Newsweek reported that the new model for “nutritional genomics” suggests that just as drug effectiveness varies by individual and interacts with genes, so too do the effectiveness of nutritional strategies.
According to the report, food interactions with genes are even more complex than those of drugs, because foods include combinations of substances while drugs are usually single agents, taken one a time. The article mentioned a number of potentially remedial substances regulated as “dietary supplements” in the food category, including green tea.
Also included were spices such as turmeric (contains “curcumin, the yellow pigment in turmeric, an ingredient in curry spice. Curcumin reduces the action of a number of genes that promote inflammation, which is linked to heart disease, colon cancer and Alzheimer’s.” Not coincidentally, “India has the lowest incidence of Alzheimer’s in the world”.)
The article noted: “New research suggests a continual interaction, in which certain foods enhance the action of protective (or harmful) genes, while others tend to suppress them.”
The Newsweek article also suggested some of the ethical complexities this new model of nutrition and genetics is creating; for example, the question of whether to conduct genetic testing and then tell the patient that a certain gene makes certain foods (or lifestyle choices such as smoking) riskier. For example, the gene variant (or allele) for a proten known as Apo E4, apparently increases the risk of heart disease. At the same time, the allele “also doubles the risk of developing Alzheimer’s. Since there’s not much that can be done to prevent it, many doctors are reluctant to give patients this news, and many patients don’t want to know it themselves.” The problem is as much one of informed consent as of genetic screening.
And, we may wonder how the ethical dilemma translates across to the CAM (complementary and alternative medicine) arena, since it stands to reason that the efficacy of CAM therapies (such as acupuncture) and/or risk of some therapies would similarly be interactive with genetics.
Another implication of the article is that despite biomedicine’s effort to conceptualize medicine as lending itself (generally speaking) to a great deal of standardization, the claim of medical traditions such as Ayurveda and traditional oriental medicine (and even homeopathy) that cures are individualized seems to be gaining momentum with the modern focus on the impact of genes. In that sense, nutritional genomics may help straddle the standardization/individualization divide that has characterized the philosophical chasm between the biomedical and CAM camps.
Recently there has been a regulatory movement toward greater standardization of dietary supplements, for example, since consistency and quality of product through good manufacturing practices can help increase consumer safety. Labeling rules for dietary supplements are designed to ensure that consumers get clear information, even if supplements are not tested for safety and efficacy like drugs. While good manufacturing practices and clear labeling serve regulatory purposes of consumer protection, disclosure may have to be even more precise (as with drugs) if even standardized supplements affect patients differently based on their genetic makeup.
As the science of nutritional genomics improves and grow more precise, the synthesis of East and West may grow even more interesting. Some claims will fall away while others may find a richer rationale in the interplay between standardization and individualized prescription. As claims and expectations shift, so too will legal and ethical dilemmas associated with the balance between offering patients choices, and using technology for beneficent purposes while following the maxim to do no harm.
“Jose Ordovas has glimpsed the future of medicine, and there’s good news for anyone who has just paid $4 for a pint of pomegranate juice. Ordovas, director of the Nutrition and Genomics Laboratory at Tufts University, believes the era of sweeping dietary recommendations for the whole population–also sometimes known as fads–may be coming to an end. Red wine may be better for your arteries than ice cream, but you can’t create a diet that’s optimal for everyone, Ordovas says–or, to put it another way, even Frenchmen get heart attacks sometimes. Within a decade, though, doctors will be able to take genetic profiles of their patients, identify specific diseases for which they are at risk and create customized nutrition plans accordingly. Some people will be advised to eat broccoli, while others will be told to eat … even more broccoli.
Maybe you have to be a nutritionist to appreciate the beauty of that scheme. The promise of nutritional genomics–a field that barely existed five years ago–is not to overturn a century’s worth of dietary advice but to understand on the most basic level how health is determined by the interplay of nutrients and genes. The old paradigm was of a one-way process, in which “bad” foods gave you heart disease or cancer unless “good” genes intervened to protect you. New research suggests a continual interaction, in which certain foods enhance the action of protective (or harmful) genes, while others tend to suppress them….
The model for nutritional genomics is the work that has already been done on drug-gene interactions. Researchers are starting to unravel the mystery of why a drug may be a lifesaver for one person while causing a fatal reaction in another, and in a third has no effect at all. Why do a third of patients fail to respond to the antidepressants known as SSRIs, including Prozac, Paxil and Zoloft? The drugs are meant to increase levels of the neurotransmitter serotonin by blocking its “reuptake,” or clearance from the brain. Obviously, they can work only if serotonin is being produced in the first place. Last month researchers at Duke University discovered that some people have a variant gene which reduces the production of serotonin by 80 percent–making them both susceptible to major depression and resistant to treatment with SSRIs…..
But food interactions are usually far more complicated. “Normally, you take one drug at a time and for a limited amount of time,” says Dr. Muin Khoury, director of the Office of Genomics and Disease Prevention at the Centers for Disease Control and Prevention. “If you have a certain genetic variant, you stay away from a particular drug or take a different dose.” But nutrients come in bulk, you consume them for a lifetime and you can get them without a prescription, even the Trucker’s Pancake Special….. It will be years before researchers have a good diagram of the circuit. That hasn’t prevented the growth of a fledgling industry in personalized nutritional supplements to treat everything from osteoporosis to obsessive-compulsive disorder. At least one company will even profile your genes to take the guesswork out of choosing makeup.
But pieces of the diagram are beginning to emerge. Green tea contains potent antioxidants known to help prevent heart disease and certain cancers, but only some women seem to show a reduction in breast cancer from drinking it…..
You can see where we’re headed. We’re starting to take the guesswork out of the things we eat…..
More generally, there is the danger that insurance companies will discriminate against people with risk factors in their genome. Ruth DeBusk, author of “Genetics: The Nutrition Connection”….But Jim Kaput, who founded a genomics-research company, wonders about people who get the correct nutritional advice for their genotype and then refuse to follow it. “Should the insurance company be obliged to pay for their health care, too?”
….More likely, nutritional genomics will create opportunities for drug companies to isolate, concentrate, synthesize and improve on the compounds in nature, which they’ve been doing for a hundred years. What Cole and his colleagues seek is to shed light on the mystery of how the human body has evolved the miraculous ability to overcome, once in a while, the threat posed by the consequences of its own appetites.
From: “Diet and Genes: It isn’t just what you eat that can kill you, and it isn’t just your DNA that can save you–it’s how they interact,” Newsweek Jan. 17 (2005).