Friday, September 13, 2013

Carbohydrates


Carbohydrates and energy
Why is  it important to consume carbohydrates?  Carbohydrates is a readily available energy source of our body compared to other nutrients protein and fat which needs more time to process.   They generates  4 kilocalories per gram of food.  Whether you eat grains or fruits, they all same in terms of calorie making.  AMDR for  carbohydrate is 45%-65%, fat is 20%-35% and of protein is 10%-35% of your total kilocalorie (Kcal) intake.  ADMR describes the portion of the energy intake that should come from each macronutriet.  It stands for Acceptable Macronutrient Distribution Ranges and can also be understood as the calorie composition of a diet that gives adequate energy as required and other nutrients.

Carbohydrates and monosaccharides
What are carbohydrates?  They are made up of varying numbers of sugar molecule.  The simplest types of carbohydrate are called sugars. Carbohydrates consist of one sugar molecule is called monosaccharides.  For example, glucose (the most abundant sugar in blood), fructose (the mosta bundant sugar in fruits and vegetables), and galactose (found in dairly products) are belong to monosaccharide.  Glucose and galactose are used as a source of energy (ATP).  Glucose is the only energy source for red blood cell.  Therefore, it is very important to consume enough vegetables and fruits. 

Disaccharides
Second, disaccharides consist of two monosaccharies bonded together.  The most common disaccarides are lactose (galactose and glucose), maltose (glucose and glucose), and sucrose (fructose and glucose). The lactose is the most abundant in milk.  While many babies produce enough enzyme, lactase, to digest the high amount of lactose found in milk, some people doesn't not have enough lactase so they can't breakdown lactose into galactose and glucose.  This is called lactose intolerance.  Maltose is not found in many food; however, it is formed by breakdown of starches.  For example, during the brewing process, cereal starch such as barley are converted to maltose.  Sucrose is found in many plants, such as sugar cane and sugar beets. 

Polysaccharides
Finally, one of the most nutritious carbohydrates, complex carbohydrates consist of many monosaccharides. Also, the complex carbohydrates are divided into oligosaccharides and polysaccharides.  The oligosaccharides are components of cell membrane.  They include dried beans, soybeans, peas, and lentils.  They are raffinose and stachyose.  Because humans lack the enzymes needed to digest these two carbohydrates, they pass undigested into large intestine, where bacteria break them down.  As a result, some people experience abdominal discomfort (bloating and cramps) and flatulence (gas).  Oligosaccharides are also made in the breasts as a human milk.  This helps infants from disease-causing pathogens; therefore, breastfeeding is encouraged to women.

Amylose and amylopectin
Polysaccharides are made up of many monosaccharides bonded together by glycosidic bonds.  Through photosynthesis, plants synthesize glycosidic bonds.  Some polysaccharides have an orderly linear appearance, whereas others are shaped like branches on a tree.  The three most common polysaccharides are starch, fiber, and glycogen. 


To store this importance source of energy plants convert the glucose for starch.    There are two types of starch, amylose (linear structure with alpha-1,4 glycosidic bond) and amylopectin (branched structure with alpha-1,6 glycosidic bond).  Amylopectin is more easy to digested because of branched points can make enzymes can hydrolyze multiple glycosidic bonds simultaneously.  As a result our bodies can breakdown glycogen quickly when we need energy.  

Because of its tightly packed structure, amylose is more resistant to digestion than other starch molecules. Therefore, amylose has been found to be an effected prebiotic.  Unlike amylopectin, amylose is insoluble in water.  Plants generally contain a mixture of both types of starch – amylose and amylopectin.  Examples of starch foods are grains (such as corn, rice, and wheat), products made from grains (pasta and bread), and legumes (beans, lentils, and split peas).  Potatoes, sweet potatoes, and winter squashes also source of starch. 

Amylopectin is a soluble polysaccharide and highly branched polymer of glucose found in plants. Branching takes place with α(1→6) bonds occurring every 24 to 30 glucose units, resulting in a soluble molecule that can be quickly degraded as it has many end points for enzymes to attach onto. In contrast, amylose contains very few α(1→6) bonds, or even none at all.  This causes it to be hydrolyzed more slowly but have higher density and be insoluble.  Its counterpart in animals is glycogen, which has the same composition and structure, but with more extensive branching that occurs every 8 to 12 glucose units.  Humans and other animals that eat plant foods also use amylase, an enzyme that assists in breaking down amylopectin.  Starch is made of about 70% amylopectin by weight, though it varies depending on the source (higher in medium-grain rice to 100% in glutinous rice, waxy potato starch, and waxy corn, and lower in long-grain rice, amylomaize, and russet potato).  Amylopectin is highly branched, being formed of 2,000 to 200,000 glucose units. Its inner-chains are formed of 20-24 glucose subunits.
Dissolved amylopectin starch  has a lower tendency of retrogradation r(gelling) during storage and cooling. For this main reason the waxy starches are used in different applications mainly as thickening agent or stabilizer.  

Fiber
Unlike starch, fiber cannot be digested in the human small intestine.  This is due to its structure, beta-glycosidic bond that are resistant to digestive enzymes.  Undigested fiber passes from the small to the large intestine relatively intact. Then, intestinal bacteria began to break down the fiber, producing gas, lipids, and other substances.  Moreover, dietary fiber promotes the selective growth of beneficial intestinal bacteria, which is turn help inhibit the growth of other disease-causing (pathogenic) bacteria.  

Also, fiber is categorized according to its solubility in water.  Soluble and viscous dietary fiber, for example, is found in oats, barley, legumes, rice bran, psylium seeds, soy, and some fruits.  These foods help soften fecal matter, reduction strain and making elimination easier.  Moreover, they help reduce cholesterol levels in some people.  According to research, the viscous fiber may bind with dietary fat and cholesterol in the gastrointestinal (GI) track making it less likely to be absorbed.  

Insoluble dietary fiber is cellulose and hemicellulose.  Cellulose is the most abundant insoluble dietary fiber in food.  Whole-grain four, wheat bran, whole-grain  breakfast cereals, seeds, and many vegetables including carrots, broccoli, celery, peppers and cabbage.  Because insoluble fiber do not dissolved in water, they do not form viscous gels.  Nor do bacteria in the GI tract, which helps to increase fecal weight and volume.  Generally, large amounts of fecal mass move through the colon quickly by stimulating peristalsis contractions in the colon, propelling the material forward.  When consumed with sufficient amounts of fluid, insoluble fiber can help prevent and alleviate constipation.

Dietary Reference Intakes for Carbohydrates
The Institute of Medicine's Dietary Reference Intakes (DRIs) are based maily on ensuring that the brain has adequate glucose for its energy needs.  The  USDA (United States Department of Agriculture) recommends people to take 130g per day for adults, minimum amount of glucose utilized by the brain.  As there are 4 kcal per gram of carbohydrate, this means a person needing 2,000 kcal daily should consume between 225 and 325 g of carbohydrates (900 and 1,300 kcal, respectively).    

Sources  



McGuire, M. & Beerman, K. A. (2011),  Nutritional Sciences.  New York; Wadsworth

Food and Drug Administration (2013). Claims That Can Be Made for Conventional Foods and Dietary   Supplements. Retrieved on 09/12/2013 from.  http://www.fda.gov/Food/IngredientsPackagingLabeling/LabelingNutrition/ucm111447.htm

Wednesday, September 11, 2013

Benefits of having Fall Fruits and Vegetables


Benefits of having Fall Fruits and Vegetables

Now it is a harvest season and close to the Harvest Full Moon Festival, September 19 this year.  Well, it is considered to have higher nutrition in the seasonal fruits and vegetables.  Let’s check which they are.  Joan Endyke provided some tips from Healthy Eating Fall Harvest of Plenty at Tauon Gazette.  Fruits and vegetables contain a lot of antioxidants, vitamins and minerals so it boosts our immune systems. 

Pomegranates: They bring a fun start to fall. Toss the seeds into fruit salads or green salads or add them to dishes for a splash of color and flavor. Cranberry-pomegranate sauce makes for an interesting side dish. Pomegranates are high in antioxidants, vitamin C and folic acid, a B vitamin.
Dates: De-pitted fresh dates (without added sugar) are available at Whole Foods. They can be chopped and added to salads or used in trail mix for a snack. Naturally sweet, dates contain tannins, which are antioxidants that help prevent illness, as well as potassium, magnesium and copper.
Apples: Cut them up and add to salads or combine with roasted sweet potatoes. This fall staple is high in fiber and contains the active ingredient quercetin, a natural antihistamine to combat seasonal allergies and clear up colds.
Pears: They can be used in salads or sliced and sprinkled with cinnamon sugar for school lunches. Like apples, pears are a good source of fiber.
Acorn squash: Slice it into halves and remove the seeds. Drizzle butter or margarine in the middle; sprinkle with cinnamon or cinnamon-sugar and bake for about an hour or until soft. Scoop out and serve. You can roast the seeds and eat them, just like pumpkin seeds. Acorn squash provides an excellent source of vitamin A.
Brussels sprouts: Toss them with olive oil and season with lemon and pepper. Roast for 30-40 minutes at 400 degrees until crispy on the outside. Good source of vitamin K and the B vitamin, folate.
Kale: It’s full of natural flavonoids that help protect against several types of cancers. Sautee colorful peppers (high in vitamin C) in olive oil until tender. Add chopped kale, stir and cook for 5 minutes until the kale absorbs the flavor of the peppers but remains crisp. Season and enjoy. It contains a lot of vitamin A, vitamin C, and Vitamin K in addition to minerals copper, potassium, iron, manganese, and phosphorus.

Kiwi: It offers flavor and color to brighten up fruit salads. This sweet green fruit is super-high in vitamin C and a great addition to a fall banquet



Saturday, September 7, 2013

How to Read Food Labels


How to read Food Labels

It can help you make healthier choices of food if you lean how to read and understand food labels.  American Heart Association provides some tips for making the most of the information on the Nutrition Facts label:


Start here. Note the size of a single serving and how many servings are in the package.
Check total calories per serving. Look at the serving size and how many servings you’re really consuming. If you double the servings you eat, you double the calories and nutrients, including the Percent Daily Value (% DV).
Limit these nutrients. Remember, you need to limit your total fat to no more than 56–78 grams a day — including no more than 16 grams of saturated fat, less than two grams of trans fat, and less than 300 mg cholesterol (for a 2,000 calorie diet).
Get enough of these nutrients. Make sure you get 100 percent of the fiber, vitamins and other nutrients you need every day.
Quick guide to % DV. The % DV section tells you the percent of each nutrient in a single serving, in terms of the daily recommended amount. As a guide, if you want to consume less of a nutrient (such as saturated fat, cholesterol or sodium), choose foods with a lower % DV — 5 percent or less is low. If you want to consume more of a nutrient (such as fiber), seek foods with a higher % DV — 20 percent or more is high.
In addition to the Nutrition Facts label, a lot of foods today also come with nutrient content claims provided by the manufacturer. These claims are typically featured in ads for the foods or in the promotional copy on the food packages themselves. They are strictly defined by the FDA. The chart below provides some of the most commonly used nutrient content claims, along with a detailed description of what the claim means.
a food claims to be...
It means that one serving of the product contains...
Calorie free
Less than 5 calories
Sugar free
Less than 0.5 grams of sugar
Fat
Fat free
Less than 0.5 grams of fat
Low fat
3 grams of fat or less
Reduced fat or less fat
At least 25 percent less fat than the regular product
Low in saturated fat
1 gram of saturated fat or less, with not more than 15 percent of the calories coming from saturated fat
Lean
Less than 10 grams of fat, 4.5 grams of saturated fat and 95 milligrams of cholesterol
Extra lean
Less than 5 grams of fat, 2 grams of saturated fat and 95 milligrams of cholesterol
Light (lite)
At least one-third fewer calories or no more than half the fat of the regular product, or no more than half the sodium of the regular product
Cholesterol
Cholesterol free
Less than 2 milligrams of cholesterol and 2 grams (or less) of saturated fat
Low cholesterol
20 or fewer milligrams of cholesterol and 2 grams or less of saturated fat
Reduced cholesterol
At least 25 percent less cholesterol than the regular product and 2 grams or less of saturated fat
Sodium
Sodium free or no sodium
Less than 5 milligrams of sodium and no sodium chloride in ingredients
Very low sodium
35 milligrams or less of sodium
Low sodium
140 milligrams or less of sodium
Reduced or less sodium
At least 25 percent less sodium than the regular product
Fiber
High fiber
5 grams or more of fiber
Good source of fiber
2.5 to 4.9 grams of fiber

If you can’t remember the definitions of all of the terms, don’t worry. You can use these general guidelines instead:
    “Free” means a food has the least possible amount of the specified nutrient.
    “Very Low” and “Low” means the food has a little more than foods labeled “Free.”
    “Reduced” or “Less” mean the food has 25 percent less of a specific nutrient than the regular version of the food.

This content was retrieved from American Heart Association website: http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/HeartSmartShopping/Reading-Food-Nutrition-Labels_UCM_300132_Article.jsp

What Label Language Means


Thursday, September 5, 2013

Answers & Explanations for the Fact or Fiction Game


Academy of Nutrition and Dietetics made an interesting game about Fact or Fiction on nutrition.
There are 10 questions and now you can check your nutrition literacy!

1.  In a healthy eating plan, all the foods I eat should be low in fat  (Fiction). 
Your goal should be to eat fewer foods that are high in solid fats.  That doesn't mean every single food you eat must be low in fat.  Select lean cuts of meats or poultry and fat-free or low-fat milk, yogurt and cheese.  Look for foods that are in low in saturated fats, trans fats and cholesterol.  Switch from solid fat to oils when preparing food.
2.  Snacking may keep me from becoming ravenously hungry and overeating at mealtime (Fact).
Healthful snacking -- including carbohydrates and proteins like whole grain crackers with low-fat cheese or fat-free yogurt with fresh fruit -- can help your body stay fueled so you will be less inclined to overeat at your next meal.  But don't overdo it on the snacks; keep your portions small.
3.  Eating too many carbohydrates causes weight gain (Fiction).
Eating too many calories, from any source -- carbohydrates, fat or protein -- combined with an inactive lifestyle, will likely cause you to gain weight.  Make at least half your grains whole.  Choose 100% whole-grain breads, cereals, crackers, rice and pasta.  And, get 30 minutes of physical activity most days of the week.

4.  Vegetarian diets are healthful (Fact).
A well-planned healthful vegetarian eating plan emphasizes fruits, vegetables, whole grains and fat-free or low-fat diary alternatives and is low in saturated fats, trans fats, cholesterol, and salt and added sugars.  Depending on the types of vegetarian diet, protein sources amy include eggs, milk, cheese, yogurt, soy-based products, grain fods such as bread, cereal, pasta and rice, beans and nuts.  With planning, most people, including children, can healthfully follow a vegetarian diet.


5.  Eating sugar causes diabetes (Fiction).
If you don't have diabetes, eating sugar won't cause you to get diabetes.  Since foods that are high in sugar also are often high in caloreis, over-eating chose foods can lead to weight gain.  Being obese and inactive increase your risk for diabetes.  Cut back on extra calories, by choosing foods and drinks with little or no added sugars.

6.  FAD diets work (Fact).
Fact, with a significant "but."  You may lose pounds quickly on a fad diet.  But over the long term, you are unlikely to maintain that loss.  Fad dieters often return to their old eating habits and regain the weight.  Meanwhile, many fad diets require you to give up foods or entire food groups that most people need for good health.  The best way to reach and maintain a healty weight is to develop an eating plan you can follow for life, combined with regular physical activity.

7.  Frozen or canned fruits and vegetables are not as nutritious as fresh (Fiction).
In almost cases, there is little nutritional difference between frozen or canned and fresh.  In fact, canned or frozen produce is generally processed at its peak, so it may contain more nutrients than fresh produce.  On the other hand, canned or frozen produce may contain added sugar or salt.  Read food labels when purchasing these items.
8.  It's easy to spot whole-grain food products:  They're brown (Fiction).
Color is not a reliable method for identifying healthy food products.  The most reliable information is on the food label.  To get the full range of health benefits provided by whole grains, including fiver, vitamins, minerals and antioxidant, eat three or more servings of whole grains everyday.
9.  I should limit my daily salt intake to about one teaspoon (Fact).
According to the 2005 Dietary Guidelines for Americans, most people's daily sodium intake should be 2,300 milligrams or less. That's about the amount of sodium that limiting sodium in one teaspoon of salt.  Research shows that limiting sodium to less than 2,300mg per day may reduce your risk of high blood pressure.  Keep in mind, most of the sodium we eat comes from processed foods, so check the Nutrition Facts food label for information on the amount of sodium contained in a serving of your favorite foods.

10.  I'll gain about 10 pounds a year by eating an extra 100 calories a day (Fact).

One hundred calories per day adds up to about  a pound of weight gain per month.  On the other hand, look at it this way:  you can lose 10 pounds in  a year cutting 100 calories per day and increasing physical activity.  Try to get at least 30 minutes of actiity most days of the week.

Wednesday, September 4, 2013

Nutrition Fact or Myth Game

Nutrition Fact or Fiction Game?

Academy of Nutrition and Dietetics made an interesting game about Fact or Fiction on nutrition.

There are 10 questions and now you can check your nutrition literacy!

1.  In a healthy eating plan, all the foods I eat should be low in fat  (Fact or Fiction).

2.  Snacking may keep me from becoming ravenously hungry and overeating at mealtime (Fact or Fiction).

3.  Eating too many carbohydrates causes weight gain (Fact or Fiction).

4.  Vegetarian diets are healthful (Fact or Fiction).

5.  Eating sugar causes diabetes (Fact or Fiction).

6.  FAD diets work (Fact or Fiction).

7.  Frozen or canned fruits and vegetables are not as nutritious as fresh (Fact or Fiction).

8.  It's easy to spot whole-grain food products:  They're brown (Fact or Fiction).

9.  I should limit my daily salt intake to about one teaspoon (Fact or Fiction).

10.  I'll gain about 10 pounds a year by eating an extra 100 calories a day (Fact or Fiction).

You can click the below to find answers and explanations

http://www.eatright.org/nnm/games/MythOrFact/index.html

Have a happy and nutrition evening!

From your nutritionist Yali.







Tuesday, September 3, 2013

Antioxidants and Foods


What is Antioxidants?

Atoms contain negatively charged electrons, and an abundance of  electrons in an atom or molecule can result in an overall net negative charge.  such an atom or molecule is therefore said to be "reduced".  When electrons are remove, the atoms or molecules has a more positive charge and is said to be "oxidized."  Antioxidant is a compound that readily gives up electrons (and hydrogen ions) to other substances.  So, it protects our body from free radicals, which are highly reactive molecules with an unequal balance of charge.  

These free radicals are can be harmful.  First, oxidation of DNA can break and damage it, potentially causing mutations in genes and possibly cancer.  They can oxidize fatty acids associated with cell membranes, causing them to become weak and break down and also damage proteins.  

To get more antioxidants, we should consume a variety of fruits and vegetables with different colors.  

Reference:

McGuire, M. & Beerman, K. A. (2011),  Nutritional Sciences.  New York; Wadsworth

Examples of Antioxidants 
inVitamins and Mineral :  Vitamin C, E, A and Selenium

Photo was found from www.recipeforlife.biz .  

Friday, August 30, 2013

Why organic?


<-- Organic lamb



                    Organic flower --->







Why organic foods?

It is still controversial whether organic food is environmentally safer or nutritionally better than conventional food.   According to the Organic Trade Association’s 2012 Organic Industry Survey shows that the U.S. organic industry grew by 9.5 percent overall in 2011 to reach $31.5 billion in sales (2012).  Sale of organic foods is one of the fastest growing market segments worldwide as well.  People often buy organic food because they believe organic farms produce more nutritious and better tasting food from healthier soils. We can find the truth about nutrition of organic food through a research paper.    There are two comparable studies in 2010 and 2013 about organic food nutritional values.

In California, 13 pairs of commercial organic and conventional strawberry agroecosystems were tested to see if there are significant differences in fruit and soil quality in 2010.
“A two-year study led by John Reganold of Washington State University that published Sept. 1, 2010, in the peer-reviewed online journal PLoS One, the research study analyzed 31 chemical and biological soil properties, soil DNA, and the taste, nutrition and quality of three strawberry verities on 13 convention and 13 organic commercial fields in California.  

Findings in the paper showed organic strawberries had significantly higher antioxidant activity and concentrations of ascorbic acid and phenolic compounds, longer shelf life, and dry matter. In addition, the organic soils excelled in the areas of carbon sequestration, nitrogen, microbial biomass, enzyme activities, and micronutrients.”

In contrast, in 2012, Stanford researchers study concluded that organic food has no more nutritious than their conventional food.   An analysis of 237 studies of organic produce, meats and dairy foods, concluded that organic foods are no more nutritious than their conventional counterparts.  However, “advocates of organic foods say that the study takes a narrow view of organic food choices.”  People choose organic food because they can avoid pesticides, hormones, and other chemicals. 

Reporter Kenneth Chang in New York Times answers to questions to Standford study and organic foods.  I am going to quote a few important commonly asked questions and answers.

Q1.  Why would the Stanford team focus on whether there are nutritional differences between organic food and conventionally produced food?
A1.  A 2010 study by Washington State University scientists found organic strawberries have more vitamin C and antioxidants than conventional strawberries. Organic tomatoes also have more of a type of antioxidant called polyphenols than commercially grown tomatoes, according to a study published in July by scientists at the University of Barcelona.  However, other variables, like ripeness, may influence nutritional content even more. A peach or berry that reaches peak ripeness with the use of pesticides could contain considerably more vitamins than a less-ripe organically grown fruit.  They concluded no about whether choosing organic produce, meats and milk would lead to better nutrition generally.  That is, just following “organic” for everything does not bring obvious, immediate health benefits.

Q2.  Is organic milk a better option than commercial milk products?
A2.  Producers of organic milk are required to allow their cows to spend a certain amount of time grazing, and that does produce a noticeable effect on the fatty acids in the milk. Compared with conventional milk, organic milk has lower levels of omega-6 fatty acids, which are believed to be unhealthy for the heart in high concentrations, and higher levels of healthful omega-3 fatty acids. The Stanford researchers noted that organic milk does have modestly higher levels of omega-3 fatty acids, based on a few small studies included in the analysis.  Organic Valley, a cooperative of organic farmers, says its organic milk shows omega-3 levels that are 79 percent higher than those in conventional milk, as well as much lower levels of omega-6.

Q3.  What about pesticides? Is there a health benefit to eating foods grown without them?
A3. Charles Benbrook, who worked as the chief scientist for the Organic Center before moving to Washington State University last month, said the benefits of organic food, in terms of pesticide exposure, would be greatest for pregnant women, for young children and for older people with chronic health problems. He cites research that looked at blood pesticide levels of pregnant women and then followed their children for several years. The studies found that women with the highest pesticide levels during pregnancy gave birth to children who later tested 4 to 7 percent lower on I.Q. tests compared with their elementary school peers.
I hope consumers are able to understand organic food and can decide what they should consume now.  Organic or conventional?


References:

Chang, K. (2012).  Organic food vs. conventional food.  New York Times.  Retrieved from http://well.blogs.nytimes.com/2012/09/04/organic-food-vs-conventional-food/?smid=fb-share
Haumann, B. (2012).  2012 Press release.  Organic Trade Association. Retrieved from   http://www.organicnewsroom.com/2012/04/us_consumerdriven_organic_mark.html
Reganold, J.P. et al (2010).  Fruit and soil quality of organic and conventional strawberry agroecosystems.  Plos ONE. 5:9.  Retrieved from http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0012346

Thursday, August 29, 2013

Health Benefits of Kales: "Truth about Kales"


Extracts from by Kathleen M. Zelman, MPH, RD, LD WebMD Expert Column, WebMd
http://www.webmd.com/food-recipes/features/the-truth-about-kale

Kale is a Nutritional Powerhouse

One cup of chopped kale contains 33 calories and 9% of the daily value of calcium, 206% of vitamin A, 134% of vitamin C, and a whopping 684% of vitamin K. It is also a good source of minerals copper, potassium, iron, manganese, and phosphorus.
Kale’s health benefits are primarily linked to the high concentration and excellent source of antioxidant vitamins A, C, and K -- and sulphur-containing phytonutrients.
Carotenoids and flavonoids are the specific types of antioxidants associated with many of the anti-cancer health benefits. Kale is also rich in the eye-health promoting lutein and zeaxanthin compounds.
Beyond antioxidants, the fiber content of cruciferous kale binds bile acids and helps lower blood cholesterol levels and reduce the risk of heart disease, especially when kale is cooked instead of raw.

Super-Rich in Vitamin K

Eating a diet rich in the powerful antioxidant vitamin K can reduce the overall risk of developing or dying from cancer, according to a study in the American Journal of Clinical Nutrition. Vitamin K is abundant in kale but also found in parsley, spinach, collard greens, and animal products such as cheese.
Vitamin K is necessary for a wide variety of bodily functions, including normal blood clotting, antioxidant activity, and bone health.
But too much vitamin K can pose problems for some people. Anyone taking anticoagulants such as warfarin should avoid kale because the high level of vitamin K may interfere with the drugs. Consult your doctor before adding kale to your diet.
Kale might be a powerhouse of nutrients but is also contains oxalates, naturally occurring substances that can interfere with the absorption of calcium. Avoid eating calcium-rich foods like dairy at the same time as kale to prevent any problems.

Eat More Kale

In summer, vegetable choices abound. But during the cooler months, there are fewer in-season choices -- with the exception of kale and other dark, leafy greens that thrive in cooler weather.
To find the freshest kale, look for firm, deeply colored leaves with hardy stems. Smaller leaves will be more tender and milder in flavor. Leaves range from dark green to purple to deep red in color.  
Store kale, unwashed, in an air-tight zipped plastic bag for up to five days in the refrigerator. "
1 | 2