Collard greens

What's New and Beneficial About Collard Greens

WHFoods Recommendations

You'll want to include collard greens as one of the cruciferous vegetables you eat on a regular basis if you want to receive the fantastic health benefits provided by the cruciferous vegetable family. At a minimum, include cruciferous vegetables as part of your diet 2-3 times per week, and make the serving size at least 1-1/2 cups. Even better from a health standpoint, enjoy collard greens and other vegetables from the cruciferous vegetable group 4-5 times per week, and increase your serving size to 2 cups.

It is very important not to overcook collard greens. Like other cruciferous vegetables overcooked collard greens will begin to emit the unpleasant sulfur smell associated with overcooking. To help collard greens to cook more quickly, evenly slice the leaves into 1/2-inch slices and the stems into 1/4-inch pieces. Let them sit for at least 5 minutes to bring out the health-promoting qualities and steam for 5 minutes. Serve with our Mediterranean Dressing. See 5-Minute Collard Greens.

Collard Greens, chopped, cooked
1.00 cup
(190.00 grams)
Calories: 63
GI: very low

NutrientDRI/DV

 vitamin K858%

 vitamin A80%

 manganese49%

 vitamin C46%

 fiber30%

 calcium27%

 choline17%

 vitamin B215%

 vitamin B614%

 iron12%

 copper11%

 vitamin E11%

 magnesium10%

 protein10%

 phosphorus9%

 omega-3 fats8%

 folate8%

 pantothenic acid8%

 vitamin B37%

 vitamin B17%

 potassium6%

Health Benefits

Unlike broccoli and kale and cabbage, you won't find many research studies devoted to the specific health benefits of collard greens. However, collard greens are sometimes included in a longer list of cruciferous vegetables that are lumped together and examined for the health benefits they provide. Based on a very small number of studies looking specifically at collard greens, and a larger number of studies looking at cruciferous vegetables as a group (and including collard greens on the list of vegetables studied), cancer prevention appears to be a standout area for collard greens with respect to their health benefits.

This connection between collard greens and cancer prevention should not be surprising since collard greens provide special nutrient support for three body systems that are closely connected with cancer development as well as cancer prevention. These three systems are (1) the body's detox system, (2) its antioxidant system, and (3) its inflammatory/anti-inflammatory system. Chronic imbalances in any of these three systems can increase risk of cancer, and when imbalances in all three systems occur simultaneously, the risk of cancer increases significantly. Among all types of cancer, prevention of the following cancer types is most closely associated with intake of collard greens: bladder cancer, breast cancer, colon cancer, lung cancer, prostate cancer, and ovarian cancer.

Detox Support Provided by Collard Greens

The detox support provided by collard greens includes antioxidant nutrients to boost Phase 1 detoxification activities and sulfur-containing nutrients to boost Phase 2 activities. Collard greens also contain phytonutrients called glucosinolates that can help activate detoxification enzymes and regulate their activity. Four key glucosinolates that have been clearly identified in collard greens in significant amounts are glucobrassicin, glucoraphanin, gluconasturtiian, and glucotropaeolin.

If we fail to give our body's detox system adequate nutritional support, yet continue to expose ourselves to unwanted toxins through our lifestyle and our dietary choices, we can place our bodies at increased risk of toxin-related damage that can eventually increase our cells' risk of becoming cancerous. That's one of the reasons it's so important to bring collard greens and other cruciferous vegetables into our diet on a regular basis.

The Antioxidant Benefits of Collard Greens

As an excellent source of vitamin C, vitamin A (in the form of carotenoids), and manganese, and a good source of vitamin E, collard greens provide us with 4 core conventional antioxidants. But the antioxidant support provided by collard greens extends far beyond the conventional nutrients into the realm of phytonutrients. Caffeic acid, ferulic acid, quercetin, and kaempferol are among the key antioxidant phytonutrients provided by collard greens. This broad spectrum antioxidant support helps lower the risk of oxidative stress in our cells. Chronic oxidative stress—meaning chronic presence over overly reactive oxygen-containing molecules and cumulative damage to our cells by these molecules—is a risk factor for development of most cancer types. By providing us with such a great array of antioxidant nutrients, collard greens help lower our cancer risk by helping us avoid chronic and unwanted oxidative stress.

Collard Greens' Anti-inflammatory Benefits

As an excellent source of vitamin K and a good source of omega-3 fatty acids (in the form of alpha-linolenic acid, or ALA), collard greens provide us with two hallmark anti-inflammatory nutrients. Vitamin K acts as a direct regulator of our inflammatory response, and ALA is the building block for several of the body's most widely-used families of anti-inflammatory messaging molecules. In addition to these two anti-inflammatory components, one of the glucosinolates found in collard greens—glucobrassicin—can be readily converted into an isothiocyanate molecule called I3C, or indole-3-carbinol (I3C). I3C is an anti-inflammatory compound that can actually operate at the genetic level, and by doing so, prevent the initiation of inflammatory responses at a very early stage.

Like chronic oxidative stress and chronic weakened detox ability, chronic unwanted inflammation can significantly increase our risk of cancers and other chronic diseases (especially cardiovascular diseases).

Collard Greens and Cardiovascular Support

Researchers have looked at a variety of cardiovascular problems—including heart attack, ischemic heart disease, and atherosclerosis—and found preliminary evidence of an ability on the part of cruciferous vegetables to lower our risk of these health problems. Yet regardless of the specific cardiovascular problem, it is one particular type of cardiovascular benefit that has most interested researchers, and that benefit is the anti-inflammatory nature of collard greens and their fellow cruciferous vegetables. Scientists have not always viewed cardiovascular problems as having a central inflammatory component, but the role of unwanted inflammation in creating problems for our blood vessels and circulation has become increasingly fundamental to an understanding of cardiovascular diseases. Of particular interest here has been the isothiocyanate (ITC) sulforaphane, which is made from glucoraphanin (a glucosinolate) found in collard greens. Not only does this ITC trigger anti-inflammatory activity in our cardiovascular system, it may also be able to help prevent and even possibly help reverse blood vessel damage.

A second area you can count on collard greens for cardiovascular support involves their cholesterol-lowering ability. Our liver uses cholesterol as a basic building block to product bile acids. Bile acids are specialized molecules that aid in the digestion and absorption of fat through a process called emulsification. These molecules are typically stored in fluid in our gall bladder, and when we eat a fat-containing meal, they get released into the intestine where they help ready the fat for interaction with enzymes and eventual absorption up into the body. When we eat collard greens, fiber-related nutrients in this cruciferous vegetable bind together with some of the bile acids in the intestine in such a way that they simply stay inside the intestine and pass out of our body in a bowel movement, rather than getting absorbed along with the fat they have emulsified. When this happens, our liver needs to replace the lost bile acids by drawing upon our existing supply of cholesterol, and as a result, our cholesterol level drops down. Collard greens provide us with this cholesterol-lowering benefit whether they are raw or cooked. However, a recent study has shown that the cholesterol-lowering ability of raw collard greens improves significantly when they are steamed. In fact, when the cholesterol-lowering ability of steamed collard greens was compared with the cholesterol-lowering ability of the prescription drug cholestyramine (a medication that is taken for the purpose of lowering cholesterol), collard greens bound 46% as many bile acids (based on a standard of comparison involving total dietary fiber).

In addition to the support factors described above, it would be wrong to talk about the cardiovascular benefits of collard greens without mentioning their diverse array of B vitamins. Collard greens are a very good source of vitamins B2, B6, and choline, and a good source of vitamins B1, B3, folate, and pantothenic acid. A well-balanced intake of B vitamins - especially vitamins B6, B12, folate, and choline - can be important in controlling cardiovascular disease risk. Since excessive or deficient intake of these B vitamins can have an unwanted impact on your disease risk, it is great to have a food like collard greens that provide a helpful amount of so many B vitamins.

Collard Greens and Digestive Support

The fiber content of collard greens—over 7 grams in every cup—makes this cruciferous vegetable a natural choice for digestive system support. Yet the fiber content of collard greens is only one of their digestive support mechanisms. Researchers have determined that the sulforaphane made from a glucosinolate in collard greens (glucoraphanin) helps protect the health of our stomach lining by preventing bacterial overgrowth of Helicobacter pylori in our stomach or too much clinging by this bacterium to our stomach wall.

Other Health Benefits From Collard Greens

The anti-inflammatory nature of glucosinolates/isothiocyanates and other nutrients found in collard greens has been the basis for new research on inflammation-related health problems and the potential role of collard greens in their prevention. Current and potentially promising research is underway to examine the benefits of collard greens in relationship to our risk of the following inflammation-related conditions: Crohn's disease, inflammatory bowel disease, insulin resistance, irritable bowel syndrome, metabolic syndrome, obesity, rheumatoid arthritis, type 2 diabetes, and ulcerative colitis.

Description

All cruciferous vegetables provide integrated nourishment across a wide variety of nutritional categories and provide broad support across a wide variety of body systems as well. For more on cruciferous vegetables see:

Collards are leafy green vegetables that belong to the same family that includes cabbage, kale, and broccoli. While they share the same botanical name as kale, Brassica oleracea, and some resemblance, they have their own distinctive qualities. Like kale, collards are one of the non-head forming members of the Brassica family. Collards' unique appearance features dark blue green leaves that are smooth in texture and relatively broad. They lack the frilled edges that are so distinctive to their cousin kale.

Long a staple of the Southern United States, collard greens, unlike their cousins kale and mustard greens, have a very mild, almost smoky flavor. Although they are available year-round they are at their best from January through April.

History

Like kale, cauliflower and broccoli, collards are descendents of the wild cabbage, a plant thought to have been consumed as food since prehistoric times and to have originated in Asia Minor. From there it spread into Europe, being introduced by groups of Celtic wanderers around 600 B.C. Collards have been cultivated since the times of the ancient Greek and Roman civilizations. While collards may have been introduced into the United States before, the first mention of collard greens dates back to the late 17th century. Collards are an integral food in traditional southern American cuisine.

How to Select and Store

Look for collard greens that have firm, unwilted leaves that are vividly deep green in color with no signs of yellowing or browning. Leaves that are smaller in size will be more tender and have a milder flavor. They should be displayed in a chilled section in the refrigerator case to prevent them from wilting and becoming bitter.

Place collard greens in a plastic bag, removing as much of the air from the bag as possible. Store in the refrigerator where they should keep fresh for about three to five days.

How to Enjoy

A Few Quick Serving Ideas
WHFoods Recipes That Feature Collard Greens

Safety

Collard Greens and Pesticide Residues

According to the Environmental Working Group (EWG) in their 2014 report, Shopper's Guide to Pesticides in Produce, conventionally grown collard greens are contaminated with concentrations of organophosphate insecticides, which are considered to be highly toxic to the nervous system. While they were not among the 12 varieties of produce most concentrated in overall pesticide residues (and therefore not part of the EWG's traditional "Dirty Dozen"), the EWG felt that this organophosphate concentration was relevant enough to bring attention to collard greens. They actually renamed their produce category of concern from "Dirty Dozen" to "Dirty Dozen Plus" with leafy greens such as collard greens and kale (as well as hot peppers) being the "Plus" conventionally grown produce. Therefore, individuals wanting to avoid pesticide-associated health risks may want to avoid consumption of collard greens unless they are grown organically.

Collard Greens and Oxalates

Collard 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 collard greens. 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?

Collard Greens as a "Goitrogenic" Food

Collard greens are sometimes referred to as a "goitrogenic" food. Yet, contrary to popular belief, according to the latest studies, foods themselves—collard greens included—are not "goitrogenic" in the sense of causing goiter whenever they are consumed, or even when they are consumed in excess. In fact, most foods that are commonly called "goitrogenic"—such as the cruciferous vegetables (including cabbage, broccoli, kale, and cauliflower) and soyfoods—do not interfere with thyroid function in healthy persons even when they are consumed on a daily basis. Nor is it scientifically correct to say that foods "contain goitrogens," at least not if you are thinking about goitrogens as a category of substances like proteins, carbohydrates, or vitamins. With respect to the health of our thyroid gland, all that can be contained in a food are nutrients that provide us with a variety of health benefits but which, under certain circumstances, can also interfere with thyroid function. The term "goitrogenic food" makes it sound as if something is wrong with the food, but that is simply not the case. What causes problems for certain individuals is not the food itself but the mismatched nature of certain substances within the food to their unique health circumstances. For more, see an An Up-to-Date Look at Goitrogenic Substances in Food.

Nutritional Profile

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 (similar to other information presented in the website, this DV is calculated for 25-50 year old healthy woman); 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.

Collard Greens, chopped, cooked
1.00 cup
190.00 grams
Calories: 63
GI: very low
Nutrient Amount DRI/DV
(%)
Nutrient
Density
World's Healthiest
Foods Rating
vitamin K 772.54 mcg 858 246.4 excellent
vitamin A 722.00 mcg RAE 80 23.0 excellent
manganese 0.97 mg 49 13.9 excellent
vitamin C 34.58 mg 46 13.2 excellent
fiber 7.60 g 30 8.7 excellent
calcium 267.90 mg 27 7.7 excellent
choline 72.96 mg 17 4.9 very good
vitamin B2 0.20 mg 15 4.4 very good
vitamin B6 0.24 mg 14 4.1 very good
iron 2.15 mg 12 3.4 very good
vitamin E 1.67 mg (ATE) 11 3.2 good
copper 0.10 mg 11 3.2 good
protein 5.15 g 10 3.0 good
magnesium 39.90 mg 10 2.9 good
phosphorus 60.80 mg 9 2.5 good
pantothenic acid 0.41 mg 8 2.4 good
folate 30.40 mcg 8 2.2 good
omega-3 fats 0.18 g 8 2.2 good
vitamin B3 1.09 mg 7 2.0 good
vitamin B1 0.08 mg 7 1.9 good
potassium 222.30 mg 6 1.8 good
World's Healthiest
Foods Rating
Rule
excellent DRI/DV>=75% OR
Density>=7.6 AND DRI/DV>=10%
very good DRI/DV>=50% OR
Density>=3.4 AND DRI/DV>=5%
good DRI/DV>=25% OR
Density>=1.5 AND DRI/DV>=2.5%

References

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