New York, April 2 (IANS) Researchers have uncovered fresh evidence to support what mothers everywhere have long been saying: the immune system needs food to function properly. Working on mice in a lab study, University of Chicago researchers found that restricting their subjects’ diet by 30 percent significantly decreased the amount of available B cells, which produce antibodies and maintain immune memory.

Without these cells, the immune system must re-learn how to fight a threat if it reappears.

Findings of the study have been published in the latest issue of the journal Physiological and Biochemical Zoology.

“Animals live different lifestyles, so they may use different types of defences against infection depending on the situation. Perhaps this is why immune defences vary seasonally in most species,” said Lynn Martin, a co-author of the study.

Research on the relationship between food and the immune system could have profound implications for humans. Martin and fellow researchers cite previous studies that have found that infections are “more frequent and tend to be chronic in malnourished children”.

Vaccines, for example, must prompt B cells to produce sufficient antibodies for immune memory. Previous studies have found that vaccines for measles have a significantly lower rate of efficacy among the malnourished.

“A 30 percent restriction in food intake doesn’t affect body mass and only minimally reduces activity in deer mice, but it eliminates the long-term immune protection provided by antibodies.”

Although other variables may be at work, the authors propose that for both wild animals and humans, food availability impinges on immunity and future research should determine what specific components of a diet - calories, protein, micronutrients - are responsible.