Eating PotatoesGives Your Immune System a Boost

Eating potatoes isnot only good for bowel health,but also for the whole immune system,especiallywhen they come in the form of a potato salad or eaten cold.In a study on an

animalmodel,researchers in Spainfound that pigs fed large quantities of raw potato starch(RPS)not only had ahealthier bowel,but also decreased levels of white blood

cells,such asleucocytes and lymphocytes in their blood .White blood cells are produced as aresult of inflammation or disease, generally when the body is challenged.

The generaldown-regulation of leucocytes observed by the Spanish researchers suggests anoverali beneficial effect,a generally more healthy body.The reduction inleucocyte

levels was about 15percent. Lower lymphocyte levels are also indicative of reduced levels ofinflammation, but the observed reduction in both lymphocyte density and

lymphocyte apoptosisis surprising.

In what was thelongest study of its kind,pigs were fed RPS over 14 weeks to find out theeffect of starch on bowel health."The use of raw potato starch in thisexperiment is

designed to simulatethe effects of a diet high in resistant starch,"said study leader JoseFrancisco Perez at the Universitat Autonoma de Barcelona,Spain.

Humans do not eatraw potatoes,but they do eat a lot of foods that contain resistant starch,

such as cold boiledpotatoes,legumes,grains,green bananas,pasta and cereals.About 1 0 percent ofthe starch eaten by human is resistant starch-starch that is not digested inthe

small intestine andso is shunted into the large intestine where it ferments .Starch consumption isthought to reduce the risk of large bowel cancer and may also have an effect

on irritable bowelsyndrome (IBS).

Immunology expertLena Ohman's team previously found that the overall lymphocyte levels do notvary for IBS patients,but that lymphocytes are transferred from the

peripheral blood tothe gut,which support the hypothesis of IBS being at least partially aninflammatory disorder. She says the decrease in lymphocytes observed by the

Spanish is thereforeinteresting,and a diet of resistant starch may be worth trying in lBS patients.Ohmanis currently at the Department of Internal Medicine,Goteborg

University,Sweden.Thestudy is published in the journal Chemistry and Industry,the magazine of theSCI.What a kind ofstarch is resistant starch after all?

A.It cannot bedigested in the small intestine and ferments in the large intestine.

B. It may raiseleucocyte and lymphocyte levels in the body.

C. It may bringabout at least partially inflammatory disorder.

D. It may causeirritable bowel syndrome.