Does Breast Cancer Change Patients' Dietary Habits?

Does breast cancer change patients' dietary habits?

EK Salminen1, HK LagstroÈm2*, SP HeikkilaÈ1 and SJ Salminen2

1Department of Oncology, University of Turku, Turku, Finland; and 2Biochemistry and Food Chemistry, University of Turku, Turku, Finland

Purpose: The results of epidemiological studies on diet and cancer are often dif®cult to interpret on an individual level and may in¯uence patients' beliefs, attitudes and behaviour. This study investigated the behaviour of breast cancer patients and their attitudes to dietary changes and the need of dietary advice during their disease. Patients and methods: The study population consisted of breast cancer patients visiting the Department of Oncology in Turku University Hospital for treatment or follow-up in August and September 1999. A questionnaire was given to a total of 123 subjects. Results: The majority, 65%, were attending the clinic for treatment, 35% for follow-up. Ninety-seven patients (86%) consumed a normal Finnish diet, six (5.3%) were vegetarians and 10 (8.1%) vegetarians consuming ®sh and chicken occasionally. Eleven patients (8.9%) considered diet a factor contributing to their breast cancer and 38 (31.9%) had changed their dietary habits after the diagnosis of breast cancer. The numbers were higher in younger patients with higher educational background. The main reason for change in diet was the desire to be cured of cancer (52.9% of those patients who had changed their dietary habits), in 11.8% to alleviate the symptoms of nausea and 11.8% were advised by health care professionals. The main changes reported included a reduction in the consumption of animal fat, sugar and red meat and increased consumption of fruit, berries and vegetables. Forty-nine patients (39.8%) used vitamin and mineral supplements and 27 (21.9%) consumed dietary supplements including natural products and probiotics. The source of information on how to change the diet was for 33.3% the mass media, 19.4% were advised by doctors and nurses and 11.1% by dietitians. One-third of the patients expressed a need for more information on dietary factors. Conclusion: Breast cancer patients' need of control over their own life prompts an interest in alternative dietary habits after diagnosis, the focus being on a healthier diet. Expert dietary information is considered important. Many patients mentioned a lack of precise dietary recommendations for their individual disease situation and depended on information from outside their treatment centre. Descriptors: breast cancer; diet; vitamins; attitudes European Journal of Clinical Nutrition (2000) 54, 844±848

Introduction dations, ie low in fat, rich in fruit, vegetables and ®bre, as in the USA a prudent diet thought to lower cancer risk has A substantial amount of research has addressed the effect of been advocated (Glade, 1999). In Finland, dietary recom- diet on breast cancer risk (Barnard & Nicholsson, 1997; mendations directed to lower the risk of cancer and cardiac Krebs-Smith, 1998), and 30 ± 40% of cancers are estimated diseases and prevent overweight have recently been issued to be diet-related. Although interpretations of the results of (Government Advisory Committee for Nutrition, 1998; Aro dietary studies may often be controversial, they may none- & Pietinen, 1999). theless in¯uence patient behaviour, which may also be One-third of cancers are considered to be related to in¯uenced by beliefs and attitudes. Breast cancer has dietary factors, and the role of diet is suggested especially been shown to be one of the human malignancies asso- in the case of hormone-related malignancies, such as breast ciated with diet, excessive weight and excessive energy cancer (Levi, 1999). Protection and risk reduction through consumption (Nixon & Rodgers, 1999). Large-scale studies dietary intervention is considered possible (Krebs-Smith, are currently under way in the USA to investigate the 1998; Wargovich & Levin, 1996). Very few people, how- in¯uence of dietary intervention during follow-up on the ever, are in fact ready to make major changes in their eating outcome of breast cancer. These studies involve compar- habits while they are apparently healthy; only 9% of ison of patients' diets following current health recommen- Americans currently eat the recommended ®ve servings of fruit and vegetables daily (Holmes et al, 1999a). *Correspondence: H LagstroÈm, Department of Biochemistry and Food Treatment of breast cancer is not without consequences Chemistry, University of Turku, Vatselankatu 2, FIN-20014 Turku, for the general health and well-being of the patient, Finland. although the goal is the cure of cancer. After treatment E-mail: hanna.lagstrom@utu.® for breast cancer, weight gain, elevated liver enzymes and Guarantor: E Salminen. È Contributors: ES designed the study, organized the project, drafted and altered hormonal levels (Kailajarvi et al, 2000) have been ®nalized the manuscript; HL analyzed and interpreted the data, critically observed. One of the common consequences is fatty degen- revised the article and contributed to the ®nal approval of the article; SH eration of the liver. These changes can be persistent and collected and helped to analyze the data; SS interpreted the data, revised in¯uence the general health of the patient, making dietary the manuscript, contributed to data analysis and ®nal approval of the counselling a relevant issue to consider. The bene®cial manuscript. Received 8 February 2000; revised 13 August 2000; accepted effect of a healthy lifestyle, including a balanced diet, 20 August 2000 can in view of the organ effects of breast cancer treatment Diet and breast cancer EK Salminen et al 845 be signi®cant. Some of the questions arising in the patient's diet in breast cancer and their use of different foods, mind at the diagnosis of cancer are: have I been eating the vitamins and supplement products were clari®ed by struc- wrong food, did my lifestyle have something to do with this tured questions. The source of their information on matters cancer? At diagnosis and especially during later follow-up of diet and their altered need for information were also in fear of recurrence, patients' interest in diet and its probed. in¯uence on health becomes actual and often friends and The data were transferred to SPSS (Release 9.0) for relatives advise how they should behave and what changes statistical analysis. Demographic patient characteristics in medication or diet could improve the chances of cure. (age, education, time since diagnosis and treatment) and In this study the frequency of reporting dietary changes dietary variables are reported as frequency distributions. and use of supplements and vitamins among breast cancer The associations between demographic characteristics and patients was assessed in order to establish whether the patients' dietary beliefs, attitudes and behaviours were diagnosis of breast cancer in¯uences patients' dietary analysed using the chi-square test. habits. The Ethical Committee of Turku University Hospital approved the study. Patients and methods Results This survey was conducted at the Department of Oncology and Radiotherapy, Turku University Hospital. A tested 17- Patient sample characteristics are presented in Table 1. item questionnaire with 16 structured and one open ques- There were 45 patients with a 1 y history, 33 with 2 y, 24 tion was completed by 123 breast cancer patients during the with 2 ± 5 y and 21 with a history of breast cancer over 5 y. period August to September 1999. The inclusion criteria During the survey most of the participants were receiving were based on patients' willingness to participate and treatment. Most (85.8%) reported consuming what they general condition allowing understanding of the questions considered a normal Finnish diet, 5.3% were vegetarians, and purpose of the study. The questionnaire was not given and 10 (9%) were vegetarians using ®sh and chicken to patients considered by the personnel to be unable to occasionally. Eleven patients (8.9%) held dietary factors participate due to a late phase of the disease. The patients to be related to breast cancer, 65 (52.8%) felt they were not were adult women, representing all stages of breast cancer related and 47 (38.2%) answered `don't know'. The from early-diagnosed local cancer visiting the department patients with over 2 y history of breast cancer replied for postoperative radiotherapy to advanced disease receiv- more often that dietary factors are related to breast cancer ing chemotherapy. The patient characteristics are presented when compared to newly diagnosed patients (15.6% vs in Table 1. The questionnaire was completed anonymously, 5.1%; P 0.05). as questions concerning the use of alternative medication Of the total, 38 patients (31.9%) had changed their diet were also included. after learning of their cancer. The number was higher Items covered included the patient's characteristics and among younger (20 ± 64 y, 36.1%) when compared to their dietary knowledge and habits and changes in these older patients (65 ± 90 y, 21.4%), although the difference following diagnosis. The subjects' beliefs as to the role of was not statistically signi®cant (P 0.15). One-third of the patients (35.9%) with higher educational level changed Table 1 Sample characteristics of breast cancer patients their dietary habits and 22.5% of those of lower level; the difference was not statistically signi®cant (P 0.14). Number of Percentage of The most common reasons reported for changing diet patients patients (multiple reasons were allowed) were desire for cure in Total 123 100 20=38 cases (52.9%), to alleviate symptoms of nausea Age group=years (4=38 (11.8%), and to follow doctor's instructions 4=38 20 ± 34 3 2.4 (11.8%) of those patients who had changed dietary habits. 35 ± 49 37 30.1 Ten patients (29%) mentioned having considered a change 50 ± 64 46 37.4 65 ± 79 24 19.5 to a healthier diet even before the diagnosis of cancer. 80 5 4.1 When asked about changes the patients had introduced in Unanswered 8 6.5 their diet, the most common steps included a reduction in Education consumption of animal fat, red meat, sausages and sugar Comprehensive school or corresponding 42 34.1 and increased consumption of fruits, berries and vegetables. Vocational school or corresponding 27 22.0 Vocational college and=or high school 34 27.6 The latter change was reported by 23 (60.5%) of patients Academic education 19 15.4 who had changed dietary habits, avoidance of fatty foods Others 0 0.0 by 15 (36.8%), of sugar=sugared products by 10 patients Unanswered 1 0.8 (26.3%) and of red meat by eight patients (21.1%). These Time of diagnosis Within a year 45 36.6 modi®cations were based on information obtained from the 1 ± 2 y earlier 33 22.8 mass media for 13 patients (33.3%), from doctors and 2 ± 5 y earlier 24 19.5 nurses for seven patients (19.4%), from a dietitian for > 5 y earlier 21 17.1 four patients (11.1%), from family members for six patients Treatment (16.7%), and other sources for 12 patients (30.6%), and Radiotherapy 15 12.2 Chemotherapy 40 32.5 again multiple sources were allowed. Forty-seven per cent As adjuvant 19 15.4 of patients felt that their condition had improved with the Hormone therapy 23 18.7 dietary changes adopted. As adjuvant 15 12.2 Of the total study population, 49 patients (39.8%) were Follow-up 42 34.1 Unanswered 3 2.4 consuming vitamin and mineral supplements and eight patients (21.9%) dietary supplements including natural

European Journal of Clinical Nutrition Diet and breast cancer EK Salminen et al 846 products and probiotics. The patients with over 2 y history The study population was representative of Finnish of breast cancer used vitamins, special natural products and breast cancer patients as it was a population-based sample supplements as often as newly diagnosed patients (46.7% and we followed the guidelines of Finnish Breast Cancer vs 48.7%; P 0.83). Those in the younger age group (20 ± Group for treatment. Decisions to make unconventional 64 y) consumed these products signi®cantly more with dietary changes were often reached under the in¯uence of longer history of disease (53.5% vs 34.5%; P 0.008) the media or advice from friends and relatives. The national than the older group (65 ± 90 y), although the difference research and health care institutes have undertaken large- was not statistically signi®cant (P 0.08). In contrast, the scale surveys. Public and health professionals are regularly use of vitamins, natural products and health foods was informed of results and recommendations for healthy diet higher among patients with higher education compared to and lifestyle are easily available (Helakorpi et al, 1999). those of lower level (comprehensive school or corresponding) Nonetheless, patients tended to seek and follow advice 56.3% and 31.0%, respectively (P 0.008). from outside their care centre. It is important that the In addition to dietary habits, other lifestyle changes were doctors treating or following breast cancer patients recog- probed. Four patients (3.3%) had stopped smoking, nine nize this tendency. Knowledge about a healthy diet and (7.3%) had stopped consuming alcohol and 33 (26.8%) had current recommendations is essential, since interventions increased their level of physical exercise. Six patients that increase the patient's beliefs in diet and health associa- (7.1%), all in the age group 50 ± 64 y, were using alter- tions and communicate diet recommendations can encou- native medicine approaches. Available dietary information rage healthful dietary change (Patterson & Kristal, 1996). on diet and cancer was found insuf®cient by 37=123 A small group of patients changed their diet due to patients (34.3%), adequate by 25 (23.1%), excessive by nausea, a common adverse effect of cancer treatment. one patient (0.9%) and 45 patients (41.7%) replied that they Effective drug treatment against nausea is available and did not know. Information was found insuf®cient by 43.9% dietary changes can improve the outcome. The recom- of patients with over 2 y history of breast cancer and 28.4% mendations include a low residue diet and timing of among newly diagnosed patients (P 0.10). In the younger food intake, and its composition should be planned with age group (20 ± 64 y), 36.4% considered that available professional advice. dietary information was insuf®cient and 20.8% correspond- Belief in the implication of dietary factors in breast ingly in the older age group (65 ± 90 y; P 0.16). On the cancer was less prevalent than expected among the patients. other hand available dietary information was found insuf®- The percentage of women citing dietary factors as con- cient statistically signi®cantly more often among patients tributing to the risk of cancer was lower in this study than with higher education compared with those who had the 20 ± 23% reported in a US population (Barnard & completed comprehensive school, 41.1% and 20.0%, Nicholsson, 1997). The readiness of Finnish patients to respectively (P 0.03). A summary of results is presented change diet after diagnosis re¯ects a resolve to ®ght the in Table 2. disease. However, the weapons and advice concerning diet were not taken from health professionals, but obtained in most cases from friends, relatives and the media. This may also imply that health professionals both in primary care Discussion and follow-up need more education on questions of diet and Breast cancer is considered to be a lifestyle cancer by cancer. reason of its high incidence in the Western society (Levi, In a prospective study of the intake of various vitamins 1999). It has been estimated that dietary modi®cation could and the risk of breast cancer no protective effects of result in a 30% reduction of the number of cases (Doll & vitamin C or E supplements were observed and vitamin Peto, 1985). Signi®cant differences have been observed supplementation was bene®cial only if patients were con- among various populations according to different dietary suming diets low in them (Hunter et al, 1993). Newman habits and consumption of nutrients, although the exact role et al (1998) reported that 80% of breast cancer patients of diet on the individual level requires more de®nitive reported using some nutritional supplements, the most research data (Levi, 1999; Marshall, 1999). This present common ones being vitamin E and C and multivitamins study enquired how Finnish patients adapt to current and mineral supplements. The lower incidence in our information on diet and breast cancer during their disease. patient population is most probably based on the health It emerged that one-third of patients questioned had chan- education programmes and results of the large-scale ged their dietary habits in the belief that this would help to National Public Health Institute study (SETTI), which has ®ght the disease and to promote cure. Most patients altering been commonly discussed in the Finnish mass media their eating habits adopted a more balanced diet approach- because no bene®t of vitamin supplement consumption in ing current nutrition guidelines. A speci®c subgroup made prevention of lung cancer was demonstrated (Albanes et al, dietary changes to alleviate or cure nausea. 1996). Our results are in agreement with the study from

Table 2 Summary of key questions by age, education and time of diagnosis

Age group Education Time of diagnosis

Question 20 ± 64 y 65 ± 90 y P Comprehensive school Higher education P < 2y > 2y P

Do dietary factors relate to breast cancer? (Yes) 3.4% 10.5% 0.25 4.8% 10.0% 0.23 5.1% 15.6% 0.05 Have you changed your diet after getting cancer? 36.1% 21.4% 0.15 22.5% 35.9% 0.14 28.0% 38.6% 0.23 Use of vitamins, natural and health products 53.5% 34.5% 0.08 31.0% 56.3% 0.008 48.7% 46.7% 0.83 Insuf®cient information of dietary factors and cancer 36.4% 20.8% 0.16 20.0% 41.1% 0.03 28.4% 43.9% 0.10

European Journal of Clinical Nutrition Diet and breast cancer EK Salminen et al 847 The Netherlands, showing no difference in supplement use fruits should be increased, and that the consumption of between healthy controls and subjects with breast cancer, dietary fats and sugar should be reduced. Vitamin supple- with nearly 35% of the group reporting use of dietary ments are not generally recommended. The Finnish dietary supplements (Dorant et al, 1995). Individual experiences recommendations concerning nutrient intake of the adult of positive results with health food supplements have population are very similar to the current Nordic Nutrition encouraged research into their effects on cancer patients Recommendation (1996). The goals in improving diets are during treatment and more clinical research is needed. The balanced nutrient intake, balance between energy intake use of alternative medicine approaches and complementary and expenditure, increased proportion of carbohydrates, therapies in this survey was similar to that reported from reduced intake of saturated, hard fat and sodium, and a larger survey of Finnish cancer patients conducted by moderate alcohol consumption (National Public Health Hietanen et al (1999) and by Crocetti et al (1998) from an Institute, 1999). The recommended intake of total fat is Italian study with breast cancer. The use of vitamins was the sum of recommended levels of different fatty acid relatively common among breast cancer patients, ®gures intakes. being similar to those from US studies. In the Nurses The leading causes of death in economically advantaged Health Study, women with breast cancer modestly countries are cancer and cardiovascular diseases. A genetic increased the use of multivitamin supplements after the link between the two major disease groups, cancer and diagnosis (Holmes et al, 1999b); 38% of North American cardiovascular diseases, has been suggested (Tanne-Hop- women used supplements before diagnosis compared with kins, 1999). The incidence of breast cancer is constantly 45% after diagnosis (P < 0.001). In the study in question, increasing in Finland (Engeland et al, 1993). Because the the use of multivitamins after diagnosis was not associated treatment of breast cancer can increase the risk of patients' with reduced mortality. vulnerability to cardiovascular diseases, a preventive life- Epidemiological research has indicated that a diet rich in style can be recommended. At diagnosis, the question fresh fruit and vegetables may be protective in the case of arising in the patient's mind is `How am I contributing to most common epithelial cancers, and protective effects the disease with my living habits?' Often the patient also have also been observed in several hormone-related neo- feels a need to maintain control over the situation, through plasms (Levi, 1999). In an Italian study, only carrots and control over daily life and personal diet. Whether the raw vegetables seemed to lower breast cancer risk: an modi®cation of diet after cancer diagnosis is effective in increase of one daily serving of raw vegetables was recurrence prevention remains to be shown in studies associated with 10% reduction of incidence of breast currently being conducted. Do the currently available data cancer (Franceschi & Favero, 1999). In that study the suf®ce for counselling of breast cancer patients? If there is effect seemed more bene®cial than fruit intake. The authors a detrimental effect of a high-fat diet on breast carcinoma suggested the reason to be increased intake of vegetables, survival, it is very likely modest at most (Holmes et al, leading also to high intake of olive oil and thereby to a risk 1999a,b). The same study detected no detrimental effect of reduction. The Finnish diet is still sometimes quoted as modest alcohol consumption. However, in another study peculiarly high in saturated fat (butter) and low in vege- promotion of breast cancer by alcohol intake was suggested tables. However, food consumption in Finland has changed (Stoll, 1999). gradually, generally towards dietary recommendations, Replacing red meat with poultry, dairy and ®sh pro- during the last 20 y (Helakorpi et al, 1999). The consump- ducts and increasing the intake of vegetables was found to tion of vegetables has continuously increased. The con- be bene®cial for survival (Holmes et al, 1999a,b). The sumption of fruits and berries also increased until the mid current Finnish recommendation for a healthy diet is in 1990s, but then seemed to level off. By contrast, the agreement with epidemiological observations on diet and consumption of grain and potatoes has remained quite breast cancer (Levi, 1999). Common dietary guidelines for stable. Meat consumption doubled from the 1950s to the cancer prevention can be considered bene®cial for general early 1970s. The consumption of meat is about four times well-being (Glade, 1999; Sikora, 1999), such as: (1) eat higher than that of ®sh. The consumption of liquid milk vegetables, fruits, berries and leguminous plants daily; (2) products as well as fat spreads has decreased. Finns now eat at least seven servings of whole meal cereals daily and prefer skimmed milk more often, and choose butter less avoid sugar; (3) avoid alcohol; (4) if you eat meat, reduce often than before, as recommended. Alcohol consumption, meat intake to 80 g=day, eat ®sh or chicken meat instead of on the other hand, has increased (Helakorpi et al, 1999). red meat; (5) avoid obesity or underweight (BMI between Dietary habits and food choices vary by gender: women eat 18.5 and 25); (6) go in for physical exercise regularly; (7) more vegetables, fruits and berries, but less bread and avoid fatty food, especially animal fat, and use vegetable potatoes than men. Skimmed milk ( < 0.5% fat) gained oils moderately; (8) avoid salty foods, and reduce salt use popularity more slowly in the late 1980s, and it is today the in food preparation and at the table; and (9) do not eat type of milk preferred by girls and women. Daily con- mouldy or burned (too grilled) food. At the present stage sumption of meat and processed meat products is more many patients depend on information given outside the frequent among men than women (Helakorpi et al, 1999). treatment centre, because of the lack of dietary experts In the current Finnish recommendations for the general participating in their care. Although more research is population special attention has been paid to food composi- needed on speci®c dietary supplements together with diet- tion and quality of diet, as well as to its relation to energy- ary interventions for the well-being of patients, the current yielding nutrients, not only to the intake of individual knowledge enables information to be given on healthy diet nutrients (Government Advisory Committee for Nutrition, for cancer patients. It is also important to provide cancer 1998). The food disc, the food pyramid, and a food plate patients with the services of nutrition professionals follow- model are used to describe a well-balanced and recom- ing diagnosis and during treatment and follow-up to mended diet. In addition, it is advised that the use of promote a healthy lifestyle. This answers the patient's cereals, low-fat dairy products, vegetables, berries and own needs and at the same time may prevent the negative

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