a pilot study on the use of plasma carotenoids and...

Vol. 3, 245-251, April/May 1994 Cancer Epidemiology, Biomarkers & Prevention 245

A Pilot Study on the Use of Plasma Carotenoids and AscorbicAcid as Markers of Compliance to a High Fruit and

Vegetable Dietary Intervention

LoIc Le Marchand,1 Jean H. Hankin, F. Scott Carter,Charleen Essling, Deborah Luffey, Adrian A. Franke,Lynne R. Wilkens, Robert V� Cooney, andLaurence N. KolonelCancer Research Center of Hawaii, University of Hawaii,Honolulu, Hawaii

Abstract

The authors examined the feasibility of using plasmacarotenoids and ascorbic acid as markers of compliancefor dietary intervention trials aimed at increasing thequantity and variety of the fruit and vegetable intake offree-living individuals Nineteen former cancer patientswho had been successfully treated for a stage I or IIsquamous cell carcinoma of the mouth, pharynx, larynx,or lung were recruited. Subjects served as their owncontrols. However, in order to detect any seasonaltrends, 4 individuals among the 1 9 were randomized toa nonintervention group. Subjects in the interventiongroup were counseled by dietitians with the goal ofincreasing their intake of fruits and vegetables to eightservings/day (1 serving each of dark green vegetables,yellow-orange vegetables, tomato products, and othervegetables; 3 servings of vitamin C-rich fruits; and 1serving of other fruits). Subjects in the noninterventiongroup were advised to follow their usual diet. Three-daymeasured food records kept at base line and after 3months of intervention, as well as unannounced 24-hdietary recalls, documented an increase in meanfruit and vegetable intake from 4.2 to 9.5 servings dailyin the intervention group. A concomitant increase of29% was observed in total plasma carotenoids (P =

0.02), with increases of 25% for plasma lycopene (P =

0.06), 31 % for plasma lutein (P = 0.002), 39% forplasma �3-carotene (P = 0.01), and 57% for plasmaa-carotene (P 0.01 ). Mean plasma levels of ascorbicacid increased by 27% (P < 0.001). Correlationsbetween increases in food intake and changes in plasmalevels were reasonably high (r OA.-O.7) forcarotenoids but lower for vitamin C (r = 0.2). Nosignificant change in plasma levels occurred amongcontrols, indicating no background trend in fruit andvegetable consumption during this period. It isconcluded that plasma levels of carotenoids areresponsive to substantive increases (4-5 servings) in

daily fruit and vegetable consumption and may be usefulas markers of compliance at the group level inintervention trials.

IntroductionEpidemiological studies on diet and cancer consistently

have found inverse associations between fruit and vegetableconsumption and risk for a number of epithelial cancers (1).Indeed, the data suggest that these foods contain a widerange of cancer inhibitors (2, 3) and that their consumptionmay provide a greaten protection than that achieved with anysingle fruit on vegetable constituent alone, such as particularcarotenoids, vitamin C, on folic acid (4, 5). Hence, there isa rationale for conducting intervention trials using diets richin a variety of fruits and vegetables. In such trials, neitherinvestigators nor participants would be blind to the nature of

the intervention. Thus, of particular importance would bemarkers of fruit and vegetable consumption that would be

sensitive to variations in the quantity and variety of intakeand therefore would provide objective measures of com-pliance. In an attempt to identify such compliance markers,we monitored for 3 months the serial changes in plasmacanotenoids and ascorbic acid among 1 5 former cancer pa-tients who were instructed to consume a total of 8 servings/day from 6 fruit and vegetable food groups and among 4controls who remained on their regular diet.

MethodsSubjects were individuals who had been successfully treatedfor squamous cell carcinoma ofthe lung (stage I) onthe headand neck (stage I-Il) in a single Honolulu medical centerduring 1 981 -1 992 and who had not had any recurrences onother cancers. Nineteen individuals (1 2 men and 7 women),on 66% of all eligible patients, agreed to participate. Themean age of the participants was 63.6 years (mange, 54-77).Only two ofthe subjects were currently smoking, and all butthree had smoked in the past. Because of the small sample

size and our primary interest in investigating the feasibilityof the dietary intervention, each subject served as his/herown control. However, in order to be assumed that any ob-served changes did not reflect seasonal changes in consump-tion patterns,2 we decided to randomly allocate a few sub-jects (four in total) to a nonintervention group. A 3-daymeasured food record was collected at base line and after 3

Received 7/26/93; revised 1/20/94; accepted 1/20/94.

1 To whom requests for reprints should be addressed, at Epidemiology Pro-

gram, Cancer Research Center, University of Hawaii, 1 236 Lauhala Street,Suite 407, Honolulu, HI 96813.

2 Cooney, R. V., Franke, A. A., Hankin, J. H., Custer, L., Wilkens, L. R.,

Harwood, P. J., and Le Manchand, L. Seasonal effects on intraindividualvariations in plasma micronutnients and antioxidants, manuscript in prepa-

ration.

on August 6, 2018. © 1994 American Association for Cancer Research. cebp.aacrjournals.org Downloaded from

http://cebp.aacrjournals.org/

246 High Fruit and Vegetable Pilot Intervention

Table 1 Mean intake in servings/day) at base line and during the study in the intervention group (n = 1 5)

Intake

Dank green vegetables 1)”

Base line”Intervention

� pc1 month” 2 months” 3 months”

0.2 0.8 0.7 0.5 0.01

Tomato products )1) 0.3 1.2 0.9 0.9 <0.01

Yellow orange vegetables 1) 0.4 0.7 0.9 0.7 0.14

Other vegetables 1) 1.3 1.8 2.0 2.1 0.01

Vitamin C fruits 3) 1 .2 3.7 4.3 4.1 <0.001

Otherfruits)1) 0.8 1.5 0.9 1.1 0.11

Total fruits and vegetables (8) 4.2 9.6 9.8 9.5 <0.001

‘, 3-day measured food record.

1� Unannounced 24-hour recall.

‘ p value for comparison between base line and 3 months by a pained t test.(I Recommended number of servings/day.

months of intervention. Unannounced 24-h dietary recallsalso were obtained at 1 month and 2 months. A fasting bloodsample was obtained at base line, 2 months, and 3 months.

Subjects in the intervention group were asked to in-crease their consumption of fruits and vegetables to eightservings/day (1 serving each of dank green vegetables,yellow-orange vegetables, tomato products, and other veg-etables; 3 serving of vitamin C-rich fruits; and 1 serving ofother fruits). Our definition of a serving was the same as thatused by the United States Department of Agriculture: forvegetables, 1 cup of raw or 1/2 cup of cooked vegetables or3/4 cup of juice; for fruits, 1 medium apple, orange, on ba-nana or 1/2 cup of fresh, cooked, on canned fruit on 3/4 cupof juice. Subjects in the control group were asked to followtheir usual diet.

No recommendation was made aboutthe use of vitamin

supplements. Ten subjects in the intervention group and twoindividuals in the control group reported thatthey consumedvitamin supplements (multivitamins or vitamin C). Change indosage was reported during the intervention for j3-camoteneand vitamin C supplementation by one and two subjects,respectively. They were excluded from analyses on the mel-evant plasma nutrient (Tables 3 and 4).

The dietary counseling was conducted by registered di-etitians who made regular home visits and telephone callsto the subjects and their spouses. Atthe initial home visit, thedietitian instructed the subject and spouse on procedures forkeeping a 3-day measured food record. Measuring utensils,forms, and printed directions were reviewed, and the pro-cedure for recording a sample meal was demonstrated. Inrecording or recalling their food intakes, respondents wereinstructed to either measure the individual ingredients inmixed dishes on to list the total amount, along with the pro-portion of meat, vegetables, noodles, etc. This facilitated theestimation ofthe vegetable and fruit intakes. During the next2 days, the dietitians called the subjects to answer any ques-tions or solve any problems that might have occurred. On thefourth day, another home visit was scheduled to review therecord and to suggest ways of incorporating additional veg-etables and fruits in the daily meal pattern.

We developed a list of available local items for eachfruit and vegetable group, which was printed as an “8-A-DAY’ GUIDE” (See Appendix). Diet instructions were alsodeveloped, along with an 8-A-DAY log for recording all fruitand vegetable portions consumed each day. Interventiongoals were achieved differently by the individuals. In somecases, the recommended vegetables were incorporated intomixed dishes, casseroles, soups, and salads. Juices fre-

Table 2 Mean daily nutrient intake at base line and at 3 monthintervention group based on food records (n = 1 5)

s in the

Intake Base line 3 Months 0/ change pa

Micronutnients

n-carotene (pg/d) 4,357 9,943 +128.2 0.01

a-carotene (pg/d) 1,398 1,598 +14.3 0.15

Lutein (pg/d) 1,637 5,126 +213.1 0.001

Lycopene (pg/d) 2,407 1 3,071 +443.0 0.002

l3-cryptoxanthin (pg/d) 318 370 +16.4 0.24

Total canotenoids (�ig/d) 10,1 17 30,108 +197.6 <0.001

Vitamin C (mg/d) 143 339 +137.1 <0.001

Macnonutnients

Total fat (g/d) 68 66 -2.9 0.81

,,/o calories from fat 33.5 30.8 -8.1 0.82

Saturated fat (g/d) 21 22 +4.8 0.60

Dietary fiber (g/d) 1 5 1 8 +20.0 0.1 7

a Pvalue for comparison between base line and 3 months by a pained ttest.

quently were substituted for carbonated beverages, andfruits were chosen in place of sweets for desserts and snacks.During the intervention period, the dietitians scheduled in-tenmittent home visits and telephone calls to maintain en-thusiasm and adherence to the diet among the subjects.Other activities included pamphlets and recipes on fruits andvegetables, a newsletter for the participants, and a pot-lucksupper to encourage interaction among all of the subjectsand the staff.

At the end of the 3 months, another 3-day measured

food record was collected from the subjects. The 3-day foodrecords and 24-h dietary recalls were analyzed for individualcarotenoids, ascorbic acid, and other dietary components.The major sources for our food composition database areMangels et a!. (6) for carotenoids, and the United States De-partment of Agriculture Nutrient Database for Standard Ref-emence (7) for ascorbic acid and other dietary components,along with data from Japan, China, the Philippines, GreatBritain, and analyses of selected food items.

Venous blood was collected from the 19 participantsafter a 1 2-h fast at base line, and at 2 and 3 months duringthe intervention period. All samples were protected fromlight and processed within 1 h after blood drawing. Plasmasamples were stored at -70#{176}Cand analyzed in a single batchat the end of the study. Individual camotenoid levels weredetermined by high pressure liquid chromatography (8).Briefly, plasma proteins were precipitated with ethanol con-taming bis-hydroxy-toluene as antioxidant and three inter-nal standards followed by repeated (3X) hexane extraction



Cancer Epidemiology, Biomarkers & Prevention 247

Table 3 Mean plasma vitamin value s at base line and during the study in the interve ntion group

Intake Base line 2 Months 3 Months % Change” P”

Canotenoids and ascorbic acid

f3-carotene (pg/I) 461 663 618 +39.1 0.01

a-carotene (pg/I) 62 1 03 92 + 57.3 0.01

Lutein (�igJl) 291 413 352 +31.4 0.002

Lycopene (pg/I) 199 255 242 +24.9 0.06

�-cryptoxanthin (�Jg/l) 245 248 284 +8.6 0.16

Total Carotenoids (pg/I) 1,552 2,044 1,964 +29.1 0.02

Ascorbic acid (mg/dl) 0.96 1.22 1.22 +27.1 <0.001

Other

Retinol )pg/dl) 603 643 607 +3.6 0.26

a-tocopherol (pg/dl) 13,581 15,586 13,651 +7.6 0.29

‘y-tocopherol(pg/dI) 2,010 2,299 2,188 +11.6 0.36

Cholesterol (mWdl) 195 197 194 +0.3 0.99

a [(average of 2- and 3-month values) - baselinel X 100 - baselineb p value for comparison between base line and the average of 2- and 3-month levels by paired t test.

of the lipophilic micronutnients. The combined hexanelayers were dried under nitrogen and medissolved in the

high pressure liquid chromatography mobile phase consist-

ing of methanol:dichloromethane:acetonitmile (65:25:10),

bis-hydroxy-toluene (0.025%) as antioxidant, and aqueous

bis-tnis-propane (2 mI/I of 0.5 M, pH 7.0) as buffer to preventcolumn degradation. Twelve carotenoids, netinol, ‘y- anda-tocophemol were separated on a Spherex 5-pm C18 column

(250 x 4.6 mm) (Phenomenex, Torrance, CA) and moni-

tored by a dual multiple wavelength detector at each mdi-vidual compound’s absorption maximum. Levels were

determined using peak areas and calibration curves of au-

thentic standards. Analytical accuracy and reliability were

verified by participation in the National Institute of Stand-ards and Technology “mound robin” for micronutmient analy-

sis with results consistently within 6% of the mean valuesreported for all “come” laboratories and coefficients of vania-

tion not greater than 4%, with the exception of a-carotene

for which the coefficient of variation was 6.8%.Although 1 2 carotenoid fractions were used to calcu-

late total plasma carotenoids, only the 5 major peaks (a-

carotene, n-carotene, lycopene, lutein/zeaxanthin, andj3-cryptoxanthin) are reported in detail here. Plasma ascorbic

acid was measured with the dichlomophenolindophenolmethod (9) in the Clinical Nutrition Laboratory of the Uni-

vensity of New Mexico School of Medicine (P. Carry). Totalplasma cholesterol was measured enzymatically in a cho-

lesterol oxidase/peroxidase system using a diagnostics kitNo. 352-50 from Sigma Chemical Co., (St. Louis, MO).

Summary statistics were computed for each dietary andplasma variable. The paired t test on the log-transformed

variables was used to test for changes in mean intake or

plasma level. Pearson correlation coefficients were used toexamine correlations between changes in intake and

changes in plasma levels. The changes were log trans-formed, after adding two times the SD of the change, which

ensured that all values were positive. Other types of come-lations were explored, such as that between serum change,

y, and a power of the intake change, x�. �3 was obtained asthe slope in the linear regression of log y on log x. This

allowed for nonlinear relationships between the variables.However, since the results were similar to those between the

log-transformed changes, they are not shown here.

Results

Table 1 presents the increase in mean fruit and vegetable

intake achieved by the intervention subjects for each foodgroup. Comparing the 3-day measured food records col-lected at base line and at 3 months, subjects increased their

daily total fruit and vegetable intake from a mean of 4.2

servings (mange, 1 .0-1 1 .3 servings) to a mean of 9.5 servings(mange, 3.1-15.2 servings) (P< 0.001). This increase had ahigh statistical significance for each fruit and vegetable

group except yellow-orange vegetables and other fruits, forwhich the Pvalues were 0.1 . The unannounced 24-h dietaryrecalls demonstrated similar increases in mean fruit and veg-etable intake at 1 and 2 months (Table 1 ). There also wasgood agreement between the 8-A-DAY logs (results notshown) and the data in Table 1.

The change in mean nutrient intakes between base lineand 3 months in the intervention group, as estimated fromthe 3-day food records, is shown in Table 2. The mean totalcanotenoid intake (taken as the sum of f3-canotene, lutein,lycopene, a-carotene, and f3-cryptoxanthin intakes) in-creased 3-fold to 30 mg daily (P< 0.001). The increase inmean i ntake of each spec ific camotenoid was statistically sig-nificant (P < 0.01), except for a-carotene (P = 0.15) and

f3-cnyptoxanthin (P = 0.24). Mean vitamin C intake in-

creased 2.4-fold to 339 mg daily (P< 0.001). No significantchange occurred in the mean fat intake ofthe subjects as theresult of the intervention. The mean nutrient intakes com-

puted from the 24-h recalls at 1 and 2 months (data notshown) were very similar to those found for 3 months usingthe 3-day food records (Table 2).

The changes in mean plasma levels of carotenoids andascorbic acid are shown in Table 3 for the interventiongroup. We observed an increase over base line of 29.1 % for

total plasma camotenoids (P = 0.02), with increases for spe-cific canotenoids ranging from 8.6% for plasma�3-cryptoxanthin (P = 0.1 6) to 57.3% for plasma a-carotene

(P = 0.01 ). Mean plasma levels of ascorbic acid increasedby 27.1 % (P < 0.001). Other nutrients measured in theplasma (retinol, a-tocopherol, y-tocophemol, cholesterol) did

not change significantly over the intervention period.Changes in plasma levels were similar among supplementusers and nonusers in the intervention group. No statisticallysignificant change was observed in the mean plasma valuesof subjects in the nonintervention group over the 3-month



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Fig. 1. Change in fruit and vegetable intake (A), and total plasma carotenoidlevel (B) between base line and 3 months for each participant in the inter-vention group. Numbers at the end of each line, subject number.


observation period. The changes in mean total camotenoids,�-camotene, and ascorbic acid levels in the controls were+0.0%, -0.6%, and +1 1 .0%, respectively.

The changes in total fruit and vegetable intake and totalplasma camotenoids are illustrated in Fig. 1 for each partici-pant in the intervention group. The dietary intervention wasunsuccessful in two individuals who did not increase theirfruit and vegetable intake (Patients 4 and 14). Among par-ticipants who increased their fruit and vegetable intake, four(Patients 5, 8, 1 0, and 1 2) did not experience an increase inplasma carotenoids. Overall, a certain amount of intemindi-vidual variation in the plasma response was suggested by thedata.

The correlations between the changes in dietary intakeand plasma levels of carotenoids and ascorbic acid frombase line to 3 months among the intervention group areshown in Table 4. Reasonably good correlations (i.e., 0.4-0.7) were found for change in total plasma carotenoids andchange in overall intake of fruits and vegetables, and forchanges in specific plasma camotenoid levels and changes inintake of their main food sources (dank green vegetable forlutein, tomato products for lycopene, and yellow-orangevegetables for a-carotene). These correlations are under-lined in Table 4. The correlation coefficient for change inplasma ascorbic acid and intake of vitamin C-rich fruits(r = 0.2) was lower than those observed for changes inplasma camotenoids and their food sources, possibly due tothe water-soluble nature of vitamin C and its rapid urinaryexcretion.

Although we were more interested in the ability ofplasma carotenoids and ascorbic acid levels to predictchange in food intake (Table 4), we also examined the con-relations between changes in micronutmient intake andplasma levels. Pearson correlation coefficients for these con-relations were: f3-camotene, 0.50; a-carotene, 0.25, lutein,0.41 ; lycopene, 0.54; f3-cryptoxanthin, -0.04; total carote-noids, 0.41; and ascorbic acid, 0.18.

Discussion

Because we wanted to mimic the conditions of a large-scaletrial, we did not use a controlled diet in this intervention.Instead, subjects remained on a self-selected diet but wereinstructed to consume specified numbers ofservings from sixfruit and vegetable food groups. No other instructions weremade with regard to other aspects ofthe subjects’ diets. Theparticipants were able to follow the intervention diet duringthe 1 2 weeks of the study and achieve a substantial increasein their daily fruit and vegetable intake (by an average of fiveservings) with minimal alteration to the rest of their diet onlifestyle.

This increase in fruit and vegetable intake was mespon-sible for a significant rise (by an average of 29%) in their totalplasma carotenoid levels. The data also showed that changein total plasma camotenoids correlated well (r = 0.7) with the

overall change in fruit and vegetable intake. Such a comme-lation is usually thought to be adequate for a marker of com-pliance at the group level (1 0). Thus, during an interventiontrial, change in the mean total plasma camotenoid level oventime could be used to monitor adherence to a high fruit andvegetable diet in the study group, and, probably, to monitordrift in the control group.

Our intent in this study was to increase intake of a widevariety of fruits and vegetables in a standardized way. Theemphasis was both on the quantity and variety of intake offruits and vegetables known to contain suspected cancer

Baseline 1

inhibitors, includingbutnotlimitedtocarotenoids(2, 3).Wetook a practical approach and recommended groups of fruitsand vegetables that were good food sources of specific camo-tenoids, with the hope that plasma levels of these camote-




Table 4 Pearson correlation c oefficients for chan ge in food intake a nd plasma vit amins between ba se line and 3 mont hs in the interv ention group

Food intake

Plasma levels

j3-carotene a-carotene.

Lutein Lycopene-ii�;;;;�;:-----

.xanthun

Total.

carotenoidsAscorbic

.acid

Dark green vegetables 0.52 0.32 0.39 0.45 0.32 0.76 -0.02Tomato products 0.37 0.26 0.30 0.64 0.15 0.88 -0.14

Yellow-orange vegetables 0.60 0.38 0.25 0.07 0.08 0.63 -0.32

Other vegetables 0.06 -0.32 -0.02 0.27 0.20 0.43 0.10

Vitamin C fruits -0.36 -0.14 -0.10 -0.19 -0.31 0.08 0.16

Other fruits 0.50 0.66 -0.05 0.07 -0.31 0.50 -0.45

Total fruits and vegetables 0.21 0.14 0.10 0.18 -0.02 069 -0.10

noids would provide adequate markers of intake for the foodgroups and, hence, forthe variety ofthefmuits and vegetablesconsumed.

Indeed, this study suggests that plasma lutein, lycopene,and a-carotene are appropriate markers of dark green veg-etable, tomato product, and yellow-orange vegetable intake,respectively, since there were reasonably good correlationsbetween the changes in intake and plasma levels. However,there appears to be some variation among camotenoids in themagnitude of the plasma response to a given increase inintake. At the two extremes were a-carotene, for which a

small increase in intake (14%) resulted in a relatively largerise in plasma levels (57%), and lycopene, for which a largeincrease in intake (443%) resulted in only a moderate rise inplasma levels (25%). Some of these differences may reflectvariation in intestinal absorption due to the quantity of fatingested with the particular fruits and vegetables (1 1 ) on ac-

cording to whether the foods were cooked on raw (1 2). Agreater serum response for a-carotene already has been ob-

served in past studies (13, 14).Although the fasting plasma ascorbic acid levels of our

subjects significantly increased as the result of more than a

doubling of their vitamin C intake, the correlation betweenchanges in plasma level and intake was low (r = 0.2). Thus,plasma ascorbic acid would not be a sensitive marker ofcompliance to a diet abundant in vitamin C-rich foods.

This study suggests that plasma carotenoids may con-

stitute good markers of compliance to a high fruit and veg-etable diet at the group level. However, they may not besufficiently responsive to change in intake to be used at theindividual level, for example, to identify noncompliers andattempt corrective action. This is consistent with previousobservations of a large intenindividual variation in plasmaresponse to �-camotene ingested as a dietary component onas an oral supplement (1 1 , 1 3, 1 5-1 7). Thus, other compli-ance monitoring methods, such as unannounced 24-h dietrecalls, need to be used to monitor adherence at the mdi-vidual level in dietary modification trials.

To our knowledge, this is the first published study ex-amining the response of plasma carotenoids or vitamin C toa sustained high intake of fruits and/or vegetables using astructured self-selected diet. Micozzi et a!. (1 3) have me-ported the effect on plasma carotenoid levels of consuming30, 1 2, or 6 mg of camotenoids from single foods (broccoli,carrots, or tomato juice) or from purified j3-carotene for 6weeks. The 30 men in their study were fed an identical con-trolled diet that included a constant quantity of fat (40% ofcalories) and camotenoids (�1 .6 mg/d). Compared with baseline, plasma �-camotene increased in men receiving 272 g ofcarrots/day, although much less so than in men receiving the

same amount of �3-canotene in purified form (1 3). Carrotsalso raised the plasma levels of a-carotene in these men,while plasma lutein increased in men receiving 300 g ofbroccoli/day (1 3). Plasma lycopene remained unchanged inmen receiving 1 80 g oftomato ju ice/day despite a decreasedintake of other important sources of lycopene (1 3). Theseresults are consistent with ours.

The present study also provides information on the ex-

tent to which plasma camotenoids and ascorbic acid could beexpected to rise among participants in a high fruit and veg-etable intervention trial. However, one should note that rais-ing the plasma levels of some of these nutrients would notbe the sole purpose of such a trial since, as mentioned above,much greater plasma responses are produced by purified

supplements than by foods (1 3, 1 6). The purpose of feedinglarge quantities of fruits and vegetables would be to raiseplasma and tissue levels of a large number of putative cancerinhibitors not available in purified form that may provide a

greater protection than a single orfew nutrient(s) (4, 5). It alsomay constitute a more practical approach for the prevention

of certain cancers at the population level.The rationale for such a dietary approach is strength-

ened by recent human and animal data suggesting that dailysupplementation with a single nutrient may result within afew weeks in a decrease in the plasma level ofothen nutrients

(e.g., lutein or a-tocophemol with a f3-carotene supplementof 1 2 or 1 5 mg, and total camotenoids with an a-tocophenolsupplement of 800 international units) due to negative in-temactions among antioxidants (1 3, 1 8-20). The present

study suggests that this may not occur with a comparableamount of camotenoids ingested as food components, since

no decrease in plasma level was detected for the antioxi-dants (a- and y-tocopherol) that were not included in theintervention diet. This is consistent with the observationby Micozzi et a!. (1 3) of a decrease in plasma lutein levelsonly in groups receiving purified f3-canotene and not ingroups receiving similar amounts of camotenoids from single

foods.The participants in our study were former cancer pa-

tients and, as such, were highly motivated. It is unclearwhether such a major dietary change could be achieved in

other high risk but less motivated groups (e.g., smokers) andwhether plasma carotenoids would be as clearly responsiveto a smaller increase in fruit and vegetable intake.

AcknowledgmentsWe thank the study participants, their physicians, and the Queen’s Medical

Center. We also thank Setsumi Yukimoto, Laurie Custer, Sau Ling Hicks, andYun Oh Jung for technical assistance.



Daily food guide

Appendix

1/2 cup1/2 cup

/2 cup

1/2 cup

1 cup

Kale, cooked

Pak choi (bok choi)

Mustard greens, cooked

Taro leaves, cooked

Swiss chard, cooked

Broccoli, cooked or rawKai choi or mustard cabbage, cooked


Vitamin C fruits (3 servings)

CuavasOrange juice

Papayas

Guava juiceCranberry, cranapple,

cnannaspberry juices

Pineapple juice

Passion-guava drink

Passion-orange drinkKiwi fruit

OrangesGrapefruit juice

Cantaloupes

Mangoes

Pomelos

Tang

Grapefruit

Strawberries

Other fruits (1 serving)

ApricotsDried

Cooked or canned

Fresh

Nectar

PeachesDried

Canned

FreshNectar

Honeydew melonStanfruit

Watermelon (1” thick)Tangerines

Apples

BananasGrapes

Pineapple

Dark green vegetables (1 serving)

Spinach

cooked, canned, on frozenraw

1 me&’

1 cup�/2 med

1 cup

1 cup

1 cup

1 cup1 cup

1 med

1 med

1 cup1/4 med

1 med1/,, med

1 cup/2 med

/2 cup

10 halves

/2 cup3 med

1 cup

5 halves

/2 cup1 med

1 cup

1/,0 melon

1/4 of slice

12

1 slice or /2 cup

/2 cup1 cup1/2 cup

/2 cup

‘/2 cup

/2 cup/2 cup

/2 cup/2 cup

Daily food guide

Dark green vegetable (1 serving) (cont’d)

Marungay leaves, cookedChoi sum, cooked

Ung choi (swamp cabbage), cooked

Turnip greens, cooked

Lettuce

Romaine, red leaf, or manoa

Tomato Products (1 serving)V-8 juiceTomato juiceTomato pasteSpaghetti sauce

Tomato sauce

Tomato, rawTomato, cookedTomato, cannedTomato soup

Yellow-orange vegetables (1 serving)Pumpkin,

CookedPie

Sweet potato (yellow)Carrots

RawCooked, canned, on juice

Winter squash (acorn or butternut)

Other vegetables (1 serving)

Brussels sprouts

Green peppersCauliflower

Won bok (Chinese cabbage), raw or cookedHead cabbage, raw on cookedAsparagusWatercress, raw or cookedColeslawSauerkraut

Kohlrabi, cooked

Turnips, cookedCornMixed vegetables

Beets

PeasEggplantGreen beansCelery

3/4 cup3/4 cup1/4 cup

/2 cup/2 cup

1 med1/2 cup�/2 cup

1 cup

/2 cup

/8 of pie

1 small or 1/2 cup

1 small

#{189}cup/2 cup

1/2 cup/2 cup

�/2 cup

/2 cup/2 cup/2 cup

/2 cup/2 cup/2 cup

/2 cup�/2 cup1/2 cup/2 cup

1/2 cup

�/2 cup/2 cup

/2 cup1/2 cup

,, med, 1 medium-sized fruit on tomato.

References1 . Steinmetz, K. A., and Potter, J. D. Vegetables, fruit, and cancer. I. Epide-miology. Cancer Causes Control, 2: 325-357, 1 991.

2. Wattenbeng, L. W. Inhibition of carcinogenesis by minor anutnient con-stituents of the diet. Proc. Nutr. Soc., 49: 1 73-1 83, 1990.

3. Steinmetz, K. A., and Potter, J. D. Vegetables, fruits, and cancer. II. Mecha-nisms. Cancer Causes Control, 2: 427-442, 1991.

4. Le Manchand, L., Yoshizawa, C. N., Kolonel, L. N., Hankin, J. H., andGoodman, M. T. Vegetable consumption and lung cancer risk: a population-based case-control study in Hawaii. I. NatI. Cancer. Inst., 81: 1158-1164,

1989.

5. Le Marchand, L., Hankin, J. H., Kolonel, L. N., Beecher, C. R., Wilkens,

L. R., and Zhao, L. P. Intake of specific carotenoids and lung cancer risk.Cancer Epidemiol., Biomarkers & Prey., 2: 183-187, 1993.

6. Mangels, A. R., Holden, J. M., Beecher, C. R., Forman, C. R., and Lanza,E. The canotenoid content offruits and vegetables: an evaluation of analyticaldata. J. Am. Diet. Assoc., 93: 284-296, 1993.

7. United States, Department of Agriculture. Nutrient database for standardreference, release 9. United States Department of Agriculture, 1990.

8. Franke, A. A., Custer, L. J., and Cooney, R. V. Synthetic carotenoids asinternal standards for plasma micronutnient analysis by HPLC. J. chromatogr.,614:43-57, 1993.

9. Vandenjagt, D. J., Carry, P. J., and Hunt, W. C. Asconbate in plasma asmeasured by liquid chromatography and by dichlorophenolindophenol cob-nimetry. Clin. Chem., 32: 1004-1006, 1986.

10. Creenwald, P., Witkin, K. M., Malone, W. F., Byar, D. P., Freedman, L.S., and Stern, H. R. The study of markers of biological effect in cancer pre-vention research trials. Int. J. Cancer, 52: 189-196, 1992.

1 1 . Dimitrov, N. V., Meyer, C., UlIrey, D. S., Chenoweth, W., Michelakis,A., Malone, W., Boone, C., and Fink, C. Bioavailability of J3-carotene inhumans. Am. J. Clin. Nutr., 48: 298-304, 1988.

1 2. Micozzi, M. S., Beecher, C. R., Taylor, P. R., and Khachik, F. Canotenoidanalyses of selected raw and cooked foods associated with a lower risk for

cancer. J. NatI. Cancer Inst., 82: 282-285, 1990.




13. Micozzi, M. S., Brown, E. D., Edwards, B. K., Bieni, j. C., Taylor, P. R.,Khachik, F., Beecher, C. R., and Smith, J. c. Plasma canotenoid response tochronic intake of selected foods and f3-carotene supplements in men. Am. J.Clin. Nutr., 55: 1 1 20-1 1 25, 1992.

14. Kim, H., Simpson, K. L., and Gerber, L. E. Serum canotenoids and retinol

of human subjects consuming carrot juice. Nutr. Res., 8: 1 1 1 9-1 1 27, 1988.

1 5. Constantino, J. P., Kuller, L. H., Begg, L., Redmond, C. K., Bates, M. W.Serum level changes after administration of a pharmacologic dose off3-carotene. Am. J. Clin. Nutr., 48: 1277-1283, 1988.

16. Brown, E. D., Micozzi, M. S., Craft, N. E., Bieni, J. C., Beecher, C.,Edwards, B. K., Rose, A., Taylor, P. R., and Smith, J. C. Plasma carotenoidsin normal men after a single ingestion of vegetables or purified j3-carotene.Am. J. Clin. Nutr., 49: 1258-1265, 1989.

17. Nierenbeng, D. W., Stukel, T. A., Baron, I. A., Dam, B. J., Creenbeng,E. R., and the Skin Cancer Prevention Study Group. Determinants of increase

in plasma fi-canotene after chronic oral supplementation. Am. J. Clin. Nutr.,

53: 1443-1449, 1991.

18. WilIett, W. C., Stampfer, M. J., Underwood, B. A., Taylor, I. 0., andHennekens, C. H. Vitamins A, E, and carotene: effects of supplementation on

their plasma levels. Am. J. Clin. Nutn., 38: 559-566, 1983.

19. xu, M. J., Pezia, P. M., Alberts, D. S., Emerson, S. S., Peng, Y. M., Sayers,S. M., Liu, Y., Ritenbaugh, C., and Genslen, H. L. Reduction in plasma or skin

a-tocopherol concentration with long-term oral administration of f3-carotenein humans and mice. J. NatI. Cancer Inst., 84: 1559-1565, 1992.

20. Bendich, A., and Shapiro, S. S. Effect off3-carotene and canthaxanthin onthe immune responses of the rat. J. Nutr., 1 16: 2254-2262, 1986.



1994;3:245-251. Cancer Epidemiol Biomarkers Prev L Le Marchand, J H Hankin, F S Carter, et al. dietary intervention.acid as markers of compliance to a high fruit and vegetable A pilot study on the use of plasma carotenoids and ascorbic

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