By Marilynn Preston, Energy Express

James Watson went to my high school – hail to the Tars of South Shore high – so perhaps that helps explain my longtime interest in the science of genetics and DNA and the twisted role it plays or doesn’t play in our own health and well-being.

And just now coming, something new and startling in the world of 21st-century genetics: the evolving science of epigenetics. Time magazine did a seminal cover story on it back in 2010, declaring it as the next step, the new frontier, the cutting edge of science.

Epigenetics is the science of changing the way your genes express themselves as, for instance, disease or – here’s the exciting part – reversal of disease.

“Basically, epigenetics demonstrates how environment and behavioral choices can influence our genetic code,” writes Dr. Theri Griego Raby in her latest Raby Institute for Integrative Medicine newsletter, the one with a recipe for Paleo pumpkin muffins with coconut flour.

Dr. Raby is a well-regarded pioneer and practitioner of mindbody medicine in Chicago. I’ve known her for years, and when I saw the headline of her latest email commentary – “Epigenetics … The True Preventative Medicine”– I clicked right through.

Contrary to what many of us learned in school, “genes are not fixed predetermined blueprints passed from generation to generation,” Dr. Raby writes, based on the latest epigenetic research. “Instead, our genome contains at least 4 million ‘switches’ that can be turned on and off by life experiences and environmental influences.”

Life experiences! Environmental influences! Scientists who study heredity now have evidence that lifestyle alone – your choice to smoke, the quality of your food, how you deal with stress – can alter the epigenetic markers that sit above your DNA and pretty much have all the say, not just for your lifetime but affecting your future generations. Let me put it another way: Your bad behavior today can predispose your kids and grandkids to disease and early death, even before they are conceived!

It’s fascinating stuff.

So let’s delve a bit deeper. “Epi” is a prefix that means “above.” Epigenetics looks above the doublehelix 25,000-chromosome genetic code –thank you, human genome researchers – and sees another level of influence: the cellular material that sits on top of the genome and outside it. On top and outside. Get a picture of it; color it cosmic red, and let’s continue.

That “on top” and “outside” cellular material is called the epigenome. Scientists aren’t prepared to say how many epigenome marks there are, but the number is well into the millions. Your genes are your genes, but these epigenetic marks tell your genes to switch on or switch off, to express themselves loudly or to go mute.

When your obesity gene expresses itself loudly because, let’s say, you’ve spent so much time in bed with bags of Dorito chips, you’re a candidate for “The Biggest Loser.” When you manage to mute your colon cancer gene by eating less red meat and exercising more, you’re managing your epigenome in a way that Dr. Raby would applaud.

As the biologists like to say, the genome is the hardware, and the epigenome is the software.

And the intriguing part is that to a large extent – way more than we thought possible before – you are the epigenome software programmer in charge. It’s not all fixed and predetermined. Surprise!

“How we sleep, the types and levels of stress we experience, quality of diet, the type of foods we eat, toxin exposure, alcohol, and lack of exercise can all alter our genetic makeup during gestation, early development, and throughout adulthood,” writes Dr. Raby. “For example, consuming foods rich in gene-altering methyl groups like non(genetically modified) soybeans, red grapes, or green tea may protect against disease by deactivating detrimental gene ‘switches.’”

Enough for today. If you want to read further, Google that Time piece. It’s titled “Why Your DNA Isn’t Your Destiny.” It is liberating, brings up difficult ethical questions about epigenetic drugs and leaves you with a whole new understanding of the saying, “You are what you eat.”

What habits will you pass on? “Epigenetics …is perhaps the most important discovery in the science of heredity since the gene.” – David Shenk, author of “The Genius in All of Us: Why Everything You’ve Been Told About Genetics, Talent and IQ Is Wrong.”

Marilynn Preston — fitness expert, well-being coach, and speaker on healthy lifestyle issues – is the creator of Energy Express, the longest-running syndicated fitness column in the country. She has a website, marilynnpreston.com and welcomes reader questions, which can be sent to MyEnergyExpress@aol.com.