Feed Your Genes: How to Prevent Hereditary Diseases
By Jack Challem, Experience Life
When people say things like “Heart disease runs in my family,” and “My parents had cancer, so I’m afraid I will, too,” it confirms our suspicions that DNA is destiny. The truth, however, is that it doesn’t have to be: The DNA we inherited from our parents does not necessarily determine our fate. In fact, we can modify the behavior of our DNA and genes in striking ways.
Certainly, we are all born with a set of genetic strengths and vulnerabilities, but we can bring out the best or worst in our genetic predispositions based on the nutrition, exercise and lifestyle choices we make. The payoff for playing our hand of genetic cards well is better health and, potentially, a longer life. The cost of playing that hand badly, on the other hand, can be high: We may suffer the early symptoms of health problems we would otherwise have staved off until very old age; we may contract diseases we could have avoided altogether.
We all inherit variations in our genes that make us uniquely who we are. Unfortunately, some of these variations hinder our genes’ ability to do their intended jobs. Such hindrances ultimately increase our susceptibility to disease. Furthermore, as we age, our DNA and genes get damaged (mutated), which also leads to a higher risk of disease. We can’t stop the accumulation of genetic damage or the aging process, but we can slow it down and increase our resistance to illness.
Little by little, scientists have gained a clearer idea of how nutrition influences our genes. This has given rise to a new scientific field called nutrigenomics. Over the past 10 years, nutrigenomic experts have made quantum leaps in understanding how nutrients — what we eat or don’t eat — may affect our genes. The research has shown that whether we’ve inherited good genes or bad, nutrition can improve their performance. Poor nutrition and lifestyle habits, meanwhile, can predispose our genes to be on their very worst behavior.
Next: When heart disease, osteoporosis and breast cancer run in your family
Playing to Our Weaknesses
Our individual genetic differences — weaknesses, if you will — complicate the situation. A lack of certain essential nutrients amplifies our inherited weaknesses, increasing our risk of disease. Here are three common examples of how that can happen:
Heart Disease. Roughly one-fourth of Americans inherit variations in the gene that produces a crucial enzyme involved in making DNA and regulating gene activity. This gene depends primarily on folic acid and, to a lesser extent, on vitamins B2, B6 and B12.
When this genetic weakness (which programs for an inefficient form of the critical enzyme) is combined with low intake of folic acid (common among people who don’t consume many leafy green vegetables or take appropriate supplements), the enzyme can’t do its job. The result? A greater risk of heart disease, as well as stroke, cancer and birth defects.
The problem can be easily offset, however, by increasing vegetable intake, taking folic acid supplements (400 to 800 mcg daily) or, even better, taking a high-potency multivitamin or B-complex vitamin supplement.
Osteoporosis. Researchers have identified 22 variations in the gene responsible for how our bodies use vitamin D, and one-third of Americans have a particular variation of this gene. These genetic variations interfere with the body’s use of vitamin D, low levels of which can increase the risk of osteoporosis, cancer and susceptibility to infection. The situation is compounded by the fact that there are few available food sources of vitamin D and only limited exposure to sunlight in northern latitudes during the fall, winter and spring.
Again, this genetic variation can be offset by increasing vitamin intake. Unfortunately, it is challenging for many people to get adequate vitamin D through diet alone. But spending just 15 minutes daily in the summer sun (wearing short sleeves and walking shorts, for example) prompts the body’s production of vitamin D, creating an estimated 10,000 IU. (To minimize the risk of sun damage, protect overexposed and sensitive areas, avoid the sun between 10 a.m. and 2 p.m., and don a hat and sunscreen after you’ve gotten your allotted sun time.) Some experts also suggest taking vitamin D supplements in addition, or as an alternative, to spending time in the sun. Walter Willett, MD, professor of epidemiology and nutrition at the Harvard School of Public Health, recommends that everyone take 1,000 IU daily of supplemental vitamin D, and increase it to 2,000 IU if you have a dark complexion or spend most of your time indoors.
Breast Cancer. Women who inherit mutations in the so-called breast- cancer genes (BRCA1 and BRCA2) have a substantially higher risk of developing breast or ovarian cancer. Yet these are not true breast-cancer genes but DNA-repair genes that provide the instructions for making two key proteins involved in DNA repair. Mutations in the genetic instructions for these genes prevent them from doing their intended job.
But proper nutrition can improve how these genes function. A 2005 European study published in Cancer Epidemiology, Biomarkers and Prevention found that women with BRCA1 mutations — who had higher rates of genetic damage — reduced their DNA damage to normal levels in just three months by taking a very high dose of selenium supplements. (Check with your doctor before consuming high amounts of selenium: It can be toxic to some in large doses. But most can benefit from taking 200 to 400 mcg of selenium daily — or eating an ounce of Brazil nuts, the richest food source of the mineral.)
When the repair genes for BRCA1 and BRCA2 fail to do their job, the body does have a backup system. The repair work shifts to another enzyme, and once again, good nutrition plays a role in its proper function. This repair enzyme, known as poly(ADP-ribose) polymerase is built around vitamin B3.
Next: Gene-Friendly Foods
A growing number of researchers, such as Colorado State University’s Loren Cordain, PhD, believe that many of today’s common health problems result from a conflict between our ancient genes and modern foods. Fast foods and convenience foods — loaded with refined sugars, simple carbohydrates and trans fats — don’t supply the nutritional building blocks for our genes.
Worse, because they’re “genetically unfamiliar foods,” they turn on many genes best left alone. For example, sugars turn on the genes that make insulin, high levels of which increase the risk of obesity, diabetes, heart disease and cancer. Reversing such risks involves three key steps:
The first step in eating for your genes is to limit your intake of refined sugars found in soft drinks, desserts, and most conventional packaged or bottled foods. At the same time, reduce your intake of refined carbohydrates found in most breads, cereals, muffins, bagels, pizzas and pastas. The body responds to these refined carbohydrates much the way it does to sugars. Most people are better off opting for more complex, nongrain carbohydrates, such as those in fruits, nuts and sweet veggies, like yams.
The second step is to adopt a modern version of what Cordain calls the Paleo diet. Biologically, we’re designed for lean proteins, fish and lots of vegetables, along with culinary herbs, though there is a certain degree of individual variation. (For example, some people do better than others when it comes to consuming legumes.) Protein provides amino acids, which our genes recombine to make proteins and enzymes needed in normal biochemistry. Fish (specifically, cold-water) provide the healthiest family of dietary fats — omega-3s — which turn off inflammation-promoting genes. Vegetables and culinary herbs are rich sources of antioxidants, which help prevent damage to DNA.
The third step consists of taking nutritional supplements. While ideal supplementation strategies vary by individual, virtually everyone can benefit from taking a daily high-potency multivitamin and multimineral supplement. Such supplements can help compensate for some of the genetic weaknesses all of us inherit, as well as offset absorption problems related to aging or medication use. Look for a high-quality multivitamin supplement that contains at least 25 mg of vitamins B1, B2 and B3.
Consider adding extra amounts of folic acid (about 400 to 800 mcg daily) and vitamin B12 (about 100 mcg daily), both of which are involved in DNA synthesis and repair. If you live north of 35 degrees latitude (Atlanta, Phoenix or Los Angeles, for example), and don’t spend much time outdoors, take 1,000 IU of vitamin D daily throughout the year. If you’re active outdoors most summer days, you can take a vitamin D supplement only during the winter and spring.
The realization that our nutritional status can and does affect our genetic expression — and thus our disease risks and our quality of life — gives us more reason than ever to pay close attention to the way we eat. It is no longer a matter of merely watching our weight, or striving for a particular ratio of carbs, proteins and fats. It’s a matter of supplying the raw materials required for building and maintaining our DNA — the structure and instructions on which our very lives depend.
Nutrition expert Jack Challem lives in Tucson, Ariz., and is the author of several books, including Feed Your Genes Right: Eat to Turn Off Disease-Causing Genes and Slow Down Aging (John Wiley & Sons, 2005).
Why Exercise Is Good for Your Genes
We all know that exercise helps build muscle and lowers blood fats. But exercise also turns on a lot of genes involved in burning fat and carbs — which sets in motion a cascade of welcome metabolic activities.
Everything we do — or don’t do — turns genes on and off. For example, exercise turns on the FAT/CD36 gene, which increases the burning of fats. It also kicks into gear the ADRB2 gene, involved in burning fat your body has stored. Exercise also boosts the activity of the PDH gene, which helps burn carbs.
Test at Your Own Risk
If you’re curious and have some extra money to spend, you can get a partial snapshot of how some of your genes might increase your requirements for specific nutrients. But many experts advise against such direct-to-consumer genetic tests, citing the risk of incomplete, confusing and misinterpreted results, along with the potential for questionable supplement and diet swindles. Federal health officials advise consumers to consult their doctors or trained genetics counselors before undergoing any genetic testing.
For anywhere from $250 to $1,200, there are a few companies that will mail you a test kit comprising two plastic swabs for gently scraping a few cells from the inside of your cheeks. Mail the swabs back, and about a month later you’ll get a rundown of your known genetic strengths and weaknesses, along with related dietary and health advice.
While it can be useful to know if your genetic traits might predispose you to an increased risk for heart disease, diabetes, osteoporosis and a few other conditions (particularly if you’re motivated to make lifestyle changes to reduce those risks), it’s important to keep the value of such results in perspective.
First, these tests offer only a partial picture: They cover only about two-dozen genes out of approximately 20,000. Second, the most important dietary recommendations are also the most universal: Virtually everyone can benefit from reducing sugars, refined carbs and unhealthy fats, while increasing their intake of vegetables and other whole foods, and getting more exercise. And even those without genetic risks tempt fate by eating junk foods, gaining weight, smoking and not exercising.
So unless you’ve already made these changes and are looking to take your already-great regimen to the next level, you’re better off spending your money on more veggies.