Americans' health is not what it should be. Diabetes and obesity are increasing at an alarming rate. The prevalence of heart disease, cancer, stroke and other devastating illnesses remains stubbornly — and unacceptably — high. Our lifestyle habits — the way we eat, exercise, smoke and drink — reflect the truth: We are simply not taking care of ourselves.
You've heard the advice to lose weight, exercise, eat more fruits and vegetables and quit smoking often enough. The ideas are so simple that they may seem trivial in a medical system dominated by high-tech procedures, gee-whiz surgery and genetically engineered drugs.
But will improving your lifestyle actually make you healthier and help prevent diseases?
The short answer, of course, is yes. Two studies published in 2008 demonstrate the enormous power of even a few lifestyle changes:
Genes alone do not determine your health. How you live matters. In fact, new studies suggest that your lifestyle choices may actually improve your genes!
We are born with about 25,000 genes. Our parents pass them on to us. These genes determine many physical and some personality traits. Some genes also increase or decrease the risk of disease.
But genes aren't static. As cells grow and divided, errors (mutations) crop up in our DNA. Fortunately, our cells have ways to detect and correct most genetic errors. But errors can slip through and may start a cell down the path to disease, including cancer.
Many mutations develop on their own. Others are triggered by the environment. That's how smoking and radiation increase the risk of cancer.
While most research has looked at how bad things happen to good genes, a few scientists are starting to ask if good lifestyle choices can actually make good things happen to genes.
For example, researchers asked 22 men who were scheduled for prostate biopsies to eat four servings of either broccoli or peas per week. At the end of the 12 months, the men who ate broccoli showed genetic changes that might reduce the risk of prostate cancer.
In another study, scientists from California followed 30 men who were getting prostate biopsies periodically to check for early prostate cancer. The men made extensive changes to their diets and exercise habits. They also took steps to reduce stress. Their weight, abdominal obesity, blood pressure and blood lipids all improved. In just three months, tissue changed, too: 48 of the genes were ramped up and 453 were turned down.
In a third experiment, researchers studied how exercise affects telomeres. These are special bits of DNA located on the ends of chromosomes. Telomeres protect chromosomes. But as cells divide, their telomeres get shorter and shorter. Getting older, oxidative stress and obesity all make telomeres shorter. In turn, short telomeres have been linked to an increased risk of coronary artery disease, heart failure, diabetes and osteoporosis. In a study of 2,401 twins, regular exercise was linked to longer telomeres. The DNA of the most active subjects scored about 10 years "younger" than those from the least active subjects. Telomeres may help explain how regular exercise seems to slow the aging process.
Our unique genetic profiles play an important role in determining health and longevity. Heredity may deals us a hand of cards, but lifestyle determines how we play those cards. Now we're beginning to see that our lifestyle choices can actually reshuffle the deck, for worse or for better.
Healthy habits pay big dividends. Lifestyle changes can be difficult to achieve. Given the enormous health benefits they have, the change is worth your effort. Your health is too important to be left to your doctors.
Harvey B. Simon, M.D. is an Associate Professor of Medicine at Harvard Medical School and a member of the Health Sciences Technology Faculty at Massachusetts Institute of Technology. He is the founding editor of the Harvard Men's Health Watch newsletter and author of six consumer health books, including The Harvard Medical School Guide to Men's Health (Simon and Schuster, 2002) and The No Sweat Exercise Plan, Lose Weight, Get Healthy and Live Longer (McGraw-Hill, 2006). Dr. Simon practices at the Massachusetts General Hospital; he received the London Prize for Excellence in Teaching from Harvard and MIT.