When Environment Speaks Louder Than Genes and Rethinking the North-South IBD Gradient
- 1 day ago
- 5 min read
Dr. Haifa Hamdi is a research scientist, holistic nutritionist, and author whose work focuses on cancer, autoimmune, and digestive health. She is passionate about helping families embrace healthier lifestyles and inspiring a world where health is joyful and empowering.
Why does inflammatory bowel disease vary by region, and what does that reveal about our environment? This article uncovers how lifestyle, diet, and exposure shape disease risk, offering a powerful new perspective on prevention and long-term health.
The question that should not exist
During my postdoctoral work on inflammatory bowel disease in Lille, as part of a research project supported by the Association François Aupetit, I was invited to step in for my supervisor during a public presentation at the Palais des Congrès de Paris in 2011.
It was a rainy Sunday in Paris. Outside, the sky was dark. Inside, the conference room was brightly lit. I could clearly see the faces of the patients in the audience: attentive, curious, and hopeful. They had come not only to listen, but to understand, to engage with the research, and to interact with us as scientists.
After the presentation, they came forward. One moment has stayed with me ever since. A mother approached me and spoke about her daughter, who was living with both Crohn’s disease and primary sclerosing cholangitis. Her voice was calm, but her question carried urgency. “Do you think moving to North Africa could help her?”
She had not come to ask about medication. She had come with information. She had read about the North-South gradient in inflammatory bowel disease, the consistently lower incidence reported in regions such as North Africa and parts of Southern Europe compared to Northern countries.
She was trying to turn a scientific observation into a life decision. That question should not exist in isolation. And yet, for many families, it does.
When experience becomes hypothesis
That moment reflects a broader reality: patients are often the first to connect patterns between environment and disease. Later that day, an elderly man approached me. A veteran, he spoke with a quiet clarity shaped by experience.
“I’ve lived with ulcerative colitis for years,” he said. “I believe it started after what we were exposed to during the war.”
He explained that others in his unit had developed similar symptoms over time. Then he asked, “Do you think the body can recover from something like that?” There was no frustration in his tone, only reflection. “When I have a flare,” he added, “I slow down. I pray. I try to stay steady.”
His words were not framed in clinical terms, yet they echoed an area of active scientific inquiry: environmental exposures, chemical, physical, or biological, can leave lasting imprints on the body.
Patients may not always use scientific language, but they often recognize patterns long before those patterns are formally explained.
The body under constant pressure
Not long after, another couple came forward. The woman spoke first, gently placing her hand on her husband’s arm. “For him, everything becomes stress,” she said. “Even small things. If he misplaces his keys, it becomes overwhelming.”
Her husband nodded. “It feels like my system never switches off,” he said. “Even when nothing is happening, it feels like something is.”
In that moment, the strain was unmistakable, visible in his posture, his breath, the way he held himself. This was not stress as an abstract concept, but as a constant physiological state.
It was also a reminder of something rarely addressed: the silent burden of digestive disease. These conditions are often difficult to discuss openly. Conversations around bowel function, bleeding, and discomfort remain deeply private, frequently associated with embarrassment or stigma. This silence can intensify the weight patients already carry, isolating them further in an experience that is both physical and deeply personal.
What the gradient is really telling us
These conversations are not separate from the data, they reflect it. A substantial body of research shows a clear North-South gradient in inflammatory bowel disease, with higher incidence in Northern Europe and North America compared to Southern regions. When families move from lower-incidence areas to higher-incidence environments, their risk increases, often within a single generation.
This pattern cannot be explained by genetics alone. It points to the dynamic interaction between genes and environment. In this context, the environment is not a passive backdrop. It is an active force, shaping microbiota, immune development, metabolic balance, and resilience over time.
I experienced this shift personally when I relocated from the South to the North. The contrast in food was striking. Sugar was everywhere. Shelf life had become a priority. Many foods appeared intact, yet lacked the diversity, freshness, and complexity I had grown up with, qualities that influence not only taste, but biological signaling.
The body does not respond to all foods in the same way. Fresh, nutrient-dense, minimally processed foods interact differently with the gut microbiome and immune system than highly processed, standardized alternatives.
Children are especially sensitive to these differences. Their systems are still developing, learning how to interpret and respond to environmental signals. When that environment is misaligned with biological needs, the effects can be amplified. The rise in pediatric inflammatory conditions is not random. It is a signal.
A responsibility we can no longer delay
The North-South gradient does not point to geography as a solution. It points to the environment as a driver. If we take this seriously, our response cannot remain limited to treatment alone. It must extend to prevention, how we design food systems, how we support families, how we educate children, and how we align daily life with biological needs.
This perspective is at the core of my work, translating science into accessible knowledge and helping families navigate increasingly complex environments with clarity and confidence.
It also informs my upcoming children’s book, The Farm Friends, which aims to help young audiences and their parents reconnect with the foundations of health through nature, food, and everyday experiences that support the body’s balance from an early age.
Because if we want to change the trajectory of chronic disease, we cannot wait until adulthood to intervene. We must start earlier by helping children understand their bodies, build sustainable habits, and develop a balanced relationship with their health.
The most important question is no longer where the disease is more common. It is whether we are ready to act on what we already know, to protect the next generation.
Follow me on Facebook, Instagram, LinkedIn and visit my website for more info!
Read more from Haifa Hamdi
Haifa Hamdi, Scientist, Nutritionist, and Author
Dr. Haifa Hamdi is a research scientist, holistic nutritionist, and author dedicated to advancing health and wellness. After earning her Ph.D. in Immunology, she built an international career across Europe and North America, contributing to the development of cell therapy protocols to treat cancer and autoimmune disease patients. Her research includes more than 15 peer-reviewed scientific publications, with expertise in lung cancer therapies, immune tolerance, and innovative approaches to inflammatory and infectious diseases. She is also collaborating on new strategies for managing and treating inflammatory bowel disease (IBD). Her mission: to inspire a world where health is seen not as a burden, but as a joyful and empowering journey.
