Our genes are our destiny, so said the conventional wisdom. Whatever cards Mother Nature dealt us—good or bad—were ours for life.
Wrong. Hit the reset button. Most of the time, it’s epigenetics that decides our destiny, and even if we have a “bad” gene, that’s only half the story.
We inherit two of every gene—one from our mother, one from our father—and hopefully at least one in each of these pairs is a “good” gene, which is sufficient for us to live healthy, mostly disease-free lives. The problem comes when we lose or inactivate that good gene that is functioning normally. This is the relatively new science of epigenetics.
Our genes are surrounded by a network of chemical messengers that affect what the gene does. And those chemical messengers—collectively known as the epigenome—are affected by what we eat, environmental toxins we’re exposed to, stress levels and other lifestyle factors.
Take two identical twins: they have the exact same genes because they came from the same egg, but sometimes one sibling grows up to have diabetes or cancer and the other does not. How does that happen? Epigenetics trumps genetics.
Geneticist Randy Jirtle, Ph.D., devised a landmark experiment with two mice that carry the Agouti gene—a “bad” gene that gives mice yellow-colored fur and makes them prone to obesity, diabetes and cancer. The offspring of Agouti mice are always identical to the parents—yellow, obese and susceptible to life-shortening diseases. But by feeding the mothers a different diet, Dr. Jirtle got a very different result in their offspring.
This photo on this page shows two genetically identical mice that carry the Agouti gene. Their mothers, while pregnant, were both fed a
diet laced with endocrine-disrupting bisphenol A (BPA). However, the diet of the mother of the mouse on the right was supplemented with choline, folic acid, betaine and vitamin B12. The end result: The yellow daughter on the left, the one with the mother that did not have a supplemented diet, is obese and prone to disease. The brown daughter on the right is not diabetic, and is smaller, fitter, leaner and healthier. The nutrients fed to the mother of the healthier brown mouse can attach to a gene and turn it off, virtually erasing the effects of the Agouti gene.
Ajay Goel, Ph.D., director of epigenetics and cancer prevention at the Baylor Research Institute in Texas, explains: “[There are] countless suppressor and activator areas that determine how our genes are expressed. We are finding that these gene-modifying areas are turned off or on by environmental influences such as diet, exercise, hormones, chemicals, toxins and probably other factors unknown to us. Twenty years ago, if you’d said cancer is a hereditary disease, everyone would have agreed. But we know now that the hereditary predisposition for cancer is much less than 5 percent, so most cancers are epigenetically driven,” indicating that our health choices are usually more relevant than inherited genes in this instance.
Sometimes the genes we inherit are not a gene dysfunction in and of themselves, but can affect the way our bodies respond to certain stimuli. For example, think about the inherited mutations in BRCA1 and BRCA2 genes, the genes that are linked to risk of breast and ovarian cancer. They make radiation-associated breast cancer more likely because the mutations mean your body can’t readily repair DNA breaks caused by exposure to radiation. If you have those genes, you are more likely to develop breast cancer, but then again, not every recipient does. What we know about epigenetics tells us you probably want to stay away from mammograms, airport scanners and other forms of radiation that would encourage those genes to express badly.
The Paleo diet conversation likes to talk about human gene changes taking 10,000 years or more, but epigenetic changes can be almost immediate. Dr. Goel described the Japanese history of cancer as a classic example: “Japan in the 1950s had a low incidence of colon cancer. When Japanese moved to pineapple fields in Hawaii, however, in one generation their rate of colon cancer was the same as [that of] the Hawaiians who worked the fields. Their genes didn’t change, but their diet and environment did.”
Successive generations do not necessarily bounce back. Epigenetic changes, both good and bad, can be transmitted from one generation to another, which is rather faster than the evolutionary changes resulting from natural selection.
And that “good” gene we hopefully inherit? Although, as Dr. Goel explained, “it is enough for most people to live their lifetime with that one good gene expressing,” we see quite clearly from the immigrant Japanese farmworkers that epigenetics can actually cause a healthy gene to become unhealthy. However, he continued, “You can reverse it.”
One way of encouraging healthy expression of genes is the use of curcumin. Curcumin is the active ingredient in turmeric, and gives many Indian dishes their rich yellow color. The consensus from more than six thousand studies is that it is a potent antioxidant and anti-inflammatory that can encourage healthy expression of genes. Curcumin has more evidence-based medical literature supporting its use in cancer prevention, for example, than any other nutrient.
Although the typical American diet, even in a health-conscious home, contains very little of this valuable ingredient, Dr. Goel estimated the daily Indian diet contains about 100 mg of curcumin. He and his family take a daily 250 mg curcumin supplement. “More is not necessarily better,” he said, (though up to 10 g a day is generally considered safe). “Curcumin works on hundreds of genes and hundreds of pathways. If you take cancer cells and put curcumin or other diet-based botanicals on them, you can reverse the tendency for bad genes to express.” It can be taken in capsules, but traditionally curcumin is used in cooking, and some research shows heat makes it more water soluble, thus more usable by the body.
Researchers spent 10 years and $3 billon on the Human Genome Project to map the human gene blueprint, thinking they would be able to revolutionize the diagnosis, prevention and treatment of perhaps all human diseases by targeting specific genes. It turned out the causes of disease are much more complicated than finding one “bad” gene. Now scientists have begun the much more complex task of mapping our epigenetics, because health and susceptibility to disease are, in part, the result of epigenetic changes. Mapping the human epigenome is expected to take decades to complete.
Scientists like to say that our genes are like computer hardware, and epigenetics is like computer software. An extra dose of vitamins, exposure to toxins like pesticides and radiation, a critical stress such as divorce or job loss can tweak the epigenome and alter the software.
Epigenetics teaches us that nutrition and environmental toxins are no small matter. Not only are they talking to our genes, they can cause changes that are inherited by our children. It is the ultimate balance of nature versus nurture.
Don’t Drink the (Bottled) Water
Researchers recently raised new alarms about BPA exposure. One study warned of fetal exposure; another warned of miscarriages.
Even though BPA, or bisphenol A, has been removed from baby bottles and infant formula packaging because of consumer concerns about its estrogen hormone-mimicking effects, babies are still exposed while in the womb.
A September report from the Breast Cancer Fund cited 60 animal and human studies linking prenatal BPA exposure to an increased risk of health problems ranging from breast cancer and prostate cancer to decreased fertility, early puberty, neurological problems, immune system changes and more. Ten studies have found BPA in fetal tissue, including umbilical cord blood, as well as in amniotic fluid, the report noted.
In another study, it was found that women with the highest levels of BPA in their blood were significantly more likely to miscarry than women with the lowest levels.
BPA is a building block for chemicals and plastic resins. Its versatility made it one of the most common chemicals in modern life, and it is still widely used to coat cash-register receipts (one more reason to have yours texted or emailed), to line metal food cans, in some water bottles, bicycle helmets, eyeglasses and medical equipment. Researchers at the Centers for Disease Control and Prevention measured BPA in 93 percent of about 2,500 urine samples from a broad national sample of adults.
So you buy a sippy cup that is BPA-free. But is it safe? Maybe not. BPA in many consumer products is being replaced by its chemical cousin, bisphenol S (BPS). Researchers report that the estrogenic activity of BPA and BPS “is of a comparable potency.” BPS was detected in 81 percent of the urine samples analyzed worldwide in 2012.
There is an entire bisphenol chemical family ranging from AB and AF, to TMC and Z. Any one of these can be in your BPA-free baby bottle or your polycarbonate sports bottle.
Mary Budinger is an Emmy-award winning journalist who covers integrative medicine.
