This research focused on 160 older, sedentary adults aged 65+ with cardiovascular risk factors and had some symptoms of mild cognitive impairment. This includes difficult remembering things, making decisions and focusing on tasks. The researchers were interested in the impact of diet and physical activity on cognitive ability. Mild cognitive impairment is a risk factor in developing Alzheimer’s Disease. Worldwide an average of 15% of older adults is estimated to have mild cognitive impairment (https://pubmed.ncbi.nlm.nih.gov/35977150/). Studies give widely varying figures but use varying diagnostic and inclusion criteria. None the less, assessing and reversing mild cognitive impairment has major public health benefits.

Participants followed a diet of high-fibre, low-sodium foods such as fruits, vegetables, nuts, beans, grains and lean meat plus low-fat dairy (called DASH diet, or Dietary Approaches to Stop Hypertension).

Participants were placed into four groups.

  • One group did only aerobic exercise.
  • One group followed the DASH diet without any exercise
  • One group followed both the exercise and the DASH diet.
  • One group were given health-related educational phone calls

The exercises compromised 45 minute sessions with a warm up followed by walking, jogging or cycling, three times a week.

The researchers wanted to investigate the impact of both physical activity and diet on cognitive abilities.

The participants followed the Dietary Approaches to Stop Hypertension (DASH) diet. The DASH diet consists of high-fibre, low-sodium foods such as fruits, vegetables, nuts, beans, grains, and lean meat, as well as low-fat dairy.

The researchers divided the participants into four groups:

  • One group did only aerobic exercise.
  • One group adhered to the DASH diet (without any exercise).
  • One group both exercised and adopted the DASH diet.
  • One group received health-related educational phone calls.

Those who exercised worked out three times per week in 45-minute sessions, including warmup exercises followed by walking, jogging, or cycling.

Blumenthal and his team assessed reasoning and memory skills at baseline and six months later with cognitive tests, testing cardiorespiratory fitness with treadmill stress tests. They also investigated cardiovascular wellbeing by measuring blood pressure, blood sugar and lipids.

Finally, the team assessed the participants’ cardiovascular health by measuring their blood pressure, blood sugar, and lipids.

Where people both exercises and changed their diets, participants gained a 5-point average increase in executive function, compared with groups who either just exercised or changed diet. This is equivalent to a 9-year improvement in executive function. 

Executive function enables us to plan and organise goal-driven actions and focus and self-regulate our behaviour. Memory did not significantly improve. 

Lead researcher James Blumenthal PhD said “The results are encouraging in that in just 6 months, by adding regular exercise to their lives, people who have cognitive impairments without dementia may improve their ability to plan and complete certain cognitive tasks.”

Limitations in the research are: a lack of larger samples and longer time periods for follow up.  

Research click link here