Cancer & Nutitrion




Epidemiological studies of populations whose diets contain high levels of soy show that they have a lower incidence of and mortality from hormone dependent cancers such as cancer of the breast and prostate. In vitro studies have shown that genistein and diadzein, two isoflavones found in soy, can inhibit the growth of breast cancer and prostate cancer tissue. Conversely, dietary oestrogens from soybean products have been implicated as a possible cause of infertility and liver disease in some animal species, although these effects seem to be species specific. (From bmj.bmjjournals.com)

Diet, micronutrients and prostate cancer: a review of the evidence.
Gallagher RP, Kutynec CL.
Prostate cancer is the most common life threatening cancer in males in Canada, however, relatively little is known about it etiology. Recent popular interest has focused on the role of diet. Information from a series of 13 analytic studies suggests that risk of the disease is positively related to intake of dietary fat. Furthermore, the relationship between fat consumption and prostate cancers of aggressive behavior appears to be stronger than that seen for all prostate cancers combined. Evidence from studies examining the relationship of beta-carotene and Vitamin A to prostate cancer is ambiguous with some investigations showing a direct association with risk and others showing no association. More recently, several studies have shown an inverse association between tomato products or lycopene consumption and prostate cancer. As well, indirect evidence suggests that consumption of soy based products (such as tofu) contains genistein and other isoflavones which may decrease risk of prostate cancer. Insufficient evidence is available on the relationship of prostate cancer to either lycopene or genistein to make dietary recommendations to prostate cancer patients or the general population. More research is urgently needed on the topic of dietary correlate of prostate cancer. (from www.ncbi.nlm.nih.gov)

Soy Saponins and the Anticancer Effects of Soybeans and Soy-Based Foods
Kerwin S.M
While the cancer protective effect of soy-based diets has been the subject of numerous studies, the constituents of soy that may give rise to this effect remain elusive. Recent publications describing anticancer activity of crude and purified soybean saponins have sparked a renewed interest in these compounds. In this review, I summarize the epidemiological studies concerning the cancer protective effects of soy and the efforts to elucidate the constituents responsible for this effect. The recent reports of the anticancer activity of soy saponins is placed in context with reports of promising anticancer activity of structurally related non-dietary saponins from other legumes. While recent studies have demonstrated a direct effect of soy saponins on cancer cells, alternative mechanisms of cancer prevention by these agents are also discussed. It is concluded that the soy saponins may represent promising leads both in terms of elucidating the soy constituents involved in the cancer protective effect of soy as well as in the discovery of anticancer agents with novel mechanisms of action. (From ingentaconnect.com)

Risks and Benefits of Soy Phytoestrogens in Cardiovascular Diseases, Cancer, Climacteric Symptoms and Osteoporosis
Sirtori C.R
Phytoestrogens, plant chemicals classified as isoflavones, coumestans and lignans, display estrogen-like activity because of their structural similarity to human estrogens and exhibit high affinity binding for the estrogen receptor . They are common components of food items such as grains, beans, fruits and nuts. Isoflavones are primarily found in soybeans and foods made from soy. In particular, significant therapeutic properties have been generally attributed to soy isoflavones, but most of the claims have been poorly, or not at all, confirmed by well designed clinical trials. Such is the case of the purported role of soy isoflavones in reducing plasma cholesterol levels. This link is now not supported by many authors or by appropriately designed clinical studies. The role of isoflavones in cancer prevention, particularly of tumours under endocrine control (breast, prostate and others) is again only supported by weak to nonexisting clinical evidence. A similar case is that of the prevention/treatment of postmenopausal symptoms and osteoporosis. Disturbing data have been reported on potential negative effects of soy isoflavones on cognitive function in the aged, particularly relating to tofu intake. Recent studies have finally indicated a potential role for soy isoflavones in inducing chromosomal changes in cells exposed in vitro and potentiating chemical carcinogens. These findings may not, however, be extrapolated to clinical conditions. Available data do not appear to unequivocally support beneficial effects of soy isoflavones, and warn against their wide use, in the absence of satisfactory clinical findings. (from ingentaconnect.com)

Dietary Supplementation with Fermented Soy Nutraceutical, Haelan 951: Tumor Regression and Improved Treatment Responses in Patients diagnosed with Breast Cancer.
Vijaya Nair
This paper supports the contention that fermented soy isoflavones could be used in the treatment of existing tumors, especially breast cancers, either alone or in conjunction with conventional chemotherapeutic agents. Researchers have found that the chemotherapy agents significantly increased Nuclear factor-kappaB (NF-kappaB) activity affects cell survival and determine the sensitivity of cancer cells to cytotoxic agents such as cisplatin, docetaxel, and adriamycin as well to ionizing radiation. Data is now emerging to show that soy isoflavone supplementation may protect cells from oxidative stress-inducing chemotherapeutic agents by inhibiting NF-KB activation and decreasing DNA adduct levels. The phytochemical ingredients in the dietary fermented soy nutraceutical, Haelan 951 act as biological response modifiers by promoting immunostimulation, redifferentiation of malignant cells, and inhibiting tumor neovascularization.

Current research in the area of soy and breast cancer is focused on the effects of soy exposure early in life, the influence of phytoestrogens before and after menopause, and interactions with genetic polymorphisms. Breast cancer survivors who presently rely on tamoxifen to inhibit endogenous estrogen or on aromatase inhibitors to prevent its production need to know how phystoestrogens in fermented soy nutraceuticals such as Haelan 951, can benefit them. Urgent action is needed and the focus to reconcile the different and conflicting results may well lie in taking a deeper look at understanding the benefits and mechanism of action of fermented soy supplementation both in chemoprevention and as a therapeutic dietary supplementation to support the nutritional requirements of patients diagnosed with breast or any other type of cancers.

Future research in advocating dietary supplementation with fermented soy nutraceutical such as Healan951, in patients diagnosed with cancers need to address pertinent issues such as: (1) the role of the fermented soy supplement in the prevention and reversal of cancer related asthenia, anorexia and cachexia. (2) The role of the phytochemicals in the fermented soy supplement that may help reduce toxicity and improve the efficacy of conventional cancer therapy and (3) the identification of the nutritional factors in the fermented soy nutraceutical that selectively help to arrest tumor cell growth and metastasis. (from cancer-disarmed.com)

Interactions of Genistein and the Innate Immune System in Breast Cancer.
T. D’Alessandro, R. Moore, and S. Barnes. University of Alabama at Birmingham, AL.
During inflammatory responses, activated neutrophils and macrophages are recruited to sites of injury where they produce reactive nitrogen and oxygen species (RNOS). Diets enriched with soy have been associated with a reduced incidence of proinflammatory diseases. Isoflavones (e.g., genistein) found in foods have been implicated in this process because their phenolic group reacts with RNOS; we showed previously that nitration and chlorination of genistein occurs in vitro. It has been suggested that some incidences of breast cancer are the result of an inflammatory challenge early in life. This initial event is propagated by later events giving an end result of cancerous lesions. Our aim is to study the interactions of 1) inflammatory cells of the innate immune system and genistein to determine genistein’s effect on oxidant production in localized environments and 2) the aforementioned system in the presence of breast epithelial cells to determine whether genistein and its metabolites play a role in modulating breast cancer formation and progression. Studies using human polymorphonucleocytes have provided insight into the formation of chlorinated and nitrated genistein metabolites upon activation with a phorbol ester. The generation of chlorinated products is dependent on phorbol 12-myristate 13-acetate whereas nitrated products need the presence of an NO· generating system such as sodium nitrate (NaNO2). Ongoing studies are investigating the interactions of genistein with macrophages. The focus of these studies is genistein’s interaction with the NO· generating system iNOS. Other experiments are being conducted using coculture techniques involving the mouse macrophage cell line RAW 264.7 and either the breast epithelial cell line MCF-7 or MCF-10A. This study focuses on cellular interactions during oxidative stress, and genistein’s ability to modulate breast cancer status. (From nutrition.org)