Cranberries are a member of the heather family and related to blueberries, bilberries, and lingonberries.

The most commonly grown species is the North American cranberry (Vaccinium macrocarpon), but other types are found in nature.

Due to their very sharp and sour taste, cranberries are rarely eaten raw.

In fact, they’re most often consumed as juice, which is normally sweetened and blended with other fruit juices.

Other cranberry-based products include sauces, dried cranberries, and powders and extracts used in supplements.

Cranberries are rich in various healthy vitamins and plant compounds, some of which have been shown to be effective against urinary tract infections (UTIs).

This article tells you everything you need to know about cranberries, including their nutrition facts and health benefits.

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Fresh cranberries are nearly 90% water, but the rest is mostly carbs and fiber.

The main nutrients in 1 cup (100 grams) of raw, unsweetened cranberries are ():

  • Calories: 46
  • Water: 87%
  • Protein: 0.4 grams
  • Carbs: 12.2 grams
  • Sugar: 4 grams
  • Fiber: 4.6 grams
  • Fat: 0.1 grams

Carbs and Fiber

Cranberries are primarily composed of carbs and fiber ().

These are mainly simple sugars, such as sucrose, glucose, and fructose ().

The rest is made up of insoluble fiber — such as pectin, cellulose, and hemicellulose — which pass through your gut almost intact.

Cranberries also contain soluble fiber. For this reason, excessive consumption of cranberries may cause digestive symptoms, such as diarrhea.

On the other hand, cranberry juice contains virtually no fiber and is usually diluted with other fruit juices — and sweetened with added sugar ().

Vitamins and Minerals

Cranberries are a rich source of several vitamins and minerals, especially vitamin C.

  • Vitamin C. Also known as ascorbic acid, vitamin C is one of the predominant antioxidants in cranberries. It is essential for the maintenance of your skin, muscles, and bone.
  • Manganese. Found in most foods, manganese is essential for growth, metabolism, and your body’s antioxidant system.
  • Vitamin E. A class of essential fat-soluble antioxidants.
  • Vitamin K1. Also known as phylloquinone, vitamin K1 is essential for blood clotting.
  • Copper. A trace element, often low in the Western diet. Inadequate copper intake may have adverse effects on heart health ().
SUMMARY Cranberries are primarily made up of carbs and fiber. They also boast several vitamins and minerals, including manganese, copper, and vitamins C, E, and K1. Keep in mind that cranberry juice has almost no fiber.

Cranberries are very high in bioactive plant compounds and antioxidants — particularly flavonol polyphenols (, , ).

Many of these plant compounds are concentrated in the skin — and are greatly reduced in cranberry juice ().

  • Quercetin. The most abundant antioxidant polyphenol in cranberries. In fact, cranberries are among the main fruit sources of quercetin (, , ).
  • Myricetin. A major antioxidant polyphenol in cranberries, myricetin may have a number of beneficial health effects (, ).
  • Peonidin. Alongside cyanidin, peonidin is responsible for the rich red color of cranberries and some of their health effects. Cranberries are among the richest dietary sources of peonidin (, ).
  • Ursolic acid. Concentrated in the skin, ursolic acid is a triterpene compound. It’s an ingredient in many traditional herbal medicines and has strong anti-inflammatory effects (, ).
  • A-type proanthocyanidins. Also called condensed tannins, these polyphenols are believed to be effective against UTIs (, 13, ).
SUMMARY Cranberries are a rich source of various bioactive plant compounds. Some of these, such as A-type proanthocyanidins, may help prevent UTIs.

UTIs are among the most common bacterial infections — especially among women ().

They’re most often caused by the intestinal bacterium Escherichia coli (E. coli), which attaches itself to the inner surface of your bladder and urinary tract.

Cranberries contain unique phytonutrients known as A-type proanthocyanidins or condensed tannins.

A-type proanthocyanidins prevent E. coli from attaching to the lining of your bladder and urinary tract, making cranberries a potential preventive measure against UTIs (13, , , , ).

In fact, cranberries are among the richest fruit sources of proanthocyanidins — especially the A-type (, ).

A number of human studies indicate that drinking cranberry juice or taking cranberry supplements may reduce the risk of UTIs in both children and adults (, , , , , , ).

Systematic reviews and meta-analyses support these findings, especially for women with recurrent UTIs (, , ).

In contrast, a few studies have not found any significant benefits (, , ).

Not all cranberry products are effective against UTIs. In fact, proanthocyanidins may be lost during processing, making them undetectable in many products ().

On the other hand, cranberry supplements — which contain sufficient amounts of A-type proanthocyanidins — may be a useful preventive strategy.

If you suspect that you have a UTI, talk to your healthcare professional. The primary course of treatment should be antibiotics.

Keep in mind that cranberries are not effective for treating infections. They only reduce your risk of getting them in the first place.

SUMMARY Cranberry juice and supplements may reduce your risk of UTIs. However, they do not treat this infection.

Cranberries may have a number of other beneficial health effects.

Prevention of Stomach Cancer and Ulcers

Stomach cancer is a common cause of cancer-related death worldwide ().

Infection by the bacterium Helicobacter pylori (H. pylori) is considered a major cause of stomach cancer, stomach inflammation, and ulcers (, , , ).

Cranberries contain unique plant compounds known as A-type proanthocyanidins, which may cut your risk of stomach cancer by preventing H. pylori from attaching to the lining of your stomach (, , , ).

One study in 189 adults suggested that drinking 2.1 cups (500 ml) of cranberry juice daily may significantly reduce H. pylori infections ().

Another study in 295 children found that daily consumption of cranberry juice for 3 weeks suppressed the growth of H. pylori in about 17% of those infected ().

Heart Health

Heart disease is the leading cause of death worldwide.

Cranberries contain various antioxidants that may be beneficial for heart health. These include anthocyanins, proanthocyanidins, and quercetin (, , , ).

In human studies, cranberry juice or extracts have proven beneficial for various heart disease risk factors. Cranberry products may help by (, , , , , ):

  • increasing your levels of HDL (good) cholesterol
  • lowering levels of LDL (bad) cholesterol in people with diabetes
  • protecting LDL (bad) cholesterol from oxidation
  • decreasing stiffness in blood vessels among people with heart disease
  • lowering blood pressure
  • decreasing blood levels of homocysteine, thus cutting your risk of inflammation in blood vessels

That said, not all studies found similar results.

SUMMARY If consumed regularly, cranberries or cranberry juice may reduce your risk of stomach cancer. The juice and extract also improve several risk factors for heart disease, including cholesterol levels and blood pressure.

Cranberries and cranberry products are usually safe for most people if consumed in moderation.

However, excessive consumption may cause stomach upset and diarrhea — and may also increase the risk of kidney stones in predisposed individuals.

Kidney Stones

Kidney stones form when certain minerals in your urine reach high concentrations. It is often very painful.

You can minimize your risk through your diet.

Most kidney stones are made of calcium oxalate, so excessive amounts of oxalate in your urine is one of the main risk factors ().

Cranberries — especially concentrated cranberry extracts — may contain high levels of oxalates. For this reason, they are considered a risk factor for kidney stones when consumed in high amounts (, , ).

However, human studies have provided conflicting results and the issue requires further research (, ).

Susceptibility to developing kidney stones varies between individuals. In most people, cranberries probably do not significantly affect kidney stone formation.

Still, if you are prone to getting kidney stones, it may be sensible to limit your consumption of cranberries and other high-oxalate foods.

SUMMARY High consumption of cranberries may increase the risk of kidney stones in predisposed individuals.

Cranberries are widely consumed dried, as a juice, or in supplements.

They’re a good source of a few vitamins and minerals — and exceptionally rich in several unique plant compounds.

Some of these compounds may help prevent UTIs, stomach cancer, and heart disease.