Summary: Combining aerobic exercise with the heart-healthy DASH diet improved the ability to think, recall, and make decisions in older people who experienced cognitive decline and mild cognitive impairment.
Source: American Geriatrics Society
Cognitive impairment without dementia (CIND), or mild cognitive impairment, is a condition that affects your memory and may put you at risk for Alzheimer’s disease and dementia. According to the U.S. National Library for Medicine, signs of mild cognitive impairment may include frequently losing things, forgetting to go to events and appointments, and having more trouble coming up with words than other people of your age.
Some experts believe that risk factors for heart disease also are risk factors for dementia and late-life cognitive decline and dementia. Recently, researchers examined two potential ways to slow the development of CIND based on what we know about preventing heart disease. They published the results of their study in the Journal of the American Geriatrics Society.
The research team had a theory: That the healthy lifestyle behaviors that slow the development of heart disease could reduce heart disease risk and also slow cognitive decline in older adults with CIND. These behaviors include regular exercise and a heart-healthy diet, such as the DASH (Dietary Approaches to Stop Hypertension) diet.
In order to investigate their theory, the researchers designed a study titled “Exercise and NutritionaL Interventions for coGnitive and Cardiovascular HealTh EnhaNcement” (or ENLIGHTEN for short). The goal of the study was to examine the effects of aerobic exercise (sometimes known as “cardio” or “cardiovascular” exercise because it involves activities that increase the circulation of oxygen through the blood) and the DASH diet on cognitive functioning in older adults with CIND.
The ENLIGHTEN study examined 160 adults 55-years-old or older. The study participants were older adults who didn’t exercise and had memory problems, difficulty thinking, and making decisions. They also had at least one additional risk factor for heart disease, such as high blood pressure (also known as hypertension), high cholesterol, diabetes, or other chronic conditions.
Participants took a number of tests to measure their heart disease risk factors and cognitive ability. Researchers also assessed participants’ dietary habits and ability to perform daily activities. The participants were then randomly assigned to one of four groups: a group doing aerobic exercise alone, a group following the DASH diet alone, a group doing aerobic exercise and following the DASH diet combined, or a group receiving standard health education.
People in the exercise group did 35 minutes of moderate intensity aerobic exercise (including walking or stationary biking) three times per week for six months. They were supervised for three months and then exercised unsupervised at home for three months. Participants in the exercise group did not receive any counseling in the DASH diet and were encouraged to follow their usual diets for six months.
People in the DASH eating plan group received instruction about how to meet DASH guidelines in a series of weekly sessions for three months and then bi-weekly for the remaining three months. Participants in the DASH group were asked not to engage in regular exercise until the completion of the six-month study.
People in the exercise and DASH group followed the exercise and DASH programs for six months. The participants who were enrolled in the health education group received weekly educational phone calls for three months and then bi-weekly calls for three months. Phone calls were conducted by a health educator on health topics related to heart disease. Participants were asked to maintain their usual dietary and exercise habits for six months until they were re-evaluated.
At the conclusion of the six-month intervention and assessment, participants were free to engage in whatever activity and dietary habits they desired, with no restrictions.
The results of the research team’s study showed that exercise improved the participants’ ability to think, remember, and make decisions compared to non-exercisers, and that combining exercise with the DASH diet improved the ability to think, remember, and make decisions, compared to people who didn’t exercise or follow the diet–even though they didn’t perfectly follow the programs they were assigned to during the six-month interventions.
The researchers concluded that their findings are promising proof that improved ability to think, remember, and make decisions can last one year after completing a six-month exercise intervention. They suggested that further studies would be needed to learn more.
About this neuroscience research article
Source: American Geriatrics Society Media Contacts: Daniel E. Trucil – American Geriatrics Society Image Source: The image is in the public domain.
Longer Term Effects of Diet and Exercise on Neurocognition: 1‐Year Follow‐up of the ENLIGHTEN Trial
OBJECTIVES To evaluate the longer term changes in executive functioning among participants with cardiovascular disease (CVD) risk factors and cognitive impairments with no dementia (CIND) randomized to a diet and exercise intervention.
DESIGN A 2 (Exercise) × 2 (Dietary Approaches to Stop Hypertension [DASH] eating plan) factorial randomized clinical trial.
SETTING Academic tertiary care medical center.
PARTICIPANTS Volunteer sample of 160 older sedentary adults with CIND and at least one additional CVD risk factor enrolled in the ENLIGHTEN trial between December 2011 and March 2016.
INTERVENTIONS Six months of aerobic exercise (AE), DASH diet counseling, combined AE + DASH, or health education (HE) controls.
MEASUREMENTS Neurocognitive battery recommended by the Neuropsychological Working Group for Vascular Cognitive Disorders including measures of executive function, memory, and language/verbal fluency. Secondary outcomes included the Clinical Dementia Rating‐Sum of Boxes (CDR‐SB), Six‐Minute Walk Distance (6MWD), and CVD risk including blood pressure, body weight, and CVD medication burden.
RESULTS Despite discontinuation of lifestyle changes, participants in the exercise groups retained better executive function 1 year post‐intervention (P = .041) compared with non‐exercise groups, with a similar, albeit weaker, pattern in the DASH groups (P = .054), without variation over time (P’s > .867). Participants in the exercise groups also achieved greater sustained improvements in 6MWD compared with non‐Exercise participants (P < .001). Participants in the DASH groups exhibited lower CVD risk relative to non‐DASH participants (P = .032); no differences in CVD risk were observed for participants in the Exercise groups compared with non‐Exercise groups (P = .711). In post hoc analyses, the AE + DASH group had better performance on executive functioning (P < .001) and CDR‐SB (P = .011) compared with HE controls.
CONCLUSION For participants with CIND and CVD risk factors, exercise for 6 months promoted better executive functioning compared with non‐exercisers through 1‐year post‐intervention, although its clinical significance is uncertain.