Introduction 

Cranberries are wholesome fruits with long-necked pink blossoms resembling the heads of cranes, hence, they received the name cranberries.

Cranberries grow throughout the cooler regions of the northern hemisphere with 98% of the world supply coming from the United States and Canada. This round glossy deep red-coloured marble-sized fruit tastes somewhat sour like a raw apple or tart. You might have noticed a demand for cranberries growing over the holiday season for adding a zingy tart flavour and a pop of vibrant red colour to various desserts and drinks.

The good news is that along with the flavour and colour, cranberries come packed with numerous health benefits. Let’s dive deeper into this aspect of cranberries before picking them for your next festive preparation or making them a part of regular nutrition.

How to select cranberries?

While selecting cranberries look for firm, plump, yellowish, or dark red coloured cranberries. Discard the shrivelled ones. Fresh cranberries stay fresh in the refrigerator for about 3 to 4 weeks or if frozen can last for up to a year.

Nutritional composition of cranberries 

A portion of 100 gm of raw cranberries contains:

Gut-friendly nutrients in cranberries

Polyphenols

Polyphenols are a large family of compounds found in fruits, vegetables and seeds featuring more than one phenolic unit.¹

Cranberries contain various types of polyphenols, such as flavonoids, phenolic acids, and proanthocyanidins (PAC).² Along with PAC they also contain quercetin, myricetin, peonidin, ursolic acid and anthocyanins. In a study conducted on the American diet, free and bound polyphenols were examined in 20 commonly consumed fruits and cranberries were found to have the highest total polyphenols.³ These polyphenols contribute to the fruit's vibrant colour and potential health-promoting properties.

Fibre

Cranberries are low in protein and fat but a good source of dietary fibre. 100gm of raw cranberries contain approximately 3.6 grams of dietary fibre.  

Vitamins C, E, and K

Cranberries are a very good source of vitamin C (14 mg per 100 grams), vitamin E and vitamin K in small quantities. 

Carbohydrate

100 grams of cranberries give approx. 12 grams of carbohydrates. Bifidobacteria is a type of helpful bacteria present in our guts that consumes a carbohydrate called xyloglucan found in cranberries.⁴

SCFA

The fermentation of polyphenols by gut bacteria produces various metabolites, including short-chain fatty acids (SCFAs). SCFAs are crucial metabolites that play an essential role in maintaining gut health. 

How cranberries consumption can benefit your gut

Reduces risk of gastric cancer and peptic ulcer disease by preventing H. pylori infection

Helicobacter pylori infection is a major cause of peptic ulcer disease and gastric cancer. In research, it has been observed that cranberries prevent H. Pylori from attaching to the lining of the stomach and inhibit its colonisation.⁵ Consequently, this protects it from inflammation and reduces the risk of stomach cancer.⁶   

Prevents E. coli infection

Proanthocyanidins (PACs) are in the flavanol family – a class of polyphenols. Cranberry PACs help prevent the formation of biofilm which is an early step in the development of infection. So certain harmful bacteria, including E. coli, fail to adhere to the cell wall and infection is controlled. This benefits gut and urinary tract microbiota.

Acts as a prebiotic

Prebiotics are agents which promote the growth of “good” bacteria in your digestive tract. Fermentation of polyphenols creates a helpful environment for the growth of beneficial bacteria (such as Bifidobacteria and Lactobacilli). Quercetin, a polyphenol found in cranberries, has positive effects on the growth of Lactobacillus acidophilus. 

Acts as an antioxidant

Free radicals are highly reactive and unstable molecules that can be generated normally in metabolic processes of the body or due to triggers like exposure to X-rays, cigarette smoking, air pollution, and industrial chemicals.⁷ Free radicals are constantly trying to bind with another molecule or atom in the body in search of an electron to pair up with to become stable. In this process, they damage the cells and tissues in the body leading to inflammation and oxidative stress which causes a variety of health problems. Polyphenols found in cranberries exert their antioxidant effects by donating electrons to free radicals to stabilise them and prevent their harmful effects. 

Helps to reduce inflammation

Many polyphenols can modulate signals in inflammatory pathways by suppressing inflammatory mediators thus helping to reduce inflammation.⁸ 

Helps to maintain gut microbiota diversity

Selecting the growth of certain kinds of bacteria which are beneficial to the body and inhibiting the growth of certain harmful bacteria is called selective modulation. This can be achieved by specific polyphenols.⁹ Cranberry products have been shown to promote the growth of Bacteroidaceae and decrease the abundance of Enterobacteriaceae in the gut microbiota. A balanced gut microbiota is essential for a healthier gut environment, further reducing inflammation.²   

Acts as an energy source for gut microbiomes

Cranberries contain 12 grams of carbohydrates per 100 grams with nearly 4 grams coming from sugars and about 3.6 grams from dietary fibre. A carbohydrate found in cranberries called xyloglucan is an energy source for a good bacteria named bifidobacteria in our guts. 

Helps to maintain gut barrier health

Short-chain fatty acids (SCFAs) contribute to the maintenance of a healthy gut barrier by promoting the production of mucus and reinforcing tight junctions between intestinal cells. 

Helps to regulate gastric pH

Short-chain fatty acids (SCFAs) can help regulate the pH balance in the gut, creating an environment less favourable for the growth of harmful bacteria. They prohibit the growth of harmful bacteria by maintaining an ideal pH balance in the gut.

Dietary incorporation of cranberries 

Fresh cranberries taste a little bitter, so they might not suit everyone's taste palette, but you can use them in cakes, breakfast bars, pastries, cookies, bread and muffins to receive their health benefits. If you like the zingy tart flavour of cranberries you can add it to salads, salsa, smoothies, or cereals.

Cranberry jams, spreads, sauce, jellies, and conserves are some of the easy-to-consume and long-lasting cranberry products.

On a medicinal level cranberry capsules are also available to consume under medical guidance.

Cranberry juice and dried cranberries are other commonly consumed forms of cranberry. 

FAQs

Are there any side effects of cranberries?

Excess cranberry consumption can cause an upset stomach or diarrhoea. Do not drink cranberry juice while you're taking blood-thinning medications e.g. warfarin. They can increase the blood-thinning effect of the anticoagulation agent. Cranberries have relatively high levels of oxalate which can raise the risk of kidney stones in some people. If you have kidney stones, consult your doctor before taking cranberry supplements.  

Do cranberries help urinary tract infections?

Some people take cranberry juice every day to prevent UTIs from happening, so it might help to prevent the infection, but there is no evidence present to show it treats the infection once it has already started.

Summary

Cranberries are round glossy deep-red coloured marble-sized fruits which taste somewhat sour like raw apples and are packed with nutrients with various health benefits. Cranberries are found to have the highest amount of polyphenols when 20 commonly consumed fruits were analysed for their polyphenol content. Polyphenols are plant-origin compounds acting as antioxidants. 

Cranberries have an important role in maintaining a healthy gut. Regular consumption of cranberries helps to maintain balance and diversity of your gut microbiota. Cranberries act as prebiotics helping the growth of good bacteria and inhibiting the growth of harmful bacteria. H. Pylori is a leading cause of peptic ulcer disease and gastric ulcer. Cranberries prevent the infection from H. Pylori by preventing it from attaching to the walls of the stomach. 

The same effect has been observed with E. coli, a common cause of urinary tract infections. So cranberry supplements are usually recommended for preventing urinary tract infections. 

Cranberries are also a good source of fibre essential for gut health. People with kidney stones or taking blood thinning medications should take extra precautions when consuming cranberry. Overall, cranberries are an excellent addition to your daily 5 with their gut-friendly effects and zingy tart taste with a pop of red.