Dr. Mercola's Comments:

You may think you’ve inherited a “bad heart” or are prone to breast cancer (or any disease for that matter) because a close family member had it. But please toss these thoughts from your mind right now, because you, and you alone, are in control of your health destiny.

This study on identical twins is just the latest to show that your lifestyle, in this case your diet, trumps your genes in terms of how your health pans out. Identical twins really give a unique and valuable opportunity to see just how big an influence your habits have on your health, as of course identical twins start out exactly the same, genetically speaking.

However, as this new study shows, they often don’t end up the same.

Among men who ate a healthful Mediterranean-style diet, heart rate variability was higher, which reflects good autonomic function of the heart. For those who scored in the top quarter for eating a Mediterranean-style diet, the benefits to heart rate variability equated to a 9-14 percent lower risk of heart-related death.

Even among identical twins who have the exact same DNA, dietary choices influence the health of their heart come middle age.

Great News: Your Genes Can Be Influenced!

Epigenetic "malleability" helps to explain why identical twins become distinct as they age, health-wise, and it explains how you can actually tweak your genes for better or worse, too.

In fact, you ARE changing your genetics daily and perhaps even hourly from the foods you eat, the air you breathe, and even by the thoughts you think.

You are the "caretaker" of your genetic roadmap.

As you age, your genome does not change but your epigenome changes dramatically, especially during critical periods of life, such as adolescence. It is influenced by physical and emotional stresses -- how you respond to everything that happens in your environment, from climate change to childhood abuse.

The secret is in the methyl groups that overlie the DNA molecule, which is the realm of the epigenome.

When a gene is turned off epigenetically, the DNA has usually been "methylated." When methyl groups adhere to a segment of DNA, they inhibit the gene from being expressed.

For the most part you do not manifest disease merely by a defective gene, but by the regulation or expression of your gene by epigenetic influences.

This is good news as scientists have discovered it is easier to make epigenetic changes than to fix damaged genes. Your epigenome becomes dysfunctional easier -- but it’s also easier to fix.

That’s good news -- it means you aren’t doomed by bad genes!

How Genetic Expression Works

In his book, The Biology of Belief, Dr. Lipton explains the foundation of epigenetics, and how the true secret to life does not lie within your DNA, but rather within the mechanisms of the cell membrane.

In this way -- which is contrary to conventional medical science -- it is actually the cell’s membrane -- operating in response to environmental signals picked up by the membrane’s receptors -- that control the “reading” or “expression” of the genes inside.

For instance, researchers from the Linus Pauling Institute at Oregon State University recently explained at Experimental Biology 2010 how altered "histone modifications” can impact the expression of many degenerative diseases, ranging from cancer and heart disease to biopolar disorder and even aging itself.

As Dr. Jean-Pierre Issa at the M.D. Anderson Cancer Center explains, histones can essentially “hug” DNA so tightly that it becomes “hidden from view for the cell.” So while you have tumor suppressor genes in your body right now in ALL of your cells, you also have proteins called histones.

If a tumor suppressor gene is hidden, it cannot be utilized, and in this way too much histone deacetylases, or HDACs, will “turn off” these cancer suppressors.

Now here’s where epigenetics comes in … there are many HDAC inhibitors out there that will essentially block the HDAC, allowing your tumor suppressor genes to activate and fight cancer. These HDAC inhibitors exist, at least in part, in common foods like broccoli and other cruciferous vegetables, garlic and onions.

By adding these foods to your diet, you are supporting your body’s ability to fight tumors.

And this is only one example of many.

How to “Remind” Your Cells to be Healthy

Ideally you’re already leading a healthy lifestyle, eating right, exercising and managing stress, but if you’re not it’s never too late to start.

Each tissue only uses about 10 percent to 20 percent of its gene complement, and you want to be sure that those genes are the most advantageous ones possible for your health.

You can begin to “remind” your cells to express in a healthful way, long before you manifest a disease, by encouraging your genes to express positive, disease-fighting behaviors by leading a healthy lifestyle.

To get started, I highly recommend you take this free assessment to determine your Nutritional Type. Your body responds uniquely to food -- your fuel -- based on your genetics, biochemical makeup, family history, and your own interaction with your environment. This is why it’s so important to find out which foods are right for your body … and that’s exactly what Nutritional Typing does for you.

Even if you’re already eating healthy, organic foods, it might not be enough for you to reach your highest level of wellness and optimal genetic expression. You could actually be eating an all-organic diet -- and still be missing the mark of peak wellness.

So please take a few minutes to discover your Nutritional Type and learn what foods will best support your epigenetic health.

When it comes to epigenetic expression, keep in mind that diet is only part of the equation. You can also turn your genes on and off with your emotions.

Most people have emotional traumas that can adversely affect their health, but using techniques like energy psychology you can go in and correct the trauma and actually regulate the expression of your genes. My favorite technique for this is Meridian Tapping Technique/Emotional Freedom Technique (MTT/EFT).

And remember, it’s never too late to start “training” your genes to express in a positive way. Whether you have hereditary health problems you’re trying to circumvent or not, everyone’s genes can benefit from good nutrition and attention to stress management.