Eating PotatoesGives Your Immune System a Boost

Eating potatoes isnot only good for bowel health,but also for the whole immune system,especially

when they come inthe form of a potato salad or eaten cold.In a study on an animalmodel,researchers in

Spain found that pigs fed large quantities of rawpotato starch(RPS)not only had a healthier bowel,but also

decreased levels ofwhite blood cells, such as leucocytes and lymphocytes（淋巴细胞）in their blood. White

blood cells areproduced as a result of inflammation or disease,generally when the body ischallenged.

The generaldown-regulation of leucocytes observed by the Spanish researchers suggests anoverall

beneficial effect,agenerally healthier body.The reduction in leucocyte levels was about 15percent.Lower

lymphocyte levelsare also indicative of reduce levels of inflammation,but the observed reductionin both

lymphocyte densityand lymphocyte apoptosis is surprising.

In what was thelongest study of its kind,pigs were fed RPS over 14 weeks to find out theeffect of

starch on bowelhealth."The use of raw potato starch in this experiment is designed tosimulate the effects of

a diet high inresistant starch,"said study leader Jose Francisco Perez at theUniversitat Aut6noma de

Barcelona,Spain.

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

boiledpotatoes,legumes,grains,green bananas,pasta and cereals.About 10 percent of thestarch eaten by

human is resistantstarch一starch that is notdigested in the small intestine and so is shunted into the large

intestine where itferments.Starch consumption is thought to reduce the risk of large bowel cancerand may

also have an effecton irritable bowel syndrome(lBS).

Immunology expertLena Ohman's team previously found that the overall lymphocyte levels do notvary

for lBS patients,butthat lymphocytes are transferred from the peripheral blood to the gut,whichsupports

the hypothesis oflBS being at least partially an inflammatory disorder. She says the decrease inlymphocytes

observed by theSpanish is therefore interesting,and a diet of resistant starch may be worthtrying in IBS

patients.Ohman iscurrently at the Department of Internal Medicine,Goteborg University,Sweden.The

study is publishedin the journal Chemistry and Industry，the magazine of the SCI.What form ofpotato is the most nutrient to the human body?

A.Potato soup.

B.Potato cake.

C.Potato salad.

D.Hot boiled potato.