On December 19, the medical journal Neurology published a new study out of Duke University wherein researchers were able to reverse years of cognitive impairment among people age 55+. Dr. James Blumenthal from the Department of Psychiatry and Behavioral Sciences at Duke University Medical Center led the research team. They experimented with 160 seniors, with an average age of 65, who had some sort of cardiovascular risk factor, and who had cognitive impairment without dementia.

What is Cognitive Impairment?

Cognitive impairment is when a person has trouble remembering, learning new things, concentrating, or making decisions that affect everyday life. It ranges from mild to severe. In mild forms, people may notice a difference in their mental abilities but can still perform everyday activities. Ten to fifteen percent of people age 50+ have some level of cognitive impairment. As of now, there is no medical treatment.¹ More than sixteen million people in the U.S. live with it. The CDC expects that number to skyrocket as the baby boomers age.² Could the work of Dr. Blumenthal and colleagues help prevent this explosion of cognitive decline?

What are Cardiovascular Risk Factors?

This study only involved people with cardiovascular risk factors. These are conditions that would make heart attack, stroke, and other serious problems more likely. People in this study had conditions such as high blood pressure, diabetes, obesity, or high concentrations of fat in the blood.  They may also have been smokers. Not only do these situations increase the risk of heart attack, they are also associated with starting and speeding up cognitive decline.³ For this reason, the treatment in the Duke University study may not be as effective for everyone. People who have risk factors and who already have cognitive decline without dementia may be more responsive to this treatment than others.

How to Reverse Cognitive Impairment

Here’s how to reverse years of progressive cognitive impairment for people age 55+: eat well and exercise. Numerous studies over the past several years have shown that people with better diets and better fitness think and remember better.³ But that didn’t necessarily mean if you were already losing your memory that exercise would get your memory back. What is different about the current study is that researchers took higher risk people who were already having problems, coached them in better diet, put them on an exercise plan, and waited to see if it made a difference. It did. It made a big difference in executive function. That’s people’s ability to manage time, switch tasks, pay attention, plan, organize, remember details, avoid saying or doing the wrong thing, multitask, and do things based on experience.

Which Diet Improves Thinking and Memory?

Dr. Blumenthal and colleagues specifically tested the DASH diet (Dietary Approaches to Stop Hypertension). Generally speaking, they recommended high consumption of fruits, vegetables, legumes, and nuts. They recommended low consumption of red meats and processed meats, and against over-consuming fats. In this study, reduced sodium intake also improved executive function.

It’s worth noting that other studies have also connected the Mediterranean diet with slower cognitive decline, improved cognitive function, and decreased risk of dementia.⁴ However, these studies were only observational. They did not measure what happens when people change their behavior, as the current Duke study does.

What’s the Best Way to Improve Memory and Thinking?

The current study tells us that the best way to improve memory and thinking is a combination of aerobic exercise and the DASH diet. Of all the singular interventions, exercise had the largest effect. However, exercise plus diet had an even greater effect. Dr. Blumenthal and colleagues only used the DASH diet, but diets other than the DASH may be effective as well.

References:

1. Blumenthal J, Smith P, Mabe S, et al. Lifestyle and neurocognition in older adults with cardiovascular risk factors and cognitive impairments. Neurology. December 2019; DOI: https://doi.org/10.1212/WNL.0000000000006784
2. S. Department of Health and Human Services, Centers for Disease Control and Prevention. Cognitive Impairment: A Call for Action Now! February 2011. Available at: https://www.cdc.gov/aging/pdf/cognitive_impairment/cogimp_poilicy_final.pdf
3. Blumenthal JA, Smith PJ, Mabe S, Hinderliter A, Welsh-Bohmer K, Browndyke JN, Lin PH, Kraus W, Doraiswamy PM, Burke J, Sherwood A. Lifestyle and neurocognition in older adults with cardiovascular risk factors and cognitive impairment. Psychosomatic Medicine. 2017 Jul 1;79(6):719-27.
4. van de Rest O, Berendsen AA, Haveman-Nies A, de Groot LC. Dietary patterns, cognitive decline, and dementia: a systematic review. Advances in Nutrition. 2015 Mar 5;6(2):154-68.