Medical Bulletin 01/August/2025 - Video

A new study published in the American Journal of Preventive Medicine reveals that just 15 minutes of brisk walking per day can significantly reduce the risk of death, especially among low-income populations. The findings support the promotion of walking as a simple, accessible, and cost-effective way to improve public health, particularly in underserved communities.

While the health benefits of walking are well known, few studies have focused on walking pace and mortality outcomes in low-income or predominantly Black populations.

The research team analyzed data from the Southern Community Cohort Study (SCCS), which recruited approximately 85,000 adults aged 40–79 between 2002 and 2009, primarily through community health centers in 12 southeastern U.S. states. Using structured questionnaires, participants provided baseline information about their walking habits, lifestyle, demographics, and medical history.

The study included data from 79,856 participants, 66% of whom were Black and 30% white. The cohort was linked to the National Death Index to track mortality data through December 31, 2022. During a median follow-up period of 16.7 years, 26,862 deaths were recorded.

The analysis showed that fast walking for at least 15 minutes per day reduced overall mortality by nearly 20%, while slow walking for more than three hours per day offered a smaller benefit. The protective effects of fast walking persisted even after adjusting for other lifestyle and physical activity factors.

“By demonstrating the benefits of fast walking which is a low-cost and largely accessible activity we provide direct evidence to inform targeted public health interventions and policies to improve health outcomes,” said senior author Wei Zheng, MD, PhD, MPH, the Anne Potter Wilson Professor of Medicine and director of the Vanderbilt Epidemiology Center.

“Brisk walking offers a convenient, accessible and low-impact activity that individuals of all ages and fitness levels can use to improve general health and cardiovascular health specifically,” Zheng emphasized.

Reference: NA. Daily Walking and Mortality in Racially and Socioeconomically Diverse U.S. Adults. American Journal of Preventive Medicine, 2025 DOI: 10.1016/j.amepre.2025.107738

Study Shows Poor Sleep Habits May Be Linked to 172 Diseases

A study published in Health Data Science has revealed strong associations between poor sleep patterns and the risk of developing 172 different diseases. Led by researchers from Peking University and Army Medical University, the study analyzed sleep behavior in 88,461 adults from the UK Biobank, making it one of the most comprehensive investigations into the health effects of sleep regularity to date.

While sleep duration has traditionally dominated public health discussions, this study shifts the spotlight to sleep regularity including bedtime consistency and circadian rhythm stability as a critical but underappreciated factor in long-term health outcomes.

The researchers used actigraphy a method of objectively measuring movement and sleep to track participants’ sleep over an average period of 6.8 years. The data were then cross-referenced with clinical records to examine associations with disease risk. Results showed that 92 diseases had over 20% of their risk attributable to poor sleep behavior. Notably, people with an irregular bedtime after 12:30 a.m. were found to have a 2.57-fold higher risk of liver cirrhosis. Additionally, low interdaily stability a measure of circadian rhythm consistency increased the risk of gangrene by 2.61 times.

The study also challenges long-standing assumptions about “long sleep” (defined as nine hours or more). While earlier studies based on self-reports linked long sleep to heart disease and stroke, the objective data here showed such an association with only one disease. Misreporting may explain the discrepancy: 21.67% of long sleepers actually slept less than six hours, confusing time spent in bed with actual sleep time.

"Our findings underscore the overlooked importance of sleep regularity," said Prof. Shengfeng Wang, senior author of the study. "It's time we broaden our definition of good sleep beyond just duration."

Reference: imeng Wang, Qiaorui Wen, Siwen Luo, Lijuan Tang, Siyan Zhan, Jia Cao, Shengfeng Wang, Qing Chen. Phenome-wide Analysis of Diseases in Relation to Objectively Measured Sleep Traits and Comparison with Subjective Sleep Traits in 88,461 Adults. Health Data Science, 2025; 5 DOI: 10.34133/hds.0161

Sausages, Sodas, and Cancer: Ultra-Processed Foods May Be Linked to Higher Lung Cancer Risk

A high intake of ultra-processed foods (UPFs) is associated with an increased risk of lung cancer, according to new research published in thejournal Thorax. While further studies are needed to confirm the findings across diverse populations, the researchers suggest that reducing consumption of these foods may help curb the global burden of lung cancer.

Lung cancer remains the most commonly diagnosed cancer worldwide, with an estimated 2.2 million new cases and 1.8 million deaths reported in 2020 alone. Ultra-processed foods which are industrially manufactured, contain multiple additives, and are typically ready-to-eat or heat have already been linked to several chronic health issues. The current study sought to explore whether ultra-processed foods consumption could also be tied to lung cancer.

Researchers analyzed data from the U.S. Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trials, which enrolled 155,000 participants aged 55 to 74 between 1993 and 2001. Of these, 101,732 individuals who had completed a detailed food frequency questionnaire were included in the current analysis. Foods were categorized into four groups, with particular focus on ultra-processed foods such as sour cream, cream cheese, fried foods, margarine, soft drinks, pizza, and hot dogs.

Participants were followed for an average of 12 years, during which 1,706 cases of lung cancer were diagnosed the majority being non-small cell lung cancer (NSCLC). Those with the highest intake of ultra-processed foods were 41% more likely to develop lung cancer than those with the lowest intake, even after adjusting for potential confounders like smoking and overall diet quality. Specifically, high ultra-processed foods consumption was linked to a 37% higher risk of non-small cell lung cancer and a 44% increased risk of small cell lung cancer (SCLC).

“This is an observational study, and as such, no firm conclusions can be drawn about cause and effect,” the researchers cautioned. However, they highlighted the poor nutritional profile of ultra-processed foods and the harmful substances they can contain. “Industrial processing alters the food matrix, affecting nutrient availability and absorption, while also generating harmful contaminants.”

The study concludes: “If causality is established, limiting trends of ultra-processed foods intake globally could contribute to reducing the burden of lung cancer.”

Reference: Wang K, Zhao J, Yang D, et al

Association between ultra-processed food consumption and lung cancer risk: a population-based cohort study

Thorax Published Online First: 29 July 2025. doi: 10.1136/thorax-2024-222100