Cognitive health: Mediterranean diet, active lifestyle may protect

Originally designed to assess cognition over a 2-year period, timing and the financial impact of the COVID-19 pandemic have necessitated reducing the follow-up period to a single year, and the research is ongoing, with the scientists recruiting a wider sample of participants.

The study authors feel that the modified shape of the study will provide sufficiently strong findings.

The primary outcome in which the authors of the study are interested is a 12-month change in visual memory and learning for participants.

The researchers are also interested in observing the intervention’s effect on a range of areas, including mood, quality of life, and health costs, as well as cardiovascular health and arterial stiffness.

The participants in the study are 60-to-90-year-old individuals living in the two Australian states of South Australia and Victoria. Individuals were recruited from independent living retirement communities, and as a result of the pandemic, from the larger community as well.

Special attention is being paid to biomarkers associated with cognitive decline, such as glucose regulation, inflammation, nutrients, and oxidative stress.

Participants were assigned to either a MedWalk intervention group or a control group who maintained their usual diet and activity level.

The intervention is a combination of dietary modification alongside a supervised walking regimen, fortified with psychosocial behavioral change techniques. Participants receive intensive support for the first 6 months, with additional help remaining available for the next 6, to help them stay on track.

The researchers provide instruction in the ways a Mediterranean diet differs from a typical Australian diet, to help participants understand the concept underlying this way of eating.

For example, the researchers are providing extra-virgin olive oil for free, since it is so key to a Mediterranean diet, as well as other foods.

After an assessment of baseline aerobic fitness, participants engage in group walking sessions for the first 6 months, followed by monthly sessions for the remainder of the test year.

Conner Middelmann, certified nutritionist specializing in the Mediterranean diet, not involved in the current study, noted to Medical News Today that studies from 2014 and 2023 suggested that following a Mediterranean diet was associated with fewer cases of dementia.

Other studies, such as one in 2015 and another one in 2023, found an association between a Mediterranean diet and lower rates of Alzheimer’s disease, the most common form of dementia.

However, Middelmann cautioned that, “[w]hile these studies suggest a link between the Mediterranean diet and a reduced risk of dementia, it’s important to bear in mind that many factors can influence dementia risk, including genetics, lifestyle, and overall health.”

“Therefore, maintaining a healthy diet, such as the Mediterranean diet, is just one aspect of a comprehensive approach to brain health and dementia prevention,” she added.

A Mediterranean diet may contribute to brain health in various ways, Middelmann explained:

• the diet is rich in antioxidants that combat oxidative stress and inflammation, “which are thought to be significant contributors to cognitive decline and neurodegenerative diseases”
• it contains omega-3 fatty acids, particularly docosahexaenoic acid (DHA), which is vital for brain health, and “omega-3s [in general] have been linked to improved cognitive function and a lower risk of cognitive decline“
• the Mediterranean diet is high in fiber that can help keep the gut microbiome in balance.
• it is also low in processed grains and sugars, reducing the risk of insulin resistance and inflammation
• the consumption of ultra-processed foods, which have been linked to dementia, is not encouraged in the diet.

Finally, Middelmann said, sharing meals with family and friends and regular exercise are other aspects of the Mediterranean diet that have been associated with brain health.

Similarly, walking regularly is associated with slower cognitive decline.

A 2022 study found a dose-dependent relationship between the number of steps taken and reducing the risk of dementia.

That study found that taking 10,000 steps a day lowered the risk of dementia by 50%

A 2023 study of people in the United States and Australia found a link between walking speed and dementia, and a 2017 study published in the British Journal of Sports Medicine concluded that aerobic exercise such as walking can strengthen cognitive impairment.

“Walking may improve brain health in one or more ways. Walking may increase brain blood flow, depending on the intensity, duration, and frequency of walking,” explained brain health coach Ryan Glatt from the Pacific Neuroscience Institute, not involved in this study.

In addition, said Glatt, it may “benefit levels of brain activity, and may reduce feelings of overall stress while improving feelings of well-being.”

“Walking may also incorporate social elements and exposure to nature, both of which may also have brain benefits,” said Glatt.

The current study’s data-collection period will be completed by the end of 2023.