Our lifestyle choices profoundly impact how long we live. While exercise and diet are essential for well-being, understanding the combined effect of these habits on mortality is still evolving. The EPIC-Norfolk study sheds light on how physical activity (PA) and diet quality—particularly the Mediterranean diet—work together over time to influence longevity.
This study, involving nearly 10,000 participants, demonstrates how sustained physical activity and diet improvements correlate with lower mortality rates. Here’s a breakdown of their findings and what they mean for your health.
Lifestyle Choices on Health and Longevity
Decades of research underscore that physical activity and a balanced diet reduce mortality risk. A physically active lifestyle not only lowers the incidence of cardiovascular diseases (CVD) but also reduces cancer risk, which collectively account for a significant percentage of all deaths. The Mediterranean diet, rich in fruits, vegetables, whole grains, and healthy fats, consistently shows positive outcomes for heart health and reduced cancer risk.
Recent analyses reveal that physical activity and diet quality aren’t just complementary but can be mutually reinforcing. For instance, being active often leads to healthier food choices, while a nutrient-dense diet can boost energy for staying active. Yet, a few misconceptions persist—some believe that high levels of exercise can counteract a poor diet, or vice versa. This study aims to address these assumptions by examining the impact of maintaining, improving, or declining in both PA and diet quality over time.
EPIC-Norfolk Study
The EPIC-Norfolk study, part of the larger European Prospective Investigation into Cancer and Nutrition, is a long-term cohort study based in Norfolk, United Kingdom. The researchers recruited over 25,000 men and women aged 40-79 from 1993 to 1997. For this specific analysis, the sample was narrowed to 9,349 participants, all of whom had completed detailed assessments of both physical activity and dietary habits.
This study uniquely tracked participants over time, gathering data in two primary stages. From 1993-2004, researchers measured baseline levels of PA and diet quality and then reassessed them periodically. They continued to follow participants’ mortality data through 2022, observing how changes in their lifestyle habits influenced mortality risks. This comprehensive approach provided a nuanced understanding of how lifestyle shifts—positive or negative—play out over decades.
Physical Activity and Diet Quality
To measure physical activity, researchers assessed both occupational and leisure-time activities. They calculated physical activity energy expenditure (PAEE), an indicator of total PA, which was calibrated to ensure accuracy. For diet quality, participants completed a food frequency questionnaire that researchers scored using the Mediterranean Diet Score (MDS). A higher MDS indicated better diet quality, specifically alignment with Mediterranean dietary principles. By tracking these values over time, researchers could examine the impact of starting, maintaining, or adjusting these behaviors on mortality.
This study’s strength lies in its repeat assessments, which allowed researchers to track how changes in PA and diet influenced mortality, something rarely explored in similar studies.
Physical Activity, Diet, and Mortality Rates
The EPIC-Norfolk study found that both baseline PA and diet quality significantly impacted mortality. Participants who had higher levels of PA and followed a Mediterranean diet showed reduced risks for all-cause, cardiovascular, and cancer-related mortality. Specifically, each 1-standard deviation (SD) increase in baseline PAEE led to a 10% reduction in all-cause mortality. Similarly, for every 1-SD improvement in MDS, the risk of all-cause mortality dropped by 7%.
When participants increased their PA and diet quality over time, the impact was even more substantial. Those who maintained high levels of both had a 22% lower mortality risk than those with low PA and diet quality. This pattern was consistent across cardiovascular and cancer mortality, demonstrating that these lifestyle factors act as protective buffers against chronic illnesses.
These findings align with previous studies but offer added insight into the impact of sustained improvement. High physical activity and diet quality at baseline already confer benefits, but consistently working on these aspects or making improvements leads to even better outcomes.
Impact of PA and Diet Trajectories
The researchers classified participants into 16 groups based on different combinations of PA and diet quality. The groups ranged from those who consistently maintained low levels to those who improved or declined over time. The group with sustained high PA and high MDS (Mediterranean Diet Score) enjoyed a 22% lower risk of all-cause mortality compared to those who maintained low levels of both.
One key finding was that either a consistently high PA level or high diet quality alone provided some protection against mortality, yet the combination had the most profound effect. Participants who improved both their PA and diet quality over time experienced up to a 40% reduction in mortality risk, whereas those who declined in both saw an increase of 47%.
This analysis demonstrates that consistent high performance in one lifestyle area doesn’t fully compensate for deficiencies in another. While the debate over whether exercise can “outrun” a poor diet or vice versa has persisted, this study suggests that neither is a substitute for the other. For optimal health, the best approach is to commit to both regular physical activity and a high-quality diet.
How to Integrate Physical Activity and Diet
If the EPIC-Norfolk study proves anything, it’s that even small improvements in physical activity and diet quality can add up. Here’s how to adopt and maintain these healthy changes:
- Set Achievable PA Goals: Try walking for 30 minutes a day, five days a week. Gradually increase the duration or intensity based on your comfort level. Whether it’s a brisk walk or a bike ride, regular movement can improve your PA levels significantly over time.
- Incorporate Mediterranean Foods: Introduce one or two new foods into your diet each week. Swap red meat for fish, snack on nuts instead of chips, and use olive oil as a primary fat source. Gradual changes make it easier to stick to the diet.
- Build Consistency Over Time: Lifestyle habits don’t change overnight. The EPIC-Norfolk study shows that cumulative, sustained changes matter. Take small, achievable steps, and focus on building lasting habits.
- Monitor Progress: Use simple tools like a pedometer for tracking steps or a food diary. Monitoring encourages accountability and allows you to see improvements.
These practical steps show that you don’t need to make drastic changes to see a benefit. Small, consistent steps have a cumulative effect, as demonstrated by the EPIC-Norfolk study’s findings.
Public Health Implications
The implications of this study extend beyond individual health. Public health policies can play a pivotal role in encouraging sustained physical activity and a high-quality diet. From community-based fitness programs to nutrition education in schools, public health initiatives can help individuals make informed lifestyle choices.
Healthcare systems might benefit by integrating lifestyle support into routine care. For instance, programs that encourage physical activity and provide dietary guidance can significantly improve population health. Since diet and PA are modifiable factors, prioritizing these behaviors could reduce healthcare costs associated with managing chronic diseases.
Furthermore, the EPIC-Norfolk study’s findings could reshape public health messaging. Instead of promoting physical activity or diet separately, public health campaigns can focus on the combined impact. Highlighting this combined benefit could encourage people to adopt both practices more consistently.
Conclusion
The EPIC-Norfolk study underscores a powerful message: maintaining or improving both physical activity and diet quality can extend your life. By embracing the Mediterranean diet and staying active, individuals can reduce mortality risk from cardiovascular diseases, cancer, and other causes. This research highlights that it’s never too late to improve your habits—small, sustained changes can make a significant difference.
Whether you’re just starting on a health journey or looking to maintain good habits, remember that both diet and exercise contribute to longevity. And while it might seem challenging at first, this study’s findings remind us that consistency, not perfection, is key. Making steady improvements in both areas offers a practical path to a longer, healthier life.
The study is published in the journal BMC Medicine. It was led by Soren Brage from University of Cambridge.
