Not all cranberry juice is created equal – here’s what you need to know.
By Annie Hayes
Getting your daily dose of cranberries is often more convenient – not to mention, cost-efficient – in liquid form, and cranberry juice benefits are certainly not to be sniffed at.
However, not all cranberry juice is created equal. Many varieties are packed with additives and loaded with sugar to make the tart cranberry flavour palatable. For maximum cranberry juice benefits, pick a brand that is made solely from cranberries, free from added sugar or other juices, and not made from concentrate.
13 cranberry juice benefits
So far, the science on cranberry juice benefits is limited. ‘No health claims regarding cranberry juice have been approved by the European Food Safety Authority, due to a lack of evidence to support the claim,’ says Hobson. However, that doesn’t necessarily mean cranberry juice benefits don’t exist, and research on the whole fruit has been promising.
Here’s what we know so far about cranberry and cranberry juice benefits:
- Cranberry juice is high in vitamin C
Your average 150ml serving of cranberry juice contains 45mg of vitamin C, equivalent to 56 per cent of your Recommended Daily Amount (RDA). Vitamin C is water-soluble, which means you need to get it from your diet every day. It has a number of important functions, from producing collagen – ‘the most abundant protein in the body,’ says Hobson – to neutralising free radicals in its role as an antioxidant.
- Cranberry juice may prevent and treat UTIs
A urinary tract infection (UTI) occurs when bacteria enters the urinary system, which includes the kidneys, bladder, ureters, and urethra. Cranberries have natural antibacterial benefits, and certain compounds in them are thought to inhibit bacterial growth. ‘Research has suggested that two components of cranberries called fructose and proanthocyanidins may help prevent bacteria – especially E.coli – from sticking to the lining of the bladder,’ says Hobson.
However, the research is mixed. ‘A large review of the evidence including 24 studies and almost 4,500 participants found that cranberry products including juices, syrups and supplements did not significantly reduce the occurrence of a UTI overall,’ he says. ‘Neither did it reduce the occurrence in any subgroup including older people, women with recurrent UTIs or pregnant women.’
- Cranberry juice may protect heart health
Most of the heart-healthy benefits of cranberries relate to their impressive antioxidant content – much of which, unfortunately, is locked within the skin. ‘Cranberries are rich in flavanols, which are a type of polyphenol,’ says Hobson. ‘However, they are concentrated in the skin and levels drop significantly once the cranberries are juiced.’
Most of the positive benefits surrounding cranberries and heart disease is largely due to flavanols like anthocyanins and quercetin. ‘However, there is some research linking cranberry juice to a reduction of the risk factors for heart disease, including an increase in ‘good’ HDL cholesterol,’ he says. ‘It has also been shown that cranberry juice may help to improve arterial stiffness, which could be of benefit for people with coronary heart disease.’
‘There is some research linking cranberry juice to a reduction of the risk factors for heart disease, including an increase in ‘good’ HDL cholesterol.’
- Cranberry juice may reduce blood pressure
Drinking cranberry juice may help to improve blood pressure, according to a large review that analysed risk factors for heart disease. ‘Analysis showed that specific interventions significantly reduced both systolic and diastolic blood pressure by 1.52 mmHg,’ says Hobson.
However, this involved drinking more than 400ml of cranberry juice per day, ‘which goes against public health recommendations of just 150ml per day of fruit juice,’ he says. ‘High consumption of fruit juice contributes to your free sugar intake, which in itself can increase other risk factors for heart disease such as weight gain.’
The takeaway? Cranberry juice isn’t a magic remedy for high blood pressure, but may be helpful alongside other lifestyle changes, such as cutting down on salt and increasing your intake of fruits and vegetables.
- Cranberry juice may improve cholesterol levels
Drinking cranberry juice appears to increase levels of ‘good’ HDL cholesterol. One study found that drinking 225ml of cranberry juice three times a day increased HDL cholesterol by an average of 10 per cent, which the researchers equated to an approximate 40 per cent reduction in heart disease risk. The researchers suspected that the effect may be due to the high levels of antioxidants present, says Hobson.
‘Like other studies involving cranberry juice, the intake required to get the desired effect was high and probably unrealistic in practice, especially as there are many other more effective ways to reduce your cholesterol with diet,’ he continues. ‘This study didn’t monitor diet, exercise and alcohol intake, all of which can have a significant influence on cholesterol levels.’
6 Cranberry juice prevents dental plaque
Dental plaque is a bacterial film that continuously forms on your teeth. When saliva combines with food and fluids in the mouth, it forms between your teeth and along your gum line. ‘The bacteria in plaque produce acids that attack tooth enamel, which can cause cavities,’ says Hobson. Cranberry juice appears to make it difficult for the bacteria streptococcus mutans to stick to the surface of the tooth, according to research published in the British Dental Journal.
‘The study also found that cranberry juice disrupted the formation of glucan, which is the building block of plaque,’ Hobson continues. ‘However, it would be counterintuitive to recommend drinking a sweet fruit juice to protect your teeth, which is why researchers suggest the possibility of isolating the protective compounds in cranberry juice to use in oral hygiene products.’
- Cranberry juice prevents gut infections
Cranberries can influence your gut microbiota, the bacteria that live in your large intestine. While many of them are extremely important for your health, some of them cause infections and diseases.
‘It has been suggested that the compounds proanthocyanidins may be responsible for the natural antimicrobial properties of cranberries, and that together with other compounds found in the fruit they contribute to mechanisms which may underlie potential clinical benefits on gastrointestinal infections,’ says Hobson.
- pyloriis a common infection-causing bacteria. ‘Studies have suggested that A-type proanthocyanidins may prevent H. pylorifrom attaching to the stomach lining,’ he says. ‘One study suggested that 500ml of cranberry juice daily may significantly reduce H. pylori infections, which are a cause of peptic ulcer disease and gastric cancer.’
- Cranberry juice fights age-related damage
Antioxidants help to protect our cells against the oxidative damage caused by free radicals. The free radical theory of ageing (FRTA) proposes that organisms age because cells accumulate free radical damage over time.
‘Free radicals are produced naturally in the body as a by-product of metabolism,’ says Hobson. ‘When free radicals outweigh antioxidants in the body, it can lead to oxidative stress, which has the potential to cause cell and tissue damage – contributing to diseases such as heart disease and cancer. ’
Like many fruits and vegetables, cranberries contain antioxidant compounds that help to fight against the damage caused by free radicals, he says. ‘Cranberry juice contains significantly less antioxidants than the fresh fruit, although it may offer some health benefits.’
- Cranberry juice supports post-menopausal health
The menopause is characterised by a decline in the hormone oestrogen, which may be a heart disease risk factor for post-menopausal women, says Hobson. ‘It’s thought that oestrogen has a beneficial effect on the inner layer of artery wall, helping to keep blood vessels flexible, meaning they can relax and expand with blood flow,’ he says.
Research linking cranberry juice to heart disease has suggested that it may help to improve cholesterol levels, and therefore improve blood flow through arteries. Like other berries, cranberries are high in phytoestrogens – naturally occurring plant compounds that attach to oestrogen receptors, and may act in a way similar to the oestrogen produced by the body.
‘Cranberries, like other berries, contain phytonutrients. which have been shown to help reduce inflammation in the body.’
- Cranberry juice is a potent anti-inflammatory
Inflammation is your body’s immune response to something harmful or irritating. This is a good thing in small doses, since it helps to heal and repair ailments. But when it’s chronic, inflammation can eventually start damaging healthy cells, tissues, and organs.
‘The effect of inflammation in the body is now widely understood to play a role in the development of many diseases,’ says Hobson. ‘Cranberries, like other berries, contain phytonutrients. which have been shown to help reduce inflammation in the body.’
- Cranberry juice reduces diabetes risk
Cranberries may help to ward off type 2 diabetes due to their high polyphenol content – including quercitin, procyanadins and anthocyanins. ‘A study published in the Journal of Nutrition suggests that drinking 240ml of cranberry juice twice a day could reduce the risk of type 2 diabetes and heart disease,’ says Hobson. ‘The polyphenols found in cranberry juice were thought to help protect cells from damage and disease.’
- Cranberry juice may reduce flu virus severity
Cranberry juice contains high molecular weight materials (NDM). In a test tube study, researchers found that NDMs interfere with the life cycle of the flu virus by preventing it from attaching itself to cells. In addition, cranberry juice is also high in vitamin C, which is essential for an effective immune system.
‘Vitamin C is important for immunity, [particularly] during and after intense physical exercise, according to a Cochrane review,’ says Hobson. ‘Vitamin C helps to suppress the activation of viral genes, which protects against colds, and also mops up inflammatory chemicals, which may help to improve symptoms.’
- Cranberry juice protects brain health
Cranberries contain a compound called ursolic acid, which may help to protect brain cells from injury or degeneration caused by excess domoic acid. Known as excitotoxicity. it can contributes to brain damage caused by stoke and may be involved in neurodegenerative disorders such as Alzheimer’s and Parkinson’s.
Furthermore, drinking fruit or vegetable juice regularly has been associated with a decreased dementia risk. In a large epidemiological study, people who drank three or more servings of fruit and vegetable juices per week had a 76 per cent lower risk of developing Alzheimer’s disease than those who drank juice less than once per week.