Cranberries: Health benefits, nutritional content, and risks
Cranberries are a favorite part of Thanksgiving celebrations, consumed as cranberry sauce, cranberry drinks, and dried cranberries added to stuffing, casseroles or dessert.
No one knows for sure how they became associated with holiday feasts, but historians guess it had something to do with the Native Americans, who used cranberries not only for food and medicine but also to make dyes for clothing and blankets.
Cranberries are native to North America. They are farmed on approximately 40,000 acres across the northern United States (U.S.) and Canada.
Cranberries are a healthful food, due to their high nutrient and antioxidant content. They are often referred to as a "super food." Half a cup of cranberries contains only 25 calories.
The nutrients in cranberries have been linked to a lower risk of urinary tract infections, prevention of certain types of cancer, improved immune function, and decreased blood pressure.
This MNT Knowledge Center feature is part of a collection of articles on the health benefits of popular foods.
Possible health benefits of cranberries
A diet with a high proportion of fruits and vegetables has been shown to offer health benefits.
In addition, cranberries are a good source of various vitamins and antioxidants.
Historically, they have been used by Native Americans as a treatment for bladder and kidney diseases.
Early settlers from England used them to treat poor appetite, stomach complaints, blood disorders, and scurvy.
Here are some ways that cranberries can enhance health:
1) Urinary Tract Infections (UTIs)
The cranberry is perhaps best known for its role in preventing UTIs, especially for those with recurrent infections. The high level of antioxidant proanthocyanidins (PACs) in cranberries helps to stop certain bacteria from adhering to the urinary tract walls. In this way, the PACs in cranberries help prevent infection.
However, researchers at the Texas A&M Health Science Center College of Medicine in Houston found that while cranberry capsules can do this, cranberry juice is unlikely to have the same effect. This is because it takes an very high concentration of cranberry to prevent bacterial adhesion. The juices we drink do not contain such high amounts of PACs.
"Cranberry juice, especially the juice concentrates you find at the grocery store, will not treat a UTI or bladder infection. It can offer more hydration and possibly wash bacteria from your body more effectively, but the active ingredient in cranberry is long gone by the time it reaches your bladder."
Dr. Timothy Boone, PhD, vice dean of the Texas A&M Health Science Center College of Medicine in Houston
2) Cardiovascular Disease
Some evidence suggests that the polyphenols in cranberries may reduce the risk of cardiovascular disease (CVD). It does this by preventing platelet build-up and reducing blood pressure, through anti-inflammatory mechanisms.
Research has shown that the nutrients in cranberries can help slow tumor progression, and that they can have a positive impact on prostate, liver, breast, ovarian, and colon cancers.
The proanthocyanidins in cranberries may also benefit oral health. They do this by preventing bacteria from binding to teeth, according to researchers at the Center for Oral Biology and Eastman Department of Dentistry at the University of Rochester Medical Center. Cranberries may also be beneficial in preventing gum disease.
One half cup (55 grams) of chopped cranberries contains:
0.25 grams (g) of protein
0.07 g of fat
6.6 g of carbohydrate, including 2.35 g of sugar
2 g of fiber
5 milligrams (mg) of calcium
0.12 mg of iron
3.5 mg of magnesium
6 mg of phosphorus
44 mg of potassium
1 mg of sodium
0.05 mg of zinc
7.7 mg of vitamin C
0.5 micrograms (mcg) of folate DFE
35 IU of Vitamin A
0.72 mg of vitamin E
2.75 mcg of vitamin K
Cranberries also contain the B vitaimins thiamin, riboflavin, niacin, and vitamin B6.
They are a good source of vitamin C, fiber, and vitamin E.
Vitamin C is a powerful, natural antioxidant. According to the National Institutes of Health (NIH), not only can Vitamin C block some of the damage caused by free radicals, but it also improves iron absorption from plant sources, boosts the immune system, and aids in making collagen which helps wound healing.
High fiber intakes are associated with significantly lower risks for developing a range of health conditions, including coronary heart disease, stroke, hypertension, diabetes, obesity, and certain gastrointestinal diseases.
Increased fiber intake has also been shown to lower blood pressure and cholesterol levels, improve insulin sensitivity, and enhance weight loss for obese individuals.
Vitamin E is a fat-soluble antioxidant that is involved in immune function. It may help prevent or delay the chronic diseases associated with free radicals, such as heart disease, cancer, cataracts, Alzheimer's, and arthritis.
Cranberries also contain vitamin K, manganese, and a large array of phytonutrients. These are naturally occurring plant chemicals that help to protect the body from harmful free radicals. They have anti-inflammatory and cancer-preventing properties.
Incorporating more cranberries in the diet
Fresh cranberries are harvested in September and October, so fall is the best time to get them in season. They can be refrigerated for up to 2 months, and they can be frozen for later use. Cranberries should be firm to the touch and unwrinkled.
They are also available dried or in a can, but some may contain added sugars. Check the ingredient label and make sure that the product contains cranberries only.
Cranberry juice is often mixed with other fruits and added sweeteners. Look for juice with cranberries as the first ingredient.
Cranberry sauce is an important part of any Thanksgiving meal, but there are many other ways to enjoy this fruit all year round.
Here are some tips:
- Make a homemade trail mix with unsalted nuts, seeds, and dried cranberries.
- Include a small handful of frozen cranberries in a fruit smoothie.
- Add dried cranberries to your oatmeal or whole grain cereal.
- Toss dried or fresh cranberries into your favorite muffins or cookie recipe.
- Include fresh cranberries in an apple dessert like pie or cobbler for extra flavor.