Cancer, Epigenetics, along with Nutrigenomics - How Food Affects Your Cancer GenesOne of the causes of cancer is actually abnormal genes. Cancer causing genes are called oncogenes along with genes of which prevent cancer are called tumor suppressor genes. Cancers can occur when the normal genes are not functioning normally. Genes, as you know, are the blueprints to the body. They tell a cell what This particular will be along with what This particular will do. We could not function if the process did not run well. There is actually a system in place of which is actually designed to keep Great genes running along with suppress bad genes. This particular process is actually called epigenetics.
Epigenetic adjustments are modifications to the genome of which are heritable during cell division although do not involve a change in DNA sequence. Expression of genes is actually not regulated by the DNA sequence, which is actually the same in every cell, although by epigenetic marking along with packaging. This particular process regulates chromatin structure through DNA methylation, histone variants, post-translational modifications, nucleosome positioning factors or chromatin loop along with domain organization.
How can This particular cause cancer? Well, if a tumor suppressor gene is actually abnormally turned off, or an oncogene is actually turned on, then cancer (carcinogenesis) can occur. One key is actually a chemical change to the DNA called methylation. First, we need to define the process to make This particular clearer.
DNA contains four bases: adenine, guanine, cytosine, thymidine, although there is actually a fifth base methylated cytosine. DNA methyl-transferase (DNMT) produces methyl-cytosine where cytosines precede guanine (CpG). The CpG areas are not symmetric although clustered in CpG islands located at promoter regions. The promoter region is actually the region at the beginning of a gene along with This particular controls the start of gene transcription. If the promoter is actually off, then the gene never is actually expressed.
Abnormal methylation in cancer has been known for 20 years. Hypo-methylated areas turn on normally silent areas such as virally inserted genes or inactive X-linked genes. Hyper-methylated areas silence tumor suppresser genes.
We know of which cancers have abnormal levels of methylation along with we know foods can help prevent cancers. is actually there a link between foods along with epigenetics? Yes!
The study of food nutrients along with their effect on disease through epigenetics is actually known as nutrigenomics. This particular is actually a growing field, in fact, This particular is actually exploding. A Google search for the term nutrigenomics produces 127,000 entries.
Epidemiologic studies suggest there are bad foods along with Great foods. BAD: red meat, processed meat, grilled meat, dairy, animal fat, partially hydrogenated fats. Great: Fish, fruits, vegetables, tree nuts, omega-3 fatty acids, whole grains.
You can study the epigenetic effects of bad or Great foods. I'm going to talk about some of the cancer preventing foods along with how their mechanisms include epigenetic effects.
Foods with epigenetic effects include green tea, cruciferous vegetables, along with grapes. Usually we hear about antioxidants along with foods. Antioxidants are important although there are beneficial substances in foods called polyphenols which can affect genes. Of the polyphenols, different forms exist although flavonoids are the most highly cited for health benefits along with are found in a variety of vegetables along with fruits. Types of flavonoids include flavanols in tea, isothiocyanate in cruciferous vegetables, anthocyanidins in grapes along with berries, flavonone in citrus fruits, flavonols in onions, isoflavones (genistein) in soy.
All tea contains polyphenols, although the highest levels are in green along with white tea. Green tea has been well studied along with appears to have anti-cancer benefits. In China, green tea drinkers are 50% less likely to develop gastric or esophageal cancer (Carcin 2002; 23 (9): 1497), along with 2 cups daily added to topical tea extract reversed oral leukoplakia (J. Nutri Biochem 2001; 12 (7): 404).
Green tea has powerful antioxidant effects although This particular also helps to balance normal methylation in DNA. In fact, one study in esophageal cancer cells demonstrated of which EGCG via green tea is actually able to turn on tumor suppressor genes of which had been chemically silenced by methylation (Cancer Research 2003;63:7563).
Cruciferous vegetables include broccoli, cauliflower, kale, Bok choi along with their anti-cancer effects have been demonstrated in epidemiologic studies. These powerful vegetables not only induce enzymes of which break down carcinogens although they also inhibit DNA methylation allowing tumor suppressor genes to thrive. Inhibiting abnormal methylation also helps cruciferous vegetables to inhibit the cancer causing action of tobacco smoke by preventing the formation of nitrosamine-DNA adducts.
Grapes, which contain reserveratrol, are excellent for heart health along with they have anti-cancer activity. Grapes work by preventing the formation or initiation along with promotion of cancers. They don't have methylating actions as discussed above although they work by modulation histones.
Histones are the chief protein component of the DNA chain (chromatin). They act as spools for the DNA to wind around which then shortens the length of the DNA to 30,000 times shorter than an unwrapped strand. This particular process not only allows the long DNA chain to fit into a cell although also plays a role in gene expression because how the genes are wound affects which are exposed along with available for turning on or off. Rolling the spool a different way could expose some other genes along with change their expression.
Histones are modified after translation by acetylation, methylation, phosphorylation, ubiquitination. The adjustments occur at lysine residues (except for phosphorylation of serine or threonine). When the histone is actually acetylated the charge is actually changed along with the histone loosens its grip on the DNA strand along with the DNA unwinds, exposing the genes to be transcribed, or repaired.
When histone tails (H3,H4) are acetylated, genes are transcribed, when they are deacetylated, genes are turned off. Histone deacetylases work to maintain deacetylated sites.
Resveratrol, found in grapes, activates Sirtuins; SirT1 (Sir2 proteins). There are at least 7 Sir2-like proteins along with they are histone deacetylators. Sirtuins are induced in animals during starvation states. They seem to have a life preservation effect. Interestingly, when an animal is actually starved, This particular can live longer. When the calorie intake of rodents was decreased by 40% in rodents, they actually lived 50% longer along with appear to have fewer chronic diseases. The same benefit occurs when rodents when they are given resveratrol in their diet.
Resveratrol deacetylates histones causing tighter packing of the chromatin along having a lower level of transcription of DNA. This particular silencing of the DNA is actually thought to be the mechanism of life prolongation, heart health, along with its beneficial actions to prevent cancers. This particular is actually why grapes or red wine is actually beneficial to your health. How much red wine should you drink? No one knows for sure, although any beneficial effects might be negated after two glasses a day because of the alcohol. I wouldn't advise drinking more than This particular until more is actually known. The data is actually very promising, although more research is actually needed.
Our knowledge of disease expanded inside the genomic era due to the human genome project although the study of genes is actually not enough. Epigenetics is actually a very important along with complicated concept of which helps explain how genes are turned on or off. As more studies are completed we will be able to unlock the mechanisms to diseases along with produce fresh therapies of which could turn off bad genes along with turn on Great genes. More importantly, these studies will demonstrate how foods affect your genes along with can prevent or reverse diseases or cancers. Nutrigenomics, the study of how food chemicals (nutrients) affect genes, is actually a growing field along with promises to change the way we look at along with eat our meals. Some of the most beneficial foods include green tea, cruciferous vegetables along with grapes, although don't stop there. The more fruits along with vegetables the better when This particular comes to your health.