Tuesday 22 September 2015

World's Healthiest Foods rich in vitamin C

World's Healthiest Foods rich in
vitamin C
FoodCalsDRI/DV

 Papaya119224%

 Bell Peppers29157%

 Broccoli55135%


 Strawberries46113%

 Pineapple83105%

 Oranges6293%

 Kiwifruit4285%

 Cantaloupe5478%

 Cauliflower2973%

For serving size for specific foods see the Nutrient Rating Chart.
  • Basic Description
  • Role in Health Support
  • Summary of Food Sources
  • Nutrient Rating Chart
  • Impact of Cooking, Storage and Processing
  • Risk of Dietary Deficiency
  • Other Circumstances that Might Contribute to Deficiency
  • Relationship with Other Nutrients
  • Risk of Dietary Toxicity
  • Disease Checklist
  • Public Health Recommendations
  • References

Basic Description


Vitamin C may be the most familiar of all of the nutrients. Although most adults would be hard pressed to name a good food source of biotin or riboflavin, most everyone can name citrus fruits as good sources of vitamin C. It is also a commonly used nutritional supplement.
The first use of modern scientific methods to assess disease treatment was when the British navy used foods containing vitamin C (although the vitamin itself would remain undiscovered for nearly two centuries) to prevent scurvy among sailors. You could make a good case that this nutrition experiment is among the most important scientific findings in human history.
Despite the familiarity of the U.S. public with vitamin C and the popularity of vitamin C supplements, food intake of vitamin C by the average U.S. adult is not much higher than the Dietary Reference Intake (DRI) level. For men in the U.S. twenty years and older, this average is 96 milligrams per day, and for women in the U.S. twenty years and older, it is 82 milligrams per day. (The DRIs for these two groups are 90 milligrams and 75 milligrams, respectively.) So even though U.S. adults are averaging adequate intake of vitamin C intake from their food, the amount is not as high as some people might expect given widespread familiarity and interest in vitamin C.
Of the World's Healthiest Foods, a staggering 27 rate as excellent sources of vitamin C. Six of these contain a full day's requirement of vitamin C in a single serving. We also rate 14 very good and 14 good sources of the vitamin. This should give you plenty of variety with which to build a menu plan that easily exceeds your vitamin C goal.


Role in Health Support


Protection Against Excess Free Radicals


Vitamin C is probably best known as an antioxidant. This is a word that we use frequently but don't always stop to think about in terms of its meaning. Antioxidants are forms of molecules that help keep chemical reactions in our body in check. In particular, antioxidants help prevent excessive activity on the part of free radical molecules. (Free radicals are forms of molecules that tend to be very reactive, and too many free radicals in the wrong place at the wrong time can do damage to our cells and tissue.) Vitamin C and other antioxidants help prevent that damage. Damage to the lens of the eye, damage to molecules circulating around in our bloodstream, and damage to genetic material (DNA) in our cells are all examples of damage that have been shown to be prevented under certain circumstances by vitamin C.
One interesting application of vitamin C as an antioxidant is its ability to transform iron into a state that is better absorbed in the intestine. Including vitamin C-rich foods in recipes with your best iron sources can potentially be a way to enhance iron absorption.


Collagen


Vitamin C is required to produce collagen, a protein that plays a critical role in the structure of our bodies. Collagen is the framework for our skin and our bones, and without it, we would quite literally fall apart.
This is exactly what we see with severe vitamin C deficiency, or scurvy. People who have this condition lose teeth, bleed easily, and lose the strength of their bones. Luckily, it doesn't take much vitamin C to prevent this problem. As we've known for more than two centuries, a single lime per day would usually be enough. (However, as described earlier, we have dozens and dozens of great food choices that will give us as much vitamin C as a single lime!)


Brain Health


Vitamin C is necessary to make certain neurotransmitters. These neurotransmitters are the signals that carry thoughts, feelings, and commands around our brains and throughout our nervous system.
In particular, we need vitamin C to produce serotonin, a hormone that plays a critical role in wide variety of body systems, including the nervous system, endocrine system, immune system, and digestive system. Many of our moods, daily bodily rhythms (including sleep-wake cycles), and experiences of stress and pain have serotonin included as a factor in their occurrence. Some of the most commonly used prescription medications for depression (SSRIs, or Selective Serotonin Reupdate Inhibitors) also target this hormone. While we are not suggesting that dietary intake of vitamin C will automatically improve the quality of any experiences described above, we do recommend that you include vitamin C-rich foods on a daily basis as part of your overall well-being.


Summary of Food Sources


Our best food sources of vitamin C have a single thing in common: they are all plant foods. Even though many—even most—animals make vitamin C in their bodies, only plants make it to the degree that they provide a rich source of the nutrient when eaten.
Probably most of you associate citrus fruits with vitamin C. This is not a myth—all of our listed citrus fruits (orange, grapefruit, lime, and lemon) are excellent sources of vitamin C.
Many non-citrus fruits are highly rated sources, as well. Papaya, strawberries, pineapple, kiwifruit, cantaloupe, and raspberries are also excellent vitamin C sources. Cranberries, blueberries, and watermelon are examples of very good sources, while apples, pears, and bananas are in the good category. You should expect almost any fresh fruit to be a good, very good, or excellentsource of dietary vitamin C.
In addition, many vegetables contain vitamin C. All of the greens on our website are excellent sources of vitamin C. We are big fans of green leafy vegetables as sources of many nutrients and encourage their inclusion in daily diets. Our 3-Minute Swiss Chard is an easy and tasty recipe to get you started.
Many of the cruciferous vegetables are excellent sources of vitamin C. These foodshave many potential health benefits and are the focus of many of our recipes. Very good sources of vitamin C in the vegetable group include summer and winter squash, green beans, and carrots.
Our Herbs and Spices can also be very helpful in boosting your vitamin C intake. One WHFoods serving of parsley, for example, provides you with over half of our WHFoods recommended daily amount of vitamin C!
In case you are feeling lost in the flurry of good vitamin C sources, let's take a step back and make this easy. If you are getting two to three servings of fruit per day, and three to five servings of vegetables, you are almost certainly getting enough dietary vitamin C. If you find yourself worried, make sure you get a serving of fresh green leafy vegetables daily, since this amount will provide you with over one-third of the requirement in one sitting.


Nutrient Rating Chart


Introduction to Nutrient 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 World's Healthiest Foods that are either an excellent, very good, or good source of vitamin C. Next to each food name, you'll find the serving size we used to calculate the food's nutrient composition, the calories contained in the serving, the amount of vitamin C contained in one serving size of the food, 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.


World's Healthiest Foods ranked as quality sources of
vitamin C
FoodServing
Size
CalsAmount
(mg)
DRI/DV
(%)
Nutrient
Density
World's
Healthiest
Foods Rating
Papaya1 medium118.7168.0822434.0excellent
Bell Peppers1 cup28.5117.4815798.9excellent
Broccoli1 cup54.6101.2413544.5excellent
Brussels Sprouts1 cup56.296.7212941.3excellent
Strawberries1 cup46.184.6711344.1excellent
Pineapple1 cup82.578.8710522.9excellent
Oranges1 medium61.669.699327.2excellent
Kiwifruit1 2 inches42.163.968536.5excellent
Cantaloupe1 cup54.458.727825.9excellent
Cauliflower1 cup28.554.937346.2excellent
Kale1 cup36.453.307135.1excellent
Cabbage1 cup43.551.606928.5excellent
Bok Choy1 cup20.444.205952.0excellent
Grapefruit0.50 medium41.044.035925.8excellent
Parsley0.50 cup10.940.435488.7excellent
Turnip Greens1 cup28.839.465332.9excellent
Beet Greens1 cup38.935.864822.1excellent
Mustard Greens1 cup36.435.424723.4excellent
Collard Greens1 cup62.734.584613.2excellent
Raspberries1 cup64.032.234312.1excellent
Swiss Chard1 cup35.031.504221.6excellent
Tomatoes1 cup32.424.663318.3excellent
Lemons and Limes0.25 cup13.423.613142.2excellent
Spinach1 cup41.417.642410.2excellent
Asparagus1 cup39.613.86188.4excellent
Sea Vegetables1 TBS10.812.161626.9excellent
Fennel1 cup27.010.44149.3excellent
Thyme2 TBS4.87.681038.0excellent
Sweet Potato1 cup180.039.20525.2very good
Winter Squash1 cup75.819.68266.2very good
Green Peas1 cup115.719.56264.1very good
Blueberries1 cup84.414.36194.1very good
Cranberries1 cup46.013.30186.9very good
Watermelon1 cup45.612.31166.5very good
Green Beans1 cup43.812.13166.7very good
Summer Squash1 cup36.09.90136.6very good
Carrots1 cup50.07.20103.5very good
Plum1 2-1/8 inches30.46.2785.0very good
Garlic6 cloves26.85.6275.0very good
Basil0.50 cup4.93.82518.8very good
Dill0.50 cup1.93.78547.5very good
Romaine Lettuce2 cups16.03.7655.6very good
Potatoes1 cup160.916.61222.5good
Avocado1 cup240.015.00201.5good
Onions1 cup92.410.92152.8good
Banana1 medium105.010.27142.3good
Apple1 medium94.68.37112.1good
Pear1 medium101.57.65101.8good
Beets1 cup74.86.1282.0good
Leeks1 cup32.24.3763.3good
Apricot1 whole16.83.5055.0good
Celery1 cup16.23.1344.6good
Cucumber1 cup15.62.9144.5good
Peppermint2 TBS5.32.42310.9good
Cilantro0.50 cup1.82.16328.2good
World's Healthiest
Foods Rating
Rule
excellentDRI/DV>=75% OR
Density>=7.6 AND DRI/DV>=10%
very goodDRI/DV>=50% OR
Density>=3.4 AND DRI/DV>=5%
goodDRI/DV>=25% OR
Density>=1.5 AND DRI/DV>=2.5%


Impact of Cooking, Storage and Processing


The same thing that makes vitamin C so important—its ability to protect against free radical damage—also makes it very prone to damage by heat, oxygen, and storage over time. In fact, the relative instability of vitamin C in foods presents a compelling argument in favor of fresh food dietary approaches like the one we advocate at World's Healthiest Foods.
The vitamin C content of food will start to decline as soon as it is picked, even though this decline can be slowed down and minimized by cooling and retention of the food in its whole form. But a fresh, vitamin C-rich vegetable like broccoli—if allowed to sit at room temperature for 6 days—can lose almost 80% of its vitamin C. That potential vitamin C loss is one of the reasons it is so important to store broccoli (and all other vitamin C-rich foods) according to the methods that we describe in our individual food profiles. All of our food profiles include sections on How to Select and Store, and for each food we provide you with exact storage times and conditions that will help minimize nutrient loss from each food.
Long-term storage of vegetables can cost a significant amount of vitamin C. Kept frozen for a year, kale can lose half its vitamin C or more. Canning is even more detrimental, with 85% of the original vitamin C lost over the same year.
While cooking will lower the amount of vitamin C in most foods, but the amount of vitamin C lost will vary widely by cooking method. For example, basket-steaming broccoli for 15 minutes will reduce the vitamin C content by nearly one quarter. That's one of the reasons why our WHFoods method for steaming broccoli never lasts longer than 5 minutes!


Risk of Dietary Deficiency


As described earlier, the average dietary intake for vitamin C in the United States is just above the Dietary Reference Intake (DRI) level for both adult men and adult women. From this standpoint, U.S. adults aren't at significant risk for vitamin C deficiency. However, average total calorie intake in the U.S. also tends to be too high, and while we may be doing okay in terms of our average vitamin C intake, we may also be overeating in order to do so. Whole, natural foods—especially fresh vegetables—can play a major role in providing ample vitamin C without increasing the risk of overeating. It's one of the reasons we recommend this food group so highly.
At the risk of oversimplifying, if you are eating multiple servings of fresh fruits and vegetables every day, you are very likely to be getting enough vitamin C.


Other Circumstances that Might Contribute to Deficiency


Since smoking increases free radical damage, smokers will need more dietary vitamin C. The National Academy of Sciences recommends that smokers get an extra 35 mg of vitamin C every day, about the amount found in one-half of a medium orange.

Relationship with Other Nutrients

Vitamin C can increase the absorption of iron (especially the iron found in plant foods) and may help lower the risk of dietary iron deficiency. You'll sometimes see us recommending the additional of a vitamin C-rich food to meals and recipes for this reason.
Antioxidants in foods tend to work together in important and synergistic ways to provide protection against free radical damage. The most well-known of these connections is that between vitamin E and vitamin C. Specifically, vitamin C helps to protect vitamin E in people, such as smokers, who have chronic overproduction of free radicals.
Similarly, we see the flavonoid class of plant-based antioxidants helping to make the free radical protection from vitamin C that much stronger. This is great news, given that the foods that are most flavonoid-rich also tend to be among our better vitamin C sources. This synergistic protection is but one of many potential explanations for why the health benefits of plant-based diets cannot be replicated by nutrient supplements.
A great example of vitamin C and flavonoids in a whole, natural food is fresh oranges. In this fruit, most of the vitamin C is found in the watery orange-colored portions, while many of the flavonoids are found in the white-colored linings and section dividers. (This distribution of vitamin C and flavonoids in oranges is one of the reasons that it can be helpful to consume the "pulp" along with the juice if you decide to consume a processed juice version of this food.)


Risk of Dietary Toxicity


The National Academy of Sciences has established a Tolerable Upper Intake Level (UL) of 2000 mg per day for adults. While it is plausible that in rare situations—particularly with a rich intake of citrus juices—an individual could be above this UL from foods alone, we are not aware of any evidence to suggest that vitamin C intake from foods ever is responsible for toxicity symptoms.


Disease Checklist

  • Common cold
  • Scurvy
  • Capillary fragility
  • Asthma
  • Gingivitis
  • Gout
  • Musculoskeletal injury
  • High blood pressure
  • Seasonal allergies
  • Smoking


Public Health Recommendations


In 2000, the National Academy of Sciences released a set of Dietary Reference Intakes (DRI) for vitamin C that included a range of Recommended Dietary Allowances (RDA) by age and gender. These are summarized in the chart below. (Note that the recommendations for infants under age one are Adequate Intake (AI) standards.) 
  • 0-6 months: 40 mg
  • 6-12 months: 50 mg
  • 1-3 years: 15 mg
  • 4-8 years: 25 mg
  • 9-13 years: 45 mg
  • 14-18 years, female: 65 mg
  • 14-18 years, male: 75 mg
  • 19+ years, female: 75 mg
  • 19+ years, male: 90 mg
  • Pregnant women, 14-18 years: 80 mg
  • Pregnant women, 19+ years: 85 mg
  • Lactating women, 14-18 years: 115 mg
  • Lactating women, 19+ years: 120 mg
The 2000 DRI report also included a Tolerable Upper Intake Level (UL) for vitamin C of 2000 mg for adults. Although the report does not draw a distinction between dietary vitamin C and supplements, it would be hard to routinely go above this UL from food alone.
According to the DRI, smokers require extra vitamin C, and should add 35 mg to their daily RDA from the chart above. You'd find those 35 mg in a single serving of beet or mustard greens.
The Daily Value (DV) of vitamin C that you'll see on food labels is 60 mg.
We adopted 75 milligrams per day—the DRI for adult women 19 years and older—as our WHFoods recommended daily intake level for vitamin C.

References

  • Bruno RS, Ramakrishnan R, Montine TJ, et al. Alpha-tocopherol disappearance is faster in cigarette smokers and is inversely related to their ascorbic acid levels. Am J Clin Nutr. 2005;81:95-103.
  • Carr AC, Frei B. Toward a new recommended dietary allowance for vitamin C based on antioxidant and health effects in humans. Am J Clin Nutr 1999;69:1086-107.
  • Felicetti E, Mattheis JP. Quantification and histochemical localization of ascorbic acid in ‘Delicious,’ ‘Golden Delicious,’ and ‘Fuji’ apple fruit during on-tree development and cold storage. Postharvest Biol Tech 2010;56:56-63.
  • Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: National Academy Press; 2000;284-324.
  • Frei B, Birlouez-Aragon I, Lykkesfeldt J. Authors’ perspective: What is the optimal intake of vitamin C in humans? Crit Rev Food Sci Nutr 2012;52:815-29.
  • Korus A, Lisiewska Z. Effect of preliminary processing and method of preservation on the content of selected antioxidative compounds in kale (Brassica oleracea L. var. acephala) leaves. Food Chem 2011;129:149-54.
  • Pellegrini N, Chiavaro E, Gardana C, et al. Effect of different cooking methods on color, phytochemical concentration, and antioxidant capacity of raw and frozen Brassica vegetables. J Agric Food Chem 2010;58:4310-21.
  • Raseetha S, Leong SY, Burritt DJ, et al. Understanding the degradation of ascorbic acid and glutathione in relation to the levels of oxidative stress biomarkers in broccoli (Brassica oleracea L. italica cv. Bellstar) during storage and mechanical processing. Food Chem 2013;138:1360-9.
  • Sanhueza C, Ryan L, Foxcroft DR. Diet and the risk of unipolar depression in adults: systematic review of cohort studies. J Hum Nutr Diet 2013;26:56-70.
  • Zhan L, Hu J, Ai Z, et al. Light exposure during storage preserving soluble sugar and L-ascorbic acid content of minimally processed romaine lettuce (Lactuca sativa L. var. longifolia). Food Chem 2013;136:273-8.


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