Among the fruits and vegetables richest in health-promoting antioxidants, berries such as cranberries rank right up there at the top of the list. Antioxidants are essential to optimizing health by helping to combat the free radicals that can damage cellular structures as well as DNA. Provided that you do not experience any digestive difficulty, we recommend enjoying cranberries raw because they provide you with the best flavor and the greatest benefits from their vast array of nutrients, and may also offer the benefit of digestion-aiding enzymes.
The cranberry "presscake" (or what is left behind in terms of skins and flesh after the juice has been processed out) typically contains the bulk of the phytonutrients when evaluated in lab studies.
When speaking in general terms about the health benefits of cranberries, it is important to know that the most commonly consumed form of this food is juice processed from the berries and typically produced by adding generous amounts of sugar.
This form of cranberry CANNOT provide you with cranberry's full phytonutrient benefits.
Cranberries have long been valued for their ability to help prevent and treat urinary tract infections. Now, recent studies suggest that this native American berry may also promote gastrointestinal and oral health, lower LDL and raise HDL (good) cholesterol, aid in recovery from stroke, and even help prevent cancer.
While the acidity of cranberries was at one time an important target of research, we now know that cranberry's ability to provide UTI benefits is not primarily related to its acidity, but rather to its proanthocyanidin (PAC) content. The PACs in cranberry have a special structure (called A-type linkages) that makes it more difficult for certain types of bacteria to latch on to our urinary tract linings. Include in these types of bacteria are pathogenic (infection-causing) strains of E. coli - one of the most common microorganisms involved in UTIs. By making it more difficult for unwanted bacteria like E. coli to cling onto the urinary tract linings, cranberry's PACs help prevent the expansion of bacterial populations that can result in outright infection.
Also, prevention of stomach ulcers is one very intriguing new direction in the cranberry research, based on this exact same principle of blocking bacterial adhesion to the lining of an organ system. (In the case of stomach ulcer, it's the stomach lining that's at risk, and the bacteria involved are the Helicobacter pylori bacteria.) For the cardiovascular system and for many parts of the digestive tract (including the mouth and gums, stomach, and colon) cranberry has been shown to provide important anti-inflammatory benefits. It's the phytonutrients in cranberry that are especially effective in lowering our risk of unwanted inflammation, and virtually all of the phytonutrient categories represented in cranberry are now known to play a role. These phytonutrient categories include proanthocyanidins (PACs), anthocyanins (the flavonoid pigments that give cranberries their amazing shades of red), flavonols like quercetin, and phenolic acid (like hydroxycinnamic acids).
In the case of our gums, the anti-inflammatory properties of cranberry can help us lower our risk of periodontal disease. Chronic, excessive levels of inflammation around our gums can damage the tissues that support our teeth. It's exactly this kind of inflammation that gets triggered by ongoing overproduction of certain cytokines. (Cytokines are messaging molecules, and the pro-inflammatory cytokines tell our cells to mount an inflammatory response. As messages are sent more frequently and more constantly, the inflammatory response becomes greater.) Phytonutrients in cranberry help reduce this inflammatory cascade of events precisely at the cytokine level.
Production of pro-inflammatory cytokines like interleukin 6 (IL-6) and RANTES (Regulated on Activation Normal T-cell Expressed and Secreted) is lowered by the activity of cranberry phytonutrients. In addition, cranberry phytonutrients inhibit the activity of the enzymes cyclo-oxygenase 1 (COX-1) and cyclo-oxygenase 2 (COX-2). These COX-1 and COX-2 enzymes are key factors in the production of other pro-inflammatory messaging molecules, and by inhibiting these enzymes, cranberry's phytonutrients significantly lower our risk of unwanted inflammation.
Dietary consumption of cranberry has also been shown to reduce the risk of chronic, unwanted inflammation in the
stomach, large intestine (colon) and cardiovascular system (especially blood vessel linings).
Although previously mentioned in this Health Benefits section, the antioxidants found in cranberry are especially important contributors to its potential for health support. From a research perspective, there are two especially important points to consider when thinking about the antioxidant benefits of cranberries. First is the amazing array of antioxidants that are found exclusively in whole cranberries. Cranberry's special combination of phenolic antioxidants, proanthocyanidin antioxidants, anthocyanin antioxidants, flavonoid antioxidants, and triterpenoid antioxidants is without a doubt unique. Also, unique is the particular combination of three antioxidant nutrients-resveratrol, piceatannol, and pterostilbene-found in cranberry. Second are the research findings regarding the synergy between these nutrients. The phytonutrients in cranberry provide maximal antioxidant benefits only when consumed in combination with each other, and also only when consumed alongside of conventional antioxidant nutrients present in cranberry like manganese and vitamin C. When cranberry processing disrupts this antioxidant combination, health benefits from cranberry are decreased. Multiple studies in multiple health benefit areas point to this same conclusion-it's the overall blend of cranberry antioxidants that provides us with the strongest health benefits.
One further point about cranberry antioxidant research seems worthy of mention. In several research studies, cranberries were unable to provide significant antioxidant benefits when those benefits were measured in terms of blood values. In these studies, it took a much closer look at activities going on inside of our cells to demonstrate the antioxidant benefits of cranberries. The need to look inside of our cells to find cranberry antioxidant benefits may be telling us that the special value of cranberries may often involve metabolic events that are taking place "behind the scenes." In other words, these benefits may sometimes be missed in more broadly focused research studies, and cranberry may in fact have a stronger research track record than previously assumed.
No area of cranberry research has been more intriguing in the past 10 years than research on cranberry and cancer, even though the majority of studies in this area have involved lab studies on human cancer cells or animal experiments. On a virtual year-by-year basis, scientists continue to identify new mechanisms that establish cranberries as anti-cancer agents.
These mechanisms are now known to include: blocked expression of MMPs (matrix metalloproteinases); inhibition of ODC (ornithine decarboxylase enzymes); stimulation of QRs (quinone reductase enzymes); inhibition of CYP2C9s (Phase I detoxification enzymes); and triggering of apoptosis (programmed cell death) in tumor cells. It's important to point out that this amazing list of anti-cancer properties in cranberry is not sufficient to establish cranberry as a food to be used in the treatment of cancer. However, it is a list that appears consistent with other studies of cranberry and cancer showing dietary intake of this food to help prevent cancer occurrence.
These cancer-preventive benefits of cranberry are especially likely in the case of breast, colon, lung, and prostate cancer. None of the cancer-related benefits of cranberries should be surprising, since cranberry is loaded with antioxidant and anti-inflammatory nutrients. Chronic excessive oxidative stress (from lack of sufficient antioxidant support) and chronic excessive inflammation (from lack of sufficient anti-
inflammatory compounds) are two key risk factors promoting increased likelihood of cancer. With its unique array of antioxidant and anti-inflammatory nutrients, cranberry seems ideally positioned to help us lower our risk of cancer development.
Digestive Tract Benefits:
When you add up the health-related benefits of cranberry for our mouth and gums (decreased risk of periodontal disease), stomach (decreased risk of stomach ulcer), and colon (decreased risk of colon cancer), it's impossible not to conclude that cranberry is unique among fruits in its ability to provide us with digestive tract benefits. Every category of phytonutrient known to be provided by cranberry is also known to play a role in digestive tract support. In the case of cranberry's proanthocyanidins, it's decreased adherence of the bacterium Helicobacter pylori to our stomach wall that's made possible by intake of cranberry. In the case of cranberry's flavonoids, anthocyanins and triterpenoids, provide antioxidant and anti-inflammatory benefits that decrease our risk of colon cancer, and also our risk of periodontal disease.
Recent research has also shown that cranberry may be able to help optimize the balance of bacteria in our digestive tract.
Health Benefits & Nutritional Profile:
Participants in one recent study involving cranberry juice intake (in amounts of approximately 2 ounces per day and over the course of about 3 months) were able to increase the numbers of Bifidobacteria in their digestive tract while maintaining other bacterial types (Bifidobacteria are typically considered to be a desirable and "friendly" type of bacteria). As a result, the relative amount of Bifidobacteria was increased, and the bacterial environment of the digestive tract may have become more favorable. Given the vast array of phytonutrients in cranberry and the known connection between so many of these phytonutrients and digestive tract health, we expect to see the digestive benefits of cranberry becoming more and more apparent in future research on this incredible berry.
While familiar nutrients like vitamin C and fiber play a very important role in cranberry's health benefits, it's the astonishing array of phytonutrients in cranberries that has gotten the special attention of health researchers. There are at least 5 key categories of health-supportive phytonutrients in cranberries, as summarized in the following chart:
Phytonutrient Type: Specific Molecules:
- Phenolic Acids: Hydroxybenzoic acids including vanillic acids; hydroxycinnamic acids including caffeic, coumaric, cinnamic, & ferulic acids
- Proanthocyanidins: Epicatechins
- Anthocyanins: Cyanidins, malvidins, & peonidins
- Flavonoids: Quercetin, myricetin, kaempferol
- Triterpenoids: Ursolic acid
The vast majority of phytonutrients presented in this chart have been studied for their antioxidant, anti-inflammatory, and anti-cancer properties, and in many cases the results have been impressive. Equally important in the cranberry research has been the finding that isolated phytonutrients in cranberry do not account for the same degree of health benefit as phytonutrients taken as a complete, synergistic group. What this research finding means is simple: it's the whole cranberry that supports our health best.
Many of these phytonutrients offer:
- Antioxidant health benefits
- Anti-inflammatory health benefits, and
- Anti-cancer health benefits.
Cranberries are an excellent source of:
- Vitamin C
- A very good source of dietary Fiber
- A good source of Manganese and
- A good source of Vitamin K.
Cranberries were used by the Indians decoratively, as a source of red dye, and medicinally, as a poultice for wounds since not only do their astringent tannins contract tissues and help stop bleeding, but we now also know that compounds in cranberries have antibiotic effects.
Fresh cranberries, which contain the highest levels of beneficial nutrients, are at their peak from October through December, just in time to add their festive hue, tart tangy flavor and numerous health protective effects to your holiday meals. When cranberries' short fresh season is past, rely on frozen cranberries, dried cranberries, or unsweetened cranberry juice made from whole berries to help make every day throughout the year a holiday from disease.
How to Select and Store:
A fruit with a short season, fresh cranberries are harvested between Labor Day and Halloween and appear in markets from October through December. Choose fresh, plump cranberries, deep red in color, and quite firm to the touch. Firmness is a primary indicator of quality. In fact, during harvesting, high quality cranberries are often sorted from lesser quality fruits by bouncing the berries against barriers made of slanted boards. The best berries bounce over the barriers, while the inferior ones collect in the reject pile.The deeper red their color, the more highly concentrated are cranberries' beneficial anthocyanin compounds. The Early Black cultivar (variety) of cranberry-with its particularly deep red color-has been found in one research study to have the highest concentration of anthocyanins.
Although typically packed in 12-ounce plastic bags, fresh cranberries, especially if organic, may be available in pint containers. Fresh ripe cranberries can be stored in the refrigerator for up to 20 days. Before storing, discard any soft, discolored, pitted or shriveled fruits. When removed from the refrigerator, cranberries may look damp, but such moistness does not indicate spoilage, unless the berries are discolored or feel sticky, leathery or tough. Once frozen, cranberries may be kept for several years.
To freeze, spread fresh cranberries out on a cookie sheet and place in the freezer. In a couple of hours, the fully frozen berries will be ready to transfer to a freezer bag. Don't forget to date the bag before returning to the freezer. Once thawed, frozen berries will be quite soft and should be used immediately.
Dried cranberries are sold in many groceries and may be found with other dried fruits.
Tips for preparing cranberries:
While not as fragile as blueberries, fresh cranberries should be treated with care. Just prior to use, place cranberries in a strainer and briefly and gently rinse under cool running water.
When using frozen berries in recipes that do not require cooking, thaw well and drain prior to using. For cooked recipes, use unthawed berries since this will ensure maximum flavor. Extend the cooking time a few minutes to accommodate for the frozen berries.
Healthiest Way of Preparing Cranberries:
Cranberries retain their maximum amount of nutrients and their maximum taste when they are enjoyed fresh and not prepared in a cooked recipe. That is because their nutrients—including vitamins, antioxidants, and enzymes- are unable to withstand the temperature (350̊F/175̊C) used in baking.
A few quick serving ideas:
- Take advantage of cranberries' tartness by using them to replace vinegar or lemon when dressing your green salads.
- Add color and zest to a green salad with a handful of raw cranberries.
- To balance their extreme tartness, combine fresh cranberries with other fruits such as oranges, apples, pineapple or pears. If desired, add a little fruit juice, honey, maple syrup, or agave to chopped fresh cranberries.
- For an easy-to-make fruit salad, place 2 cups fresh berries in your blender along with ½ cup of pineapple chunks, a quartered skinned orange, a sweet apple (such as one of the Delicious variety) and a handful or two of raw walnuts or pecans. Blend till well mixed but still chunky.
- Combine whole blended cranberries in equal parts with your favorite fruit juice and sparkling mineral water for a lightly sweetened, refreshing spritzer. For even more color appeal, garnish with a slice of lime.
- Use dried cranberries in anything you may add raisins.
- Mix dried cranberries with raw nuts & seeds for a delicious snack.
Cranberries and Oxalates:
Cranberries are among a small number of foods that contain measurable amounts of oxalates, naturally -occurring substances found in plants, animals, and human beings. The relationship between cranberries and formation of kidney stones containing oxalates is not what you might expect, however. In the case of cranberries, the oxalate content is actually quite low, between 5-7 milligrams per 3.5 ounces. However, despite their low oxalate content, cranberries are able to increase the amount of both oxalates and calcium in the urine, resulting in urine with increased concentrations of calcium oxalate. (The acidity of cranberries and other aspects of their chemical composition appear responsible for this impact on the urine.) Individuals at risk of calcium oxalate kidney stone formation will most likely want to avoid cranberries for the above reasons, and if considering inclusion of cranberries in their diet, should consult beforehand with a qualified healthcare provider. For some other, less common types of kidney stones - including struvite stones (containing magnesium sulfate) and brushite stones (one form of stones containing calcium phosphate), intake of cranberry juice may actually help lower a person's risk. As you can see, the relationship between cranberry juice and kidney stones can sometimes be confusing, and for this reason, if you are in doubt about this aspect of your health, we recommend a consult with your healthcare provider before making a decision about cranberries in your diet.
Cranberries and Warfarin:
Warfarin is a prescription anticoagulant medication that has widely been used to help prevent formation of blood clots in individuals with a strong tendency toward clotting, and to help prevent future episodes in individuals who have already experienced formation of unwanted blood clots. Over the past ten years, there have been a small number of published case studies reporting cranberry juice-related problems by individuals taking warfarin. Despite the small number of cases, however, these reported problems have been quite serious, and in one circumstance, involved the death of an individual who was following his doctor's medical prescription for warfarin and while also consuming cranberry juice. The connection between cranberry juice and warfarin treatment has now been clearly shown to involve the detoxification enzyme family CYP2C9. The activity of this enzyme family is needed to break down warfarin so that its anticoagulant activity does not become excessive. (If CYP2C9 enzymes in the liver cannot successfully metabolize and neutralize warfarin, it can become too difficult for a person to stop an occurrence of bleeding.) Even though we now know that cranberry juice can inhibit CYP2C9 enzymes, researchers are still not clear about the risk posed by cranberries and cranberry juice for individuals who have been placed on a warfarin prescription. In lab studies, cranberry juice has repeatedly been shown to inhibit the breakdown of warfarin by CYP2C9 enzymes. However, in a recent study on health human volunteers who consumed three 8.5-ounce glasses of double-strength cranberry juice along with a single dose of warfarin, this inhibiting of CYP29C enzymes failed to occur. Overall, these research results seem somewhat confusing, and to err on the safe side, we encourage and recommend that all persons taking warfarin consult with their healthcare provider before incorporating cranberries or cranberry juice into the diet.