and bright in color. The deeper the orange-color, the more beta-carotene is present in the carrot. Avoid carrots that are excessively cracked or forked as well as those that are limp or rubbery. In addition, if the carrots do not have their tops attached, look at the stem end and ensure that it is not darkly colored as this is also a sign of age. If the green tops are attached, they should be brightly colored, feathery and not wilted. Since the sugars are concentrated in the carrots' core, generally those with larger diameters will have a larger core and therefore be sweeter.

Carrots are hardy vegetables that will keep longer than many others if stored properly. The trick to preserving the freshness of carrot roots is to minimize the amount of moisture they lose. To do this, make sure to store them in the coolest part of the refrigerator in a plastic bag or wrapped in a paper towel, which will reduce the amount of condensation that is able to form. They should be able to keep fresh for about two weeks. Carrots should also be stored away from apples, pears, potatoes and other fruits and vegetables that produce ethylene gas since it will cause them to become bitter.

If you purchase carrot roots with attached green tops, the tops should be cut off before storing in the refrigerator since they will cause the carrots to wilt prematurely as they pull moisture from the roots. While the tops can be stored in the refrigerator, kept moist by being wrapped in a damp paper, they should really be used soon after purchase since they are fragile and will quickly begin to wilt.

How to Enjoy

For some of our favorite recipes, click Recipes.

Tips for Preparing Carrots:

Wash carrot roots and gently scrub them with a vegetable brush right before eating. Unless the carrots are old, thick or not grown organically, it is not necessary to peel them. If they are not organically grown, peel them; most all conventionally grown carrots are grown using pesticides and other chemicals. If the stem end is green, it should be cut away as it will be bitter. Depending upon the recipe or your personal preference, carrots can be left whole or julienned, grated, shredded or sliced into sticks or rounds.

Carrots are delicious eaten raw or cooked. Beta-carotene is not destroyed by cooking; in fact, cooking breaks down the fiber, making this nutrient and carrots' sugars more available, thus also making them taste sweeter. Take care not to overcook carrots, however, to ensure that they retain their maximum flavor and nutritional content.

A f\Few Quick Serving Ideas:

Shredded raw carrots and chopped carrot greens make great additions to salads.

Combine shredded carrots, beets and apples, and eat as a salad.

For quick, nutritious soup that can be served hot or cold, purée boiled carrots and potatoes in a blender or food processor, and add herbs and spices to taste.

Spiced carrot sticks are a flavorful variation on an old favorite at parties or at the dinner table. Soak carrot sticks in hot water spiced with cayenne, coriander seeds and salt. Allow to cool, drain and serve.

Combine freshly squeezed carrot juice with soymilk and bananas to make a nutrient-dense breakfast shake.

Safety

Carrots and Carotoderma

Excessive consumption of carotene-rich foods may lead to a condition called carotoderma in which the palms or other skin develops a yellow or orange cast. This yellowing of the skin is presumably related to carotenemia, excessive levels of carotene in the blood. The health impact of carotenemia is not well researched. Eating or juicing high amounts of foods rich in carotene, like carrots, may over tax the body's ability to convert these foods to vitamin A. The body slowly converts carotene to vitamin A, and extra carotene is stored, usually in the palms, soles or behind the ears. If the cause of the carotenemia is eating excessively high amounts of foods like carrots, the condition will usually disappear after reducing consumption.

Nutritional Profile

Carrots are an excellent source of vitamin A. In addition, they are a very good source of vitamin C, vitamin K, dietary fiber and potassium.

For an in-depth nutritional profile click here: Carrots.

In-Depth Nutritional Profile

In addition to the nutrients highlighted in our ratings chart, an in-depth nutritional profile for Carrots is also available. This profile includes information on a full array of nutrients, including carbohydrates, sugar, soluble and insoluble fiber, sodium, vitamins, minerals, fatty acids, amino acids and more.

Introduction to Food Rating System Chart

The following chart shows the nutrients for which this food is either an excellent, very good or good source. Next to the nutrient name you will find the following information: the amount of the nutrient that is included in the noted serving of this food; the %Daily Value (DV) that that amount represents; the nutrient density rating; and the food's World's Healthiest Foods Rating. Underneath the chart is a table that summarizes how the ratings were devised. Read detailed information on our Food and Recipe Rating System.

Carrots, raw
1.00 cup
122.00 grams
52.46 calories

Nutrient

Amount

DV
(%)

Nutrient
Density

World's Healthiest
Foods Rating

vitamin A

34317.40 IU

686.3

235.5

excellent

vitamin K

16.10 mcg

20.1

6.9

very good

vitamin C

11.35 mg

18.9

6.5

very good

dietary fiber

3.66 g

14.6

5.0

very good

potassium

394.06 mg

11.3

3.9

very good

vitamin B6 (pyridoxine)

0.18 mg

9.0

3.1

good

manganese

0.17 mg

8.5

2.9

good

molybdenum

6.10 mcg

8.1

2.8

good

vitamin B1 (thiamin)

0.12 mg

8.0

2.7

good

vitamin B3 (niacin)

1.13 mg

5.6

1.9

good

phosphorus

53.68 mg

5.4

1.8

good

magnesium

18.30 mg

4.6

1.6

good

folate

17.08 mcg

4.3

1.5

good

World's Healthiest
Foods Rating

Rule

excellent

DV>=75%

OR

Density>=7.6

AND

DV>=10%

very good

DV>=50%

OR

Density>=3.4

AND

DV>=5%

good

DV>=25%

OR

Density>=1.5

AND

DV>=2.5%

Wednesday, July 2, 2008

Computer Power Management

Low power consumption is an important goal in designing modern electronic systems. Most previous studies of low-power techniques focused on either hardware or software to reduce power consumption. “Power Management” is an effective approach to reduce power consumption by various electronic systems without any significant degrading of their performances.

What is “Power Management”?

Power management is a process that allows computers and monitors to enter low-power states when sitting idle. The low power modes of inactive computers can involve reducing central processing unit power consumption or spinning down the hard disk. Inactive monitors with enabled power management enter low-power modes by turning off monitor output.

Power management does not reduce the performance of computers and monitors. It simply adds features to reduce their power consumption at the time when they are not in use. Most power management savings come from reducing power when the machine is not fully active by adding low-power or “sleep” modes that kick in when idle. “Sleep” modes usually involve slowing the clock rate of the central processing unit, and may include spinning down the hard disk, turning off entire system components such as video cards, sound cards or disk controllers.

Why Power Management is essential?

Worldwide, computers and monitors in commercial and industrial settings use millions of kilowatts of electricity each day. Two simple steps can save more than half of this energy.

· Enable power management functions that place computers and monitors in low-power mode during periods of inactivity.

· Turning off computers and monitors after work.

When using energy efficient machines, they save money on electricity as well as reduce pollution from power plants. In addition to the environmental benefits of reducing energy consumption, power management can improve equipment reliability by reducing waste heat.

History of the Power Management

In the early days of personal computing, under operating systems like DOS and CP/M (Control Program / Monitor or Control Program for Microcomputers) operating systems, there was no such an operation called power management. Those computers either used 100% of their power requirements or were switched off. Personal computer power management history dates back at least to 1989, when Intel produced processors with technology to allow the central processing unit (CPU) to slow down, suspend, or shut down part or all of the system platform, or even the CPU itself, to preserve and extend battery life. The increasing importance of power management reflects the increasing number of PCs in use and their transition to tools that go wherever people go.

PC power management was first introduced in laptop computers to allow longer operating times while running on battery power. Later it was brought into the desktop PC market. Many early power management systems had long recovery times, awkward configuration methods and low energy savings. However, power management has improved rapidly, becoming more powerful, reliable and easier to use. It also now delivers considerably more energy savings. In 1993 Intel and Microsoft introduced Advanced Power Management (APM) which becoming an industry standard. The APM protocol supports power management by defining how power management commands are communicated within the PC system.

How does Power Management work?

As the following figure shows, computers are logically organized as a hierarchy of layers. Those at the top are the software that the user directly interacts with. Those closer to the bottom direct the physical control of electrical signals. Power management can involve the application software and the operating system (sometimes these are not involved), and always requires action by the firmware (BIOS), processor and peripheral hardware.

The BIOS (Basic Input/Output System) is a combination of hardware and firmware (software in read-only memory), distinct from the operating system, that intermediates between the processor and other parts of the system. In the first generation of power management (machines built through 1993 or 1994), it was controlled only by the BIOS. As of 1996, the BIOS is still a key component, but more of the configuration and control is rising into the operating system and occasionally into application software. However, control signals must still pass through each intermediate layer for action to occur.




Figure 1: PC Power Management key components and communication paths

In the above figure, the numbers indicate the various steps in initiating power management. It shows the communication paths which allow power management to occur.

Number 2 The BIOS send periodic signals (about once per second) to the operating system to begin power management

Number 3 If this signal is passed through by the operating system, it will trigger the start of the power management timers in the BIOS. The operating system will only pass the signal through if it detects no activity from the application software

Number 4 If there is no activity, the operating passes the signal back to the BIOS, which begins a timer

Number 1 The BIOS continues to monitor keyboard and mouse activity

Number 5 After a specified time with no activity, the BIOS will initiate power management by sending appropriate messages to some or all of the hard disk, peripheral cards, processor, and video card

After initiating a change in mode, the BIOS begins another timer which indicates when to initiate the next power management mode. If at any time the BIOS receives an interrupt request (keyboard, mouse, or network activity), the BIOS will signal the required peripheral cards, processor, and video card to return to an active mode (usually only a demand for hard disk activity will cause the hard disk to spin up). Examples of peripheral cards include network interfaces and CD-ROM drives.

Power management has four major components for the following activities.

1. To monitor activity levels of the processor, input devices (such as the keyboard and mouse), and communication peripherals (network or modem).

2. To utilize timers to decide when to initiate the shift to a lower power mode.

3. To changes the power management status need to be communicated to the correct device and actually occur.

4. To recognize when activity resumes and return to a higher power (or full-power) mode.

PC Power Management modes

Before the release of Windows 95, Microsoft operating system software was only minimally involved in desktop PC power management (and application software was only used for monitor power management, not for controlling the PC itself). Thus the BIOS was, and remains, a critical component. Three companies dominate the production of BIOS systems used in x86-based PCs. This means that computers from different manufacturers may use the same power management. The following activities applies to Advanced Power Management (APM), and not necessarily to early (1993 and earlier) implementations of power management. To enter APM modes, they must be enabled, and the specified amount of time must pass without activity. Note that hibernate is not an APM mode.

Full-on Mode:

· All components fully powered; no power management occurring.

APM Enable Mode:

· CPU is slowed or stopped (depending on BIOS); all other devices still draw full power.

· Some systems have a ‘doze’ mode that is similar to APM Enabled.

PC Savings: 0-25% Recovery time: instantaneous

APM Standby Mode:

· CPU may be stopped depending on operation or activity; most devices are in low power mode.

· Monitor enters its first power management mode.

· Activity can trigger a return to enabled or full-on, depending on the system and activity.

PC Savings: 20-30%

Monitor Savings: 60-90%

APM Suspend Mode:

· CPU is stopped; most power-managed devices are not powered (network card may stay on).

· Maximum power savings under APM.

· Activity can trigger a return to standby, doze or full-on, depending on the BIOS

PC Savings: 25-45%

Monitor Savings: 0-10% Recovery time: 3 to 10 seconds

Hard Disk Power Down : (this is not an APM mode)

· Hard disk spin in stopped; this is independent of other power management (hence not a system mode), so that the remainder of the system can be fully operational or power down.

· Disk control electronics are still powered to facilitate quick reactivation

PC Savings: 10%

Recovery time: 3–10 seconds (disk savings independent of other savings)

Hibernate: (this is not an APM mode)

· All memory contents and system state saved to disk.

· System resistant to power loss

PC Savings: 90-100% Recovery Time: 15-60 seconds

Workstation Savings: 95% Recovery Time: <60>

Off Mode

· No operational parameters are saved

· System resets and starts at full-on mode

· Most systems use no power (a few draw a small amount).

PC Power Management with Networks

Maintaining network connections during power management was a problem for many earlier systems. Some new systems continue to have problems with this, but many have been tested to work properly under common networking systems. Currently, most power management problems with networked PCs are a result of the way the network operating system works rather than with the PC hardware.

Monitor Power Management

Even though the PC must be the initiator, power management has been more successful in monitors than in PCs. Compared to power managing PCs, monitors are usually simpler, have much more energy savings potential, power manage more reliably, and are less likely to interfere with operation or network connections. Because of this, it is even more important to enable monitors for power management than it is to enable PCs.

Monitor power management is in most cases independent of PC power management in that the monitor can power down even if the PC doesn’t, and vice-versa. However, the monitor is still dependent on the PC for power management initiation. This is necessary since the monitor does not directly receive the activity information needed to know when to begin and end power management. Once the first low-power mode is entered, however, the monitor has an internal timer and will shift to succeeding low-power modes even if the PC doesn’t send additional signals. While delay times may differ, for the most part, the monitor and PC are driven by the same activity for beginning and ending low-power modes (though network activity is an exception to this).

The structure of monitor power management control is shown in Figure 1. The PC always initiates the process, with the initial timers within the BIOS, or special software that comes with the video card. Successive power management modes can be activated by either the PC's timer or the monitor's internal timer.

Some PCs have a “convenience” electrical outlet on the back for plugging in the monitor. PCs that can switch off the power to this outlet allow energy savings from monitors that can't power manage on their own. In addition, if the monitor is plugged into the PC (whether the outlet is power-managed or not), then the monitor will be switched off when the PC is switched off (otherwise they often remain on, albeit with a blank screen).

Potential Barriers to Power Management

Even though a computer or monitor may have power management features, power management may not always operate effectively. There are many reasons why power management can be defeated in systems that have the feature.

Software Interactions

Some application software can interfere with power management, depending on how it is configured and the particular machine it is used on. One example is the ‘auto-save’ feature on many word processors and spreadsheets. If the feature saves the document even if no changes have been made, this will unnecessarily cause the processor and hard disk to stay awake, defeating power management partially or entirely.

Some screensavers will periodically load complex images from the hard disk, keeping the disk from powering down. A screensaver can keep the monitor and processor from power managing, unless set to a specific power management mode; many screensavers lack a power management mode and so need to be turned off for power management to occur.

Upgrades

Power management capabilities may change when PCs are upgraded by replacing the processor, the motherboard, or add-on cards (e.g. the network interface). Software upgrades of operating systems or utility software can cause power management to be disabled. Before upgrading many similar machines, determine if the proposed change interferes with power management. If it does, consider looking for alternatives that do not.

Networks

Computer networks pose special challenges for power management. Once a PC is connected to a network, the user may want to access the machine remotely, others may rely on being able to connect to it at any time, and services such as disk backups may operate during nights or weekends. This can mean that the simplest power management strategy, simply turning the machine off, can no longer be used for the PC (though the monitor can and should be turned off). Remote access by modem has the same effect as does a computer set up to receive faxes.

Future Directions of the Power Management

Power Management in Monitors

There are several important emerging monitor technologies that offer some relief in the historical increase in power. Most of today's monitors are Cathode Ray Tubes (CRTs). The two technologies that show promise in gaining significant market share in the near future are Liquid Crystal Display technologies, and thin CRTs.

Flat-panel displays used with today's laptop computers use far less power than CRTs, but currently their high cost limits their use with desktop PCs. This is changing as manufacturers seek to bring costs down and build larger displays.

Power Management in PCs

Not only power management for PCs for periods when they are not fully active, there are also opportunities to reduce active power. Active power can be lowered with techniques such as reducing the chip count through more integration of functions, lowering the power supply voltage, using a more efficient power supply, or switching to smaller (less energy-intensive) expansion cards.