In September 2015, Monica was diagnosed with breast cancer, which was already in the middle stage. Monica was an identical twin, and her 38-year-old sister Erika had also had regular mammograms and ultrasounds without ever detecting cancer. In Monica’s left breast, a tumor had grown to be the size of a tennis ball, and the cancer cells had spread to her lymph nodes.
These twins share the same genes, so why did one develop cancer and not the other?
We have always thought that it is the genes , our DNA, that determine everything about us. In fact, there is another decisive factor: the “switch” of genes. To put it this way, a gene determines that two twins have the same necklace, but the“switch” of the gene determines whether they wear it or not, when they wear it, and how long they wear it.
The key to determining whether this gene is switched “on” or “off” is the epigenetic factor.
Each person’s DNA is fixed. The DNA is determined the moment the father’s sperm joins with the mother’s egg. There are about 200 types of cells in the body, but they have the same DNA.
However, the same DNA creates different types of cells through the direction of epigenetic factors, and the differences between these cells are enormous.
Similarly, epigenetic factors can also promote the generation or non-generation of cancer cells.
In the human body, there are about 50 trillion cells, and each cell contains about 6 feet of DNA. The reason why such long genes can fit into the nucleus of a cell is because of the way the DNA is wrapped.
The spools around which the DNA is wrapped are called histones. A piece of DNA has to be wrapped around 30 million of these spools. In the diagram, each of the circular spools represents a histone, and the threads that wrap around it are DNA.
Epigenetic factors can bind to the “tails” of histones, or to DNA. They are attached to histones or DNA like tags.
Epigenetic factors (methyl groups) that bind to DNA can directly “turn off” genes.
Epigenetic factors also control the state of DNA entanglement on histones. It can make the genes tightly wrap around histones in a compressed state. At this point, gene expression is suppressed, and the body is unable to read these genes. The genes are in the “off” state.
They can also loosen the DNA strands wrapped around the histones. The loosened DNA is no longer suppressed, so the body can then read this DNA information. This means that the genes are in an “on” state.
Changes in epigenetic factors may ultimately determine whether or not a person has a particular disease. For instance, after an epigenetic factor is turned off, the gene of a protein that inhibits cancer cannot be expressed, so this protein is no longer produced, then a tumor will form. However, if the gene is left on, it may prevent the tumor from appearing.
Turn On Good Genes and Turn Off Bad Ones to Avoid Cancer, Genetic Diseases
We cannot change our genes. So how can we turn on the good genes and turn off the bad ones to prevent cancer from developing?
Diet, alcohol, tobacco and drug intake, psychological stress, and living environment all have an impact on epigenetic factors. They affect genes in two main ways—DNA methylation and histone modification.
More and more studies have found that diet is a key to controlling gene expression.
A methyl group is an epigenetic factor that can enter cells through the diet, and when it is tagged on DNA, it is called DNA methylation.
Methyl groups can turn off genes. In normal cells, oncogenes are turned off by the methyl groups and remain silent; cancer suppressor genes are not methylated, so they are turned on. In cancer cells, the opposite is true.
Another approach, histone modification, has a similar rationale.
In short, when foods that are beneficial to fighting cancer are consumed, their ultimate goal is the same, regardless of the way in which they affect genes: to turn off oncogenes and turn on cancer suppressor genes.
Nutrients and Foods That Change Gene Expression to Fight Cancer
- Catechins
Polyphenols are found in fruits and vegetables, and they protect the body against diseases. Dietary polyphenols alter the epigenetic factors of cancer cells, including through the activation of silent genes, thus fighting cancer.
Catechins are tea polyphenols, which are the most abundant bioactive compounds in green tea, accounting for more than 50 percent of the active compounds in it, and their anticancer effects have been widely studied.
Catechins can prevent the methylation of cancer suppressor genes. Once these genes are highly methylated, they become inactive and cannot act as cancer inhibitors. The intake of catechins protects the activity of beneficial genes and makes the cells produce anticancer proteins to fight and treat cancer.
A study by researchers at the University of New Jersey was published in Cancer Research. It demonstrated that catechins in green tea can inhibit DNA methylation and reactivate cancer suppressor genes that had been silenced by high methylation, in colon, skin, esophageal, and prostate cancer cells.
Another study published in the journal Carcinogenesis showed that catechins had the same modulating effect on DNA methylation in skin cancer cells.
In addition, a large number of studies have demonstrated that catechin ingestion has a significant inhibitory effect on cancer cells in the oral cavity, breasts, stomach, ovaries, and pancreas.
- Resveratrol
Resveratrol is a plant polyphenol that exists naturally in grape skins. Fruits such as mulberries, cranberries, blueberries, and peanuts also contain resveratrol.
Resveratrol has antioxidant, anti-inflammatory, and anti-cancer properties, and has an effect on signaling pathways that control cell division, growth and apoptosis, and cancer cell metastasis. The anti-proliferative property of resveratrol has been demonstrated in liver, skin, breast, prostate, lung, and colorectal cancer cells.
Researchers at the University of Arizona found that resveratrol prevents epigenetic silencing of cancer suppressor proteins in breast cancer cells.
Scientists at the National Institutes of Health have demonstrated that resveratrol can inhibit the expression of anti-apoptotic proteins in breast cancer cells, thereby inducing apoptosis, or the cell death of cancer cells. Therefore, these researchers concluded that resveratrol is an excellent choice for targeted therapy of breast cancer.
- Isoflavones
Many people are familiar with soy isoflavones in soybeans and soy products, which are a type of isoflavones. Isoflavones are also found in foods such as broad beans and the root of kudzu vine.
Soy isoflavones are a type of phytoestrogen. Its cancer-preventing and anti-cancer properties are reflected in its effect on histone modification and DNA methylation, thus regulating the ability of gene transcription.
Studies have shown that soy isoflavones can reactivate the expression of cancer suppressor genes in prostate cancer cells. It has also been found that soy isoflavones and other isoflavones can regulate the expression of non-coding RNAs in several types of cancer cells.
Researchers at the University of Missouri conducted a human anti-cancer trial using soy isoflavones. Thirty-four healthy premenopausal women were given 40 mg or 140 mg of isoflavones daily during one menstrual cycle, and the researchers then evaluated the genetic changes in these individuals. The results showed that taking isoflavones caused hypermethylation of two breast cancer-related genes, and it silenced these breast cancer genes.
- Isothiocyanates
Isothiocyanate is a dietary compound found in cruciferous vegetables (including broccoli, cabbages, kales, and collard greens). It inhibits the growth of cancer cells and exhibits the ability to promote cancer cell apoptosis.
In a human study conducted at Oregon State University, the consumption of 68 g of broccoli sprouts was shown to inhibit the activity of histone deacetylase in peripheral blood mononuclear cells, thus achieving cancer prevention. In addition, researchers at another university in the United States have demonstrated through cell culture experiments that isothiocyanates can inhibit methyltransferases in breast cancer cells and suppress the hTERT gene, which is overexpressed in about 90 percent of cancers.
In addition, there are several nutritional elements that can control and treat cancer. A review in the journal Epigenomics concluded that the following nutrients and foods can alter epigenetic factors in two ways.
Foods that fight cancer by regulating DNA methylation: selenium (Brazil nuts), isothiocyanates (broccoli), catechins (green tea), resveratrol (grapes), and isoflavones (soy beans).
Foods that fight cancer by modulating histone modification: isoflavones (soy beans), curcumin (curry), catechins (green tea), resveratrol (grapes), isothiocyanates (broccoli), selenium (Brazil nuts), and allyl mercaptan (garlic).