The New York University Women’s Health Study (NYUWHS), featured in the peer-reviewed journal Environmental Health Perspectives (EHP), conducted a study tracking the correlation between the risk of obesity-related cancers in women and the annual average of neighborhood walkability. Between the years 1985 and 1991, the NYUWHS recruited 14,274 women and followed them for approximately thirty years, verifying their residential addresses every two years.
Annually, the researchers collected data from each participant, including geocoded residential addresses, the accessibility to destinations associated with those addresses, and an average annual measure of neighborhood walkability. By looking at this data, the study highlights valuable insights into the ongoing discourse on cancer and obesity and their relationship with environmental influences.
What is Happening in a Body with Obesity
Excessive body fat and an unhealthy distribution of fat can result in an individual becoming overweight or obese. Metrics like waist-to-hip ratio, waist circumference, and fat distribution play a crucial role in assessing the risk of developing diseases and associated health risks. Understanding the fat distribution is particularly important, as visceral fat surrounding internal organs poses a greater health risk compared to subcutaneous fat just beneath the skin.
Being overweight or obese impacts the body in various ways. Elevated body weight can lead to increased insulin levels and insulin growth-like factors, disrupting normal bodily functions. Additionally, it influences sex hormones and triggers prolonged inflammation. As time progresses, these conditions can accumulate, amplifying the associated risks. Individuals grappling with obesity face an elevated susceptibility to diseases, including cardiovascular disease, high blood pressure, diabetes, stroke, and specific types of cancer.
The Links Between Obesity and Cancer
With over 40% of adults in the United States falling into the categories of obesity or overweight, obesity has emerged as a growing health concern. The condition significantly increases the risk of developing various cancers, particularly among women. In the United States, approximately 55% of diagnosed cancers in women are linked to obesity, whereas the corresponding figure for men is around 24%.
The direct correlation between obesity and cancer risk in women extends to 13 specific types of cancers, encompassing adenocarcinoma of the esophagus, post-menopausal breast, colon and rectum, gallbladder, kidneys, liver, meningioma, multiple myeloma, ovaries, pancreas, thyroid, upper stomach, and uterus. Notably, these 13 cancers collectively make up 40% of all cancers diagnosed in the United States each year.
With obesity being such a prominent issue in the developed world, more and more time and effort is being devoted to its research. With that, there is increasing evidence that proves how moderate-intensity physical activities, such as walking, play a significant role in meeting the recommended exercise levels and maintaining good health.
Results of the NYUWHS Study
The study concluded that residing in neighborhoods with higher walkability levels is associated with a decreased risk of both overall and site-specific obesity-related cancers. The hazard ratios, which measure the likelihood of these health outcomes, were analyzed in relation to a 1-standard deviation increase in average annual neighborhood walkability, providing additional insights.
In the context of this research, a hazard ratio serves as a statistical gauge to evaluate how the risk of a specific event changes in response to a particular factor. It precisely quantifies the correlation between neighborhood walkability and the risk of obesity-related cancers. A 1-standard deviation increase in walkability, indicating a neighborhood’s walkability has risen by one standard deviation from the mean of the entire dataset, corresponds to notable reductions in the risk of various cancers. Specifically, there is a 12% decrease in the risk of overall obesity-related cancer, an 11% reduction in postmenopausal breast cancer risk, an 18% decrease in ovarian cancer risk, a 13% reduction in endometrial cancer risk, and a substantial 32% decrease in multiple myeloma risk.
Additionally, the study revealed an interesting nuance—the relationship between neighborhood walkability and the risk of overall obesity-related cancer was more robust among women residing in neighborhoods with higher levels of poverty compared to those in areas with lower poverty levels. This implies that the positive impact of walkability on reducing the risk of obesity-related cancers is particularly pronounced in economically disadvantaged areas, emphasizing the importance of considering socioeconomic factors in public health interventions.
Walkable Neighborhoods Encourage Healthier Habits and Lifestyles
While the cancer risks associated with low physical activity and obesity in women are understood, there is still a lack of effective intervention addressing these concerns. It is crucial to consider the impact of urban landscape designs on health and disease patterns. Walkable neighborhoods not only promote walking habits – they actively boost overall physical activity and reduce reliance on cars. This, in turn, may inspire individuals to adopt more vigorous activities like running and cycling, ultimately contributing to a reduction in the risks associated with obesity-related cancers.