Nutrition Journal Prevalence, sources, and predictors of soy consumption in breast cancer

Carolyn A Lammersfeld
Address: Cancer Treatment Centers of America® (CTCA) at Midwestern Regional Medical Center
2610 Sheridan Road60099ZionILUSA

Jessica King email@example.com
Address: Cancer Treatment Centers of America® (CTCA) at Midwestern Regional Medical Center
2610 Sheridan Road60099ZionILUSA

Sharon Walker email@example.com
Address: Cancer Treatment Centers of America® (CTCA) at Midwestern Regional Medical Center
2610 Sheridan Road60099ZionILUSA

Pankaj G Vashi email@example.com
Address: Cancer Treatment Centers of America® (CTCA) at Midwestern Regional Medical Center
2610 Sheridan Road60099ZionILUSA

James F Grutsch
Address: Cancer Treatment Centers of America® (CTCA) at Midwestern Regional Medical Center
2610 Sheridan Road60099ZionILUSA

Christopher G Lis
Address: Cancer Treatment Centers of America® (CTCA) at Midwestern Regional Medical Center
2610 Sheridan Road60099ZionILUSA

Digant Gupta email@example.com
Address: Cancer Treatment Centers of America® (CTCA) at Midwestern Regional Medical Center
2610 Sheridan Road60099ZionILUSA

Nutrition Journal Prevalence, sources, and predictors of soy consumption in breast cancer
10.1186/1475-2891-8-2BioMed Central Page 1 of 7 (page number not for citation purposes) Research * Corresponding author
Background: A number of components in soy appear to have anticancer properties, including the isoflavones, genistein and daidzein. The use of soy by women with breast cancer is now being questioned because of the estrogen-like effects of isoflavones and possible interactions with tamoxifen. Clinicians providing nutrition counseling to these women are concerned because the availability of soy foods has increased dramatically in the past few years. The goal of this study was to quantify the intake of isoflavones in women with breast cancer.Methods:A cross-sectional study of 100 women with breast cancer treated at Cancer Treatment Centers of America ® between 09/03 and 02/04. Each patient completed a soy food frequency questionnaire (FFQ) that was scored by Fred Hutchinson Cancer Research Center. Demographic and clinical predictors of soy intake were evaluated using one-way non-parametric Mann Whitney test and non-parametric spearman's rank correlation.Results: Mean age was 50.5 years (std. dev. = 9.4; range 31-70) and mean BMI was 27.3 kg/m 2 (std. dev. = 6.75; range 17-59). Genistein and Daidzein consumption was limited to 65 patients with a mean intake of 11.6 mg/day (std. dev. = 21.9; range 0-97.4) and 7.6 mg/day (std. dev. = 14.1; range 0-68.9) respectively. Soy milk (37%) and pills containing soy, isoflavones, or "natural" estrogen (24%) were the two biggest contributors to isoflavone intake.Conclusion:Our study suggests that the isoflavone intake of breast cancer patients at our hospital was quite variable. Thirty-five patients reported no soy intake. The mean daily intake of 11.6 mg genistein and 7.4 mg daidzein, is the equivalent of less than 1/4 cup of tofu per day. This amount is higher than what has been previously reported in non-Asian American women.

Background

Soy foods are known to have a number of health benefits, ranging from the well-documented cholesterol-lowering effects of soy protein, which may lower risk of cardiovas-cular disease [1], to the potential for decreasing bone loss in healthy, postmenopausal women [2,3]. A number of soy components are also thought to have anticancer properties, including isoflavones (genistein, daidzein, gly-citein), phytic acid, protease inhibitors, saponins, phytosterols and lignans [4]. Indeed, in vitro research indicates that isoflavones in particular may have antiestrogenic effects [5] and rodent studies have demonstrated associations of decreased risk of mammary tumors with soy intake [6]. Furthermore, it has been suggested that the lower risk for developing breast cancer in Asian countries may be related to soy intake [7][8][9]. A meta-analysis by Trock, et. al found that soy intake was associated with a 14% reduced risk of breast cancer in all women [10].

However, amid this promising research, other studies have raised the question of potential risk associated with the consumption of soy by women with breast cancer due to possible estrogenic effects of soy. An animal study in ovariectomized mice by Hsieh et al. using MCF-7 estrogen receptor (ER) positive breast cancer cells showed that low (and physiologically significant) concentrations of genistein may stimulate the proliferation of these cells [11]. Another study, in ovariectomized, athymic mice implanted with MCF-7 cells, found that genistein negated the inhibitory effect of tamoxifen on MCF-7 tumor growth in vivo [12]. One of the few human studies available noted epithelial cell hyperplasia as well as increased nipple-fluid aspirate in post-menopausal women who consumed an isoflavone-rich diet [13]. Because no clear consensus about the physiological effects of soy exists, the consumption of soy foods by women with breast cancer has become a controversial issue, and the need for further research continues to exist.

Meanwhile, clinicians providing counseling to breast cancer patients are concerned because the availability, familiarity and therefore, consumption, of soy foods by the American public has increased dramatically over the past 15 years [14,15]. Numerous studies have examined the soy food intake of Asian women [16,17], Dutch women [18], US women [19] and even women at high risk for breast cancer [20], however, very limited information is available regarding the consumption of soy foods by women actually diagnosed with breast cancer. This study attempts to quantify the amount and type of soy food intake in women with breast cancer.

Methods

Study Population

This cross-sectional study investigated a consecutive case series of 100 new breast cancer patients treated at Cancer Treatment Centers of America ® (CTCA) at Midwestern Regional Medical Center (MRMC) between 09/03 and 02/ 04. Only patients with a histologically confirmed diagnosis of breast cancer were included in this study. Other criteria for entry into the study included a minimum age of 18 years, willingness to sign informed consent and literacy in the English language. Patients were excluded if they were unable to give informed consent or understand or cooperate with study conditions. Every new patient with a diagnosis of breast cancer that scheduled an appointment at our institution between 09/03 and 02/04 was asked to participate in this study. One hundred percent of patients consented to participate, often citing a willingness to help others with this disease, as their primary motivator.

A trained registered dietitian described the study and determined eligibility after patients signed in at the clinic. As part of the consent process, patients were assured that refusal to participate in the study would not affect their future care in any way. Patients filled in the questionnaires before undergoing any therapy at our hospital. The Institutional Review Board at MRMC approved the study.

Questionnaire

After obtaining informed consent, each patient was asked to complete a soy food frequency questionnaire (FFQ) that was developed and validated by Fred Hutchinson Cancer Research Center. A detailed description of the FFQ has been previously published, but briefly, this 40-item soy FFQ was developed specifically to estimate soy food consumption and isoflavone intake over the past 3 months. For each food item, respondents were asked about frequency of consumption and the usual serving size consumed for each food. Options for portions size were small, medium, or large. Examples were given for a medium portion of each food item. A small portion was defined as a half of a medium portion and a large portion as one and a half times that of a medium portion. Isoflavone calculations were performed using the Nutrient Data System for Research (NDS-R) software version developed by the Nutrition Coordinating Center, University of Minnesota, Minneapolis, MN, Food and Nutrition Database. This FFQ was found to be reliable in two different studies examining two different populations [21,22]. Isoflavone values from this FFQ have also been shown to correlate well with blood levels of isoflavones [23]. In addition to completing the FFQ, subjects were also asked to detail any changes they had made to their diets since being diagnosed with cancer by answering two additional questions. The first question asked, "which response best describes your current diet?" The choices for this question included: Standard American diet, lacto-ovo vegetarian, no red meat, vegan, macrobiotic, & other with a blank for fill-in. The second question was open-ended & simply asked if any changes had been made to diet post-diagnosis. If the answer was yes, a description was requested. These responses were then categorized and coded for analysis.

Statistical Analysis

All data were analyzed using SPSS 11.5 (SPSS Inc., Chicago, IL, USA). Means, medians and standard deviations of genistein and daidzein intake were calculated. Soy foods with highest reported consumption were determined. All continuous variables were examined for normal distribution. Demographic and clinical predictors of soy intake (genistein and daidzein intake) were evaluated using one-way non-parametric Mann Whitney test or non-parametric spearman's rank correlation depending upon the underlying distributions of the variables. Among the predictors to be evaluated were age at diagnosis, body mass index (BMI), stage at diagnosis, ethnicity, prior treatment history (newly diagnosed versus those who had failed prior treatment elsewhere), menstrual status, estrogen and progesterone receptor status, and tamoxifen use. The soy consumption was categorized into 2 groups: those who had consumed any soy food in the last three months versus those who had not. The relationship of demographic and clinical predictors was also examined with the following soy consumption variables: weekly gram weight of soy foods consumed, weekly milligrams of genistein in soy foods consumed and weekly milligrams of daidzein in soy foods consumed. The significance level for all analyses was set at alpha = 0.05 and all tests were 2-sided.

Results

Patient Characteristics

A total of 100 breast cancer patients were approached in the clinic between 9/03 and 2/04 and were screened for eligibility by the clinical oncology nutritionist. One Hundred patients were found to be eligible for participation. Of 100 eligible patients, 100 consented to participate and completed the soy survey. The final study sample consisted of 100 patients with a response rate of 100%. The majority of this cohort was white (81%). The mean age was 50.5 years (std. dev. = 9.4; range 31-70). The mean BMI was 27.3 (std. dev. = 6.7; range 17.1-59.2). Fifty-nine percent were ER+, 37% ER-, and 4% unknown. Twentynine percent were on tamoxifen, 7% on Arimidex, % 11% on both. Twenty-three percent of participants reported following a vegetarian diet. Table 1 describes the characteristics of our patient cohort in greater detail.

Prevalence of Soy Use

The prevalence of soy consumption in our patient cohort was 65%. Consumers were defined as those who consumed at least one soy food in the past three months. The mean intake of genistein and daidzein in the previous three months was 11.6 mg/day (std. dev. = 21.9; range 0-97.4) and 7.6 mg/day (std. dev. = 14.1; range 0-68.9) respectively. Median intake of genistein and daidzein was 1 mg/day and 0.64 mg/day respectively. Table 2 provides data on the soy foods with the highest reported consumption. Table 3 provides data on the major contributors to isoflavone intake.

Predictors of Soy Use

Age at diagnosis, BMI, and weekly milligrams intake of genistein and daidzein were non-normally distributed and therefore non-parametric methods were used to analyze the relationships between them. An interesting relationship was observed between the change in diet after cancer diagnosis question and soy intake. The mean daily milligram of genistein consumed was 5.6 and 10.8 respectively for those who did not change their diet after cancer diagnosis (n = 30) and those who switched over to a more vegetarian diet (n = 23). Similarly, the mean daily milligram of diadzein consumed was 3.3 and 7.0 for those who did not change their diet after cancer diagnosis (n = 30) and those who switched over to a more vegetarian diet (n = 23). In the open ended question asking respondents to describe changes to their diets since diagnosis, 14 respondents mentioned soy intake. Interestingly, there were 7 responses reporting increasing soy intake since diagnosis, and 7 responses reporting decreasing soy intake since diagnosis. In addition to changing towards a vegetarian diet, other changes mentioned were decreasing sugar, increasing vegetables and fruits, decreasing portions, & decreasing fat.

Discussion

In our study of 100 women diagnosed with breast cancer, the intake of soy isoflavones was quite variable ranging from 0 to 161.4 mg per day. This is similar to the range of 0 to > 150 mg/day reported by Frankenfeld et al. [23]. We found 35% of these subjects to be soy non-consumers, which is also similar to the findings by Frankenfeld et al. [22,23].

The mean intake of isoflavones in this population is higher than that reported in other US women and in women in the Bay Area Breast Cancer Study [19,24], but lower than that reported in Asian populations [25][26][27]. Isoflavone intake in the women in this study was similar to that previously reported for vegetarians [21,22]. In fact, many of the patients in this study reported making diet changes since their diagnosis. Twenty-three patients reported following a vegetarian diet.

The ten soy foods with the highest reported consumption ( Table 2) contributed to 68% of isoflavone intake. Soy sauce and soy condiments had the highest reported consumption, yet contributed very little to isoflavone intake (see Table 3). Soymilk and pills containing soy, isoflavones, or "natural" estrogens contributed to 61% of total isoflavone (daidzen and genistein) intake of all participants (Table 3). An interesting finding was that these pills contributed to 24% of total isoflavone intake of all participants, yet these pills were consumed by < 9% of the participants. These pills can be very concentrated sources of isoflavones. Women consuming these pills had isoflavone intakes at the higher end of the range reported for this cohort. These women had intakes of isoflavones that exceeded 100 mg/day, which according to Messina and Wood is an intake that no more than 5% of older adults in Japan and China consume [27]. This suggests that some Veggie soy or tofu burger 12

Soy cheese 12

Packaged mixed dishes with soy or tofu 10

Tofu or soy breakfast sausage 9

Soy drinks 9 women with breast cancer may be consuming isoflavones in amounts above and beyond what appears to be safely consumed in Asian countries. Inquiring about isoflavone supplement intake may be one way to screen women with breast cancer for isoflavone consumption that may be excessive.

Another interesting finding was that many of the foods with high consumption were processed soy foods, including bars, burgers, cheese, packaged dishes, sausages, and drinks. In contrast, the soy consumed in Asian countries is minimally processed. A study by Allred et al. evaluated mice transplanted with MCF-7 cells that were exposed to various soy products with equal amounts of genistein aglycone equivalents. They found mice exposed to more processed soy had increased tumor growth compared to mice that received less processed soy [28]. This raises the question of whether or not we should also be concerned with the degree of processing in soy foods that are con-  FFQs have been criticized for being too vague when it comes to serving sizes. The definition of serving sizes is often open to individual interpretation. The soy FFQ used in our study defines a medium serving size for the foods in the questionnaire; and defines small and large servings in relation to the medium serving. FFQs have also been criticized for being prone to measurement error. How often one consumes a particular food is often hard to answer and/or remember. FFQs may result in underreporting based on the theory that people behave differently when observed. Finally, the number of foods on a FFQ can be limited, and preparation is not always taken into account [29]. For example, the FFQ used in this study only asked about soy foods. There are isoflavones in other foods such as beans, peas, flour, coffee, etc., which were not evaluated with this instrument. To this point, it has been reported that isoflavone containing foods other than soy make a minimal contribution to total isoflavone exposure [19]. A possible defense of this limitation is that we used a FFQ that has been validated when compared to plasma levels of isoflavones and when given at different intervals with time between measurements [21][22][23].

Conclusion

Despite these limitations, this study adds to the limited information that currently exists on quantifying soy isoflavone intake in women with breast cancer. We found isoflavone intake in women with breast cancer in this study to be similar to the intake of isoflavones in vegetarians, but less than that in Asian woman. Although vegetarian diets can vary, they generally are not associated with an increase in breast cancer risk or mortality [30,31]. Potential utility of this study is that clinicians may be able to use the list of foods in Table 3 to quickly screen women with breast cancer for isoflavone intake. As was previously mentioned, asking women with breast cancer about isoflavone containing pills is one way to identify some women with intakes that may be excessive. In this cohort, soymilk, pills, and bars containing soy contributed to 73% of isoflavone intake. Asking about these three foods may be one way to quickly estimate isoflavone intake in women with breast cancer. Ideally, future studies should evaluate isoflavone intake in women with breast cancer being treated at multiple centers, in order to determine if these results are broadly representative of isoflavone intake in these women. Additional studies are also needed to determine what a safe and acceptable level of isoflavone intake is in women with breast cancer given the potential biphasic effect of isoflavone exposure.

Table 1 :
1Subject characteristics (N = 100)Characteristic
Categories
Number
Percent (%)

Ethnicity
Caucasian
81
81
African American
15
15
Hispanic
3
3
Asian
1
1

Tumor Stage at Diagnosis
Stage 0
4
4
Stage I
21
21
Stage II
44
44
Stage III
17
17
Stage IV
11
11
Unknown
3
3

Menstrual Status
Premenopausal
53
53
Postmenopausal
37
37
Perimenopausal
4
4
Unknown
6
6

ER/PR status
ER + PR +
48
48
ER + PR -
11
11
ER -PR +
1
1
ER -PR -
36
36
Unknown
4
4

Tamoxifen/Arimidex use
Neither
50
50
Tamoxifen only
29
29
Arimidex only
7
7
Both
11
11
Unknown
3
3

Table 4
4displays the

Table 2 :
2Ten soy foods with highest reported consumptionSoy Food
Percent Patients

Soy sauce
37

Soy milk
23

Soy bars
18

Roasted soy nuts
13

Tofu
13

Table 3 :
3Top ten contributors to isoflavone intakeSoy Food

Table 4 :
4Spearman rank correlations between demographic and clinical factors and soy consumption (N = 100) of patients with breast cancer. In fact, many of the patients in this study reported making diet changes since their diagnosis. Our sample size might not have been large enough to accommodate the number of post hoc subgroup comparisons made within this study. This study was not an attempt to scientifically evaluate the impact of soy consumption on breast cancer but rather to describe what proportion of people with breast cancer use soy foods. The non-normal distribution of age at diagnosis, BMI, and weekly milligrams intake of genistein and daidzein could be a result of relatively small sample size of our study.Predictors
Soy consumption
(yes versus no)

Weekly gram weight of
soy

Weekly milligrams of
Genistein

Weekly milligrams of
Daidzein

Age at Diagnosis
0.014
0.06
0.12
0.12

BMI
-0.04
-0.11
-0.11
-0.11

Ethnicity
-0.23*
0.18
0.13
0.13

Stage at Diagnosis
-0.18
-0.25*
-0.25*
-0.24*

Prior Treatment History
-0.12
-0.19
-0.18
-0.18

Menstrual Status
0.07
0.11
0.14
0.14

Estrogen/Progesterone
Receptor Status

0.16
0.08
0.07
0.07

Tamoxifen Use
-0.21*
-0.20
-0.16
-0.16

* p < 0.05

(page number not for citation purposes)
AcknowledgementsThis study was funded by Cancer Treatment Centers of America ® . We thank Norine Oplt, chief of our Cancer Registry, for providing us with reliable and updated demographic data.Competing interestsThe authors declare that they have no competing interests.Authors' contributionsCAL was the main author of the manuscript, participated in concept, design, data collection, data analysis and data interpretation. JK and SW participated in concept, design, data collection and writing. PGV participated in concept, design and data interpretation. JFG and CGL assisted with the statistical analysis and data interpretation. DG participated in concept, design, analysis, data interpretation and writing. All authors read and approved the final manuscript.Publish with Bio Med Central and every scientist can read your work free of charge
The soy health claim. J Henkel, FDA Consumer. 17Henkel J: The soy health claim. FDA Consumer 2000, 17:.

Dietary soy isoflavones and bone mineral density: results from the study of women's health across the nation. G A Greendale, G Fitzgerald, M H Huang, B Sternfeld, E Gold, T Seeman, S Sherman, M Sowers, Am J Epidemiol. 155Greendale GA, Fitzgerald G, Huang MH, Sternfeld B, Gold E, Seeman T, Sherman S, Sowers M: Dietary soy isoflavones and bone min- eral density: results from the study of women's health across the nation. Am J Epidemiol 2002, 155:746-54.

One year soy isoflavone supplementation prevents early postmenopausal bone loss, but without a dose-dependant effect. H Y Huang, H P Yang, H T Yang, T C Yang, M J Sheih, J Nutr Biochem. 178Huang HY, Yang HP, Yang HT, Yang TC, Sheih MJ: One year soy iso- flavone supplementation prevents early postmenopausal bone loss, but without a dose-dependant effect. J Nutr Biochem 2006, 17(8):509-17.

Soy for breast cancer survivors: a critical review of the literature. M J Messina, C L Loprinzi, J Nutr. 131Messina MJ, Loprinzi CL: Soy for breast cancer survivors: a crit- ical review of the literature. J Nutr 2001, 131:3095S-3108S.

The interaction in the immature mouse of potent oestrogens with coumestrol, genestein and other utero-vaginotrophic compounds of low potency. Y Folman, G S Pope, J Endocrinol. 34Folman Y, Pope GS: The interaction in the immature mouse of potent oestrogens with coumestrol, genestein and other utero-vaginotrophic compounds of low potency. J Endocrinol 1966, 34:215-25.

Soy intake and cancer risk: a review of the in vitro and in vivo data. M J Messina, V Persky, K D Setchell, S Barnes, Nutr Cancer. 21Messina MJ, Persky V, Setchell KD, Barnes S: Soy intake and cancer risk: a review of the in vitro and in vivo data. Nutr Cancer 1994, 21:113-31.

Dietary effects on breast cancer risk in Singapore. H P Lee, L Gourley, S W Duffy, J Esteve, J Lee, N E Day, Lancet. 337Lee HP, Gourley L, Duffy SW, Esteve J, Lee J, Day NE: Dietary effects on breast cancer risk in Singapore. Lancet 1991, 337:1197-2000.

Japan Public Health Center-Based Prospective Study on Cancer Cardiovascular Diseases Group. S Yamamoto, T Sobue, M Kobayashi, S Sasaki, S Tsugane, J Natl Cancer Inst. 95Yamamoto S, Sobue T, Kobayashi M, Sasaki S, Tsugane S: Japan Pub- lic Health Center-Based Prospective Study on Cancer Cardi- ovascular Diseases Group. J Natl Cancer Inst 2003, 95:906-13.

Population-based case-control study of soyfood intake and breast cancer risk in Shanghai. Q Dai, X O Shu, Jin F Potter, J D Kushi, L H Teas, J Gao, Y T Zheng, W , Br J Cancer. 85Dai Q, Shu XO, Jin F, Potter JD, Kushi LH, Teas J, Gao YT, Zheng W: Population-based case-control study of soyfood intake and breast cancer risk in Shanghai. Br J Cancer 2001, 85:372-8.

Meta-Analysis of Soy Intake and Breast Cancer Risk. B J Trock, L Hilakivi-Clarke, Clarke R , J Natl Cancer Inst. 98Trock BJ, Hilakivi-Clarke L, Clarke R: Meta-Analysis of Soy Intake and Breast Cancer Risk. J Natl Cancer Inst 2006, 98:459-71.

Estrogenic effects of genestein on growth of estrogen receptor-positive human breast cancer (MCF-7) cells in vitro and in vivo. C Y Hsieh, R C Santell, S Z Haslam, W G Helferich, Cancer Res. 58Hsieh CY, Santell RC, Haslam SZ, Helferich WG: Estrogenic effects of genestein on growth of estrogen receptor-positive human breast cancer (MCF-7) cells in vitro and in vivo. Cancer Res 1998, 58:3833-8.

Dietary genistein negates the inhibitory effect of tamoxifen on growth of estrogen-dependent human breast cancer (MCF-7) cells implanted in athymic mice. Y H Ju, D R Doerge, K F Allred, C D Allred, W G Helferich, Cancer Res. 62Ju YH, Doerge DR, Allred KF, Allred CD, Helferich WG: Dietary genistein negates the inhibitory effect of tamoxifen on growth of estrogen-dependent human breast cancer (MCF- 7) cells implanted in athymic mice. Cancer Res 2002, 62:2474-7.

Stimulatory influence of soy protein isolate on breast secretion in pre-and postmenopausal women. N L Petrakis, S Barnes, E B King, J Lownestein, J Wiencke, M M Kee, R Miike, M Kirk, L Coward, Cancer Epidemiol Biomarkers Prev. 5Petrakis NL, Barnes S, King EB, Lownestein J, Wiencke J, Kee MM, Miike R, Kirk M, Coward L: Stimulatory influence of soy protein isolate on breast secretion in pre-and postmenopausal women. Cancer Epidemiol Biomarkers Prev 1996, 5:785-794.

Soy products try to penetrate the main-stream. E Parle, Chemical Market Reporter. 25714Parle E: Soy products try to penetrate the main-stream. Chemical Market Reporter 2000, 257:14.

Soy Foods Association of North America. Soyfood sales and trends. Soy Foods Association of North America. Soyfood sales and trends [http://www.soyfood.org/sales/sales.html]

Dietary intake and sources of isoflavones among Japanese. K Wakai, I Egami, K Kato, T Kawamura, A Tamakoshi, Y Lin, T Nakavama, M Wada, Y Ohno, Nutr Cancer. 33Wakai K, Egami I, kato K, Kawamura T, Tamakoshi A, Lin Y, Naka- vama T, Wada M, Ohno Y: Dietary intake and sources of isofla- vones among Japanese. Nutr Cancer 1999, 33:13-145.

Serum isoflavones and soya food intake in Japanese, Thai and American end-stage renal disease patients on chronic haemodialysis. P Fanti, T J Stephenson, I M Kaarianen, B Rezkalla, Y Tsukamoto, T Morishita, M Nomura, C Kitiyakara, L J Custer, A A Franke, Nephrol Dial Transplant. 18Fanti P, Stephenson TJ, Kaarianen IM, Rezkalla B, Tsukamoto Y, Morishita T, Nomura M, Kitiyakara C, Custer LJ, Franke AA: Serum isoflavones and soya food intake in Japanese, Thai and Amer- ican end-stage renal disease patients on chronic haemodial- ysis. Nephrol Dial Transplant 2003, 18:1862-1868.

Intake of dietary phytoestrogens by Dutch women. L K Boker, Y T Schouw, Van Der, M J De Kleijn, P F Jacques, D E Grobbee, P H Peeters, J Nutr. 132Boker LK, Schouw YT van der, de Kleijn MJ, Jacques PF, Grobbee DE, Peeters PH: Intake of dietary phytoestrogens by Dutch women. J Nutr 2002, 132:1319-1328.

Intake of dietary phytoestrogens is low in postmenopausal women in the United States: The Framingham Study. M J De Kleijn, Y T Schouw, Van Der, P W Wilson, H Adlercreutz, W Mazur, D E Grobbee, P F Jacques, J Nutr. 131de Kleijn MJ, Schouw YT van der, Wilson PW, Adlercreutz H, Mazur W, Grobbee DE, Jacques PF: Intake of dietary phytoestrogens is low in postmenopausal women in the United States: The Framingham Study. J Nutr 2001, 131:1826-1832.

Correlates of soy food consumption in women at increased risk for breast cancer. C Y Fang, M Tseng, M B Daly, J Amer Diet Assoc. 105Fang CY, Tseng M, Daly MB: Correlates of soy food consumption in women at increased risk for breast cancer. J Amer Diet Assoc 2005, 105:1552-1558.

Development of a soy food frequency questionnaire to estimate isoflavone consumption in US adults. P Kirk, R E Patterson, J Lampe, J Amer Diet Assoc. 99Kirk P, Patterson RE, Lampe J: Development of a soy food fre- quency questionnaire to estimate isoflavone consumption in US adults. J Amer Diet Assoc 1999, 99:558-563.

Validation of a soy food frequency questionnaire with plasma concentrations of isoflavones in US adults. C L Frankenfeld, R E Patterson, T F Kalhorn, H E Skor, W N Howald, J W Lampe, J Amer Diet Assoc. 102Frankenfeld CL, Patterson RE, Kalhorn TF, Skor HE, Howald WN, Lampe JW: Validation of a soy food frequency questionnaire with plasma concentrations of isoflavones in US adults. J Amer Diet Assoc 2002, 102:1407-1413.

Validation of a soy food-frequency questionnaire and evaluation of correlates of plasma isoflavone concentrations in postmenopausal women. C L Frankenfeld, R E Patterson, N K Horner, M L Neuhouser, H E Skor, T F Kalhorn, W N Howald, J W Lampe, Am J Clin Nutr. 77Frankenfeld CL, Patterson RE, Horner NK, Neuhouser ML, Skor HE, Kalhorn TF, Howald WN, Lampe JW: Validation of a soy food-fre- quency questionnaire and evaluation of correlates of plasma isoflavone concentrations in postmenopausal women. Am J Clin Nutr 2003, 77:674-80.

Phytoestrogen Consumption and Breast Cancer Risk in a Multiethnic Population: the Bay Area Breast Cancer Study. P L Horn-Ross, E M John, M Lee, S L Stewart, J Koo, L C Sakoda, A C Shiau, J Goldstein, P Davis, E J Perez-Stable, Am J Epidemiol. 154Horn-Ross PL, John EM, Lee M, Stewart SL, Koo J, Sakoda LC, Shiau AC, Goldstein J, Davis P, Perez-Stable EJ: Phytoestrogen Con- sumption and Breast Cancer Risk in a Multiethnic Popula- tion: the Bay Area Breast Cancer Study. Am J Epidemiol 2001, 154:434-441.

M Messina, W Mccaskill-Stevens, J W Lampe, Addressing the Soy and Breast Cancer Relationship: Review, Commentary, and Workshop Proceedings. 98Messina M, McCaskill-Stevens W, Lampe JW: Addressing the Soy and Breast Cancer Relationship: Review, Commentary, and Workshop Proceedings. J Natl Cancer Inst 2006, 98:1275-1284.

Soy for Breast Cancer Survivors: A Critical Review of the Literature. M J Messina, C L Loprinzi, J Nutr. 131Messina MJ, Loprinzi CL: Soy for Breast Cancer Survivors: A Critical Review of the Literature. J Nutr 2001, 131:3095S-3108S.

Soy isoflavones, estrogen therapy, and breast cancer risk: analysis and commentary. M J Messina, C E Wood, Nutrition Journal. 717Messina MJ, Wood CE: Soy isoflavones, estrogen therapy, and breast cancer risk: analysis and commentary. Nutrition Journal 2008, 7(17):1-12.

Soy processing influences growth of estrogen-dependent breast cancer tumors. C D Allred, K F Allred, Y H Ju, T S Goeppinger, D R Doerge, W G Helferich, Carcinogenesis. 25Allred CD, Allred KF, Ju YH, Goeppinger TS, Doerge DR, Helferich WG: Soy processing influences growth of estrogen-depend- ent breast cancer tumors. Carcinogenesis 2004, 25:1649-1657.

Do Food Frequency Questionnaires Have Too Many Limitations. D Brown, Journal of the American Dietetic Association. 106Brown D: Do Food Frequency Questionnaires Have Too Many Limitations? Journal of the American Dietetic Association 2006, 106:1541-42.

Lifelong vegetarianism and risk of breast cancer: a population-based case-control study among South Asian migrant women living in England. Dos Santos Silva, I Mangtani, P Mccormack, V Bhakta, D Sevak, L Mcmichael, A J , Int J Cancer. 2Dos Santos Silva I, Mangtani P, McCormack V, Bhakta D, Sevak L, McMichael AJ: Lifelong vegetarianism and risk of breast can- cer: a population-based case-control study among South Asian migrant women living in England. Int J Cancer 2002, 2:238-44.

Mortality in vegetarians and nonvegetarians: detailed findings from a collaborative analysis of 5 prosepctive studies. T J Key, G E Fraser, M Thorogood, P N Appleby, V Beral, G Reeves, M L Burr, J Chang-Claude, R Frentzel-Beyme, J W Kuzma, J Mann, K Mcpherson, Am J Clin Nutr. 3SupplKey TJ, Fraser GE, Thorogood M, Appleby PN, Beral V, Reeves G, Burr ML, Chang-Claude J, Frentzel-Beyme R, Kuzma JW, Mann J, McPherson K: Mortality in vegetarians and nonvegetarians: detailed findings from a collaborative analysis of 5 prosepc- tive studies. Am J Clin Nutr 1999, 3(Suppl):516S-524S.


Incorporating a Gender Perspective into Cuba's Health System: Realities and Challenges

MSLeticia Artiles
Incorporating a Gender Perspective into Cuba's Health System: Realities and Challenges
BA26D1F1AF74A691C9FA893CF3345905
The article describes progress and challenges in incorporating a gender perspective into the Cuban health system.Results obtained thus far indicate progress in raising consciousness and in concentration on the interaction between biological and social factors, in particular recognizing gender as a social determinant of health.Weaknesses are also identifi ed, and recommendations made for introduction of a gender perspective in various areas of the health system such as policy making; services planning, organization and delivery; population health assessments; and human resources training and development.KEYWORDS Gender issues, gender bias, health care systems, delivery of health care, Cuba Peer Reviewed

INTRODUCTION

The evolution of gender perspective's incorporation into health systems has gone hand in hand with the advance of women's position in social movements.In the 1970s and 1980s, the approach to studying female social disadvantage was limited to 'what women lack,' relying on the implicit assumption that the problem resided in women themselves.[1] As a result, in the health fi eld the articulation of gender was reduced to maternal and child health, women's morbidity and mortality indicators and, at best, comparisons of women's health to men's.[2] In effect, this resulted in a symbolic equation of woman with mother, with family, in turn generating myths of femininity that infl uenced all areas of a woman's life, irrespective of any other factors.[3] According to this equation, a woman is educated for her roles of good mother and wife, the axis of feminine subjectivity.Health systems and their organization do not escape these assumptions.[4] The binary concept of masculinity and femininity based on biological sex has changed over time.More recently, conceptualization of sex has evolved considerably, expanding to embrace the concept of gender, which goes beyond physiological considerations to contemplate the social construction of functions, stereotypes and prejudices that have hindered women's equality and their full exercise of economic, social and cultural rights.[5] Adopting a gender perspective in health planning, policies and programs implies identifying, analyzing and acting on health inequalities derived from interactions between sex and gender differences and other forms of inequality such as socioeconomic status, age, ethnicity, sexual orientation and functional capacities.

Applying a gender perspective A gender perspective articulates a subject's position, a point of view; constitutes a point of departure and an endpoint; delimits the fi eld of observation; proposes a meaning for what is observed; and defi nes criteria for describing, interpreting and explaining the phenomena observed.[6] This construction lays the basis for women and men having different outlooks, resulting in visions of femininity and masculinity involving imagery, symbolic structures and representations stemming from different paths and starting points.An understand-ing of these complexities and differing outlooks is essential for any person, man or woman, to apply a gender perspective.In the health fi eld, consciousness must be coupled with skills to apply this perspective in any arena, from development of public policy to patient care.

Regional policies PAHO's 46th Governing Council approved a

Plan of Action for Implementing the Gender Equality Policy 2009-2014, whose aim is to help achieve gender equality in health status and development through research, policies and programs that pay due attention to gender differences in health and health determinants and actively promote equality between women and men.[5,7] PAHO has urged member states to include such a policy in their activities.In my opinion, Cuba's unifi ed health care system gives it a relative advantage in the potential to fully apply a gender perspective, compared to other countries in the Americas that have health care delivery systems fragmented along public, private and social security lines.This paper assesses Cuba's progress in incorporating a gender perspective into its health system over the last few years, identifying current strengths, weakness and challenges that affect prospects for its thoroughgoing application.I will also propose some considerations-effectively, recommendations-concerning several actions that would favor extension of this perspective to various areas of Cuba's health system.

CUBA'S POTENTIAL

Cuba's relative advantage in prospects for incorporating a gender perspective in health stems fi rst from the political will of government, in keeping with its focus on social justice and its continued commitment to eliminate all forms of discrimination-whether by class, gender or race-as refl ected in the Council of State's resolution approving and enacting the National Action Plan following the Beijing conference.[8] Such political will is key to analyzing and introducing a gender perspective in health policies, strategies, statistics, programs, research and projects to improve health services, incorporating social factors, particularly gender, not simply as variables but as tools and standards for improved decision making.

Added to this strength is the fact that Cuba has a unifi ed and integrated health system, not fragmented into private, public and other service delivery schemes as in some other countries.This permits periodic auditing and inspections that help ensure adequate program implementation at all levels throughout the country.Moreover, results from research at health sciences universities are deposited directly into the health system, since these universities are under the jurisdiction of the Ministry of Public Health (MINSAP, its Spanish acronym), facilitating introduction of fi ndings into practice.Thus, a gender perspective explicitly included in MINSAP's mission, vision and strategy would have more likelihood of being organically applied throughout the sector.However, when it comes to gender, the advantage of a single, unifi ed health system has been insuffi ciently leveraged for greater equity, a value inherent in Cuban health care.

Perspective

This and other weaknesses translate into challenges to be faced in order to take advantage of existing opportunities to determine which interventions to implement, relying on process and implementation analysis of health promotion, disease prevention, curative care and rehabilitation actions.

TOWARDS A GENDER PERSPECTIVE IN CUBA'S HEALTH SYSTEM

MINSAP has no explicit gender policy.However, the health system's free, universal coverage offers equal access by men and women to resources for their health and wellbeing, contributing to the goal of achieving "higher levels of health protection for the entire population," as stated in MINSAP's strategy document providing public health projections through 2015.The same document recognizes the continuing challenge of improving attention to "special population groups," including women, as well as priority for research in areas such as men who have sex with men.However, comprehensive consideration of gender-specifi c needs constitutes a pending agenda.[9] Thus, there is no single structure devoted to gender in MINSAP.However, several national centers have been assigned the role of promoting a gender perspective: the National Health Promotion and Education Center (CNPES, its Spanish acronym), the National STI/HIV/AIDS Prevention Center (CNPITS/VIH/SIDA, its Spanish acronym); the National Center for Sex Education (CENE-SEX, its Spanish acronym); the National School of Public Health (ENSAP, its Spanish acronym); and the 14 medical universities across the country.Most of the provincial medical universities have women's studies units, meant to raise awareness among students and faculty of the importance of considering gender in research and analysis of health information.

A notable step forward is disaggregation by sex of data in MIN-SAP's Health Statistics Yearbook, and the calculation of the sex ratio for consideration of morbidity, mortality and other health statistics, important information for gender analysis.[10]In addition, since 2009, MINSAP's Science and Technology Division has included in its research priorities women's and men's perceptions in identifying gender-specifi c practical and strategic needs, as social determinants of health.[11] MINSAP has strengthened its human resource capacity-building, both centrally and in centers such as CNPES, CNPITS/VIH/SIDA, CENESEX, the National Maternal-Child Health Program, women's studies and sex education units at medical universities and in a research and training center on gender located in ENSAP.

Civil society has been an important player in this process, as in other health-related activities.In this regard, the role of the Federation of Cuban Women (FMC, its Spanish acronym) deserves particular mention, including its Women's and Family Centers and neighborhood health promoters.Other neighborhood organizations also assist in MINSAP vaccination and cancer screening, among other programs.Together with the local FMC, they sponsor health forums, providing information and opportunities to discuss issues of interest to women and related to gender equity in the family and community.Also in the realm of civil society: the Gender and Health Network, the Latin American Social Medicine Society affi liate in the Cuban Society of Public Health, promotes and supports training, research and publications to strengthen knowledge of social determinants of health and gender perspective.And fi nally, the Cuban Society of Family Medicine and the Menopause Division of the Cuban Obstetrics and Gynecology Society include gender issues in their training and research activities.

CHALLENGES AHEAD

We still have some distance to go to bring gender analysis into the decision-making process, with gender-infl ected epidemiologic profi les and exploration of gender intersectionalities [12] with social status, geography, ethnicity, abilities, life stage and sexual diversity.We need to lay out a strategy to strengthen this process, training change agents who will move actions forward greater incorporation of a gender perspective.To consolidate progress to date and move ahead, health professionals are needed who have training and sensitivity to social medicine and the competencies necessary to extend a gender perspective to all areas of health service management and delivery.

Health policies

In addition to more capacity building, if they are to infl uence policy towards incorporation of a gender perspective, Cuban health professionals also need access to data disaggregated by sex and to have thorough knowledge of sociological factors: social contexts; health-related cultural beliefs, attitudes and cultural practices; housing and sanitary conditions relevant to the distribution of women's and men's domestic roles; gender-infl uenced access to power, to public offi ce and decision making at all levels; and in any related spheres in which inequities affect health.

To introduce a gender perspective in public policies, those who participate in their formulation and application must recognize: the economic value of unpaid work and reproduction, division of labor by gender, intergender subordination as a health risk factor for men and women and as a determinant of vulnerability for some social groups; the status of women and their real opportunities in the labor market; differences in opportunities for women and men in the public sphere and in access to power; and sex-specifi c impact of biological and social factors on health and differing health needs.Such recognition by those who design public policies demands true sensitivity, not just lip service, to the infl uence of gender on health.Incorporating this perspective in decision making will facilitate more integrated and humane development in all spheres of the health system.

Health services planning Moser identifi ed six basic tools for gender-based planning: identifi cation of gender roles, consideration of differences in access to and control of resources, assessment of gender-specifi c needs, role balance and intersectoral planning, relation between roles and needs, and inclusion of stakeholders in the planning process.[13] Weissman further recommends including nature-of-care needs; differential socialization patterns regarding symptom recognition, disease perception and serviceseeking behavior; and structural and institutional factors that differentially facilitate or obstruct health service access.[14] Gender-based planning also implies political decisions about the changes a gender perspective can introduce in institutional power structures in the medium and long term (for example, greater participation by women in leadership of the health system); review and adaptation of institutional structures and procedures to create capacity for gender-based project planning and implementation; and implementation and evaluation tools for gender analysis and health problem defi nition.

REFERENCES

Perspective

Health service organization Health services are usually evaluated with a pronounced medical bias, by improvements in health indicators, mortality reduction or increased effi ciency.Criteria such as needs satisfaction or exercise of client rights are usually not considered; at most, expressions of satisfaction are mentioned.Omitting a gender analysis misses the point that, "those who don't decide don't expect, and hence, they ask for very little, generating self-congratulatory evaluations," from people grateful for whatever they may receive.[15] Including a gender perspective in health care quality must include everything from treating people respectfully, cleanliness and adequate signage to shared decision making between health care provider and patient, which means active patient participation as subjects throughout the health care process, within their own social context.This in turn implies strengthening the social medicine model as opposed to the traditional doctor-centered model of care.

Globally, inclusion of a gender perspective in health services has become more common in recent decades, but still tending to focus more on women's health.Some authors argue for more attention to men's health, since men tend to die younger and from preventable causes such as intentional and unintentional injuries, myocardial infarction, cancer, cirrhosis and drug addiction, with higher rates of suicide as well.[16] This reminds us that gender does not equal women: rather, it is a conceptual tool to enrich explanatory models of health and illness, amplify epidemiologic profi les and recontextualize planning for health interventions and programs.

Population health assessment Health surveillance from a gender perspective is meant to gather, organize, analyze and use information that enables application of this perspective in the planning, organization and systematization of health services management.It can strengthen the design of policies, plans and programs to better respond to sex-specifi c needs and help reduce gender-based inequities in health and human development.

Epidemiologic surveillance from a gender perspective requires tackling the epidemiology of inequality, obtaining information for sex-specifi c epidemiologic profi les-with all their intersectionalities-and identifying modifi able differences.Current information is inadequate because in most countries data collection instruments are insuffi ciently detailed for analysis by sex.[1,7] In Cuba, sex-specifi c data are available but gender analysis is still lacking, with insuffi cient characterization of the social contexts of individuals and populations whose health inequalities generate different needs requiring different responses.

To obtain and analyze information from a gender perspective, one has to begin by recognizing the inequality existing between the sexes, within and beyond the biological and reproductive.This also requires acknowledging the impact of their roles, including differences in assigned and assumed social burdens, on the health-illness continuum; and must take into account the particular needs, contributions, risks and opportunities of each sex, stemming not only from biological differences but also from the way women's and men's positions are articulated in the social, political and economic realms.

Surveillance and population health assessment require health profi les that identify and analyze differences according to sex and their determinants within particular population subgroups.This analytic approach requires not only identifi cation of similarities and differences between the sexes but also intragender variations, resulting from differences in living conditions across population subgroups.

Thus, including a gender perspective in epidemiologic surveillance systems requires defi ning and selecting new problems that merit surveillance, as well as determining appropriate indicators and methods for data collection and analysis.This is a challenge that, if met, will improve health system and service quality.It is a broad undertaking and one that requires deeper study after application in practice.

FINAL CONSIDERATIONS

In Cuba, the health sector's institutional development and policies espoused by PAHO, WHO and the FMC have facilitated gradually increasing application of a gender perspective in the health system.The existence of a Beijing followup plan and government commitment to the various international conferences on the topic in recent decades, coupled with political and social will should ensure continued progress in this area.Explicit inclusion of the following areas should be improved as we move forward:

• Establish a comprehensive human resource development strategy in health that includes a gender perspective in education and training, as well as capacity building for practitioners and decisionmakers; • Recognize biological diversity and the inequitable distribution of power and social burdens assigned as a function of sex; • Eliminate health professionals' attitudes that stereotype classifi cation of health care demands by sex (men: more serious health problems; women: problems more emotional in nature); • Recognize sexual diversity and its intersectionalities as determinants of health and gendered epidemiologic profi les; • Recognize gender-associated risk factors; • Incorporate contributions of roles and functions in public and private life and the connections between these to make genderinformed clinical and epidemiologic diagnoses; and • Incorporate gender as a determinant of health in all areas and processes of the health sector.
 Peer Reviewed
THE AUTHORLeticia Artiles Visbal (email@example.com), anthropologist with a doctorate in health sciences, Havana.
Pan American Health Organization. E Gómez, 2010Marco Conceptual. SpanishWashingtonCurso Virtual de Género y Salud

La articulación de la categoría género y salud: un desafío inaplazable. Rev Gerenc Polit Salud. J H Estrada, 2009 Jun -Dec;8(17Spanish

La infertilidad, el maternaje frustrado. I González, Rev Cubana Med Gen Integr. 1832002

P Arés, Género, salud y cotidianidad. Havana; Spanish2000

Pan American Health Organization. Resolución CD46.R16. 46ª Consejo Directivo de la OPS. Washington, D.C; SpanishPolítica de Igualdad de Género2005

La investigación en salud para el desarrollo y el enfoque de género: una contribución necesaria para la equidad en salud. Red de Salud de las Mujeres Latinoamericanas y del Caribe (RSMLAC). González Vélez, C , Sánchez Buitrago, M , 2000Bangkok; Spanish

Pan American Health Organization. 2009. 2014. 2005Washington, D.C; SpanishPlan de Acción para la implementación de la Política de Igualdad de Género de la Organización Panamericana de la Salud

Gaceta Ofi cial de la República de Cuba. Havana; Spanish1997 May 5Council of State (CU). Plan de Acción Nacional de Seguimiento a la Conferencia de Beijing

Proyecciones de la Salud Pública en Cuba para el. HavanaMinistry of Public Health2015. 200668CU

Identifi cación y sistematización de prioridades para la investigación en salud. 2009Ministry of Pubic HealthHavana; SpanishKnowledge Management and Technology Agency (CU). Informe de Investigación

Re-thinking Intersectionality. J C Nash, Internet] Feminist Rev. 892008. 2012 Apr 6

Gender Planning and Development: Theory, Practice and Training. C Moser, 1993 Sep304LondonRoutledge

Women's health care. C Weissman, 1998The Johns Hopkins University PressBaltimore

Calidad de atención en salud reproductiva desde un enfoque de género. Investigación cualitativa con mujeres benefi ciarias del Servicio de Salud Occidente de la Región Metropolitana. M Matamala, F Berlagosky, G Salazar, L Nuñez, 1998. 1998Santiago de Chile; Spanish

Heridos corazones: subjetividad y vulnerabilidad coronaria en varones y mujeres. D Tajer, Editorial Paidós Tramas Sociales. 572962009