Diet and Exercise: Keys to Reducing Dementia Risk

Dementia is a serious issue for public health, causing both social and economic burdens. As more people are affected by dementia, finding ways to prevent it has become increasingly important. Research shows that changing behaviors related to diet and Physical Activity can help reduce the risk of developing dementia.

#Importance of Diet and Exercise

Eating well and staying active are crucial for maintaining brain health. Recent studies suggest that combining changes in diet and exercise can positively impact Cognitive Function. These studies have shown benefits not just in the general population, but also in specific groups who are more at risk for dementia.

Data from well-structured trials indicate that following a Mediterranean Diet (MD) can help improve brain function. When looking at previous research, a small increase in adherence to this diet was linked to less cognitive aging. Additionally, being more physically active is also associated with better cognitive function and a lower risk of dementia. Different factors, such as improved Heart Health and better blood flow to the brain, can explain why diet and exercise help with cognitive health.

#Research Background

Only a few interventions have looked at how combined lifestyle changes, like adopting a Mediterranean diet and increasing physical activity, affect brain function. Most of these studies have not been done in the UK. One study did find that a combination of MD and exercise improved memory in older Australians.

Many challenges make it hard for people in non-Mediterranean regions to adopt the Mediterranean diet, including cultural differences. This means that any intervention needs to be planned carefully. It is essential to ensure the interventions are based on solid research and theory, and testing their feasibility is crucial before moving on to larger studies.

#The MedEx-UK Study

The MedEx-UK study was designed as a detailed, theoretical intervention to boost adherence to the Mediterranean diet, with or without incorporating exercise, among older adults at risk of dementia. The study lasted 24 weeks and was then followed by another 24-week period to see if the changes in behavior were maintained.

The study focused on understanding how behavior is influenced by capability, opportunity, and motivation. It included techniques based on evidence to promote initial changes and help maintain those changes over time. After the first 24 weeks, participants were invited to take part in a follow-up phase where no active intervention was provided, just to see if the changes made were kept up.

The main goals were to see how feasible and acceptable the interventions were and to assess changes in behavior, cognitive function, heart health, and the processes that lead to behavior change. Outcomes were tracked both at the end of the intervention and again after an additional 24 weeks.

#Study Design

This study was registered and followed a clear protocol. Participants were recruited from three different centers in the UK. They were randomly assigned to one of three groups: a control group, a Mediterranean diet group, or a Mediterranean diet plus physical activity group. The intervention took place between March 2019 and September 2020, and the follow-up phase was completed by March 2021.

The researchers initially planned for 90 participants, but that number was increased to 108 to allow for dropouts. Participants were older adults aged between 55 and 74. To qualify, they needed to show that they had a certain risk of heart problems and normal cognitive function. They also needed to have low adherence to the Mediterranean diet and limited physical activity.

Participants were randomly assigned to one of the three groups so that each group was balanced for diet score and gender. Group assignments were made by researchers who were aware of which participants were in which groups.

#Intervention Phase

The first 24 weeks involved a focused intervention where participants in the diet groups were encouraged to change their eating habits. This was done through personalized targets based on their current diet and physical activity levels, using a website, group sessions with trained facilitators, and food vouchers.

Participants were encouraged to raise their Mediterranean diet adherence score by at least three points and to increase their physical activity to meet certain weekly targets. They were informed about their diet score through the online platform, where they could track their progress and choose specific changes to make based on their preferences.

Each group met for sessions designed to reinforce the Behavior Changes, and participants received money to help cover the cost of healthier foods. The control group received general dietary and activity advice according to national guidelines and attended a shorter session to understand their role in the study.

After the initial 24 weeks, participants were invited to continue monitoring their behaviors for another 24 weeks, but they would no longer have access to group support or food provision. During this follow-up phase, the focus was on maintaining the healthy changes they made.

#Data Collection

Before the study started, participants underwent assessments to gather baseline data on their cognitive, heart, and biological health. Due to restrictions from the COVID-19 pandemic, some follow-up measures were conducted remotely to limit contact while still gathering important data.

#Assessing Feasibility and Acceptability

The feasibility of the intervention was measured by looking at how many participants joined and stayed with the study. Additionally, engagement was assessed by attendance at group sessions and use of the online platform. Acceptability was measured through questionnaires filled out by participants at the end of the intervention and during follow-up.

#Dietary Changes

The primary dietary outcome was assessed using the Mediterranean Diet Adherence Screener (MEDAS), and participants also completed food recalls to gather more detailed information about their eating habits. After 24 weeks, those following the Mediterranean diet showed a significant improvement in their dietary adherence compared to the control group. This change remained notable even after 48 weeks.

#Changes in Physical Activity

Physical activity levels were recorded through the use of activity monitors worn by participants. Results showed that only the group aimed at increasing physical activity saw a rise in their activity levels over the 24-week period. However, overall significant differences between the groups were not observed.

#Cognitive Function Improvements

After the 24-week intervention, improvements were noted in general cognition and memory in the Mediterranean diet groups compared to the control group. These changes were not maintained at the 48-week follow-up, suggesting that longer intervention periods may be needed for sustained cognitive benefits.

#Cardiometabolic Health

While there were no significant changes to body mass index (BMI) after the 24 weeks, a notable decrease in BMI was observed in those following the Mediterranean diet and physical activity at the 48-week follow-up. Certain cardiovascular measures improved in the Mediterranean diet plus physical activity group, but not in others.

#Mechanisms Behind Changes

Participants began the study with high levels of confidence and motivation to make changes, but these decreased over the intervention. Engagement with behavior change techniques, like goal setting, became more prominent in maintaining behavior change, but social support was less frequently used, partly due to pandemic restrictions.

#Conclusion

The MedEx-UK study shows that encouraging adherence to the Mediterranean diet and increasing physical activity in older adults at risk of dementia is feasible and acceptable. The intervention led to improved eating habits, which were maintained over time, and was linked to positive cognitive and cardiovascular benefits.

Overall, this study provides valuable insights into how to design larger trials focused on lifestyle changes to prevent dementia, emphasizing the importance of thorough planning, understanding participant needs, and addressing barriers to eating well and staying active.