Can supplementary dietary fibre suppress breast cancer growth?

Dietary fiber in the prevention of obesity and obesity-related chronic diseases: From epidemiological evidence to potential molecular mechanisms

Obesity is a mostly preventable diet-related disease and currently a major challenge for human populations worldwide. Obesity is a major risk factor for diseases such as type 2 diabetes mellitus (T2DM), cardiovascular disease (CVD) and certain cancers. Dietary fiber is a complex mixture of non-digestible molecules, mostly polysaccharides. Multiple epidemiological studies have demonstrated statistically significant reductions in risks of obesity, T2DM, CVD, colorectal cancer, and pre-menopausal breast cancer with higher dietary fiber intakes. Various direct and indirect mechanisms have been proposed including altered digestion and absorption, stimulation of gut hormones including glucagon-like-peptide-1 (GLP-1) and peptide YY (PYY), reduced appetite, and altered metabolism of bile and cholesterol. These may act via pathways involving G-protein-coupled receptors (GPRs), histone deacetylase (HDAC), and aromatase enzymes. Ultimately, fiber intake contributes to improving glucose levels and insulin sensitivity, lowering risk of T2DM, CVD and certain cancers. Therefore, diets rich in dietary fiber should be encouraged to prevent obesity and associated chronic disease.

Production and anti-diabetic activity of soluble dietary fiber from apricot pulp by Trichoderma viride fermentation

Soluble dietary fiber (SDF) was prepared by Trichoderma viride fermentation by using apricot pulp as the raw material.

Wheat bran: its composition and benefits to health, a European perspective

Wheat bran is a concentrated source of insoluble fibre. Fibre intakes are generally lower than recommendations. This paper reviews the physiological effects of wheat bran and the health benefits it may provide in terms of the prevention of diseases such as colon and breast cancers, cardiovascular disease, obesity and gastrointestinal diseases. In recognition of the weight of evidence, the European Food Safety Authority has recently approved two health claims for wheat bran and gastrointestinal health.

Survival impact of integrative cancer care in advanced metastatic breast cancer

Integrative cancer treatment is of substantial interest to many cancer patients. Research is needed to evaluate the effects of integrative treatment on patient outcomes. We report survival data for a consecutive case series of advanced metastatic breast cancer patients who received a comprehensive clinical program combining conventional treatments with nutrition and supplementation, fitness and mind-spirit instruction at the Block Center for Integrative Cancer Treatment. Treatment outcomes using integrative care for this disease have not previously been documented; survival data will thus contribute to decisions concerning future research directions and design. Ninety consecutive patients with metastatic breast cancer diagnosed during 1984-1997 who received chemotherapy at the integrative cancer center were included. Prognostic factors, treatments and survival from onset of metastases were determined from analysis of scans, labs, pathology and medical records. The log-rank test and Cox proportional hazards analyses were used, and a Kaplan-Meier curve was calculated. All patients had metastatic disease at baseline, 96% were relapsed and 52% had received prior chemotherapy for metastatic disease. Median age at onset of metastasis was 46 years. Median survival was 38 months (95% CI 27,48). Published literature on populations with somewhat more favorable prognostic factors treated in conventional clinics showed median survivals of 20 to 23 months. Through the 1990s, median survival reported in metastatic breast cancer trials or observations generally ranged from 12 to 24 months. Five-year survival was 27% for Center versus 17% for comparison patients. Despite a higher proportion of younger and relapsed patients, survival of metastatic breast cancer patients at the Center was approximately double that of comparison populations and possibly even higher compared to trials published during this period. Explanations for the advantage relative to conventional treatment alone may include the nutritional, nutraceutical, exercise and psychosocial interventions, individually or in combination; self-selection of patients cannot be ruled out. Further research to evaluate the impact of integrative breast cancer treatment on survival is warranted.

Early intake appears to be the key to the proposed protective effects of soy intake against breast cancer

There is a large variation in breast cancer incidence and mortality rates worldwide. Migration studies have indicated that this variation is primarily the result of lifestyle influences. Although there has been much research conducted, definitively identifying dietary factors that impact breast cancer risk has proven difficult. In part this may be because most clinical and epidemiologic studies have focused on adult dietary exposure. However, evidence suggests that childhood and/or adolescence is the period of life when the breast is most sensitive to dietary influences. Further, the available epidemiologic and animal data suggest that early soy intake reduces breast cancer risk. Soy foods are unique dietary sources of isoflavones, diphenolic compounds that exert estrogen-like effects under certain experimental conditions. The protection effects of soy may result from the soybean isoflavones stimulating differentiation of the breast in much the same way that the elevated estrogen levels do during pregnancy. More specifically, in rats, the primary isoflavone genistein reduces mammary tumorigenesis and increases mammary tissue differentiation by leading to a reduction in the number of terminal end buds (TEB) and an increase in the number of differentiated lobules. There is need and justification for continued investigation of the early soy intake hypothesis, particularly to determine the cellular targets of soy action and to identify the signaling pathways mediating the effects on mammary gland morphology and susceptibility to breast cancer.

Effect of diet and housing on growth, body weight, survival and tumor incidences of B6C3F1 mice in chronic studies

Diet is one of the most important environmental factors influencing growth, body weight, survival, and age-related diseases of rodents in chronic studies. NIH-07 open formula diet was the selected diet for the NTP studies from 1980 to 1994. A new diet designated as NTP-2000 diet is the current diet for mice in the NTP studies beginning in 1994. This report is a summary of results of untreated control groups of B6C3F1 mice fed NTP-2000 or NIH-07 diet from several retrospective 2-year dosed-feed and inhalation studies for differences in growth, body weight, survival, and tumor incidences. The dosed-feed studies were conducted in 3 different facilities located in the United States, and all the inhalation studies were conducted in 1 facility. During dosed-feed studies, male and female mice housed in polycarbonate cages and fed the NTP-2000 diet had lower maximum body weights than those fed NIH-07 diet. However, during inhalation studies, mice housed in wire mesh cages and fed the NTP-2000 diet had higher maximum body weights than the mice fed NIH-07 diet. Survival was higher in groups fed NTP-2000 diet irrespective of sex, housing conditions, or body weight compared to the corresponding groups fed NIH-07 diet. Survival was higher in mice housed in polycarbonate cages irrespective of diet and sex compared to the respective sex and diet groups housed in wire mesh cages. During inhalation studies, survival of male and female mice fed NTP-2000 diet was higher than that of the groups fed NIH-07 diet, although the body weights of NTP-2000 diet groups were higher than those of the groups fed NIH-07 diet. When the NTP-2000 diet was used, male and female mice in dosed-feed studies and male mice in inhalation studies had markedly lower incidences of liver tumors than the corresponding groups fed NIH-07 diet. Significant decreases in the incidences of lung tumors were observed only in the male groups fed NTP-2000 diet during dosed-feed studies. These results suggest that body weight may not be the major contributing factor for mortality and liver tumors and that an interaction between diet and housing conditions appears to affect the growth, survival and tumor incidences of B6C3F1 mice.

Diet and the risk of breast cancer in a case-control study: does the threat of disease have an influence on recall bias?

It has been suggested that recall bias may explain the discrepant results between case-control and cohort studies on diet and the risk of breast cancer. Two control groups were used for this case-control study of 25 to 75-year-old breast cancer cases (n = 310). The first group consisted of population controls drawn from the Finnish National Population Register (n = 454). The second group consisted of women who were referred to the same examinations as were the cases because of clinical suspicion of breast disease but who were later diagnosed as healthy (referral controls; n = 506). Because the diagnosis was unknown at the time of interview, it was possible to assess by comparing the two control groups whether the self-reporting of diet changed under the threat of disease. Dietary habits were examined using a validated, self-administered food-frequency questionnaire. Premenopausal women misreported their consumption of liquid milk products, tea, and sugar. Reporting bias was also associated with the intake of fat and vitamins. Postmenopausal women misreported consumption of milk products. When recall bias was taken into consideration, milk was associated with increased risk of premenopausal breast cancer, whereas high consumption of poultry or high intake of monounsaturated fatty acids, n-3 fatty acids, n-6 fatty acids, and vitamin E were related to lower risk. The study suggested that oil, milk, cheese, coffee and beta-carotene may act as protective factors in postmenopausal women, whereas butter and cream may be risk factors for breast cancer. In summary, it is possible that some food items may be overreported or underreported under the threat of disease in health-conscious population. However, most of the results in this study were not modified by recall bias.

Influence of diet on mammary cancer in transgenic mice bearing an oncogene expressed in mammary tissue

Breast cancer is one of the most common cancers in women. The laboratory rat treated with strong carcinogen is the most commonly used animal model for study of breast cancer. Transgenic mouse lines with homologues of human breast cancer oncogenes have been developed. The transgenic mouse line TG.NK with c-neu, the human breast cancer oncogene homologue of erbB2, was evaluated to determine its suitability for study of intervention strategies to delay/prevent the development of breast cancer. There were no palpable mammary tumor masses up to 22-weeks of age, and almost all mice fed a purified diet developed palpable mammary tumors by 28-weeks of age. Nonpurified diets decreased the incidence and multiplicity, and delayed the development of mammary tumors as compared to a purified diet. Increasing the fiber content of nonpurified diet decreased the tumor incidence further. There is approximately a 19-week interval between weaning and development of palpable mammary masses to evaluate intervention strategies to delay or prevent the development of mammary cancer in the TG.NK mouse model. Fiber from nonpurified cereal ingredients appears to be highly beneficial in delaying the development of mammary cancer in TG.NK mice, and this observation is in agreement with human epidemiological findings. Therefore, the TG.NK transgenic mouse with oncogene c-neu (erbB2), appears to be a useful animal model for evaluation of dietary intervention strategies.

Eating to beat breast cancer: potential role for soy supplements

BACKGROUND

The study reviews the anticancer properties of natural isoflavones which occur in especially high concentration in soybeans. It considers the suitability of soybean products for clinical trials aiming to reduce the progression of breast cancer.

METHODS

Evidence is reviewed that plant isoflavones such as genistein show cytostatic activity against human mammary cancer cell lines in vitro and can also suppress carcinogen-induced mammary cancer in young and mature rats.

RESULTS

Plant isoflavones are converted in the bowel to compounds with potential antioestrogenic and antioxidative properties. These compounds show cytostatic activity for both oestrogen receptor-positive and negative human mammary cancer cell lines, and also inhibit growth and progress of the rat mammary cancer model. The high content of soybean products in the diet of Asian women has been postulated as one reason for their relatively low breast cancer incidence.

CONCLUSION

Preclinical studies suggest that soybean products be given priority for clinical trials in breast cancer protection. A pilot study could test soy protein supplements as long-term adjuvant dietary treatment after primary surgery for early breast cancer, looking for a decrease in the risk of recurrence or of second primary tumours.