A little girl whom I wrote up in my book The Autism Revolution was diagnosed with the idic 15 mutation. Because this mutation is associated with autism, her geneticist told her family that her current set of limitations were what they could expect she would live with her whole lifetime. These limitations included inability to talk, lack of social relatedness and chronic diarrhea. The family took her with reluctance and skepticism to another doctor, a primary care pediatrician with an integrative-wellness orientation, who looked for other potential contributors and found vulnerability to celiac disease. After four months off gluten the child started to babble and the diarrhea went away. The child's mother was impressed and opened her mind to investigating further ways of amplifying her child's improvements. A number of later food and gastrointestinal-based orientations, as well as a transient course of steroids to treat a medical problem, opened the child's verbal capacities further to the point where rather than simply repeating what others were saying she engaged in rich, ongoing, spontaneous reflections on what was going on around her.
Why didn't it occur to the geneticists and the genetics counselors that there might be more things shaping this child's performance than just her primary genetic diagnosis? Why didn't they look for other avenues to maximize this child's creative, expressive potential?
This story is for me a parable of how a belief in genetic determinism puts a filter on a clinician's perspectives - or if the patient or family also believes this determinism, on their aspirations as well.
Many people talk about a two-hit model: genetics creates risk and environment pulls the trigger. My colleague Robert Hendren at UCSF talks about a third hit: the belief that it is hopeless, which blinds people to things they can do.
So much of what can be done is not that complicated - it involves "lifestyle changes." Through modifying diet, exercise, sleep and exposure to toxins, many of the most common and severe chronic diseases can be prevented or at least greatly reduced in severity. This includes obesity, diabetes, heart disease, cancer and neurodegenerative diseases like Alzheimers and Parkinsons. It also includes childhood conditions like asthma, ADHD, allergies and maybe even autism and autoimmune diseases. A guest editorial last September in the New England Journal of Medicine noted that much of the $750 billion we spend on diabetes alone could be prevented by just such lifestyle changes.1
And yet we are not doing that. Why not? The NEJM editorial focused on bureaucratic obstacles to reimbursement of the care and coaching that would be required. Other obstacles include the barrage of advertising for the very products that make us sick, the cuts in income that the health care industry and sectors of agribusiness would take if people were healthier, and the fact that research on lifestyle changes is less "sexy" than genetics and molecular biology.
Systems biology is eroding the foundations of genetic determinism because it is showing the complicated webs of mutual influence across many scales of biology. It's no longer a one-way bottom-up trip from genes to everything else. But old habits of thought die hard. Even seemingly advanced formulations of systems-based personalized medicine may not go far enough. The "4P" approach to medicine - personalized, predictive, preventive, participatory - still rests largely on genetic testing, and falls very short in relation to looking at physiology - at metabolism, immune function, biochemistry, nutrition, and noxious toxicant, radiation and infectious exposures.
Other approaches, such as functional medicine, are not so short-sighted. They look to genetics to identify vulnerability, and look to environment for ways this vulnerability can be shored up. The partnership of the Institute for Functional Medicine and the Personalized Lifestyle Medicine Institute is aimed at educating both health care professionals and the general public to expand their frameworks and to be proactive.
How might a proactive lifestyle approach to genetics work? By aiming to optimize patterns of gene expression, metabolism and physiology. Healthy lifestyle improves gene expression. Biochemistry can also be influenced by lifestyle choices: An enzyme that is slowed down due to a genetic variant can often be supported by nutritional cofactors of the enzyme to speed up the chemical reaction. The impact of toxic exposures can be reduced by maintaining biochemical and metabolic resiliency. An anti-inflammatory diet reduces the cellular breakdown that leads to chronic disease and cancer.
The buildup of science to support such approaches is making it ever harder to dismiss them as quackery. The failure of so many pharmaceuticals designed to modify molecular targets is further support for a back-to-basics preventive approach to healthcare.
Lifestyle changes are more than personal choices. The food policies in the United States would not presently support the population if everyone were to change to a healthier diet overnight. We need to change at the larger as well as at the local scale.
Systems biology points toward a "middle-out" approach where physiology gets input from genes and environment but basically runs the show. Take calcium channels for example. They play many critical roles in maintaining all manner of cellular functions. They can be altered by genetics or injured by environment. We can't get rid of mutations we may already have that hamper the function of our calcium channels. But we can avoid the pesticides, the electromagnetic fields and the many other toxic exposures that can make the situation worse. And we can minimize the impact of mutations by keeping our cells and membranes healthy through a diet rich in antioxidants, healthy fats, vitamins and minerals.
Genes provide information but so does the environment. Genetic education will most effectively protect personal and public health when it teaches us about the interplay and how to make life all it can be through healthy and ecologically sound personal and public choices.
Martha Herbert, MD, PhD, is a pediatric neurologist and neuroscientist at the Massachusetts General Hospital, Harvard Medical School, where she directs the multidisciplinary TRANSCEND Research Program. She is a former CRG Board member and author of The Autism Revolution: Whole Body Strategies for Making Life All It Can Be.
1. "What's Preventing Us from Preventing Type 2 Diabetes?" Judith E. Fradkin, M.D., B. Tibor Roberts, Ph.D., and Griffin P. Rodgers, M.D., M.B.A. N Engl J Med 2012; 367:1177-1179. September 27, 2012.