Top doctor says behavior can reshape genes, urging rethink of 'fixed' destiny

Dr. Bob Lahita, a clinician and researcher who has led hospitals and emergency services in New Jersey and served on the ground at the World Trade Center on Sept. 11, argues in a new book that human behavior and environment can alter gene expression and influence health across generations.

In "Destiny, the New Genetics, and Your Future," Lahita contends that what he calls "epigenetics" — chemical and structural changes that act like switches on DNA — means that genes are not a fixed script. He writes that factors such as a pregnant mother's diet, smoking, pollution, stress, nutrition and exposure to toxins can affect the health of her children and grandchildren, and that altered behavior can change the onset and course of disease. Lahita also suggests artificial intelligence will increasingly detect epigenetic markers and could one day be used to add or subtract such marks from future genomes.

Lahita links epigenetic mechanisms to a range of conditions, including autoimmune disease, depression and cancers, and in the book raises the possibility that environmentally driven epigenetic changes could be implicated in neurodevelopmental and identity-related conditions. He frames the argument as a clinical and public-health message: "Our destiny is not fixed," he writes, and modifying exposures and behavior could reduce disease risk for current and future generations.

The broad idea that environment and behavior can influence gene expression is widely accepted in modern biology. Epigenetic processes — including DNA methylation, histone modification and noncoding RNA activity — alter how genes are turned on or off without changing the underlying DNA sequence. Researchers have documented examples in humans and animals where prenatal and early-life exposures correspond with epigenetic marks and later health outcomes. Studies of populations exposed to famine, such as the Dutch Hunger Winter, and research linking maternal smoking to altered methylation patterns in offspring are frequently cited as evidence that early exposures can leave molecular traces.

However, scientists caution that the extent to which those changes persist across multiple human generations and directly cause disease remains an active area of research. Transgenerational epigenetic inheritance — the passing of epigenetic marks beyond the first generation without continued exposure — is well documented in some plants and animal models but is contested and more difficult to demonstrate in humans because of confounding factors and the complexities of separating genetic, social and environmental influences.

Lahita's suggestion that artificial intelligence could detect epigenetic markers reflects a growing trend in biomedical research. Machine-learning tools are increasingly used to analyze large epigenomic data sets, identify patterns associated with disease and predict regulatory regions of the genome. Those approaches have helped researchers better understand which epigenetic changes correlate with clinical conditions, but detection does not equate to a simple path to modification.

Efforts to alter the epigenome therapeutically are under way in laboratory and clinical settings, focusing on drugs that affect epigenetic enzymes and experimental molecular tools that can target epigenetic regulators. Editing the germline epigenome to produce predictable changes in future generations raises substantial technical and ethical hurdles. Modifying DNA sequence with tools such as CRISPR is already tightly regulated and controversial; altering epigenetic states in a heritable way would add layers of uncertainty about off-target effects, reversibility and long-term consequences.

Lahita brings a clinical perspective rooted in decades of patient care and research to the public discussion about genetics and behavior. His book frames epigenetics as a bridge between lifestyle, environment and medical risk, arguing for preventive attention to exposures and behavior. At the same time, researchers and bioethicists emphasize the need for robust evidence, careful translation from laboratory findings to clinical advice, and public debate about the implications of epigenetic interventions.

As laboratories expand the use of artificial intelligence and high-throughput assays to map epigenetic landscapes, scientists say clearer answers will come about which epigenetic marks are causative, which are markers of exposure, and how durable those marks are across generations. For clinicians and policymakers, the challenge will be balancing emerging scientific insights with the ethical and practical constraints of intervening on the molecular mechanisms that link environment and health.