Flax Seed Studies & Reviews
Herbal Medicine, Healing & Cancer"
by Donald Yance
"Flaxseed oil is rich in essential fatty acids, particularly ALA, which, when taken in combination with sulfur-rich proteins, actually works to create a new food. This was first discovered and made famous by Johanna Budwig, a West German physician who had done a great deal of research on the oil-protein combination. She discovered that EFAs need to bind to sulfur-rich proteins (she used low-fat cottage cheese) before the body can properly assimilate them. Budwig found that by feeding people with terminal cancer this oil-protein combination, the yellowish-green substance in their blood was replaced by the healthy red pigment, hemaglobin. The phosphatides returned and the lipoproteins reappeared.
Of all the deficiencies that may exist in people with cancer, perhaps those that are most important and totally ignored are EFAs, which, when taken with protein, enhance our albumin levels. Albumin is a blood protein of immense importance to good health. When flaxseed oil and sulfur-rich protein are combined, the ALA and the EFAs in the flaxseed oil become water-soluble and electron-rich; this causes the cell membrane to become more stable by making it more flexible and fluidlike. The electron-rich fatty acids now allow for efficient transport of materials and energy between the inner and outer cell membrane. This is important to the health of all cells and to the entire immune system.
Omega-3 fatty acids are extremely important because they modulate prostaglandins, which are very active biological substances important to nearly every bodily function. They suppress tumor-promoting prostaglandin E2 by increasing prostiglandin E3 and suppressing AA. They also inhibit cancer wasting. EPA and ALA, as well as other related omega-3 fatty acids, plus GLA from evening primrose oil, have been found to kill a number of tumor-cell lines and cause a significant reduction in tumor growth in animal studies." (pp.219-220)
Mutat Res. 2004 Jul 13;551(1-2):213-22. : The influence of dietary flaxseed and other grains, fruits and vegetables on the frequency of spontaneous chromosomal damage in mice.
Trentin GA, Moody J, Torous DK, Thompson LU, Heddle JA.
Department of Biology, York University, 4700 Keele Street, Toronto, Ont., Canada M3J 1P3.
Spontaneous genetic damage, whether mutations or chromosomal aberrations, undoubtedly arise from a variety of sources including replication errors, oxidative damage, background radiation, and chemical exposure. Given the numerous correlations between diet and cancer, it seemed possible that diet could influence the spontaneous rate of DNA damage and its genetic consequences. Since diets high in vegetables, fruits, and grains are associated with lower rates of cancer, we supplemented the diets of mice and measured the frequency of micronuclei in the peripheral blood. Micronuclei arise from broken chromosomes or chromosome loss in the erythroblast. They are first seen in the short reticulocyte stage of the red blood cell but persist for the entire 30-day lifespan of the cell in mice. C57Bl mice were placed on a defined diet (AIN-93G) supplemented to 20% final dry weight with grains or freeze-dried fruits or vegetables. The micronucleus frequency was measured in a pre-exposure blood sample and every 2 weeks thereafter for 6 weeks. This was possible in spite of the low spontaneous frequency of 1/1000-2/1000 cells by the use of a novel flow cytometric method, which permitted the analysis of both the mature red blood cells and reticulocytes. Of the foods tested, flaxseed proved to be the most protective by reducing the incidence of micronuclei in both the reticulocyte and normochromatic erythrocyte cell populations by 30 and 11%, respectively. The results show that at least one class of spontaneous genetic damage can be modified by diet and suggests that short-term experiments with small numbers of animals can be used to identify dietary anticarcinogens that may influence human cancer rates.
OBJECTIVES: Dietary factors may influence the prostate and have an impact on prostatic growth and disease. A small number of studies have suggested that flaxseed-supplemented, fat-restricted diets may thwart prostate cancer growth in both animals and humans. Unknown, however, is the potential effect of such a diet on benign prostatic epithelium. METHODS: We undertook a pilot study to explore whether a flaxseed-supplemented, fat-restricted diet affects the proliferation rates in benign epithelium. We also explored the effects on circulating levels of prostate-specific antigen (PSA), total testosterone, and cholesterol. Fifteen men who were scheduled to undergo repeat prostate biopsy were instructed to follow a low-fat (less than 20% kcal), flaxseed-supplemented (30 g/day) diet and were provided with a supply of flaxseed to last throughout the 6-month intervention period. The PSA, total testosterone, and cholesterol levels were determined at baseline and at 6 months of follow-up. Reports from the original and repeat biopsies were compared, and proliferation (MIB-1) rates were quantified in the benign prostatic epithelium. RESULTS: Statistically significant decreases in PSA (8.47 +/- 3.82 to 5.72 +/- 3.16 ng/mL; P = 0.0002) and cholesterol (241.1 +/- 30.8 to 213.3 +/- 51.2 mg/dL; P = 0.012) were observed. No statistically significant change was seen in total testosterone (434.5 +/- 143.6 to 428.3 +/- 92.5 ng/dL). Although 6-month repeat biopsies were not performed in 2 cases because of PSA normalization, of the 13 men who underwent repeat biopsy, the proliferation rates in the benign epithelium decreased significantly from 0.022 +/- 0.027 at baseline to 0.007 +/- 0.014 at 6 months of follow-up (P = 0.0168). CONCLUSIONS: These pilot data suggest that a flaxseed-supplemented, fat-restricted diet may affect the biology of the prostate and associated biomarkers. A randomized controlled trial is needed to determine whether flaxseed supplementation, a low-fat diet, or a combination of the two regimens may be of use in controlling overall prostatic growth.
BACKGROUND: Phytoestrogens, which are abundant in flaxseed and soy, have chemical structures resembling those of endogenous estrogens and have been shown to exert hormonal effects, thereby affecting chronic diseases. OBJECTIVE: We compared the effects of consuming equal amounts of flaxseed or soy on estrogen metabolism and biochemical markers of bone metabolism in postmenopausal women. DESIGN: In a parallel design, the diet of postmenopausal women (n = 46) was supplemented with either a placebo, soy (25 g soy flour), or flaxseed (25 g ground flaxseed) muffin for 16 wk. Blood and 24-h urine samples were collected at baseline and at the endpoint. Urine samples were analyzed for phytoestrogens, estrogen metabolites (2-hydroxyestrone, 16alpha-hydroxyestrone), and serum hormones (estradiol, estrone, estrone sulfate). Serum and urine samples were also analyzed for biochemical markers of bone metabolism. RESULTS: Urinary concentrations of 2-hydroxyestrone, but not of 16alpha-hydroxyestrone, increased significantly in the flaxseed group (P = 0.05). In the flaxseed group, the ratio of 2-hydroxyestrone to 16alpha-hydroxyestrone was positively correlated with urinary lignan excretion (r = 0.579, P = 0.02). In the soy and placebo groups, no significant correlation was observed. No significant change in serum hormones or biochemical markers of bone metabolism was observed within or between the treatment groups. CONCLUSIONS: Supplementation with flaxseed modifies urinary estrogen metabolite excretion to a greater extent than does supplementation with an equal amount of soy. This modification by flaxseed is associated with an increase in urinary lignan excretion. Despite the shift in estrogen metabolism to favor the less biologically active estrogens, a negative effect on bone cell metabolism was not observed.
Background. Evidence is emerging that varying the type or source of dietary protein intake can have beneficial effects on chronic renal disease. Consumption of soybean and soy-based food products, as the source of plant protein, can retard the development and progression of chronic renal disease. We studied the obese spontaneously hypertensive/NIH-corpulent (SHR/N-cp) rat, a model of obesity and type II diabetes mellitus that consistently develops nephropathy resembling diabetic nephropathy. We specifically sought to determine whether changing the source of protein intake from animal protein, casein, to plant protein in the form of either soy protein concentrate or flaxseed protein in the diet has a different impact on renal function and nephropathy in this model. Methods. Male obese SHR/N-cp rats were randomly assigned to one of three diets containing either 20% casein, 20% soy protein concentrate, or 20% flaxseed meal. Except for the protein source, all three diets were identical and contained similar amounts of protein, fat, carbohydrates, minerals, and vitamins. All animals were maintained on these diets for 6 months. At the end of the study, blood sampling and 24-hour urine collections were performed for renal functional measurements, and the kidneys were harvested and examined for histologic evaluation. Results. All three groups had similar amounts of food intake and body weight gain and exhibited fasting hyperglycemia and hyperinsulinemia. Plasma glucose levels did not differ among the three groups, but plasma insulin concentration was significantly lower in rats fed flaxseed meal than those fed either casein or soy protein concentrate. Mean plasma creatinine, creatinine clearance, and urinary urea excretion also did not differ significantly between the three groups. By contrast, urinary protein excretion was significantly lower (P < 0.01) in rats fed flaxseed than in rats fed either casein or soy protein concentrate. Morphologic analysis of renal structural lesions showed that the percentage of abnormal glomeruli with mesangial expansion and the tubulointerstitial score (an index of severity of tubulointerstitial damage) were significantly reduced in rats fed flaxmeal compared to those fed casein or soy protein concentrate. Conclusion. We conclude that dietary protein substitution with flaxseed meal reduces proteinuria and glomerular and tubulointerstitial lesions in obese SHR/N-cp rats and that flaxseed meal is more effective than soy protein in reducing proteinuria and renal histologic abnormalities in this model. The reduction in proteinuria and renal injury was independent of the amount of protein intake and glycemic control. Which dietary component(s) present in flaxseed meal is (are) responsible for the renal protective effect remains to be determined.
Omega-3 fatty acids have been shown to significantly reduce the risk for sudden death caused by cardiac arrhythmias and all-cause mortality in patients with known coronary heart disease. Fatty fish, such as salmon and tuna, and fish oil are rich sources of the omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid. Flaxseed, canola oil, and walnuts also are good dietary sources of omega-3 fatty acids. In addition to being antiarrhythmic, the omega-3 fatty acids are antithrombotic and anti-inflammatory. In contrast, omega-6 fatty acids, which are present in most seeds, vegetable oils, and meat, are prothrombotic and proinflammatory. Omega-3 fatty acids also are used to treat hyperlipidemia, hypertension, and rheumatoid arthritis. There are no significant drug interactions with omega-3 fatty acids. The American Heart Association recommends consumption of two servings of fish per week for persons with no history of coronary heart disease and at least one serving of fish daily for those with known coronary heart disease. Approximately 1 g per day of eicosapentaenoic acid plus docosahexaenoic acid is recommended for cardioprotection. Higher dosages of omega-3 fatty acids are required to reduce elevated triglyceride levels (2 to 4 g per day) and to reduce morning stiffness and the number of tender joints in patients with rheumatoid arthritis (at least 3 g per day). Modest decreases in blood pressure occur with significantly higher dosages of omega-3 fatty acids.
AIM: N-3 fatty acids, especially eicosapentaenoic acid (EPA)[ie oil from cold water fish], may possess anticachectic properties. This trial compared a protein and energy dense supplement enriched with n-3 fatty acids and antioxidants (experimental: E) with an isocaloric isonitrogenous control supplement (C) for their effects on weight, lean body mass (LBM), dietary intake, and quality of life in cachectic patients with advanced pancreatic cancer. METHODS: A total of 200 patients (95 E; 105 C) were randomised to consume two cans/day of the E or C supplement (480 ml, 620 kcal, 32 g protein +/- 2.2 g EPA) for eight weeks in a multicentre, randomised, double blind trial. RESULTS: At enrolment, patients' mean rate of weight loss was 3.3 kg/month. Intake of the supplements (E or C) was below the recommended dose (2 cans/day) and averaged 1.4 cans/day. Over eight weeks, patients in both groups stopped losing weight (delta weight E: -0.25 kg/month versus C: -0.37 kg/month; p = 0.74) and LBM (Delta LBM E: +0.27 kg/month versus C: +0.12 kg/month; p = 0.88) to an equal degree (change from baseline E and C, p<0.001). In view of evident non-compliance in both E and C groups, correlation analyses were undertaken to examine for potential dose-response relationships. E patients demonstrated significant correlations between their supplement intake and weight gain (r = 0.50, p<0.001) and increase in LBM (r = 0.33, p = 0.036). Such correlations were not statistically significant in C patients. The relationship of supplement intake with change in LBM was significantly different between E and C patients (p = 0.043). Increased plasma EPA levels in the E group were associated with weight and LBM gain (r = 0.50, p<0.001; r = 0.51, p = 0.001). Weight gain was associated with improved quality of life (p<0.01) only in the E group. CONCLUSION: Intention to treat group comparisons indicated that at the mean dose taken, enrichment with n-3 fatty acids did not provide a therapeutic advantage and that both supplements were equally effective in arresting weight loss. Post hoc dose-response analysis suggests that if taken in sufficient quantity, only the n-3 fatty acid enriched energy and protein dense supplement results in net gain of weight, lean tissue, and improved quality of life. Further trials are required to examine the potential role of n-3 enriched supplements in the treatment of cancer cachexia.
Angiogenesis is important in tumor growth, progression and metastatic dissemination. Vascular endothelial growth factor (VEGF) is one key factor in promotion of breast cancer angiogenesis. VEGFs are bioactive in the extracellular space where they become available to the endothelial cells. Phytoestrogens such as lignans have been shown to alter breast cancer incidence and be cancer-protective in rats. We show that supplementation of 10% flaxseed, the richest source of mammalian lignans, to nude mice with established human breast tumors reduced tumor growth and metastasis. Moreover, flaxseed decreased extracellular levels of VEGF, which may be one mechanistic explanation to the decreased tumor growth and metastasis
The results of animal studies have demonstrated that the consumption of omega-3 fatty acids can slow the growth of cancer xenografts, increase the efficacy of chemotherapy and reduce the side effects of the chemotherapy or of the cancer. Molecular mechanisms postulated to contribute to the multiple benefits of omega-3 fatty acids include 1) suppressing the expression of cyclooxygenase-2 in tumors, thus decreasing proliferation of cancer cells and reducing angiogenesis in the tumor; 2) decreasing the expression of AP-1 and ras, two oncogenes implicated in tumor promotion; 3) inducing differentiation of cancer cells; 4) suppressing nuclear factor-kappaB activation and bcl-2 expression, thus allowing apoptosis of cancer cells; and 5) reducing cancer-induced cachexia. It seems reasonable to assume that after appropriate cancer therapy, consumption of omega-3 fatty acids might slow or stop the growth of metastatic cancer cells, increase longevity of cancer patients and improve their quality of life.
"Bioactive compounds" are extranutritional constituents that typically occur in small quantities in foods. They are being intensively studied to evaluate their effects on health. The impetus sparking this scientific inquiry was the result of many epidemiologic studies that have shown protective effects of plant-based diets on cardiovascular disease (CVD) and cancer. Many bioactive compounds have been discovered. These compounds vary widely in chemical structure and function and are grouped accordingly. Phenolic compounds, including their subcategory, flavonoids, are present in all plants and have been studied extensively in cereals, legumes, nuts, olive oil, vegetables, fruits, tea, and red wine. Many phenolic compounds have antioxidant properties, and some studies have demonstrated favorable effects on thrombosis and tumorogenesis and promotion. Although some epidemiologic studies have reported protective associations between flavonoids or other phenolics and CVD and cancer, other studies have not found these associations. Various phytoestrogens are present in soy, but also in flaxseed oil, whole grains, fruits, and vegetables. They have antioxidant properties, and some studies demonstrated favorable effects on other CVD risk factors, and in animal and cell culture models of cancer. However, because phytoestrogens act both as partial estrogen agonists and antagonists, their effects on cancer are likely complex. Hydroxytyrosol, one of many phenolics in olives and olive oil, is a potent antioxidant. Resveratrol, found in nuts and red wine, has antioxidant, antithrombotic, and anti-inflammatory properties, and inhibits carcinogenesis. Lycopene, a potent antioxidant carotenoid in tomatoes and other fruits, is thought to protect against prostate and other cancers, and inhibits tumor cell growth in animals. Organosulfur compounds in garlic and onions, isothiocyanates in cruciferous vegetables, and monoterpenes in citrus fruits, cherries, and herbs have anticarcinogenic actions in experimental models, as well as cardioprotective effects. In summary, numerous bioactive compounds appear to have beneficial health effects. Much scientific research needs to be conducted before we can begin to make science-based dietary recommendations. Despite this, there is sufficient evidence to recommend consuming food sources rich in bioactive compounds. From a practical perspective, this translates to recommending a diet rich in a variety of fruits, vegetables, whole grains, legumes, oils, and nuts.
Polyunsaturated fatty acids are potent neuroprotectors.
Lauritzen I, Blondeau N, Heurteaux C, Widmann C, Romey G, Lazdunski M.
Institut de Pharmacologie Moleculaire et Cellulaire, CNRS UPR 411, 660 route des Lucioles, Sophia Antipolis, 06560 Valbonne, France
Results reported in this work suggest a potential therapeutic value of polyunsaturated fatty acids for cerebral pathologies as previously proposed by others for cardiac diseases. We show that the polyunsaturated fatty acid linolenic acid prevents neuronal death in an animal model of transient global ischemia even when administered after the insult. Linolenic acid also protects animals treated with kainate against seizures and hippocampal lesions. The same effects have been observed in an in vitro model of seizure-like activity using glutamatergic neurons and they have been shown to be associated with blockade of glutamatergic transmission by low concentrations of distinct polyunsaturated fatty acids. Our data suggest that the opening of background K(+) channels, like TREK-1 and TRAAK, which are activated by arachidonic acid and other polyunsaturated fatty acids such as docosahexaenoic acid and linolenic acid, is a significant factor in this neuroprotective effect. These channels are abundant in the brain where they are located both pre- and post-synaptically, and are insensitive to saturated fatty acids, which offer no neuroprotection.
Application of stable and radioisotope precursor/tracer experiments resulted in the identification of various phenylpropanoid, monolignol, and lignan metabolites involved in the biosynthesis of the cancer chemopreventive secoisolariciresinol diglucoside (SDG; 1)-containing ester-linked "polymer(s)" in flax (Linum usitatissimum) seed.
Results from this study will facilitate future isolation and characterization of the proteins and enzymes involved in biosynthesis of the SDG-HMG ester-linked oligomers in flax seed.
"1: Carcinogenesis 1996 Jun;17(6):1373-6
Flaxseed and its lignan and oil components reduce mammary tumor growth at a late stage of carcinogenesis.
Thompson LU, Rickard SE, Orcheson LJ, Seidl MM.
Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Ontario, Canada.
Flaxseed, a rich source of mammalian lignan precursor secoisolariciresinol-diglycoside (S.D.) and alpha-linolenic acid (ALA), has been shown to be protective at the early promotion stage of carcinogenesis. The objective of this study was to determine whether supplementation with flaxseed, its lignan or oil fractions, beginning 13 weeks after carcinogen administration, would reduce the size of established mammary tumors (present at the start of treatment) and appearance of new tumors in rats. Dietary groups consisted of the basal diet (BD, 20% corn oil) alone or supplemented with a gavage of 2200 nmol/day S.D. [S.D., equal to level in 5% flaxseed (F)], 1.82% flaxseed oil (OIL, equal to level in 5% F) or 2.5% or 5% flaxseed (2.5% F and 5% F, respectively). After 7 weeks of treatment, established tumor volume was over 50% smaller in all treatment groups (OIL, 2.5% F, 5% F, P < 0.04; S.D., P < 0.08) while there was no change in the BD group. New tumor number and volume were lowest in the S.D. (P < 0.02) and 2.5% F (P < 0.07) groups. The combined established and new tumor volumes were smaller for the S.D., 2.5% F and 5% F groups (P < 0.02) compared to the OIL and BD groups. The high negative correlation (r = -0.997, P < 0.001) between established tumor volume and urinary mammalian lignan excretion in the BD, S.D., 2.5% F and 5% F groups indicates that the reduction in tumor size is due in part to the lignans derived from the S.D. in flaxseed. However, there was no relationship between new or total tumor development and urinary lignan levels. The effect of flaxseed oil may be related to its high ALA content. In conclusion, the S.D. in flaxseed appears to be beneficial throughout the promotional phase of carcinogenesis whereas the oil component is more effective at the stage when tumors have already been established.
Clin Cancer Res. 2003 Oct 15;9(13):4653-65. : Targeted anti-interleukin-6 monoclonal antibody therapy for cancer: a review of the rationale and clinical evidence. Trikha M, Corringham R, Klein B, Rossi JF.
Centocor, Malvern, Pennsylvania 19355 [M. T., R. C.], and Unit of Cellular Therapy and INSERM U475 [B. K.] and Service d'Hematologie et d'Oncologie Medicale and INSERM U475 [J-F. R.], Montpellier, France 34295.
Interleukin (IL)-6, a pleiotropic cytokine with varied systemic functions, plays a major role in inflammatory processes. It modulates the transcription of several liver-specific genes during acute inflammatory states, particularly C-reactive protein, and controls the survival of normal plasmablastic cells. In addition, IL-6 has been implicated in hematopoiesis as a cofactor in stem cell amplification and differentiation. This article is the first review of clinical studies in the 1990s with anti-IL-6 monoclonal antibodies (mAbs) in the treatment of patients with cancer and related lymphoproliferative disorders. In six clinical studies of mAbs to IL-6 with BE-8 or CNTO 328 in patients with multiple myeloma, renal cell carcinoma, and B-lymphoproliferative disorders, anti-IL-6 mAb treatment decreased C-reactive protein levels in all patients. In most patients, levels decreased below detectable limits. The antibodies were well tolerated, and no serious adverse effects were observed in the vast majority of studies. The fact that anti-IL-6 mAb therapy decreased the incidence of cancer-related anorexia and cachexia may also be useful in the treatment of cancer patients
Many antiinflammatory pharmaceutical products inhibit the production of certain eicosanoids and cytokines and it is here that possibilities exist for therapies that incorporate n-3 and n-9 dietary fatty acids. The proinflammatory eicosanoids prostaglandin E(2) (PGE(2)) and leukotriene B(4) (LTB(4)) are derived from the n-6 fatty acid arachidonic acid (AA), which is maintained at high cellular concentrations by the high n-6 and low n-3 polyunsaturated fatty acid content of the modern Western diet. Flaxseed oil contains the 18-carbon n-3 fatty acid alpha-linolenic acid, which can be converted after ingestion to the 20-carbon n-3 fatty acid eicosapentaenoic acid (EPA). Fish oils contain both 20- and 22-carbon n-3 fatty acids, EPA and docosahexaenoic acid. EPA can act as a competitive inhibitor of AA conversion to PGE(2) and LTB(4), and decreased synthesis of one or both of these eicosanoids has been observed after inclusion of flaxseed oil or fish oil in the diet. Analogous to the effect of n-3 fatty acids, inclusion of the 20-carbon n-9 fatty acid eicosatrienoic acid in the diet also results in decreased synthesis of LTB(4). Regarding the proinflammatory ctyokines, tumor necrosis factor alpha and interleukin 1beta, studies of healthy volunteers and rheumatoid arthritis patients have shown < or = 90% inhibition of cytokine production after dietary supplementation with fish oil. Use of flaxseed oil in domestic food preparation also reduced production of these cytokines. Novel antiinflammatory therapies can be developed that take advantage of positive interactions between the dietary fats and existing or newly developed pharmaceutical products.
PURPOSE OF REVIEW Cardiovascular disease is one of the most important causes of morbidity and mortality in western countries, generating an increasing number of admissions to intensive care units. Cardiac failure has long been associated with nutritional disorders, malnutrition and cachexia being frequent during the late phases of congestive heart failure: undernutrition is also a determinant of outcome, even after cardiac transplantation. RECENT FINDINGS It has been shown that early metabolic support can improve the recovery of the ischaemic heart. This paper reviews recent findings on substrates that can support the failing myocardium, which are mainly glucose-insulin, glutamine, taurine, selenium, thiamine, folic acid, and omega-3 fatty acids. Ischaemia-reperfusion generates tissue lesions that can be partly prevented through substrate manipulation.SUMMARY Shifting the substrate metabolism from lipids to carbohydrates and reinforcing the antioxidant status reduces the deleterious biological and clinical consequences of acute ischaemic events. The use of the glucose-insulin-potassium infusion has become widespread with the re-discovery of its value in modulating cellular metabolism and accelerating recovery of the ischaemic myocardium. Antioxidants have gained acceptance in the perioperative phase, as well as in chronic heart failure. This constitutes another piece of evidence in favour of early metabolic and nutritional intervention. There also appears to be room for the prevention of acute deterioration of cardiac function after surgery with the preoperative administration of oral supplements containing omega-3 fatty acids.
PMID: 8681458 [PubMed – indexed for MEDLINE]"medline
Carbohydrate-binding proteins in cancer, and their ligands as therapeutic agents.
Experimental evidence directly implicates complex carbohydrates in recognition processes, including adhesion between cells, adhesion of cells to the extracellular matrix, and specific recognition of cells by one another. In addition, carbohydrates are recognized as differentiation markers and as antigenic determinants. Lectins are nonenzymatic proteins present in plants and animals, which preferentially bind to specific carbohydrate structures and play an important role in cell recognition. Modified carbohydrates and oligosaccharides have the ability to interfere with carbohydrate-protein interactions and therefore, inhibit the cell-cell recognition and adhesion processes, which play an important role in cancer growth and progression. Carbohydrate ligands therefore, are candidates to play important roles in cancer therapeutics.
" 1: Cancer Lett 1999 Jul 19;142(1):91-6
Dietary supplementation with secoisolariciresinol diglycoside (SDG) reduces experimental metastasis of melanoma cells in mice.
Li D, Yee JA, Thompson LU, Yan L.
Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE 68124-0405, USA.
We investigated the effect of dietary supplementation with secoisolariciresinol diglycoside (SDG), a lignan precursor isolated from flaxseed, on experimental metastasis of B16BL6 murine melanoma cells in C57BL/6 mice. Four diets were compared: a basal diet (control group) and the basal diet supplemented with SDG at 73, 147 or 293 micromol/kg (equivalent to SDG provided in the 2.5, 5 or 10% flaxseed diet). Mice were fed the diet for 2 weeks before and after an intravenous injection of 0.6 x 10(5) tumor cells. At necropsy, the number and size of tumors that formed in the lungs were determined. The median number of tumors in the control group was 62, and those in the SDG-supplemented groups were 38, 36 and 29, respectively. The last was significantly different from the control (P < 0.01). Dietary supplementation with SDG at 73, 147 and 293 micromol/kg also decreased tumor size (tumor cross-sectional area and volume) in a dose-dependent manner compared with the control values. These results show that SDG reduced pulmonary metastasis of melanoma cells and inhibited the growth of metastatic tumors that formed in the lungs. It is concluded that dietary supplementation with SDG reduces experimental metastasis of melanoma cells in mice.
PMID: 10424786 [PubMed – indexed for flaxseed melanoma-medline MEDLINE] "
Protective effects of dietary phytoestrogens in chronic renal disease.1: J Ren Nutr 2001 Oct;11(4):183-93
Protective effects of dietary phytoestrogens in chronic renal disease.
Ranich T, Bhathena SJ, Velasquez MT.
Division of Renal Diseases and Hypertension, Department of Medicine, George Washington University Medical Center, Washington, DC 20037, USA.
Phytoestrogens are naturally occuring plant compounds that are present primarily in soybeans as isoflavones and in flaxseed as lignans. Because of their structural similarity to endogenous estrogens, phytoestrogens bind to both estrogen receptors (ER)-alpha and beta (but more strongly to ER-beta) and exert estrogen-like effects. There is increasing evidence that dietary phytoestrogens have a beneficial role in chronic renal disease. Nutritional intervention studies have shown that consumption of soy-based protein and flaxseed reduces proteinuria and attenuates renal functional or structural damage in animals and humans with various forms of chronic renal disease. It is not clear which component(s) of the soybean or flaxseed is (are) responsible for the protective effects observed in experimental animals and in limited studies in humans. Vegetable protein has been shown to have a beneficial effect on renal disease in animals and humans. Thus, the role of soy and flaxseed cannot be ruled out. Isoflavones and lignans are readily absorbed from the gut and converted to active metabolites, which may be partly responsible for the beneficial renal effects of soy protein and flaxseed. In addition, an interaction between type of protein and phytoestrogens is also possible. The biological actions of isoflavones and lignans have been well defined in different cell types in vitro and also in vivo, but how these compounds might reduce renal injury remains to be elucidated. Possible mechanisms include inhibition of cell growth and proliferation via ER-mediated mechanisms or non-ER-mediated pathways through inhibition of tyrosine protein kinases, modulation of growth factors involved in extracellular matrix synthesis and fibrogenesis, inhibition of cytokine-induced activation of transcription factors, inhibition of angiogenesis, antioxidative action, suppression of platelet activating factor and platelet aggregation, and immunomodulatory activity. To date, clinical trials in humans are few, of relatively short duration, and involve a small number of patients. Prospective randomized trials are needed to evaluate the long-term safety and effectiveness of dietary phytoestrogens on renal disease progression in patients with chronic renal failure. Copyright 2001 by the National Kidney Foundation, Inc.
FLAXSEED LIGNANS & THE IMMUNE SYSTEM -a great review
"Flaxseed contains Secoisolariciresinol diglucoside (SDG), a potent antioxidant and a known precursor of the mammalian lignans, enterolactone and enterodiol. These compounds have other pharmacological properties including phytoestrogen properties similar to isoflavones. Studies performed in the Department of Physiology, College of Medicine, University of Saskatchewan, have shown that SDG prevents the development of hypercholesterolemic atherosclerosis, reduces total cholesterol and LDL-cholesterol, and has a tendency to raise HDL-cholesterol in animal models. In addition, SDG has shown the ability to lower blood pressure, and has demonstrated that it is effective in preventing diabetes mellitus (Type I and Type II) and endotoxic shock. "
"The rapid rate of postmenopausal bone loss is mediated by the inflammatory cytokines interleukin-1, interleukin-6, and tumor necrosis factor alpha. Dietary supplementation with flaxseeds and flaxseed oil in animals and healthy humans significantly reduces cytokine production while concomitantly increasing calcium absorption, bone calcium, and bone density. Possibilities may exist for the therapeutic use of the omega-3 fatty acids, as supplements or in the diet, to blunt the increase of the inflammatory bone resorbing cytokines produced in the early postmenopausal years, in order to slow the rapid rate of postmenopausal bone loss. Evidence also points to the possible benefit of gamma-linolenic acid in preserving bone density. (Kettler D, Altern Med Rev, 6(1): 61, 2001) "
"Results of many studies indicate that consumption of n-3 fatty acids can benefit persons with cardiovascular disease and rheumatoid arthritis. However, encapsulated fish oil is unlikely to be suited to lifetime daily use and recommendations to increase fish intake have not been effective. Foods naturally rich in n-3 fatty acids, such as flaxseed meal can be used to achieve desired biochemical effects without the ingestion of supplements or a change in dietary habits. A wide range of n-3-enriched foods could be developed on the basis of the therapeutic and disease-preventive effects of n-3 fatty acids. (Mantzioris E, et al, Am J Clin Nutr, 72(1): 42, 2000) "
Evidence is emerging that dietary phytoestrogens play a beneficial role in obesity and diabetes. Nutritional intervention studies performed in animals and humans suggest that the ingestion of soy protein associated with isoflavones and flaxseed rich in lignans improves glucose control and insulin resistance. In animal models of obesity and diabetes, soy protein has been shown to reduce serum insulin and insulin resistance. In studies of human subjects with or without diabetes, soy protein also appears to moderate hyperglycemia and reduce body weight, hyperlipidemia, and hyperinsulinemia, supporting its beneficial effects on obesity and diabetes. However, most of these clinical trials were relatively short and involved a small number of patients. Furthermore, it is not clear whether the beneficial effects of soy protein and flaxseed are due to isoflavones (daidzein and genistein), lignans (matairesinol and secoisolariciresinol), or some other component. Isoflavones and lignans appear to act through various mechanisms that modulate pancreatic insulin secretion or through antioxidative actions. They may also act via estrogen receptor-mediated mechanisms. Some of these actions have been shown in vitro, but the relevance of these studies to in vivo disease is not known. The diversity of cellular actions of isoflavones and lignans supports their possible beneficial effects on various chronic diseases. Further investigations are needed to evaluate the long-term effects of phytoestrogens on obesity and diabetes mellitus and their associated possible complications.
Sulfur in human nutrition and applications in medicine.
Because the role of elemental sulfur in human nutrition has not been studied extensively, it is the purpose of this article to emphasize the importance of this element in humans and discuss the therapeutic applications of sulfur compounds in medicine. Sulfur is the sixth most abundant macromineral in breast milk and the third most abundant mineral based on percentage of total body weight. The sulfur-containing amino acids (SAAs) are methionine, cysteine, cystine, homocysteine, homocystine, and taurine. Dietary SAA analysis and protein supplementation may be indicated for vegan athletes, children, or patients with HIV, because of an increased risk for SAA deficiency in these groups. Methylsulfonylmethane (MSM), a volatile component in the sulfur cycle, is another source of sulfur found in the human diet. Increases in serum sulfate may explain some of the therapeutic effects of MSM, DMSO, and glucosamine sulfate. Organic sulfur, as SAAs, can be used to increase synthesis of S-adenosylmethionine (SAMe), glutathione (GSH), taurine, and N-acetylcysteine (NAC). MSM may be effective for the treatment of allergy, pain syndromes, athletic injuries, and bladder disorders. Other sulfur compounds such as SAMe, dimethylsulfoxide (DMSO), taurine, glucosamine or chondroitin sulfate, and reduced glutathione may also have clinical applications in the treatment of a number of conditions such as depression, fibromyalgia, arthritis, interstitial cystitis, athletic injuries, congestive heart failure, diabetes, cancer, and AIDS. Dosages, mechanisms of action, and rationales for use are discussed. The low toxicological profiles of these sulfur compounds, combined with promising therapeutic effects, warrant continued human clinical trails.
Sulfur amino acid deficiency depresses brain glutathione concentration.
Dietary sulfur amino acid content is a major determinant of glutathione concentration in some tissues. We examined whether brain glutathione (GSH), a key component of antioxidant defense important for minimizing ischemic injury, was also responsive to short-term sulfur amino acid deficiency. Female Long-Evans adult rats were fed a sulfur-deficient L-amino acid defined diet for five days; the control diet was supplemented with L-cystine and L-methionine (n = 6). Sulfur amino acid deficiency was confirmed by a reduction in liver cysteine and GSH concentrations, marked decreases in food intake, and weight loss. GSH concentration analyzed by reverse-phase high performance liquid chromatography was significantly depressed in the neocortex and thalamus of deficient rats. Brain cysteine was not decreased in a parallel manner. Classical glutathione peroxidase activity was increased in the liver and brain of sulfur amino acid deficient rats. This suggests an upregulation of antioxidant defense but these findings may be complicated by alterations in tissue composition. The depletion of brain GSH by a reduced supply of dietary precursors may be important during brain ischemia when the rate of GSH utilization and the need for synthesis are increased.
Effects of dietary polyunsaturated fatty acid supplementation in early renal insufficiency in dogs.
Dietary supplementation with polyunsaturated fatty acids (PUFAs) alters the course of experimental kidney disease in dogs. In particular, supplementation with omega-6 PUFAs hastens the decline of kidney function, and omega-3 PUFAs are renoprotective. We investigated the early stages of renal insufficiency to determine whether PUFA supplementation altered the magnitude of hypercholesterolemia or glomerular hemodynamics. Two months after 11/12 nephrectomy, dogs were randomly divided into three groups of 6 animals each. Each group of dogs was then fed a low-fat basal diet supplemented with one of three sources of lipid to achieve a final concentration of 15% added fat. Fat sources were rich in omega-3 PUFAs (menhaden fish oil, group FO), omega-6 PUFAs (safflower oil, group SO), or saturated fatty acids (beef tallow, group C). Early in renal insufficiency, before significant kidney damage, group FO had a lower (P<.05) serum cholesterol concentration and tended to have a lower urinary prostaglandin E2 (PGE2) and thromboxane A2 (TxA2) excretion than group C. In contrast, group SO had a higher mean glomerular capillary pressure (P<.05) and more glomerular enlargement (P<.05) and tended to have higher eicosanoid excretion rates than group C. These differences in lipid metabolism, glomerular hypertension and hypertrophy, and urinary eicosanoid metabolism could explain, in part, the beneficial effects of omega-3 PUFAs and the detrimental effects of omega-6 PUFAs when administered on a long-term basis in this model of renal insufficiency.
Study: Common Seed Fights Cancer
A recent Canadian study shows that a common seed may be a promising new cancer fighter, researchers say. Dr. Paul Gross of Princess Margaret Hospital and a team of researchers from the University of Toronto asked a group of newly diagnosed breast cancer patients to eat two tablespoons of ground flaxseed in a muffin each day. Then, Gross' research team analyzed samples of their tumors. The study found that flax actually slowed the growth of breast cancer. "The scientific community is very interested in this study," Gross said. "We've been bombarded by other investigators from around the world." Researchers found that in less than a month, the women taking flaxseed slowed their rate of tumor growth by up to 33 percent. There also was nearly a 60-percent drop in the spread of the most aggressive cancer cells. "Flaxseed is the first nutritional product that has been studied, and that has produced hard scientific evidence," Gross said. According to the study, researchers believe that a fiber in the seed helps to sweep the hormone estrogen out of the body, which blocks its ability to make tumors grow. Flax would be the first cancer treatment that isn't a chemical, researchers said. However, since flax is a food, it doesn't have the backing of a drug company. Researchers said that they don't know how much longer they would be able to continue their work. Some cancer support groups believe that the data shouldn't be ignored. "There is a community out there who are hungry for this kind of information, and it won't bother them that it's not a pharmaceutical," Sue Wright of the Willow Breast Cancer Support Center. "In fact, it might even encourage them."
