As more of us swal­low pills to cover di­etary lapses, new re­search sug­gests our money is bet­ter spent on hero veg­eta­bles, nutri­tion­ist Jen­nifer Bow­den re­ports.

New Zealand Listener - - THE GREEN SUPPLEMENT -

Good news about the health ben­e­fits of broc­coli, cab­bage and cau­li­flower just keeps on com­ing. But, as for the sup­ple­ments we’re in­creas­ingly swal­low­ing in the hope they will make up for our di­etary lapses, new re­search sug­gests they may be do­ing more harm than good. If you’re tak­ing mul­tivi­ta­min, vi­ta­min C and D, beta-carotene, cal­cium and se­le­nium sup­ple­ments for heart health or to in­crease your life ex­pectancy, you’re wast­ing your time and money. In fact, if taken in combi- na­tion with statins, an­tiox­i­dant mix­tures and niacin, you’re in dan­ger of shortening your life.

This anal­y­sis comes from a sys­tem­atic re­view of ran­domised con­trol tri­als (the gold stan­dard for prov­ing cau­sa­tion), pub­lished in the Jour­nal of the Amer­i­can Col­lege of Car­di­ol­ogy in June. It con­cluded that ev­i­dence of the ben­e­fi­cial ef­fects of di­etary sup­ple­ments across all di­etary back­grounds wasn’t demon­strated and that cur­rent re­search on sup­ple­ment use re­in­forced ad­vice to eat a healthy diet with plenty of plant foods in which many of these vi­ta­mins and min­er­als are found.

The same mes­sage can be ap­plied to can­cer pre­ven­tion. The World Can­cer Re­search Fund’s 2018 re­port, “Diet, Nu­tri­tion, Phys­i­cal Ac­tiv­ity and Can­cer: a Global Per­spec­tive”, re­in­forces ad­vice to ig­nore sup­ple­ments to pre­vent can­cer and to meet nu­tri­tional needs through diet alone. The re­port is the third com­pre­hen­sive anal­y­sis since 1997 of world­wide re­search on can­cer pre­ven­tion. It notes there is strong ev­i­dence that cer­tain sup­ple­ments can be harm­ful to health – for in­stance, high-dose be­tac­arotene sup­ple­ments can in­crease the risk of lung can­cer in some peo­ple.

An ear­lier re­view, by Bri­tish med­i­cal re­search char­ity Cochrane, found that vi­ta­min E and vi­ta­min A sup­ple­ments may also be ex­tremely harm­ful.

The Jour­nal of Car­di­ol­ogy- pub­lished re­view did find, how­ever, that folic acid may have pre­ven­tive ben­e­fits for car­dio­vas­cu­lar dis­ease, and teamed with B-vi­ta­mins, may help pre­vent strokes. But the back­ing for

folic acid came with the rider that high folic-acid in­take might in­crease the risk of prostate can­cer.


Mean­while, the ev­i­dence for a diet full of fruit and veg­eta­bles keeps stack­ing up. Two ma­jor stud­ies in 2018 have high­lighted the health ben­e­fits of cru­cif­er­ous veg­eta­bles. In April, Aus­tralian re­searchers found that women aged 70 and older who ate plenty of veg­eta­bles, par­tic­u­larly cru­cif­er­ous veg­eta­bles, had less carotid artery wall thick­ness. Women who ate three or more serv­ings of veg­eta­bles each day had .05mm less carotid artery-wall thick­ness than those con­sum­ing fewer than two serv­ings. Carotid ar­ter­ies carry blood to the head and a re­duc­tion of just .1mm in carotid-wall thick­ness is as­soci-

Cru­cif­er­ous veg­eta­bles were found to be par­tic­u­larly ben­e­fi­cial in re­duc­ing the risk of breast can­cer.

Pop­ping mul­tivi­ta­min sup­ple­ments has be­come some­thing of a nu­tri­tional in­surance pol­icy to cover our di­etary lapses.

ated with a 10-18% de­crease in the risk of strokes and heart at­tacks.

Each ad­di­tional 10g of cru­cif­er­ous veg­eta­bles eaten a day low­ers av­er­age carotid artery-wall thick­ness by 0.8%.

In an­other study, un­veiled in July, draw­ing from data in the US Nurses’ Health Study, Amer­i­can re­searchers in­ves­ti­gat­ing po­ten­tial links be­tween fruit and vegetable con­sump­tion and breast-can­cer re­duc­tion re­vealed an 11% lower risk of breast can­cer among women eat­ing more than 5.5 serv­ings of fruit and veg­eta­bles a day, com­pared with those eat­ing 2.5 or fewer serv­ings.

Cru­cif­er­ous veg­eta­bles were found to be par­tic­u­larly ben­e­fi­cial in re­duc­ing the risk of breast can­cer, along with yel­low and orange veg­eta­bles – more on those later. Pre­vi­ous stud­ies had hinted at a link be­tween breast can­cer re­duc­tion and fruit and vegetable in­take, but this larger study al­lowed the re­searchers to ob­tain sta­tis­ti­cally sig­nif­i­cant smaller find­ings, par­tic­u­larly for in­di­vid­ual veg­eta­bles.

We’ve known for some time now that fruit and veg­eta­bles are good for your heart. How­ever, only re­cently have the ben­e­fits of the var­i­ous sub­groups of fruit and veg­eta­bles been re­vealed.


De­spite this, many New Zealan­ders con­tinue to fall short of the rec­om­mended daily in­take. Pop­ping mul­tivi­ta­min sup­ple­ments has be­come some­thing of a nu­tri­tional in­surance pol­icy. The most re­cent Na­tional Nu­tri­tion Sur­vey, con­ducted in 2008/09, found only 66% of the pop­u­la­tion aged 15 years and over ate the rec­om­mended three

or more serv­ings of veg­eta­bles a day, while the rec­om­mended two or more serv­ings of fruit was eaten by just 60.4%.

The same sur­vey found around half of us oc­ca­sion­ally used a di­etary sup­ple­ment and around 31% were reg­u­lar (daily or more than once a week) sup­ple­ment users. Women (35.5%) were more likely to reg­u­larly sup­ple­ment their diet than men (25.5%).

A more re­cent study sug­gests the trend to­wards sup­ple­ment re­liance is in­creas­ing. The 2015 sur­vey by South­ern Cross Health­care Group found 35% of New Zealan­ders rou­tinely used sup­ple­ments, with mul­ti­vi­ta­mins, vi­ta­min C and fish oil the most pop­u­lar. Again, us­age was higher among women (42%) than men (27%). Reg­u­lar sup­ple­ment users spent on av­er­age $21 a month on the prod­ucts.

A smaller sur­vey of 265 adults vis­it­ing their GP in the Bay of Plenty, pub­lished in 2010, found 74% were tak­ing at least one di­etary sup­ple­ment, the most com­mon be­ing a mul­tivi­ta­min.

Iron­i­cally, ev­i­dence sug­gests those most

Mount­ing ev­i­dence sug­gests that mul­tivi­ta­min users are no bet­ter off than the rest of us in car­dio­vas­cu­lar and can­cer risk.

likely to take di­etary sup­ple­ments are older adults, bet­ter ed­u­cated, with less so­cial dis­ad­van­tage – in other words, the pop­u­la­tion de­mo­graphic who al­ready have a bet­ter diet and are least likely to need a mi­cronu­tri­ent top-up.

But is it money well spent? Whether they eat well or not, mount­ing ev­i­dence sug­gests that mul­tivi­ta­min sup­ple­ment tak­ers are no bet­ter off than the rest of us when it comes to re­duc­ing their risk of car­dio­vas­cu­lar dis­ease, can­cer or ill health gen­er­ally.

The sim­ple fact re­mains – di­etary sup­ple­ments aren’t the sil­ver bul­let we’re look­ing for when it comes to our health and pre­vent­ing chronic dis­eases.

The Global Bur­den of Dis­ease study, pub­lished in 2016, es­ti­mated that about one in five pre­ma­ture deaths glob­ally, be­tween 1990 to 2016, was due to “sub­op­ti­mal di­ets”. Low-qual­ity western di­ets are a prime con­trib­u­tor – pro­cessed foods, made

with re­fined grains and high in sugar, sodium and fat, with lit­tle in the way of whole­foods such as fruits, veg­eta­bles and whole­grains.


So, which foods can help to ward off chronic dis­eases? Broc­coli is high on the list. Ranked sev­enth among veg­eta­bles for house­hold ex­pen­di­ture in 2016, there’s much more to it than fluffy flo­rets.

A cru­cif­er­ous vegetable, broc­coli is a mem­ber of the bras­sica fam­ily, along with cau­li­flower, cab­bage, brus­sels sprouts, broc­coflower and Asian cab­bages. Na­tive to the east­ern Mediter­ranean and Asia Mi­nor, it was cul­ti­vated in Italy and in­tro­duced to Eng­land and Amer­ica in the 1700s. It be­came a com­mer­cially grown crop in New Zealand only in the 1970s.

Broc­coli is packed with help­ful nu­tri­ents – one serv­ing (80g) pro­vides our en­tire daily vi­ta­min C needs (45mg), along with some vi­ta­min A, fo­late, vi­ta­mins B6 and E, di­etary fi­bre and a range of help­ful di­etary phy­tonu­tri­ents. These nu­tri­ents help the body con­vert car­bo­hy­drates and fat into en­ergy and fight in­fec­tions; they re­duce dam­age to bones and skin as well as the risk of heart dis­ease and some can­cers; they sup­port healthy de­vel­op­ment of ba­bies in early preg­nancy, weight con­trol and the man­age­ment of dis­eases such as di­a­betes.

An­other pop­u­lar cru­cif­er­ous vegetable is cab­bage. One of the old­est-known veg­eta­bles, cab­bage is a cost-ef­fec­tive and nu­tri­tious op­tion for fam­i­lies. Steamed, roasted, stir-fried or sliced into a coleslaw, cab­bage is eas­ily used through­out the sea­sons. Although his­tor­i­cally thought of as food for the poor, cab­bage is not to be scoffed at nu­tri­tion­ally. It of­fers vi­ta­mins A and C, fo­late, fi­bre and im­por­tant phy­tonu­tri­ents, such as the pur­ple-pig­mented an­tho­cyanins found in pur­ple cab­bage.

Sci­en­tific stud­ies, in­clud­ing cell cul­ture and an­i­mal stud­ies, along with hu­man clin­i­cal tri­als, sug­gest an­tho­cyanins have an­tiox­i­dant and an­timi­cro­bial ef­fects, may im­prove vis­ual and neu­ro­log­i­cal health and pro­tect against var­i­ous non-com­mu­ni­ca­ble dis­eases. They are found in pur­ple cab­bage and other red, blue and pur­ple fruits and veg­eta­bles such as berries, cur­rants, grapes and leafy veg­eta­bles.

Cau­li­flower, an­other Mediter­ranean na­tive, of­fers more in the way of vi­ta­min C

A com­plex mix­ture of vi­ta­mins, min­er­als and phy­to­chem­i­cals work syn­er­gis­ti­cally to pro­tect our health. No sup­ple­ment can hope to repli­cate these ef­fects.

than cab­bage. One boiled and drained flo­ret of cau­li­flower con­tains around 29mg of vi­ta­min C, over two-thirds of our daily re­quire­ments, along with a range of other im­por­tant nu­tri­ents.


Yel l ow and orange veg­eta­bles are typ­i­cally high in an­tiox­i­dants, par­tic­u­larly carotenoids, which give them their colour. The yel­low and orange veg­eta­bles linked to a lower risk of breast can­cer in the US study in­clude car­rots, corn, win­ter squash, and sweet pota­toes.

There are many dif­fer­ent types of carotenoids, and tra­di­tion­ally the fo­cus has fallen only on those that the hu­man body can con­vert into all-im­por­tant vi­ta­min A. How­ever, much re­search has now demon­strated the health ben­e­fits of carotenoids such as ly­copene, found in toma­toes, and lutein in broc­coli.

Both ly­copene and lutein are pow­er­ful an­tiox­i­dants that pro­tect our body from free rad­i­cals. In ex­cess, free rad­i­cals can dam­age cells and con­trib­ute to the progress of chronic dis­eases. Lutein, for ex­am­ple, works to pro­tect our eyes from dam­ag­ing free rad­i­cals, while ly­copene has re­peat­edly been linked to im­proved car­dio­vas­cu­lar health.

So, if lutein is ben­e­fi­cial for our eyes, should we take a lutein sup­ple­ment to pro­tect our eyes? In a word: no.


We don’t eat ly­copene in iso­la­tion. More to the point, we tend not to eat even toma­toes in iso­la­tion. We eat many foods to­gether to cre­ate a health-pro­mot­ing diet, and that food is a com­plex mix­ture of vi­ta­mins, min­er­als and phy­to­chem­i­cals – all of which work to­gether syn­er­gis­ti­cally to pro­tect our health.

Vi­ta­mins and min­er­als don’t pro­vide the ben­e­fits of fi­bre or the phy­tonu­tri­ents in the foods. And it turns out, the com­po­nents in one food can syn­er­gis­ti­cally com­bine with com­po­nents in other foods to im­prove our health. For ex­am­ple, sofrito is a Span­ish dish typ­i­cally con­tain­ing gar­lic, onion and toma­toes sautéed in olive oil. And yes, toma­toes in iso­la­tion are a rich source of ly­copene, a pow­er­ful an­tiox­i­dant. But this clas­sic dish boosts our an­tiox­i­dant up­take be­cause ly­copene is more eas­ily ab­sorbed from cooked toma­toes and the olive oil also en­hances ly­copene ab­sorp­tion from our gut. When re­searchers tested this com­bined dish, they found more than 40 types of polyphe­nols, com­pounds that may pro­tect against a range of chronic dis­eases.


Adding av­o­cado to your lunchtime salad is an­other ex­am­ple of syn­ergy in ac­tion. The healthy mo­noun­sat­u­rated fats in av­o­cado make it a heart-healthy op­tion, with a num­ber of clin­i­cal tri­als find­ing that av­o­cado con­sump­tion may im­prove blood choles­terol and lower car­dio­vas­cu­lar risk. In a salad, those healthy fats also boost our ab­sorp­tion of fat-sol­u­ble vi­ta­mins and an­tiox­i­dants in the other salad in­gre­di­ents, such as tomato, car­rots and leafy greens.

Re­search has also found that av­o­cado added to tomato salsa en­hanced ab­sorp­tion of ly­copene 4.4 times bet­ter, and beta-carotene (found in car­rots and leafy greens, among other things) 2.6 times bet­ter. Adding 150g of av­o­cado to a salad en­hanced lutein, al­phac­arotene and beta-carotene ab­sorp­tion by 7.2, 15.3, and 5.1 times re­spec­tively.


What these demon­stra­ble ef­fects tell us is that very com­plex in­ter­ac­tions are oc­cur­ring as we com­bine food in­gre­di­ents and dishes to meet our en­ergy needs for the day and pro­tect our long-term health. There is no sup­ple­ment on the planet that can hope to repli­cate these ef­fects. The clos­est we have come to un­der­stand­ing the ef­fects is look­ing at the di­ets of long-liv­ing pop­u­la­tion groups – such as the Mediter­ranean diet of tra­di­tional Crete.

It all comes back to those of­ten quoted but less of­ten fol­lowed guide­lines: eat more whole foods such as fruits, veg­eta­bles,

Sofrito, con­tain­ing gar­lic, onion and tomato sautéed in olive oil, con­tains over 40 types of polyphe­nols that may pro­tect against a range of chronic dis­eases.

whole­grains, nuts, seeds and legumes, along with lean meat, fish, low-fat dairy and plant­based oils such as olive oil.

A largely plant-based, whole­food diet has been shown time and again to re­duce our risk of chronic ill­nesses such as can­cer and car­dio­vas­cu­lar dis­ease. The fact that we don’t yet fully un­der­stand which com­po­nents in those foods are re­spon­si­ble for im­prov­ing our health, or how they in­ter­act with each other, in no way de­tracts from the pow­er­ful im­pact that whole­foods can have on our health and well-be­ing.

Clean bill of health: the US Nurses’ Health Study con­trib­uted to the link be­tween fruit and vegetable con­sump­tion and breast-can­cer re­duc­tion.

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