`Think Twice About Antioxidant Claims - Olive Oil Times
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Think Twice About Antioxidant Claims

By Julie Butler
Feb. 23, 2012 11:58 UTC

When one of the few food label claims to sur­vive a rig­or­ous European review was the antiox­i­dant effect of olive polyphe­nols, it made the olive oil sec­tor smile — and the range of olive extracts on the mar­ket surge — but here nutri­tion expert John Finley explains why it’s best to keep a cool head on antiox­i­dant claims.

The claim that olive polyphe­nols pro­tect blood lipids from oxida­tive dam­age (a key fac­tor in car­dio­vas­cu­lar dis­ease) was among just a hand­ful of food health claims the European Food Safety Authority (EFSA) accepted last year after review­ing more than 2,700. A reg­is­ter that would approve those claims — and ban the rest — is now before the European Parliament, which is being lob­bied to veto it before its scrutiny period ends on April 27.

Meanwhile, the list of play­ers in the olive oil extract space has bur­geoned, reports nutraingredients.com, ever since EFSA accepted the antiox­i­dant claim. Suppliers now include Genosa and Probeltebio (Spain), Indena and Phenofarm (Italy), Creagri (US), and Kaneka (Japan) in part­ner­ship with Italian olive oil com­pany Costa d’Oro.

Many high­light the EFSA find­ing and the fact that their extracts con­tain much higher con­cen­tra­tions of the olive polyphe­nol hydrox­y­ty­rosol than olive oil or olives. A 100mg dose of Genosa-pro­duced Hytolive, for exam­ple, is adver­tised as con­tain­ing the hydrox­y­ty­rosol equiv­a­lent of 500ml of extra vir­gin olive oil.

So if you want to max­i­mize the heart health ben­e­fits, are you bet­ter off using an extract than olive oil? And what should the olive oil sec­tor take into account when mak­ing antiox­i­dant claims? In order to pro­mote debate, Olive Oil Times spoke to nutri­tion expert Prof. John Finley, the leader of the National Program in Human Nutrition for the U.S. Department of Agriculture, Agricultural Research Service.

If extracts deliver a higher dose of hydrox­y­ty­rosol with­out the fat con­tent of olive oil, are they a bet­ter alter­na­tive for those who want the antiox­i­dant ben­e­fit?

Finley: Definitely not! People have evolved eat­ing food and adapted to the quan­ti­ties of bioac­tive com­pounds in food, so given a choice, obtain­ing nutri­ents and bioac­tives through food is always the best choice. We are learn­ing that for many bioac­tives, it is not a sin­gle sub­stance but the com­plex milieu in food that pro­vides the ben­e­fit. An exam­ple is that fruits and veg­eta­bles are asso­ci­ated with decreased can­cer risk, but two large stud­ies that fed iso­lated beta-carotene (the sub­stance from fruits and veg­eta­bles thought to be respon­si­ble for the decrease in can­cer) actu­ally increased lung can­cer.

Also, remem­ber the old maxim of tox­i­col­ogy: ​“Dose makes the poi­son”. This is espe­cially true with nutri­tion as there are usu­ally three sub­sets of bio­log­i­cal effects: defi­ciency, where adding more of a sub­stance improves health; ade­quacy, where adding more nei­ther improves health nor has a dele­te­ri­ous effect; and tox­i­c­ity, where adding more results in dam­age to health. Toxicity may not only man­i­fest itself by caus­ing direct harm, but also by caus­ing nutritional/metabolic imbal­ances that then result in harm.

Olive oil not only has hydrox­y­ty­rosol in it but a nat­ural blend of other com­pounds, and humans evolved con­sum­ing foods like olive oil. They did not evolve con­sum­ing hydrox­y­ty­rosol, and thus we do not know how the body may react to high doses of puri­fied hydrox­y­ty­rosol. Also keep in mind that many con­sumers are of the mind­set that if ​“a lit­tle helps you, a lot may cure you of all ills”.

What should the food and nutri­tion indus­try bear in mind in rela­tion to the use of claims such as the antiox­i­dant one approved by EFSA and now before the European Parliament?

Numerous olive oil claims were sub­mit­ted to EFSA but only one was allowed – ​“Protection of LDL par­ti­cles from oxida­tive dam­age”. The panel based its deci­sion on ​“a well-con­ducted and pow­ered study, and two smaller-scale stud­ies that showed dose-depen­dent and sig­nif­i­cant effects of olive oil polyphe­nol con­sump­tion (for three weeks) on appro­pri­ate mark­ers of LDL per­ox­i­da­tion (oxLDL)”. Supporting evi­dence included ​“one short-term and one acute study, (that used) mark­ers of LDL per­ox­i­da­tion (con­ju­gated dienes, ex vivo resis­tance of LDL to oxi­da­tion) going in the same direc­tion.

It must be kept in mind that only one of many claims was sub­stan­ti­ated, and that one was based on very lim­ited evi­dence, some of which used unsub­stan­ti­ated bio­mark­ers. The claim is good for the olive oil indus­try but it is one that could change rapidly with one neg­a­tive study (I don’t know the EFSA pro­to­col for re-eval­u­at­ing health claims).

So my advice would be to use the claim (how­ever have a backup plan if neg­a­tive data should emerge) but quickly begin work to bet­ter sup­port the claim. I don’t think inno­va­tion should be the pri­or­ity at the moment. Instead, it should be clin­i­cal tri­als that con­tinue to focus on the polyphe­nols and LDL oxi­da­tion.

A big ques­tion is what is the vari­a­tion in polyphe­nol content/composition of olive oil? What are the effects of vari­ety, sea­son, geo­graph­i­cal loca­tion, pro­cess­ing, stor­age? What con­sumer groups ben­e­fit the most from olive oil (respon­ders)? Are there groups for which olive oil is bad?

In gen­eral, the food and nutri­tion com­mu­nity should move toward an evi­dence-based approach for claims; i.e. claims are sub­stan­ti­ated or rejected based on very rig­or­ous cri­te­ria, pri­mar­ily human stud­ies that use med­ically-sig­nif­i­cant end­points. There has been much uproar over the rejec­tion of so many claims by EFSA, but this is a result, in part, of the food indus­try not under­stand­ing the rigor of an evi­dence-based review.

What does the research sug­gest about the con­sumer ben­e­fits from the antiox­i­dant effects of olive-related prod­ucts?

The prob­lem with sell­ing ​“antiox­i­dant” poten­tial is that the con­cept is still based on out-dated ideas of free-rad­i­cal scav­eng­ing. Free rad­i­cal scav­eng­ing depends on the abil­ity of the body to absorb the scav­enger with rel­a­tive effi­ciency and trans­port the scav­enger to the site of action; it is also assumed that the com­po­nent in the food is the active com­po­nent (i.e. meta­bolic trans­for­ma­tions are either not under­stood or not con­sid­ered). Not much is known about any of these processes for the indi­vid­ual polyphe­nol com­po­nents of olive oil.

But recent research is show­ing this to be a sim­plis­tic the­ory, and the true abil­ity of a food com­po­nent to exert antiox­i­dant func­tion may be medi­ated through com­plex path­ways unre­lated to free rad­i­cal scav­eng­ing.

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So in rela­tion to the prod­ucts, the EFSA health claim may help sell prod­ucts, but one neg­a­tive study or data that shows that rad­i­cal scav­eng­ing by olive oil polyphe­nols is not phys­i­o­log­i­cally mean­ing­ful can change all that.

Also, it must be remem­bered by food com­pa­nies that any health ben­e­fit related to food will result in sub­sets of ​“respon­ders” and ​“non-respon­ders”. Targeting all con­sumers max­i­mizes sales but also max­i­mizes the risk of hav­ing ben­e­fits diluted by non-respon­ders. Research tar­get­ing a select respon­der group will be more robust and lead to a stronger set of effi­cacy data.

Your research sug­gests a small amount of oxida­tive stress may actu­ally help pre­vent some chronic dis­eases. What are the impli­ca­tions of this for con­sumers and for those in the food sec­tor?

The impli­ca­tions are that con­cen­trat­ing on a sin­gle out­come such as decreas­ing oxida­tive stress by con­sum­ing tra­di­tional antiox­i­dants may not be pos­i­tive. In fact, some epi­demi­o­logic stud­ies sug­gest that peo­ple who con­sume antiox­i­dant sup­ple­ments actu­ally live shorter lives than those who do not.

The nutri­tional chal­lenge of today is obe­sity and related chronic dis­eases. Changing obe­sity does not require the addi­tion or sub­trac­tion of foods for an indi­vid­ual. Instead, it requires look­ing at the over­all diet in the con­text of lifestyle – espe­cially phys­i­cal activ­ity. We need to stop eat­ing the ​“right” foods and instead eat a var­ied diet rich in fruits and veg­eta­bles, with a caloric con­tent linked to our phys­i­cal activ­ity. No foods are inher­ently ​‘bad” – only bad in the wrong amounts. Likewise, many foods, includ­ing olive oil, can be ​“good” in the right amounts but greatly increase obe­sity in the wrong amounts.

What antiox­i­dant infor­ma­tion would be most use­ful to include on bot­tle labels?

I dis­agree with the con­cept of sell­ing prod­ucts based on indi­vid­ual ​“bioac­tive” com­po­nents; as a nutri­tion­ist, I think the empha­sis on dietary ingre­di­ents, and not on the over­all diet, has, in part, dri­ven obe­sity and dia­betes. Consumers need to look at their diet and lifestyle as a whole – the indi­vid­ual foods and com­po­nents of foods are not as impor­tant as the whole diet. Olive oil can cer­tainly be part of a healthy diet but keep in mind that the con­sump­tion of healthy polyphe­nols is linked to the con­sump­tion of lipids and calo­ries; thus olive oil con­sump­tion must be bal­anced within the diet. Depending on fac­tors like age, sex, size and activ­ity level some peo­ple may be able to con­sume fairly large quan­ti­ties whereas oth­ers should con­sume very lit­tle.

What are you cur­rently research­ing in rela­tion to antiox­i­dants?

As the National Program Leader in Human Nutrition for the Agricultural Research Service, I do not do the research myself, but I set pro­gram pri­or­i­ties for other sci­en­tists. Our pro­gram has much antiox­i­dant research includ­ing the fol­low­ing spe­cific projects:

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