More and more research is demonstrating how our genes determine the types of diseases we develop and our degree of susceptibility to a given disease. This issue should not be taken lightly, particularly when making specific suggestions to patients. For example, most have probably heard the “urban legend” that grilled meat causes colorectal cancer. Is this true? The answer is yes and no, and it depends on your genes.
Genetic Disposition for Colorectal Cancer
Heterocyclic amines (HCA) are thought to be the carcinogens that are formed in meat when it is cooked at high temperatures for long durations. HCA’s are not carcinogenic on their own; after we eat them, our liver has enzymes that must metabolically activate the HCA’s before they can bind to DNA and do their dirty work. The enzymes are called cytochrome P4501A2 (CYP1A2) or N-acetyltransferase 2 (NAT2).
As it turns out, we can either have a slow, intermediate, or rapid phenotype for CYP1A2 and NAT2; in other words, we are genetically endowed with slow, intermediate or rapidly acting enzymes. Our risk for developing colorectal cancer is thought to be increased, if we have a rapid phenotype for CYP1A2 and NAT2. This association may be particularly strong in smokers, because smoking is known to induce the activity of CYP1A2.1
Reducing Formation of HCA’s
To determine the details of these relationships, researchers performed some lab tests to assess phenotype for CYP1A2 and NAT2. The results demonstrated that there was a 9-fold increase in colorectal cancer risk for smokers who preferred their red meat well done, and if they had a rapid metabolic phenotype for both NAT2 and CYP1A2. Well-done meat was not associated with risk among nonsmokers, or even smokers with a slow or intermediate phenotype for on these enzymes.1
This study suggests that exposure to carcinogens through the consumption of well-done red meat increases the risk of colorectal cancer only in genetically susceptible individuals, as determined by polymorphically expressed genes, and only in smokers. We are told that the best way to reduce HCA’s in cooked meat include marinating, precooking by microwaving, and frequently turning the meat over during cooking.1
To Be Lucky or Not
From a clinical perspective, we need to appreciate the fact that we can be pre-disposed to developing colorectal cancer, for example; however; we have to push our genes to express the disease by adopting certain lifestyle habits. This is likely to be the case for most diseases, which suggests that one person can pursue a lifestyle of near health perfection, yet, because they slacked at a mere 2%, they develop cancer or heart disease. Meanwhile, the next-door neighbors literally pursue disease with every lifestyle choice, yet they remain free of disease. Our health habits must be commingled with our genes to determine the expression of disease. Some of us are lucky, others are not, and substantial differences can exist among family members. So you really never know who is lucky or not, until the expression of disease occurs.
What can we do?
So, how do you know what your genes have in store for you? Basically, we all have to wait and see, which is not a great answer, because it implies that we are at the mercy of our genes. Although we are, indeed, partially at the mercy of our genes, we can pursue a lifestyle that does not readily induce them to express their disease potential. In the next issue, I will discuss some mechanisms in more detail; however, for now, here are some practical ideas.
Prevent the Expression of Free Radicals
It is now known that, to a large degree, cancer, heart disease, Alzheimer’s disease, and other chronic degenerative and neurodegenerative diseases are manifestations of chronic inflammation. In particular, our dietary choices actually nudge or induce our cells to express their inflammatory potential.
Free radicals and pro-inflammatory cytokines act to induce the expression of cell-driven inflammation. So, we need to create an environment that does not allow for the proliferation of free radicals and cytokines, and this is easy to do. We need to eat less grain products (whole or refined), avoid refined sugar, and eat a lot more fruits and vegetables. Grass-fed animal products and wild game are both anti-inflammatory choices for protein. If we can adopt these eating habits and add four basic supplements (multivitamin, magnesium, EPA/DHA, and CoQ10), we will go a long way toward reducing pro-inflammatory responses that lead to the expression of disease.
Dr. Seaman is the Clinical Chiropractic Consultant for Anabolic Laboratories, one of the first supplement manufacturers to service the chiropractic profession. He is on the faculty of Palmer College of Chiropractic Florida and on the postgraduate faculties of several other chiropractic colleges, providing nutrition seminars that focus on the needs of the chiropractic patient. Dr. Seaman believes that chiropractors should be thinking like chiropractors, while providing nutritional recommendations. Doctors and patients who follow his programs report improved feelings of well-being, weight loss, dramatic increases in energy, and significant pain reduction. Dr. Seaman can be reached by e-mail at