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STRUCTURED LIPIDS

To achieve specific profiles forfats and oils, researchers andcompanies are further exploring

the potential of structured lipids.Structured lipids are trlacylglyc-

erols containing mixtures of short-,medium-, and long-chain fatty oddsattached to the glycerol backbone forspecific functionality. Although moststructured lipids currently are used formedical applications, some areappearing in food products. Their firstfood use has been in confectioneryproducts.

Structured lipids can be producedby (a) hydrolysis and esterification,(b) imeresrerificaucn. (e) lipase-inter-esterification, (d) traditional chemicalmethods. or (e) genetic manipulation.Only enzymatic interesterification andgenetic manipulation can create tar-geted structured lipids. resulting inspecific placement of the fatty acids

The following article was writtenby Barbara Fitch Heumann, senioreditor/writer for INFORM.

on the glycerol backbone. The otherprocesses produce randomized struc-tured lipids.

because MCT alone do not containessential fatty acids, they need to beused with long-chain triglycerides con-taining essential fatty acids (linoleic,linolenic, or arachidonic acid) to pro-vide balanced nutrition in enteral andparenteral nutrition products.

Researchers have found that inter-esterifying MCT and longer-chainfatty acids to form structured lipidscan provide special health benefits. Infact, some have shown that structuredlipids comprising medium-chain fattyacids and linoleic acid may be moreuseful for treating lipid malabsorptionthan are MCf and long-chain triglyc-erides combined in mixtures. A casein point is research by lkuo Ikeda andcolleagues at Kyushu UniversitySchool of Agriculture. Japan, pub-lished in Lipids in 1991.

The simplest structured lipids arecreated by interesterifying MCf andlong-chain triglycerides, according toan article by Alex Merolli. JulianneLindemann. and A.J. Del Vecchio(INFORM, Vol. 8, no. 6, June 1997,pp. 597-603). More complex struc-

INFORM, Vol. 8, no. 10 (October 1997)

Structured lipids allow fat

Why structure lipids?Several factors have prompted theincreasing interest in structured lipids.

One is the observation that longer-chain saturated fatty acids (C20 andlonger) are poorly absorbed from thedigestive tract compared to unsaturat-ed or shorter-chain fatty acids. Anoth-er is the finding that pancreatic lipasehydrolyzes only those acids esterifiedat the 1- and 3-positions on a fat'sglycerol backbone, leaving a 2-mono-glyceride that is readily absorbed nomatter what type of fatty acid is esteri-fied at that position.

Medium-chain triglycerides (MCf)are often the basis for structured lipids,Unlike traditional fatty acids, MCf godirectly into the portal vein and arerapidly converted into energy. MCf aremanufactured from fractionated medi-um-chain fatty acids (caprylic (C8:0)and capric (ClO:0)] from such oils ascoconut and palm kernel. However.

1005

tailoringlured lipids are created by interesteri-fying two oils, such as safflower andpalm kernel oils. Both of these meth-ods result in random placement offatty acids within the resulting triglyc-erides.

Researchers can create more highlysophisticated structured lipids byusing enzymes to target specific fattyacids 10 one or more positions on theglycerol backbone. However, cost hasbeen a hurdle that has discouragedcommercialization of targeted struc-tured lipids.

Medical productsThere are numerous nutritional prod-ucts available for medical applicationsfor patients with HIVfAIDS and otherchronic health conditions such asimpaired gastrointestinal function,liver disease. or congestive heart fail-ure; those recovering from surgery;and infants with food allergies ordigestion problems. Many of theseproducts may contain blended fats.However, structured lipids otTer par-ticular metabolic advantages.

Impact (manufactured by NovartisNutrition, formerly Sandoz NutritionCorp., Minneapolis, Minnesota) is onemedical product containing structuredlipids. Impact contains randomizedstructured lipids created by interesteri-fying a high-lauric acid oil and high-linoleic acid oil. It is used for patientswho have suffered major trauma orsurgery, sepsis, or cancer.

The main U.S. producers of struc-tured lipids include Stepan Co. inMaywood, New Jersey, and AbitecCorp. in Columbus, Ohio.

Stepan offers structured lipids con-taining n-3 fatty acids for manufactur-ers to incorporate in nutritional andmedical beverages and in snack bars.These ingredients are sold in eitherliquid or solid state to food manufac-turers. Some of the resulting nutrition-al products are available in health-food stores as well as in hospital set-tings.

"Patients want these productsbecause they promote well ness orrecovery. Structured lipids are valuedbecause of the unique way they are

metabolized," said Jenifer Heydinger,group leader of research and develop-ment at Stepan. This is because themedium-chain fauy acids are absorbeddirectly into the portal system to pro-vide a ready source of energy, whileessential fatty acids included are need-ed to maintain health. The company'sNeobee SL220. for instance, incorpo-rates both n-6 and n-3 fatty acids aswell as a small amount of medium-chain fatty acids.

Stepan's facility in Maywood, NewJersey. includes a pilot plant forbench-top to full-scale productioncapability. Much of its business is toprovide structured lipids tailor-madeto customer specifications.

"These are truly specialty struc-tured lipids for niche medical applica-tions," Heydinger said.

Abitec Corp. in Columbus, Ohio,also custom-designs formulations forcustomers. selling structured lipidsoriginally developed by a forerunner,Capital City Products. These includecombinations of caprylic and capricfauy acids with linoleic acid, as wellas caprylic, capric, and lauric fattyacids with linoleic and oleic acids,according to Abitec spokeswomanTheresa Mason. The former are usedin the cosmetic industry and in clinicalapplications. while the latter are usedin topical creams and lotions by thecosmetic industry.

There also is interest in incorpo-rating structured lipids in foods, bev-erages and supplements for nonclini-cal uses, such as for maintaininghealth or bodybuilding. Abitec cur-rently is working on developingstructured lipids containing docosa-hexaenoic and eicosapentaenoic acids(DHA and EPA, respectively), to pro-vide an optimum n-6 to n-3 ratio,Mason said.

Food productsCost is the main hurdle to widespreaduse of structured lipids in foods,Mason said, noting that regulatoryaction is another issue.

"In order to gain acceptance fornovel foods, we will have to overcomea certain reluctance both from formu-lators and consumers," she said.

However, randomized structured[continued on pag~/(08)

tNfORM.Vol. 8. no. 10 (October 199n

1008

p. 278). Under this proposal, the term"available" would refer to the portionof a fat substitute that is actuallydigested, absorbed and metabolized,whereas a "digestibility coefficient"would be used to calculate fat avail-ability. FDA has yet to publish anyfurther proposals on this.

Procter & Gamble Co.'s (P&G's)caprenin, meanwhile, was one of thefirst structured lipids offered in theUnited States as a potential cocoa but-ter substitute. P&G has headquartersin Cincinnati, Ohio. Developed as areduced-calorie fat with 5 calories pergram. caprenin is a randomly struc-tured lipid containing behenic acid(C22:0) obtained from hydrogenatedrapeseed oil and two medium-chainfatty acids-caprylic and capricacids-from coconut and palm kerneloils.

During 1992 through late 1995,caprenin was used by M&MlMars ofHackettstown. New Jersey, as a coat-ing fat for Milky Way II reduced-fatcandy bars that it was tesrmarketing.However, M&M/Mars discontinuedusing caprenin when it introduced itsMilky Way Lite candy bars on theU.S. market in 1996.

"We found a way to reduce thecalories and meet our goal of usingreal, standard-of-identity chocolate.Use of a fat substitute, like caprenin,met our calorie requirements, but lim-ited the marketing appeal that realchocolate provides," said MarleneMachut , spokesperson for M&MIMars. Instead, to reduce fat andcaloric content, the company substi-tuted skim milk for whole milk,reduced cocoa butter content, and

included polydex-trose in the candy.

Verifyingthat caprenin nolonger is in com-mercial use,

P&G spokeswomanLisa Hulse Jester said, "We still

hold active patents on caprenin and itis still viable for applications," bUIadded that the company instead isfocusing its efforts on olestra. its zero-calorie fat substitute currentlyapproved for savory snack use.

Meanwhile, in Japan, the structuredfat 1,3-dibenhenoyl-2-0Ieoyl-glycerol

STRUCTURED LIPIDS(confirmed/rom page 1(05)lipids already appear in some main-stream foods.

Cultor Food Science Inc. based inNew York City manufactures and mar-kets Benefat, its brand name forsalatrim, originally developed byNabisco Inc, Salatrim is a family oftriacylglycerols constituting mixturesof long-chain and short-chain saturat-ed fatty acids randomly esterifiedto glycerol. Because of its con-figuration, salatrim providesfive calories per gram,versus the nine calories pergram of typical fats.

Physical properties of aparticular salatrim fat aredetermined by the number oflong-chain fauy acids and the num-ber and length of the short-chain fattyacids on the glycerol backbone. Theshort-chain fatty acids used are acetic,propionic and butyric acids, whilestearic acid is the principal long-chainfatly acid.

Launched in the U.S. market in late1995, Benefat is used in a wide rangeof chocolate confectionery products,including coatings and centers, as wellas in baked goods in the United States,according to Julian D. Stowell, Cut-tor's business manager for the prod-uct. It appears in such products asNabisco's Snackwell's candy prod-ucts, Hershey's Reduced Fat BakingChips, and in Entenmann's reduced-fat cookies. It also is used in a rangeof baked goods in Japan, and in acommercial ice cream in Taiwan.

"Benefat represents the largestresearch and development program wehave at Cutter,' Stowell said. Theoret-ically, he said, it could be designed toreplace any fat. However, because ofits low flash point, it cannot be used asa frying fat, nor will it be used in fluidmilk-where there are less costlyways to reduce fat-or in infant for-mula, where there is no need to reducefat. Recently, Cultor introduced a liq-uid version of salatrim-Liquid Bene-fat-which is being used in suchapplications as confectionery fillingsand baked goods.

"Eventually I would anticipate italso being used in salad dressings,mayonnaise, and spreads," Stowellsaid, adding, "It will take time to winfurther use. Certainly Benefat is

designed for applications where man-ufacturers want to make claims ofreduced-fat and reduced-caloric con-tent."

Van Leer Chocolate Corp. in JerseyCity, New Jersey, incorporates asalatrim-based product to produce itsSlim Cote coatings which it then sellsto candy and confectionery manufac-

turers. Ray Major, vice presidentof manufacturing at Van Leer

Chocolate Corp., said itssalatrim products are usedby the confectionery indus-try chiefly for enrobing orfor depositing a shape such

as a chocolate chip."The only real negative is

that it doesn't mold well," Mayorsaid, noting that companies that havesampled the Slim Cote products likethe taste. In one respect, it is superiorto chocolate because it doesn't bloomeasily. In fact, exposure to heat canactually improve the shine.

"However, industry is not beatingdown the doors to use it. I think pe0-ple are cautious," Mayor said, notingthat other benefits of the product areits palatability and the fact that it pro-vides fewer calories because a portionis not absorbed.

Karen Schaich of the Departmentof Food Science at Rutgers University,New Brunswick, New Jersey, for one,believes structured lipids have beenunderused thus far.

"I think some companies havestayed away from using structuredlipids, because they are not sure howto label them, or how to get the gener-al public to understand that restructur-ing the lipid can affect the amount offat that they will actually digest,"Schaich said. "However, I seethem as the only realisticoption to provid-ing a good-tast-ing low-fat ..~chocolate."

The question offat digestibility forlabeling purposes has yet to beresolved. In December 1996, the U.S.Food and Drug AdminisLralion (FDA)published a proposal to allow nutrientcontent claims on food labels toreflect reduced digestibility{INFORM, Vol. 8, no. 3, March 1997,

INFORM. Vol. 8, no. 10 (October 1997)

1009

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(also referred to as BOB) is used com-mercially as a cocoa butter improver.Developed and produced by Fuji OilCo. Ltd. of Osaka, Japan, it hasbeen available in theJapanese market forapproximately 10years.

Although BOBcosts more thanother chocolateadditives, Fuji repre-sentative Hiroyuki Mori saidcustomers have chosen, and continueto use, BOB due to its functionality asan aruibloom agent at high tempera-tures. In 1994, Fuji filed a petitionwith FDA to seek GRAS (generallyrecognized as safe) designation forBOB.

8etapol-a targeted structured lipidUnilever scientists have used enzy-matic interesterification to develop atargeted structured lipid to closelymimic the fatty acid distribution inhuman milk fat, for use in infant for-mula. Unilever has headquarters inLondon, England.

Palmitic acid is the most abundantsaturated fatty acid in human milk. "Inbreast milk, about 70% of palmiticacid is positioned at the sn-2 positionof the glycerol backbone, whereas invegetable fats, >80% is esterified tothe outer sn-I and sn-3 positions. Thismeans that palmitic acid in vegetableoil-based formula is hydrolyzed fromthe glycerol backbone by the action ofpancreatic lipase in the gut. Freepalmitic acid may form insoluble cal-cium soaps which are excreted withthe feces, resulting in unnecessary lossof dietary energy and calcium. Thereappears to be a link between higher

levels of insoluble calcium soaps andan undesirable increase in constipationand stool hardness," said Reggy P.J.

van der Wielen of Lode-sCroklaan in The

Netherlands.Using a

1,3-specificlipase and react-ing tripalmitin

with unsaturatedfatty acids give a tria-

cylglycerol with up to 60%of the palmitic acid at the sn-l posi-tion. The resulting structured lipid,Betapol, provides improved fat andcalcium absorption, according to TedCraig, vice president of scientificaffairs for Loders Croklaan USA, withheadquarters in Glen Ellyn, Illinois.There also is some indication that useof Betapol leads to improved bonemineral density in infants, Craig said.

Loders Croklaan. a Unilever com-pany, currently markets Betapol foruse in commercial infant formulas inEurope and is working with U.S.infant formula manufacturers toapproach FDA for clearance to marketand use the product in the UnitedStates.

Loders Croklaan also is developingother structured lipids, particularlywith long-chain polyunsaturated fauyacids to increase DHA and EPA con-tent. "We are active in using enzymesto direct the structure in lipids," Craigsaid, noting that possible applicationswould be medical foods and nutraceu-ticals.

"By designing lipids through struc-turing, you can create the best of allpossible worlds," he said, noting thatenzymatic interesterification "is themost precise way to give you exactly

the configuration that you wish toachieve." However, cost is still an issue.

"We have found that even withBerapol, we had to lower the concen-tration of the structured lipid to bal-ance the benefit achieved and thecommercial value of the benefit,"Crai gadded.

Production researchResearchers in the United States.Canada, Europe, and Japan are furtherexploring the potential of usingenzymes in synthesizing structuredlipids and in developing possible foodapplications.

Alejandro G. Marangoni, associateprofessor in the Department of FoodScience, University of Guelph,Ontario, Canada, and his group haveinvestigated various methods for pro-ducing structured lipids. "Our aim was10 find a practical and useful methodthat produced high yields with lowlevels of undesirable by-products,"Marangoni said.

In a report on their study presentedduring the 1997 AOCS Annual Meet-ing & Expo, they said they compareda series of chemical and enzymaticmethods to prepare structured lipids.Prompting the study were plans to setup a pilot-plant process to manufac-ture an infant formula oil containingstructured lipids.

"Our infant formula will incorpo-rate an optimum n-6 to n-3 ratio,DHA, arachidonic acid, and long-chain saturates at position sn-2. aswell as some short- and medium-chainfatty acids," Marangoni said.

In the experiments, Marangoni andcolleagues reacted a medium-chainfatty acid-containing triglyceride withprehydrolyzed canola oil. Their find-

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STRUCTURED LIPIDS

ings showed that the lipase-catalyzedreaction gave the highest yields; italso was specific for positions! and 3on the triglyceride. No acyl migrationwas observed in the prehydrolyzed oil."The lipase reaction, however, isexpensive and difficult to scale up," hesaid.

In terms of cost and ease, he said,"the chemical method makes the mostsense." Owing to randomization of thefatty acids, "approximately 30% of theproduct may not be in the desiredposition, but the majority is."

His group hopes to havethe pilot plant in opera-tion before the end ofthe year, to producerandomized struc-tured lipids forinfant formulasand for other medi-cal applications.They already haveproduced random-ized structured lipidsin kilogram quantitiesfor medical uses.

Noting there is a lot of inter-est in structured lipids, Marangonipredicted, "Companies are going toscale up and sell these in products."

Focusing more on enzymatic inter-esterification, Casimir C. Akoh, asso-ciate professor at the University ofGeorgia's Department of Food Sci-ence and Technology, currently pro-duces gram quantities of structuredlipids in his laboratory. and is testingother bioreactors to allow productionof kilogram quantities in a single run.

"Structured lipids could offer avariety of benefits in foods. Somemight be better absorbed, some mightbe lower in calories, and others mightoffer specific physical and rheologicalproperties. I envision these might beused in infant formulas or in main-stream foods," Akoh said.

Akoh and student Lisa Vee havereported on work to produce low-calo-rie structured lipids through enzymaticsynthesis by lipase-catalyzed inter-esterification of tristearin and tri-caprin. They also have interesterifiedtristearin and tricaprylin.

Currently, the enzymes are quitecostly, Akoh said. "However, this costmay come down. Also, enzymes can

be reused, sometimes as many as 10-15 times in batch reactions. I'm notsure what will happen when you usepacked columns or have a continuousoperation, but I would anticipate theenzyme still could be reused a numberof times."

Carl-Erik Hay, associate professorand head of the Department of Bio-chemistry and Nutrition at the Techni-cal University of Denmark in Lyngby,Denmark, has set up a pilot plantusing immobilized enzymes for pro-

ducing targeted structured lipidswith polyunsaturated fatty

acids (PUFA) in the s,,-2position. The opera-

tion, which uses a!.3-specific lipasefrom Novo Nordiskin Bagsvaerd, Den-mark, producesstructured lipids inquantities ranging

from 10-100 grams.Such structured

lipids offer a potentialtreatment for persons with

malabsorption problems, suchas cystic fibrosis, Hay said. In theirresearch, H0Y and colleagues havecompared targeted structured mgtyc-erides to those produced throughchemical randomization and havefound the best absorption with the tar-geted lipids.

"Potential uses will include medi-cal applications and infant formulas,"H0Y said, noting that PUFA in the SII-

2 position appear to offer healthadvantages for visual and brain devel-opment particularly in infants bornprematurely.

"Certainly cost is the hurdle. Thus,if we can demonstrate the health bene-fits outweigh economic considera-tions, these may become viable," Heysaid.

"The main applications are infantnutrition or critical care, becausethese are the markets that can sup-port the price," said Julianne Linde-mann of Lindemann Consulting of EICerrito. California. "The main stum-bling block, particularly to usingstructured lipids in foods for the gen-eral public. is cost. We will needsome new technologies to bring thecost down."

Calgene's approachCalgene Inc. of Davis, California, hastaken another approach to creatingstructured lipids: that of using bio-engineering to produce them in plants.

Currently, its high-laurate canola,marketed under the name Laurical, isa targeted structured lipid created bygenetically inserting the lauroyl-APCthioesterase enzyme from the seed ofthe California bay tree into canola,which normally does not contain lau-ric fatty acids.

Because rapeseed and canola plantswill not put a saturated fatty acid atthe slI-2 position, this techniqueresults in the saturated fatlyacids-c-predcrninantly lauric acid~atthe 1- and 3-positions of the triglyc-eride, and the unsaturated fats (oleic,linoleic, or linolenic) at the z-positlon,according to Tony Del Vecchio, vicepresident of oils commercializationfor Calgene.

Bioengineered canola containing40% laurate content is now availableand being used in confectionery coat-ings, coffee whiteners, whipped top-pings, and center (filling) fats.

Bioengineered cancla high inmedium-chain fatty acids, located onthe 1- and 3-positions, and high-stearate canola, with saturates only inthe 1- and 3- positions, are expected tobe on the market during the1999-2000 crop year, Del Vecchiosaid. Potential applications will bemedical nutrition products for the highmedium-chain canol a, and cake andbread markets for the high-stearatecanola.

Del Vecchio, for one, believes thatusing bioengineering to create struc-tured lipids may ultimately be morecost-effective than synthetically pro-ducing them through enzymatic inter-esterification.

"Certainly during the first fewyears of commercialization, bioengi-neered structured lipids will be costly.Later on, however, as production num-bers increase, they will have costadvantages over synthetically pro-duced material," Del Vecchio said.

''This is one advantage of the cropapproach," he said, noting also thatbecause these structured lipids areplant-derived, "they give 'warm andfuzzy' feelings in marketing."

INFORM. Vol. 8. no. 10 (October 1997)

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Calgene plans to grow these tailor-made crops in a variety of locations"so we can spread the risk. II will belike having multiple production sites,"he added.

These have shown that structuredlipids can improve fat utilization inpatients who have problems digestingfat. They also lessen inflammatoryresponse, increase immune response,enhance intestinal absorption. andimprove kidney and liver function. Inanimal studies. they have been shownto reduce reticuloendothelial systeminterference.

Bistrian and his colleagues pub-lished findings in the Annuls ofSurgery in 1996 (pp. 316--333) froman enteral feeding study involving 50postsurgical cancer patients. In thestudy, those receiving the structuredlipid formula that contained n-S fattyacids experienced improved long-chain fatty acid absorption and lessgastrointestinal complications andinfections. Bistrian and colleaguesnoted that the data suggestedimproved liver and renal function dueto the use of the structured lipids.

In a second study looking at themechanism involved. they found thatfish-oil components lessened inflam-mation and improved immune func-tion. "Probably the clinical benefitsobserved are due to the fish oil, andtolerance by patients was probablydue to the structuring itself," Bistriansaid. Ross Laboratories of Columbus.Ohio, has helped provide funds forthis research.

"Ultimately, we think structuredlipids are better for proteinmetabolism," he added, noting, too,that structuring lipids improves theirabsorption. "It affords some realadvantages."

T. Peter Stein, professor of surgeryat the University of Medicine andDentistry of New Jersey. Stratford,New Jersey, also has been studyingthe metabolism of structured lipids.

"I believe they have a tremendousfuture," Stein said. noting that at thispoint they are too expensive forwidespread use and also will requireintensive clinical testing before regu-latory action can be sought.

'The fact that you get strong favor-

able response in animals fed struc-tured lipids is very encouraging."Stein said, anticipating that tailor-making fats, particularly to improvethe n-6 to n-3 ratio. could providewide health benefits.

'The potential boggles the mind:'he said. "Targeted structured lipidscould provide a quantum jump forimproving the American diet byreducing the total amount of fat calo-ries consumed and affecting the parti-tioning of fany acids between storageand oxidation by selectively placingthe fatty acids on the glycerol back-bone. It could be a new frontier inhuman nutrition."

Currently, he noted, most metabol-ic work is being conducted by drugcompanies, and generally the initialapplications will be in parenteralnutrition.

"What will probably open this fieldis that someone at a university some-where will come up with a more sim-plified method for producing 'design-er' structured lipids," Stein said.

This, he said, will eventually leadto the addition of structured lipids infoods to provide specific health bene-fits, such as decreasing the risk ofatherosclerosis: "Certainly the bio-chemical rationale is there. At thatpoint, we will be talking about massnutrition."

Numerous questions will need tobe answered, however, such as howmuch EPA would be beneficial in thediet, and where one would place it infoods, he noted.

Stein anticipates that the militaryand the National Aeronautics andSpace Administration may becomeinterested in incorporating structuredlipids to produce high-energy, palat-able foods that are easily digestible. "Ibelieve these specialized nutrient useswill come before mass marketing:'Stein said. Before that happens. how-ever, "chemists will have to conductfurther work on the chemistry andsynthesis of structured lipids:' headded. •

[~I Come visit www.aocs.org! I

Other researchIn other work, Akoh. in conjunctionwith colleagues Ki-Teak Lee. O.L.Dawe and C.S. King, has conductedlarge-scale enzymatic synthesis ofstructured lipids containing n-3 fattyacids (EPA and DHA) and medium-chain (caprylic) fatty acid and studiedtheir dietary effects on serum lipidsand immunological parameters inmice compared to soybean oil. Theyreported findings from the research,supported in part by an award fromthe North American Branch of theInternational Life Science Institute(ILSI) and Food Science Research, atthe 1997 AOeS Annual Meeting &Expo in Seattle in May.

In a dietary study lasting 21 days,they fed female mice structuredlipids or soybean oil at 20% of thediet weight. Their findings showedtotal cholesterol, low-densitylipoprotein (LOL) cholesterol, andtriacylglycerol levels decreased inthe structured lipid-fed mice versusthose fed soybean oi\. Also, the miceon the soybean oil gained moreweight than did mice on the struc-tured lipid diet.

Although there was no significantdifference in the proportion of T-lym-phocytes between the two groups,there was a higher ratio of T-helpercells to Ttcytotoxtc suppressor cells inthe mice fed structured lipids, indicat-ing there may be increased reactivityin the immune system.

"This type of structured lipid holdspromise for nutrition and improve-ment of immune function." they con-cluded.

At Beth Israel Deaconess MedicalCenter, Bruce Bistrian, physician andprofessor of medicine. and colleagueshave conducted clinical studies usingstructured lipids containing EPA.

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