The antioxidant compounds in this red fruit pass into the small intestine, where they exert a protective effect on the colon.


A team from the Instituto de Investigación y Formación Agraria y Pesquera (Ifapa) ‘Alameda del Obispo’ of Córdoba, dependent on the Junta de Andalucía, together with centers from the United Kingdom, Italy and Saudi Arabia, has determined which effective and beneficial elements of the raspberries reach the colon after digestion, and it has been shown, through an ex vivo digestion process, that is, in a real digestion, that its consumption contributes to the protection of cells against colorectal cancer.

Studies, as reported by the Discover Foundation, have determined the presence in the colon of raspberry polyphenols, compounds with antioxidant and anti-inflammatory action. In addition, they show that they play a protective role against colorectal cancer, due to their activity against stress and cell death.

In the article ‘Ex vivo fecal fermentation of human ileal fluid collected after raspberry consumption modifies (poly) phenolics and modulates genoprotective effects in colonic epithelial cells’, published in the journal Redox Biology, the scientists responsible for the study show that these substances act after intestinal digestion, preventing oxidative stress on cells and, therefore, their death.

In this way, they provide a more precise justification for including this red fruit within the recommended foods in the diet for prevent colon cancer, the one with the highest incidence in the population.

In this regard, the researcher at the Ifapa ‘Alameda del Obispo’ in Córdoba and co-author of the article, Gema Pereira-Caro, has highlighted that they have managed to determine “the exact proportion of the compounds that reach the colon after digestion. In addition, we have verified in cell cultures that microbial action transforms certain molecules, initially present in raspberry, into phenolic acids that exert beneficial action in the body“.

The study evaluated the metabolites and catabolites of raspberry polyphenols, that is, all their derivatives, with greater precision and accuracy in a physiologically relevant context, since they are develops in an environment ex vivo, that is, with a real human digestion. In addition, the research has also included the analysis of the digested mass that comes from the ileum, called ileal fluid, extracted from the bags of patients without colon.

Simulated digestion procedures cannot completely mimic the process that takes place in the body, due to the difficulty of replicate the amount of enzymes involved and the multiple reactions that occur. Nor can the components be studied in the same real process, since a surgical intervention would be necessary in a healthy patient.

After the consumption of raspberries, polyphenols that survive digestion in the small intestine enter the colon, where they are subject to microbial action. The objective of the research was to know the degradation and action of these compounds at that time.

On some occasions, the data obtained through laboratory simulations does not offer the necessary accuracy to fully understand the specific action of this fruit. In this case, the studies have been carried out working with patients who had already had a colostomy. In this way, a greater precision in the results has been achieved.

Studies have included the analysis of the digested mass that comes from the ileum, called ileal fluid, extracted from the bags of patients without colon. It includes the antioxidant compounds of raspberry not absorbed by the small intestine.

In a person without this pathology, this digest would reach the colon, where bacteria, also known as the intestinal microbiota, would degrade it. The resulting nutrients pass into the bloodstream but, at the same time, act beneficially protecting the cells of the intestinal wall.. Raspberries are rich in anthocyanins, compounds that give raspberries their red color and have a high antioxidant, anti-inflammatory and anticancer power.

After determining the compounds that are formed during digestion, the experts subjected the ileal fluid samples to fecal fermentation to replicate what would occur in the colon in healthy subjects. A) Yes, The substances produced were analyzed to detect changes in the chemical composition, specify the activity of these compounds in the protection against DNA damage and know the activation of Nrf2-ARE, a protein with high antioxidant power. In this way it is established with precision what exact component results and how it acts in the cells in the last part of the intestinal tract.

Red antioxidant substances

One of the groups of substances analyzed are anthocyanins, compounds that belong to the group of flavonoids and which, according to the Ifapa researcher in Córdoba, “are the ones that give the red color to raspberries and have a high antioxidant, anti-inflammatory and anticancer power“, Says the researcher.

This studio ex vivo It has been shown that they remain in the ileal fluid and are transformed by the intestinal microbiota. This causes a significant increase in the total concentration of phenolic and aromatic compounds available after digestion to act in the colon.

In addition, the benefits of the action of these phenolic compounds derived from the digestion of anthocyanins have been observed in the analyzed tissues, since the expression of some genes involved in the prevention of colon cancer is increased or decreased while in colostomized patients they did not occur. This highlights the importance of colonic digestion in the transformation of these bioactive compounds in raspberries.

This research has been funded through the Seventh Framework Program of the European Union, with the ‘Bachberry’ project, with the participation of the Ministry of Science and Innovation, the National Processed Raspberry Council of the United States Ministry of Agriculture, the Division of Analytical Services and Environmental Scientists (Resas) from the Government of Scotland and King Saud University of Saudi Arabia.