10 December 2008

Cereals may boost immunity

Polyphenols from cereals could restore the immune system function and could potentially extend lifespan, suggests an animal study from French and Spanish researchers.

Polyphenols from cereals could restore the immune system function and could potentially extend lifespan, suggests an animal study from French and Spanish researchers.

“The supplementation used in the present study seems to decrease the biological age of prematurely ageing mice and probably can increase the longevity of these animals,” wrote the researchers from the Complutense University of Madrid and Danone Vitapole.

Polyphenol-rich fruits such as blueberries and grapes have been branded by some as anti-ageing foods, and, if the new research can be reproduced in humans, we could see cereals joining this group.

The cereals used in this study (wheat germ and buckwheat) are rich sources of polyphenols, specifically gallic acid, catechin, p-hydroxybenzoic acid, vanillic acid, p-coumaric acid, sinapic acid, ferulic acid, quercetin, and rutin.

“The present work is the first in which polyphenolic dietary supplementation was studied as a nutritional intervention targeted at age-related immune system dysfunction,” wrote lead author Pedro Alvarez in the journal Nutrition (doi: 10.1016/j.nut.2005.12.012).

How the research was done
The researchers used prematurely ageing mice (PAM) and supplemented their diet with 20 percent (w/w) of one of two different cereals - wheat germ (16 mice, 518mg/d polyphenols) or buckwheat flour (16 mice, 14mg/d polyphenols). The cereals were provided by Danone Vitapole.

A further 26 PAM were fed a standard (control) diet, while 30 non-PAM mice were used as a further control to compare the effects of the supplements on immune function.

Immune function was measured as innate (such as chemotaxis, phagocytosis, and natural killer activity) and acquired (such as lymphoproliferation and interleukin-2 release).

After five weeks of supplementation, comparison of the two control groups (PAM and non-PAM) showed that the aged mice had significantly worse immune function than non-PAM.

When comparing the PAM control group and the two PAM-supplemented groups, the researchers found that addition of the cereal polyphenols to the diet of the mice was associated with significantly improved activity of the immune system.

Increases in phagocytosis, natural killer activity, lymphoproliferation, and interleukin-2 release were seen for both groups.

No significant differences were observed between the two cereals.

Immune function restored
“The present work has demonstrated that dietary supplementation with cereals naturally rich in polyphenols is a nutritional strategy targeted at restoring immune function in PAM, thus leading to better health and increasing the probability of ageing successfully,” concluded the researchers.

The mechanism behind the apparent benefits of the cereal polyphenols is said to involve the antioxidant activity of the cereal extracts in response to the oxidative stress associated with ageing.

“The close relation between oxidative stress and the immune system implies that the balance between oxidants and antioxidants in immune cells is critical, because they need to produce reactive oxygen species (ROS) to carry out their functions,” explained the researchers.

“Thus, the age-related increase in oxidative stress has been found to have a profound effect on immune system competence and that antioxidants exert a favourable effect on immune system function in adults and especially in aged subjects.”

In line with other findings
The findings are in line with other anti-ageing reports using polyphenols. Only recently, an animal study with Concord grape juice reported that the polyphenols in the juice were 'reversing' the effects of ageing in the brain.

Previous research has linked polyphenols, such as catechins, epicatechins, and anthocyanins to protecting against various cancers and heart disease.

Source: Decision News Media

- July 2006

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