With Broccoli prevent against prostate cancer?
A new study provides the first results of human studies, confirm the earlier observations. After a few servings a week could be enough to alter the expression of genes so that protection arises.
What is gene expression?
Each cell of the body has the same genetic information, stored on the chromosomes in the cell nucleus in the form of DNA . As a gene is called a section of DNA that, the gene product serves as a blueprint for a substance. During the development of embryonic stem cells (the first cells that arise from a fertilized egg) to highly specialized cells of the body are many genes "off" and some of them again "turned on" (expressed). Even after birth, the gene expression changes constantly, for example, when cells need materials to fulfill specific tasks such as the regeneration of blood cells or the healing of wounds.
In the degeneration of normal to malignant cells, the gene expression also plays a big role: On the one hand, the expression of "cancer-promoting" genes and the other is the "Switch off" of protective genes. The latter, for example, provide for the repair of damage and the induction of apoptosis, the programmed cell death. While the human DNA is decrypted, it is the genes and gene products only partially. This also applies to the control of gene expression, which must be accurately and extends over complicated pathways involving mediators are involved, such as hormones.
Healthy Vegetables: Broccoli and Peas
Broccoli belongs as other vegetable brassicas (eg red cabbage, kohlrabi) and other plants (eg, radish, mustard, horseradish, watercress) to the cabbage family ("cruciferous vegetables", botanical Brassicaceae, formerly Cruciferae, crucifer). Among other so-called glucosinolates contain (glucosinolates) that give them a cabbage-like odor and slightly bitter taste. Cooking prevented when chewing incurring pungent or pungent mustard oils. In the intestine, the further reduction to substances carried (isothiocyanates) that are absorbed into the blood and then degraded. From previous studies it is known that broccoli can reduce the risk for prostate cancer and its progression and that this effect is particularly pronounced in men who possess the gene GSTM1 (about 50%).
Peas like soybean to the legume family (Fabaceae, Leguminosae), or more precisely to the subfamily of Fabaceae (Faboideae). They contain phytoestrogens, which are substances that can have an effect similar to estrogen , the female sex hormones. They are considered to reason that prostate cancer in Asians occurs only very rarely, because Asian food more thereof as our western (see causes of prostate cancer and prostate cancer prevention Chemical ).
The new study
Participants in the study were 22 men aged 57-70 years, the strict exclusion criteria are not met (eg, concurrent treatment with certain medications) and partly elevated PSA levels had and partly owned the GSTM1 gene. One half of them had a year weekly 400g broccoli in addition to normal food to eat ("Broccoli Group"), the other half 400g peas ("pea-group"). All received the vegetables as frozen foods (broccoli from the same field!) And were trained in the preparation and supervised closely. Before the start of the experiment and after 6 and 12 months, the PSA values were determined and removed prostate biopsies (tissue samples).
While the PSA levels had remained the same, the researchers discovered in the investigation of prostate tissue in the broccoli group, especially in GSTM1-positive to significant changes in signaling pathways and the expression of genes that are in connection with the development of malignant tumors . Among them was the signal via the receptor for androgens (male sex hormones; Note: They influence the development and growth of prostate cancer, see causesand hormonal therapy for prostate cancer). In the pea group, however, only this last signal was changed.
Further experiments provided a possible solution to a known problem: In previous experiments on cells and animals, the degradation products of glucosinolates from broccoli could stop the proliferation of cells and induce apoptosis, which explains their action against tumors. For this, however, concentrations were required, which can not be reached with a broccoli-rich diet. The explanation: The degradation products react with specific proteins (proteins) in the blood and thus change their signaling effect on gene expression. In addition, the GSTM1 gene for a high level may provide to reactive degradation products.
In addition to these results, the study has also shown the following, the researchers said further: First, the prostate biopsy allows for determining and tracking the expression of numerous genes use, which could also improve the prediction of the likelihood of progression of prostate cancer. Second, the gene expression could be in the prostate tissue for the presence of other genes score than GSTM1 to obtain new information. Third, it is conceivable that other ingredients from the food their effect also unfold by responding with signal proteins in the blood. How could a substance which occurs in both broccoli and peas in affecting the signal path via the androgen receptor.
Conclusion of the authors
The results suggest that the intake of broccoli - depending on the GSTM1 gene - complex changes of signaling pathways has the consequence associated with the development of prostate cancer. Presumably, this occurs by a reaction between the decomposition products of mustard oil glycosides from broccoli and signal proteins in the blood. This could have one serving (100g) broccoli per week in GSTM1-positive, or more portions at GSTM1-negative, sufficient to reduce the risk for prostate cancer. In any case, support the experimental findings for the first time earlier observations that a diet rich in cruciferous can reduce the risk for prostate cancer and other chronic diseases. For an exact explanation but further studies are needed.
Swell
- Boyles, S.: Broccoli May Cut Prostate Cancer Risk. Study Shows Link Between Eating broccoli and Gene Changes. WebMD Health News, 1.7.08 (for articles )
- Traka, M., et al.: Broccoli Consumption Interacts with GSTM1 to perturb Oncogenic Signalling Pathways in the Prostate. PLoS ONE 2008 3 (7): e2568. doi: 10.1371/journal.pone.0002568 (for articles )
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