The study found that higher levels of visceral fat were more closely tied to heart failure risk than overall body weight. Larger waist measurements were linked to increased risk even in people whose body mass index (BMI) fell within a normal range. These results suggest that where fat is stored in the body may be more important than how much a person weighs. Inflammation appears to help explain why belly fat has such a strong impact on heart health. Measuring waist size may therefore provide a better way to identify people at higher risk than relying on BMI alone.

“This research helps us understand why some people develop heart failure despite having a body weight that seems healthy,” said Szu-Han Chen, lead author of the study and a medical student at National Yang Ming Chiao Tung University in Taiwan. “By monitoring waist size and inflammation, clinicians may be able to identify people with higher risk earlier and focus on prevention strategies that could reduce the chance of heart failure before symptoms begin.”

The Role of Inflammation in Heart Disease

A 2025 scientific statement from the American Heart Association on risk-based primary prevention of heart failure highlights systemic inflammation, or inflammation throughout the body, as a major contributor to heart disease. It can disrupt immune function, damage blood vessels, and promote the buildup of scar tissue in the heart. The Association has also reported that higher inflammation levels are linked to increased heart disease risk, even in people with normal cholesterol levels.

Key Findings From the Study

The researchers reported several important observations:

• 112 participants developed heart failure over a median follow-up period of 6.9 years
• Higher levels of excess fat around the waist were associated with increased heart failure risk, while higher BMI was not
• Both waist circumference and waist-to-height ratio were linked to greater risk
• Participants with higher inflammation levels, measured through blood tests, were more likely to develop heart failure over nearly seven years
• Inflammation accounted for about one-quarter to one-third of the connection between abdominal fat and heart failure risk

Implications for Prevention and Screening

“This study highlights the importance of integrating measures of central adiposity such as waist circumference into routine preventive care. Understanding upstream drivers of heart failure risk including central adiposity is key to recognizing and modifying risk,” said Sadiya S. Khan, M.D., M.Sc., FAHA, volunteer chair of the American Heart Association’s 2025 Scientific Statement: Risk-Based Primary Prevention of Heart Failure. “This study builds on prior research that highlights the importance of excess or dysfunctional adiposity in the development of heart failure, which informed the inclusion of body mass index into the PREVENT-HF risk equations to estimate risk of heart failure. However, future research should identify if central adiposity has greater predictive utility beyond strength of association.” Khan, who was not involved in the study, is also Magerstadt Professor of Cardiovascular Epidemiology and an associate professor of cardiology and preventive medicine at Northwestern University’s Feinberg School of Medicine in Chicago.

Study Limitations and Next Steps

The researchers noted that they did not have detailed data on different types of heart failure, so the findings apply to heart failure overall. Future studies are needed to explore how visceral fat and inflammation affect specific subtypes of heart failure and whether reducing inflammation could help lower risk.

Study Design and Participant Details

The analysis included health data from 1,998 African American adults living in both urban and rural areas of Jackson, Mississippi, who participated in the Jackson Heart Study. None of the participants had heart failure when they enrolled between 2000 and 2004.

Participants ranged in age from 35 to 84, with an average age of 58, and 36 percent were women. They were followed for a median of 6.9 years, through December 31, 2016.

Researchers evaluated body fat using several measures, including weight, body mass index (BMI), waist circumference, and waist-to-height ratio. Blood samples were also analyzed for high-sensitivity C-reactive protein, a widely used marker of inflammation.

The study was conducted under the guidance of Professor Hao-Min Cheng at Taipei Veterans General Hospital and National Yang Ming Chiao Tung University.

The updated guidance, released by the American College of Sports Medicine (ACSM) as a Position Stand, is built on 137 systematic reviews covering more than 30,000 participants. This makes it the most extensive and evidence-based set of resistance training recommendations to date.

“The best resistance training program is the one you’ll actually stick with,” says Stuart Phillips, distinguished professor in the Department of Kinesiology and an author on the Position Stand. “Training all major muscle groups at least twice a week matters far more than chasing the idea of a ‘perfect’ or complex training plan. Whether it’s barbells, bands, or bodyweight, consistency and effort drive results.”

Updated Guidance Reflects Surge in Strength Research

This update comes after years of growing scientific interest in muscle health and aging. The last ACSM Position Stand on resistance training for healthy adults was published in 2009, before a wave of new research on how strength impacts long term health and well-being.

“The new document reflects that surge in evidence and expands its recommendations to include more people and more types of training than ever before,” Phillips says.

A key takeaway from the updated guidelines is that the biggest benefits often come from a simple starting point. Transitioning from no resistance training to any regular activity can lead to meaningful improvements. While factors such as load, volume, and frequency can be adjusted, experts say the main priority for most adults should be building a routine they can follow consistently.

No Gym Required for Strength and Muscle Gains

Another important shift in the recommendations is the recognition that effective resistance training does not require access to a gym. Exercises using elastic bands, bodyweight movements, or simple at home routines can still produce measurable gains in strength, muscle size, and daily function.

According to Phillips, strict rules about the “ideal” training plan are no longer supported by current evidence. Instead, personal preferences, enjoyment, and the ability to maintain a routine over time are what matter most. This approach is especially important for adults who want to stay strong, healthy, and capable as they age.

Focus on Consistency Over Complexity

Athletes and highly trained individuals may still need more specialized, sport specific programs. However, for most adults, the guidance is clear. Choose a resistance training routine that fits your lifestyle and stick with it over time.

The full ACSM Position Stand is now available in Medicine & Science in Sports & Exercise.

“When searching for possible dementia prevention tools, we thought something as prevalent as coffee may be a promising dietary intervention — and our unique access to high quality data through studies that has been going on for more than 40 years allowed us to follow through on that idea,” said senior author Daniel Wang, MD, ScD, associate scientist with the Channing Division of Network Medicine in the Mass General Brigham Department of Medicine and assistant professor at Harvard Medical School. Wang is also an assistant professor in the Department of Nutrition at Harvard Chan School and an associate member at the Broad Institute. “While our results are encouraging, it’s important to remember that the effect size is small and there are lots of important ways to protect cognitive function as we age. Our study suggests that caffeinated coffee or tea consumption can be one piece of that puzzle.”

Why Prevention Matters for Dementia

Preventing dementia early is especially important because current treatments are limited and generally provide only modest benefits after symptoms begin. As a result, scientists are increasingly focusing on lifestyle factors, including diet, that may influence the development of cognitive decline.

Coffee and tea contain compounds such as polyphenols and caffeine, which are thought to support brain health. These substances may help reduce inflammation and limit cellular damage, both of which are linked to cognitive decline. However, previous research on coffee and dementia has produced mixed results, often due to shorter study periods or limited data on long-term consumption patterns and different types of beverages.

Long-Term Data Offers Clearer Insights

The NHS and HPFS datasets helped address these gaps. Participants were tracked for up to 43 years, with repeated evaluations of diet, dementia diagnoses, subjective cognitive concerns, and objective cognitive performance. Researchers analyzed how consumption of caffeinated coffee, tea, and decaffeinated coffee related to long-term brain health outcomes.

Among the more than 130,000 participants, 11,033 developed dementia over the course of the study. Individuals who consumed higher amounts of caffeinated coffee had an 18% lower risk of developing dementia compared with those who rarely or never drank it. They also reported lower rates of subjective cognitive decline (7.8% versus 9.5%) and performed better on certain objective cognitive tests.

Caffeine May Play a Key Role

Similar patterns were observed among tea drinkers, while decaffeinated coffee did not show the same associations. This suggests that caffeine may be an important factor behind the observed brain-related benefits, although more research is needed to confirm the underlying mechanisms.

The strongest effects were seen in participants who drank 2-3 cups of caffeinated coffee or 1-2 cups of tea per day. Higher levels of caffeine intake did not appear to cause harm. Instead, they showed comparable benefits to the moderate intake range highlighted in the study.

“We also compared people with different genetic predispositions to developing dementia and saw the same results — meaning coffee or caffeine is likely equally beneficial for people with high and low genetic risk of developing dementia,” said lead author Yu Zhang, MBBS, MS, PhD student at Harvard Chan School and a research trainee at Mass General Brigham.

Study Authors and Funding

In addition to Wang and Zhang, Mass General Brigham contributors included Yuxi Liu, Yanping Li, Yuhan Li, Jae H. Kang, A. Heather Eliassen, Molin Wang, Eric B. Rimm, Frank B. Hu, and Meir J. Stampfer. Additional authors were Walter C. Willett and Xiao Gu.

The research was supported by National Institutes of Health grants UM1 CA186107, U01 HL145386, U01 CA167552, R01 HL60712, P30 DK46200, R00 DK119412, R01 AG077489, RF1 AG083764, and R01 NR019992. The funding organizations had no involvement in the study design, data collection, analysis, manuscript preparation, or the decision to publish.