Promoting Vigorous Physical Activity during Youth May Lower NAFLD Risk later

Nonalcoholic fatty liver disease (NAFLD) is a prevalent and concerning health condition that's on the rise. It has been established that physical activity can play a crucial role in preventing and managing NAFLD. However, a recent groundbreaking study revealed that vigorous physical activity from young to middle adulthood has reduced the risk of NAFLD in middle age when compared with those with less vigorous physical activity. 

The study results were published in the journal JAMA Network Open. 

Nonalcoholic fatty liver disease (NAFLD) is a growing global concern. Researchers, focusing on a diverse population over 25 years, have found that consistent physical activity, especially vigorous-intensity exercise, may lower the risk of NAFLD in middle age. Tailored interventions could play a vital role in reducing NAFLD risk, offering hope in the fight against this prevalent liver condition. Previous research shows that physical activity (PA) can prevent and treat nonalcoholic fatty liver disease (NAFLD) but there is uncertainty on how long-term patterns of intensity-based physical activity, including moderate-intensity PA (MPA) and vigorous-intensity PA (VPA), might affect the prevalence of NAFLD in middle age. Hence, researchers conducted a population-based cohort study to identify distinct intensity-based PA trajectories from young to middle adulthood and examine the associations between PA trajectories and NAFLD prevalence in midlife.

This comprehensive study was conducted using data from the Coronary Artery Risk Development in Young Adults (CARDIA) study. The study encompassed a diverse group of 2,833 individuals who were part of the CARDIA study. These participants had undergone eight examinations over a span of 25 years, from 1985-1986 to 2010-2011. The diagnosis of NAFLD was based on computed tomography measurements taken in the 25th year.

Key findings:

• Among a total of 2833 participants, there were 1379 Black individuals and 1454 White individuals.
• Among the total, 1206 (42.6%) were male, and 1627 (57.4%) were female with a mean [SD] age, of 25.0 [3.6] years.
• The participants' MPA trajectories were categorized into three groups: very low stable, low increasing, and moderate increasing.
• In contrast, the VPA trajectories fell into three categories as well: low stable, moderate decreasing, and high decreasing. 
• After adjusting for various factors, including demographic characteristics, lifestyle factors, and alcohol consumption, the researchers found a noteworthy correlation.
• Participants who followed the VPA trajectories of moderate decreasing and high decreasing had a lower risk of developing NAFLD in middle age compared to those who maintained a low stable VPA trajectory.
• Even after further adjustments for baseline factors like body mass index and waist circumference, the results remained statistically significant.
• However, when it came to MPA trajectories, the results did not show a statistically significant association with NAFLD risk.

Thus, this research emphasizes that vigorous-intensity physical activity, when consistently maintained from youth through to middle age, may significantly reduce the risk of NAFLD. These findings are crucial in highlighting the importance of promoting and sustaining effective prevention programs centered around vigorous physical activity throughout a person's life. By doing so, the risk of NAFLD can be mitigated. The study underscores the need for proactive measures and initiatives to reduce the impact of NAFLD and improve the health and well-being of individuals at risk. 

Further reading: de Brito JN, McDonough DJ, Mathew M, et al. Young Adult Physical Activity Trajectories and Midlife Nonalcoholic Fatty Liver Disease. JAMA Netw Open. 2023;6(10):e2338952. DOI: 10.1001/jamanetworkopen.2023.38952