sábado, 1 de novembro de 2014

Beets

    

It is difficult to believe how the hardy, crunchy often rough looking exterior of raw beets can be transformed into something wonderfully soft and buttery once they are cooked. While beets are available throughout the year, their season runs from June through October when the youngest, most tender beets are easiest to find.
Edible green leaves are attached to the tapered round or oblong root portions that we know as beets. While we often think of beets having a reddish-purple hue, some varieties are white, golden-yellow or even rainbow colored. The sweet taste of beets reflects their high sugar content making them an important raw material for the production of refined sugar; they have the highest sugar content of all vegetables, yet are very low in calories

This chart graphically details the %DV that a serving of Beets 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 Beets can be found in the Food Rating System Chart. A link that takes you to the In-Depth Nutritional Profile for Beets, featuring information over 80 nutrients, can be found under the Food Rating System Chart.
Health Benefits
Remember all those legendary Russian centenarians? Beets, frequently consumed either pickled or in borscht, the traditional Russian soup, may be one reason behind their long and healthy lives. These colorful root vegetables contain powerful nutrient compounds that help protect against heart disease, birth defects and certain cancers, especially colon cancer.
Promote Optimal Health
The pigment that gives beets their rich, purple-crimson color-betacyanin-is also a powerful cancer-fighting agent. Beets' potential effectiveness against colon cancer, in particular, has been demonstrated in several studies.
In one study, animals under the double stress of chemically induced colon cancer and high cholesterol were divided into two groups. One group received a diet high in beet fiber while the other group served as a control. The beet fiber-fed animals rose to the challenge by increasing their activity of two antioxidant enzymes in the liver, glutathione peroxidase and glutathione-S-transferase. The liver is the body's primary detoxification organ where toxic substances are broken down and eliminated, a process that generates a lot of free radicals. Glutathione peroxidase and glutathione-S-transferase are the bodyguards for liver cells, protecting them from free radical attack, so they can continue to protect us.
In other animal studies, scientists have noted that animals fed beet fiber had an increase in their number of colonic CD8 cells, special immune cells responsible for detecting and eliminating abnormal cells. With the increased surveillance provided by these additional CD8 cells, the animals in one of the studies given beet fiber had fewer pre-cancerous changes.
In stomach cancer patients, when scientists compared the effects of fruit and vegetable juices on the formation of nitrosamines, cancer-causing compounds produced in the stomach from chemicals called nitrates, beet juice was found to be a potent inhibitor of the cell mutations caused by these compounds. Nitrates are commonly used as a chemical preservative in processed meats.
Protection Against Heart Disease
In the first study mentioned above, not only did protective antioxidant activity increase in the livers of beet fiber-fed animals, but also their total cholesterol dropped 30%, their triglycerides dropped 40% (elevated triglycerides, the form in which fats are transported in the blood, are a significant risk factor for cardiovascular disease), and their HDL (beneficial cholesterol) level increased significantly.
Beat High Blood Pressure with Beet Juice
Drinking just 2 glasses (16.9 ounces) of beetroot juice a day can significantly reduce blood pressure, shows a study in the American Heart Association journal Hypertension, which could have major implications for the treatment of cardiovascular disease. (Web AJ, Patel N, et al.)
Previously, the protective effects of vegetable-rich diets have been thought to be due to their content of antioxidant vitamins, but this study reveals that it is the dietary nitrate in beetroot juice - and in all green, leafy vegetables - whose consumption results in a decrease in blood pressure.
The nitrate in beet juice is converted by bacteria on the tongue into nitrite and swallowed in saliva, which, in the acidic environment of the stomach, is either converted into nitric oxide or re-enters the circulation as nitrite. Nitric oxide lowers blood pressure because it signals the endothelium (the lining of our blood vessels) to relax.
In healthy volunteers, blood pressure began to lessen within just 1 hour of drinking beet juice, with the peak drop of -10.48 mm/Hg occurring about 3 hours after ingestion. And beneficial blood pressure lowering effects continued to some degree for up to 24 hours!
Practical Tip: More than 25% of the world's adult population is currently hypertensive, a figure that is expected to increase to 29% by 2025. Since hypertension causes around 50% of coronary heart disease, and approximately 75% of strokes, toasting your health with a mid-morning and an early afternoon or evening glass of beet-rich vegetable juice or a cup of borscht is a daily habit that just might save your life or that of a loved one. A quick and easy recipe for Raw Borscht Soup can be found of page 248 of The World's Healthiest Foods.
Beets' Betaine Helps Lessen Inflammation
People whose diets supplied the highest average intake of choline (found in egg yolk and soybeans), and its metabolite betaine (found naturally in vegetables such as beets and spinach), have levels of inflammatory markers at least 20% lower than subjects with the lowest average intakes, report Greek researchers in the American Journal of Clinical Nutrition (Detopoulou P, Panagiotakos DB, et al.)
Compared to those whose diets contained <250 mg/day of choline, subjects whose diets supplied >310 mg of choline daily had, on average:
•    22% lower concentrations of C-reactive protein
•    26% lower concentrations of interleukin-6
•    6% lower concentrations of tumor necrosis factor alpha
Compared to those consuming <260 mg/day of betaine, subjects whose diets provided >360 mg per day of betaine had, on average:
•  10% lower concentrations of homocysteine
•  19% lower concentrations of C-reactive protein
•  12% lower concentrations of tumor necrosis factor alpha
Each of these markers of chronic inflammation has been linked to a wide range of conditions including heart disease, osteoporosis, cognitive decline and Alzheimer's, and type-2 diabetes.
In an accompanying editorial in the American Journal of Clinical Nutrition entitled, "Is there a new component of the Mediterranean diet that reduces inflammation?," Steven Zeisel from the University of North Carolina at Chapel Hill noted that choline and betaine work together in the cellular process of methylation, which is not only responsible for the removal of homocysteine, but is involved in turning off the promoter regions of genes involved in inflammation.
"Exposure to oxidative stress is a potent trigger for inflammation. Betaine is formed from choline within the mitochondria , and this oxidation contributes to mitochondrial redox status ," Zeisel continued.

"If the association between choline and betaine and inflammation can be confirmed in studies of other populations, an interesting new dietary approach may be available for reducing chronic diseases associated with inflammation," he concluded.
Recommended daily intakes of choline were set in 1998 at 550 milligrams per day for men and 425 milligrams a day for women. No RDI has been set for betaine, which, since it is a metabolite of choline, is not considered an essential nutrient.
Practical Tip: Egg yolks are the richest source of choline, followed by soybeans. Beets, spinach and whole wheat products are primary sources of betaine. (Olthof MR, van Vliet T, et al. J Nutr)
Protection against Birth Defects
Beets are particularly rich in the B vitamin folate, which is essential for normal tissue growth. Eating folate-rich foods is especially important during pregnancy since without adequate folate, the infant's spinal column does not develop properly, a condition called neural tube defect. The daily requirement for folate is 400 micrograms. Just one cup of boiled, sliced beets contains 136 micrograms of folate.
Description
Both beets and Swiss chard are different varieties within the same plant family (Amaranthaceae-Chenopodiaceae) and their edible leaves share a resemblance in both taste and texture. Attached to the beet's green leaves is a round or oblong root, the part conjured up in most people's minds by the word "beet." Although typically a beautiful reddish-purple hue, beets also come in varieties that feature white or golden roots. No matter what their color, however, beet roots aren't as hardy as they look; the smallest bruise or puncture will cause red beets' red-purple pigments, which contain beneficial flavonoids called anthycyanins, to bleed, especially during cooking.
Beets' sweet taste reflects their high sugar content, which makes beets an important source for the production of refined sugar. Raw beet roots have a crunchy texture that turns soft and buttery when they are cooked. Beet leaves have a lively, bitter taste similar to chard. The main ingredient in the traditional eastern European soup, borscht, beets are delicious eaten raw, but are more typically cooked or pickled.
The greens attached to the beet roots are delicious and can be prepared like spinach or Swiss chard. They are incredibly rich in nutrients, concentrated in vitamins and minerals as well as carotenoids such as beta-carotene and lutein/zeaxanthin.
History
The wild beet, the ancestor of the beet with which we are familiar today, is thought to have originated in prehistoric times in North Africa and grew wild along Asian and European seashores. In these earlier times, people exclusively ate the beet greens and not the roots. The ancient Romans were one of the first civilizations to cultivate beets to use their roots as food. The tribes that invaded Rome were responsible for spreading beets throughout northern Europe where they were first used for animal fodder and later for human consumption becoming more popular in the 16th century.
Beets' value grew in the 19th century when it was discovered that they were a concentrated source of sugar, and the first sugar factory was built in Poland. When access to sugar cane was restricted by the British, Napoleon decreed that the beet be used as the primary source of sugar, catalyzing its popularity. Around this time, beets were also first brought to the United States, where they now flourish. Today the leading commercial producers of beets include the United States, the Russian Federation, France, Poland, France and Germany.
How to Select and Store
Choose small or medium-sized beets whose roots are firm, smooth-skinned and deep in color. Smaller, younger beets may be so tender that peeling won't be needed after they are cooked.
Avoid beets that have spots, bruises or soft, wet areas, all of which indicate spoilage. Shriveled or flabby should also be avoided as these are signs that the roots are aged, tough and fibrous.
While the quality of the greens does not reflect that of the roots, if you are going to consume this very nutritious part of the plant, look for greens that appear fresh, tender, and have a lively green color.
Store beets unwashed in the refrigerator crisper where they will keep for two to four weeks. Cut the majority of the greens and their stems from the roots, so they do not pull away moisture away from the root. Leave about two inches of the stem attached to prevent the roots from "bleeding." Store the unwashed greens in a separate plastic bag where they will keep fresh for about four days.
Raw beets do not freeze well since they tend to become soft upon thawing. Freezing cooked beets is fine; they'll retain their flavor and texture.
How to Enjoy
Tips for Preparing Beets:
Cook beets lightly. Studies show beets' anti-cancer activity is diminished by heat.
Don't peel beets until after cooking. When bruised or pierced, beets bleed, losing some of their vibrant color and turning a duller brownish red. To minimize bleeding, wash beets gently under cool running water, taking care not to tear the skin since this tough outer layer helps keep most of beets' pigments inside the vegetable. To prevent bleeding when boiling beets, leave them whole with their root ends and one inch of stem attached.
Beets' color can be modified during cooking. Adding an acidic ingredient such as lemon juice or vinegar will brighten the color while an alkaline substance such as baking soda will often cause them to turn a deeper purple. Salt will blunt beets' color, so add only at the end of cooking if needed.
Since beet juice can stain your skin, wearing kitchen gloves is a good idea when handling beets. If your hands become stained during the cleaning and cooking process, simply rubbing some lemon juice on them will remove the stain.
A Few Quick Serving Ideas:
Simply grate raw beets for a delicious and colorful addition to salads or decorative garnish for soups.
Add chunks of beet when roasting vegetables in the oven.
Serving homemade vegetable juice? A quarter of a beet will turn any green drink into a sweet pink concoction, pleasing both the eyes and the taste buds.
Healthy sauté beet greens with other braising greens such as chard and mustard greens.
Marinate steamed beets in fresh lemon juice, olive oil, and fresh herbs.
Safety
Beeturia
If you start to see red when you increase your consumption of beets, don't be alarmed. You're just experiencing beeturia, or a red or pink color to your urine or stool. No need to panic; the condition is harmless.
Beets and Oxalates
Beets (notably beet greens) are among a small number of foods that contain measurable amounts of oxalates, naturally-occurring substances found in plants, animals, and human beings. When oxalates become too concentrated in body fluids, they can crystallize and cause health problems. For this reason, individuals with already existing and untreated kidney or gallbladder problems may want to avoid eating beets. Laboratory studies have shown that oxalates may also interfere with absorption of calcium from the body. Yet, in every peer-reviewed research study we've seen, the ability of oxalates to lower calcium absorption is relatively small and definitely does not outweigh the ability of oxalate-containing foods to contribute calcium to the meal plan. If your digestive tract is healthy, and you do a good job of chewing and relaxing while you enjoy your meals, you will get significant benefits - including absorption of calcium - from calcium-rich foods plant foods that also contain oxalic acid. Ordinarily, a healthcare practitioner would not discourage a person focused on ensuring that they are meeting their calcium requirements from eating these nutrient-rich foods because of their oxalate content. For more on this subject, please see "Can you tell me what oxalates are and in which foods they can be found?"

Nutritional Profile
Beets are an excellent source of the B vitamin, folate, and a very good source of manganese and potassium. Beets are a good source of dietary fiber, vitamin C, magnesium, iron, copper and phosphorus.
For an in-depth nutritional profile click here: Beets.

In-Depth Nutritional Profile
In addition to the nutrients highlighted in our ratings chart, an in-depth nutritional profile for Beets 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.

Beets, Boiled
1.00 cup
170.00 grams
74.80 calories
Nutrient    Amount    DV
(%)    Nutrient
Density    World's Healthiest
Foods Rating
folate    136.00 mcg    34.0    8.2    excellent
manganese    0.55 mg    27.5    6.6    very good
potassium    518.50 mg    14.8    3.6    very good
dietary fiber    3.40 g    13.6    3.3    good
vitamin C    6.12 mg    10.2    2.5    good
magnesium    39.10 mg    9.8    2.4    good
tryptophan    0.03 g    9.4    2.3    good
iron    1.34 mg    7.4    1.8    good
copper    0.13 mg    6.5    1.6    good
phosphorus    64.60 mg    6.5    1.6    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    D

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