Prunes And Bowel Cancer


Prunes have an enviable reputation as a laxative and it now seems they may protect against bowel cancer, too. Researchers from Texas A&M University and the University of North Carolina have found that eating dried plums maintains a healthy balance of bacteria within the lower colon which is associated with a lower bowel cancer risk.

Prunes protect against colon cancer

Despite their unattractive brown, wrinkled appearance, prunes have one of the highest antioxidant levels of all fruit. Prunes are made by drying certain varieties of plum, of which the most popular is the d’Agen sugar plum, in hot air at temperatures of 85oC to 90oC for 18 hours. They are then further processed to make prune juice or prune puree.

it takes around 3.5kg fresh plums to produce 1kg prunes. As a result, prunes are a concentrated powerhouse of antioxidants originally present in the fresh plums. They are also an excellent source of soluble fibre, which fuels the growth of beneficial, probiotic bowel bacteria.

The research, presented at the September 2015 Experimental Biology conference in Boston, suggests that prunes boost the growth of one particular group of beneficial bacteria (Bacteroidetes) while, at the same time, suppressing the growth of another type (Firmicutes) associated with bowel inflammation. By promoting a healthier balance of bowel bacteria, eating prunes is associated with fewer precancerous cell changes in the colon linings.

Previously, researchers found that adding prune extracts to colon cancer cells caused the cancer cells to shrink and undergo changes associated with normal programmed cell death (apoptosis) but did not harm normal human colon cells.

Prunes as a laxative

Dried prunes contain approximately 6.1 g of dietary fiber per 100 g, while prune juice contains very little fibre as it is filtered before bottling. The laxative action of prunes doesn’t come from its fibre, however, but from a substance called hydroxyphenylisatin, which was once prescribed as a laxative drug. Hydroyphenylisatin stimulates secretion of fluid into the bowel and stimulates intestinal contraction.

The laxative action of both prune and prune juice is also aided by their high sorbitol content (14.7g/100g for whole prunes and 6.1 g/100g for prune juice). This sorbitol gives prunes their sweet taste without causing large swings in blood glucose and insulin levels. In fact, snacking on dried plums increases satiety and reduces appetite so you eat less later in the day.

So, if you want the laxative action drink prune juice or eat whole prunes.

If you want the bowel cancer protection, stick to whole prunes.

Try soaking prunes over-night in green (or black) tea and serving them sprinkled with ground flaxseed, dried cranberries and a few shavings of dark chocolate. I like adding honey-flavoured Greek yoghurt, too.

You can also remove the stones from prunes (or plums) and insert whole almonds or pecan nuts into the resulting space for a polyphenol enriched healthy snack.

And in Russia, prunes are eaten coated in chocolate. Make that dark chocolate, and you have an instant antioxidant super-snack!

How do you like to eat your prunes?

Image credits: david_pacey/flickr; wikimedia; off-shell/wikimedia;

About DrSarahBrewer

Dr Sarah Brewer MSc (Nutr Med), MA (Cantab), MB, BChir, RNutr, MBANT, CNHC qualified from Cambridge University with degrees in Natural Sciences, Medicine and Surgery. After working in general practice, she gained a Master's degree in Nutritional Medicine from the University of Surrey. Sarah is a registered Medical Doctor, a registered Nutritionist, a registered Nutritional Therapist and the award winning author of over 60 popular self-help books. Sarah's other websites are and

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