Another study finding more benefits of exercise was recently published in the journal Neurology. The study by researchers at Duke University found that in older adults who were already experiencing cognitive (thinking) problems, but did not have dementia - that after just 6 months of exercise they showed improvements in thinking. What were their original thinking problems? The individuals had difficulty concentrating, making decisions, or remembering, but it was not severe enough to be diagnosed as dementia. However, these persons were considered at risk for progressing to dementia.
The 160 individuals in the study were 55 years or older (mean age 65), mainly women, evenly divided between whites and minorities, were sedentary (didn't exercise), and had heart (cardiovascular) disease or were at risk for heart disease. They were randomly assigned to one of 4 groups: 1) aerobic exercise (with no dietary changes), 2) DASH diet (with no exercise), 3) DASH diet plus exercise, and 4) the control group, who had no dietary or exercise changes - they just received some educational phone calls. The study lasted 6 months, and there were no drop outs.
In the study, the aerobic exercises were done 3 times per week: 10 minutes of warm up exercises followed by 35 minutes of continuous walking or stationary cycling. The Dietary Approaches to Stop Hypertension or DASH diet is a heart healthy diet that emphasizes eating fruits, vegetables, whole grains, as well as fish, poultry, beans, and nuts. It stresses lowering the intake of salt (sodium), sweets, sugar sweetened beverages, and fatty foods (both trans fats and saturated fats). [Note that in many ways it's similar to the Mediterranean diet with its emphasis on fruits, vegetables, whole grains, legumes, seeds, nuts, and lowering intake of meat. Studies find cognitive benefits from the Mediterranean diet.]
The six months of exercising improved thinking skills called executive function - in both the exercise alone or exercise + DASH diet group. The largest improvements were in the exercise + DASH diet group (as compared to the control group, which actually showed decline in functioning). Executive function is a person's ability to regulate their own behavior, pay attention, organize and achieve goals, and was measured in this study with a group of cognitive tests (a "standard battery of neurocognitive tests"). These executive function improvements did not occur in the DASH diet alone group or the control group. The study found no improvement in memory or language fluency in any of the groups. The exercise alone, DASH diet alone, and the combined exercise and DASH group had other health benefits by the end of the study, for example they lowered their risk factors for heart disease. Other improvements: the exercise groups had improvements in insulin levels, and the DASH groups decreased their intake of blood pressure medicines.
To illustrate how amazing these results are: at the start of the study (baseline) all participants scored as if they were in their early 90s on cognitive tests - as if they were on average about 28 years older than their actual chronological age! Then at the end of 6 months, the persons in the exercise + DASH diet showed an improvement of almost 9 years on the tests. In contrast, the control group showed an approximately 6 month worsening performance. When researchers looked at physical markers of the exercisers, they found that physical improvements and improvements in heart disease risk factors (e.g. losing weight, lowering blood pressure) were correlated with executive functioning improvements.
Other studies have found related findings, such as higher physical activity and a Mediterranean diet is associated with lower levels of dementia. The researchers point out that there is growing evidence that combining several lifestyle factors (e.g., exercise, not smoking, a healthy diet, lowering salt intake) and not just exercise alone, has the best results for better cognitive functioning among older adults. Bottom line: eat a diet rich in fruits, vegetables, whole grains, seeds, nuts and get exercise. Walking briskly, gardening, housework, walking up stairs - it all counts.
From Medical Xpress:
Getting the heart pumping with aerobic exercise, like walking or cycling for 35 minutes three times a week, may improve thinking skills in older adults with cognitive impairments, according to a study published in the December 19, 2018, online issue of Neurology, the medical journal of the American Academy of Neurology. After six months of exercise, study participants' scores on thinking tests improved by the equivalent of reversing nearly nine years of aging.
The study looked at people who had cognitive impairments without dementia, which is defined as having difficulty concentrating, making decisions, or remembering, but not severe enough to be diagnosed with dementia.
The study found that exercise improved thinking skills called executive function. Executive function is a person's ability to regulate their own behavior, pay attention, organize and achieve goals. The study found no improvement in memory.
The study involved 160 people with an average age of 65 and risk factors for heart disease, such as hypertension, who did not have dementia but reported problems with thinking skills. All participants were identified as having cognitive impairments without dementia and were sedentary at the start of the study. Researchers examined the effects of both exercise and diet, specifically the Dietary Approaches to Stop Hypertension (DASH) diet, which is a low sodium, high fiber diet rich in fruits and vegetables, beans, nuts, low fat dairy products, whole grains, and lean meats. The DASH diet was designed specifically for individuals with high blood pressure.
At both the beginning and end of the six-month study, researchers evaluated participants' thinking and memory abilities with standardized cognitive testing, cardiorespiratory fitness with treadmill stress testing, and heart disease risk factors with screenings for blood pressure, blood glucose and lipids. They also used questionnaires and food diaries to measure how closely the participants followed the DASH diet.
Researchers found that participants who exercised showed significant improvements in thinking skills when compared to those who did not exercise. Those who took part in both the exercise and diet had average scores of nearly 47 points on the overall tests of executive thinking skills, compared to an average score of about 42 points for those with exercise and diet alone and about 38 points for those who just received health education. There was no improvement in participants who only consumed the DASH diet, although those who exercised and consumed the DASH diet had greater improvements compared to health education controls.