About 5.8 million people in the United States live with Alzheimer’s disease, a devastating form of dementia that wipes out memories and disrupts thinking. Alzheimer’s disease is usually diagnosed after age 60, but according to the Alzheimer’s Association, it starts making changes in the brain years or even decades before symptoms appear.
The department of biostatistics at the University of California in Los Angeles estimates that more than 47 million Americans may have this type of “predementia,” and many may not realize it, as the disease typically causes a slow decline in functioning.
However, scientists have identified risk factors for developing Alzheimer’s, including family history of the disease and the presence of certain other chronic illnesses, including heart disease and diabetes.
But having an increased risk of Alzheimer’s disease does not guarantee a person will get it, and a new study published online on October 30, 2019, in the journal Alzheimer’s & Dementia suggested how those at high risk can lower their risk of developing dementia.
“Our data show that people with a family history with Alzheimer’s can reduce their risk for developing dementia by taking control of their brain health through many small health changes,” says Richard Isaacson, MD, lead study author and the director of the Alzheimer’s Prevention Clinic at NewYork-Presbyterian and Weill Cornell Medicine in New York City.
“Just like you can build muscle, you can build brain function, too,” Dr. Isaacson says.
Customized Recommendations Based on Individual Risk Factors
Over 18 months, researchers followed 154 patients ages 25 to 86 from the clinic. About three-quarters of the study participants were over 50, while the other 25 percent were younger than 50 (with about 10 percent between ages 25 and 40).
All had a family history of Alzheimer’s disease, and some additionally had blood biomarkers and genetic factors that put them at risk for dementia.
Through brain scans and cognitive testing, scientists classified 35 participants as having mild cognitive impairment (MCI) and put them in the “early treatment” group. The other participants, who had zero or very few cognitive issues, were put in the “prevention” group.
For a control, or comparison, population, researchers relied on two "matched" historical control cohorts, meaning tens of thousands of people who were similar to the study population in terms of age and brain function and who took cognitive tests over a long period of time but received no treatments.
Each person in the study was assigned customized recommendations based on modifiable individual risk factors. The suggestions included patient education, pharmacologic solutions (such as prescription drugs, vitamins, and supplements), and nonpharmacologic strategies (such as exercise, nutrition, improved sleep hygiene, and stress management).
The investigators also addressed dental hygiene with participants, because gum bleeding and inflammation has been associated with the development of Alzheimer’s disease in a study published in January 2019 in Science Advances.
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Small Life Changes Made a Big Difference
At the end of the study period, participants were again evaluated through a series of cognitive testing.
In the mild cognitive impairment group, those who had followed more than 60 percent of the recommendations they’d been given either maintained or improved their cognitive function. Individuals in this group who followed less than 60 percent of their recommendations, however, exhibited cognitive declines similar to those of the untreated controls.
For those in the prevention group, results were even better: Those who followed either more than 60 percent or less than 60 percent of recommendations had better cognitive function than at baseline.
“I thought if we did all this treatment with patients, they would decline at a slower rate,” says Isaacson, “but we saw improvements with all except for those with mild cognitive impairment and the lowest compliance.”
The positive effects in the MCI group especially surprised Isaacson. “The fact that the high-compliance MCI group had better cognitive function 18 months later is impressive to me,” he says.
The researchers note that the primary outcome was a change in performance on the modified Alzheimer’s Prevention Initiative Cognitive Composite test scores, per a study published in June 2014 in the Journal of Clinical Psychiatry. At 18 months, the improvements were statistically significant, with a 6.25 percent increase for the prevention group, and an 8.7 percent increase for the early treatment group.
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The Power of Tailoring Treatment to the Individual
The study authors attribute the success of the intervention to therapy that is highly personalized for each individual. On average, participants had 21 different interventions.
About one-half the interventions were more medical in nature, according to Isaacson, and included monitoring blood pressure, cholesterol, and blood sugar levels. The other half were about lifestyle changes.
And even the lifestyle recommendations were individualized. For example, while most participants were told to get physical activity, their specific exercise plans differed.
“If they had a high percent body fat and low muscle mass, then we would recommend weight training and cardiovascular and high-intensity training to reduce body fat,” says Isaacson. On the other hand, “If someone had a big belly but their muscle mass was good, we might recommend weights once a week but maybe three or four weekly high-intensity cardiovascular interval training sessions to really burn fat.”
Yuko Hara, PhD, director of Aging and Alzheimer’s Prevention with the Alzheimer’s Drug Discovery Foundation (ADDF) in New York City, points out that most of these lifestyle interventions align with many of the recommendations that the ADDF makes as First Steps to Protect Your Cognitive Vitality.
These include eating nutritious foods, getting enough sleep, exercising, alleviating stress, being social, continuing learning (for example, taking classes or learning a new language), and managing chronic illnesses (such as hypertension or diabetes).
“Long-term lifestyle interventions have more impact than a single drug,” says Hara, “and if you start early, you can maintain brain health and reduce risk for cognitive decline.”
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How Age and ‘Cognitive Aging’ Fit Into the Picture
Hara found that the effectiveness of the individualized intervention in relation to a participant’s age “intriguing.”
“The younger the participant, the greater the improvement in cognitive functions,” she observes.
For Hara, these findings reinforce the belief that people should take concrete steps today to reduce their risk for cognitive decline and dementia.
“You shouldn’t wait until you get a diagnosis before you take action,” she says.
Hara also commented that measures for “cognitive aging” improved among participants. People who didn’t already have mild cognitive impairment or mild Alzheimer’s had an estimated delay of cognitive decline by approximately three years with the individualized intervention.
“Even people who already had mild cognitive impairment showed a delay of cognitive decline by an average of two years if they were highly compliant to the interventions,” says Hara. “That’s not trivial to delay cognitive decline by so many years.”
Next Up: Longer-Term Results From More Diverse Populations
Isaacson next intends to go beyond the 18-month results and focus on findings from three years of accumulated data.
“Longer-term results will be more beneficial,” he says. “Somewhere between three and five years’ time, people start plateauing — the aging process starts catching up, and they can start going back to where their baseline was.”
The research team would also like to get information on a bigger population from more locations around the globe.
“I think for standard of care to change, we would need more evidence, because this is a single study done at a single site,” says Hara. “The study needs to be repeated at other clinical sites and in other populations.”
Although standard clinical practice may not change overnight, Isaacson encourages people to take matters into their own hands and take action now.
“Alzheimer’s may be preventable in at least one out of three cases if that person does everything right,” he says. “People should have hope.”