Certain groups of genes, like hair color and height, are fixed. Other groups of genes are continuously influenced by the environment, such as those responsible for our immune and inflammatory responses. The environment that activates or suppresses genes includes both our inner environment - our emotional, biochemical, mental, energetic and spiritual landscape - and our outer environment, encompassing factors such as the foods we eat, the amount of calories we ingest, our social rituals, and the extent to which we exercise. In other words, our DNA contributes to our characteristics but does not determine them; it’s not the presence or absence of genes alone that determines whether they build the proteins for which they’re designed. Instead, each of us actively shapes the expression of our genes every day, part of a science called epigenetics.
This genetic drift over time is most easily seen in identical twins. Although they begin life with the same genome, on average identical twins die more than ten years apart, due to their different emotional choices, the habits they’ve cultivated, and varying stress levels. Blair Justice, PhD, in his book Who Gets Sick, observes that ‘genes account for about 35% of longevity, while lifestyles, diet and other environmental factors, including support systems, are the major reasons people live longer.’
The basic process by which a gene produces a result in the body is well mapped. Signals pass through the membrane of each cell and travel to the cell’s nucleus. There, they enter the chromosome and activate a particular strand of DNA. Around each strand of DNA is a protein ‘sleeve,’ which serves as a barrier between the information contained in the DNA and the rest of the intracellular environment. In order for the blueprint in the DNA to be ‘read’, the sleeve must be unwrapped.
When a signal arrives, the protein sleeve around the DNA unwraps and (with the assistance of RNA) the DNA molecule then replicates an intermediate template molecule. The blueprint that has up to this point been concealed within the sleeve can now be acted upon. This is what scientists mean when they say that a gene ‘expresses.’ DNA instructions that are unwrapped create other actions within the cell, causing molecules to be assembled into coherent protein structures that regulate virtually every aspect of life.
Arguably the most important signals that cells receive in this ongoing process come from diet. It is by now well demonstrated that different diets lead to different patterns of genetic expression, which result in different proteins being manufactured as well as changes in energy metabolism.
In one early experiment, researchers discovered that a gene that had long been known to affect the fur color of mice, called the agouti gene, was related to a human gene that is expressed in cases of obesity and Type II diabetes. As well as having yellow coats, agouti mice eat ravenously, have an increased incidence of cancer and diabetes, and tend to die early. When they produce offspring, the baby mice are just as prone to these conditions as their parents.
But Randy Jirtle, PhD, a professor of radiation oncology at Duke University and winner of the Epigenetic Medicine award from the National Institute for Integrative Healthcare, discovered that he could make agouti mice produce normal, slender, healthy offspring by changing the expression of their genes, without making any changes to the mouse’s DNA. He did this by feeding agouti mothers a diet rich in a chemical known as methyl groups. The methyl groups worked their way through the mothers’ metabolisms to attach to the agouti genes of the developing embryos, and suppress them. Methyl-rich foods, such as beets, onions, garlic, and dark, leafy greens like kale have also been shown to have a beneficial effect on gene expression in humans.
In general, plants are loaded with genetic modifiers that help switch on more than 500 genes that create health, and off more than 200 genes that create disease. For instance, curcumin activates the Nrf2 pathway, a genetic switch that turns on the genes to produce a vast array of antioxidants and detoxification enzymes that protect mitochondria. Phytonutrients targeting the Nrf2 pathway are a powerful means through which you can direct the expression of life-sustaining genes in your body, and these include sulphoraphane (found in broccoli and other cruciferous vegetables), green tea extract, and pterostilbene (found in blueberries).
In addition to what you’re eating, what you are thinking, feeling and believing is changing the genetic expression and chemical composition of your body on a moment-by-moment basis. As we think our thoughts and feel our feelings, we initiate particular cascades of biochemicals that trigger genetic changes in our cells. Several studies show that what one thinks about one’s health is one of the most accurate predictors of longevity ever discovered - the tools of our consciousness often correlate much more strongly with our health, longevity and happiness than our genes do.
A classic example of this is Harvard physician Herbert Benson’s experiment using the ‘Relaxation Response’, in which he had healthy subjects sit quietly for 20 minutes, filling their minds with a positive phrase or belief, and focusing on relaxing their muscles from the feet all the way up to the head. Benson compared the differences in gene expression patterns between long term practitioners of the Relaxation Response and non-practitioners. Then, he put the non-practitioners through an 8 week training, and found their gene expression had changed to substantially resemble that of the long term practitioners. Among the genes that changed were those involved with inflammation, the rate at which cells regenerate, and the scavenging of free radicals, all involved with aging. “For hundreds of years Western medicine has looked at body and mind as totally separate entities, to the point where saying something ‘is all in your head’ implied that it was imaginary,” said Benson of the study. “Now we’ve found how changing the activity of the mind can alter the way basic genetic instructions are implemented.”
The fact that we have significant conscious control over the biochemical environment in which we bathe our cells, not just through our diet and lifestyles but with our beliefs, thoughts and intentions, gives us an incredible degree of leverage over our own health and happiness. With our own consciousness and actions we can unlock a hugely beneficial internal pharmacopeia of gene-altering, naturally occurring substances, modulating our gene expression to optimize health. The bottom line of epigenetics is that our genes don’t rule our destiny – we do.