Regardless of Alzheimer’s susceptibility leading a healthy lifestyle is associated with a reduced rate of memory loss
As people get older, they inevitably experience a decline in their cognitive abilities. However, the FINGER clinical trial (a reputable source) and other studies have shown that it is possible to avert cognitive decline by making adjustments to one’s way of life.
Many studies have examined the role that various aspects of one’s lifestyle play in one’s memory. Previous studies, however, tended to zero in on just one aspect of lifestyle, such as food intake, exercise, cigarette smoking, or alcohol consumption. It is crucial to investigate the interplay between a variety of lifestyle factors and the ageing of the brain.
Dr. Jianping Jia, Ph.D., a neurologist and professor at Capital Medical University in Beijing, China, and his colleagues set out to examine the synergistic effects of six lifestyle factors on memory decline in a sizable population over a period of 10 years.
Dr. Jia was quoted as saying in an article published by Medical News Today.
Numerous elderly people could gain from [e]ffective strategies for protecting against memory decline. We found that older adults, including those predisposed to memory loss due to genetics, who adhered to a number of different healthy lifestyle habits experienced a slower rate of memory decline.
BMJTrusted Source reports on the study’s findings.
Neurologist and Mayo Clinic professor Richard J. Caselli praised the study, saying it was “well done and generally supportive of findings from studies such as the FINGER study, this time in a Chinese population.”
Massive research project with ten years of follow-up
The researchers enlisted 29,072 healthy seniors aged 60 and up from all over North, South, and West China. There were more men than women among this group (51.5% versus 48.5%).
At the outset of the study, genetic testing revealed that 20.43 percent of the participants carried the APOE 4 gene, the strongest known risk factor for Alzheimer’s disease and related dementias.
Over the next decade, researchers checked in with participants in 2012, 2014, 2016, and 2019.
Participants’ memories were evaluated using the Auditory Verbal Learning Test (AVLT) at baseline and at each follow-up. This test measures immediate recall, short delay-free recall (3 minutes later), long delay-free recall (30 minutes later), and long delay recognition.
Consciousness, activity, diet, stress, and sleep are the big six.
Dr. Jia and his colleagues defined a healthy way of life based on U.S. guidelines and the results of previous studies. Six factors were singled out by them:
- consuming at least 7 out of 12 allowable food groups daily is considered to have a healthy diet (fruits, vegetables, fish, meat, dairy products, salt, oil, eggs, cereals, legumes, nuts, and tea)
- routine physical activity, defined as at least 150 minutes per week of moderate-intensity activity or at least 75 minutes per week of vigorous-intensity activity.
- Engaging in at least two forms of social activity per week (such as going to gatherings, hosting or attending a party, seeing friends and family, going on a trip, or chatting online) is recommended.
- At least twice a week, engage in some form of active cognitive activity (such as writing, reading, playing cards, mahjong, or other games).
- individuals who had smoked fewer than a hundred cigarettes in their lives (the “never smokers”) or former smokers (participants who had quit smoking at least 3 years before the study)
- either never or rarely drank alcohol
Memory loss can be delayed by adopting a healthy lifestyle.
Average performance on memory tests steadily dropped over a ten-year period for all study participants. Participants with favourable lifestyles had slower memory decline than those with unfavourable lifestyles (by 0.028 points/year), as shown by the highest memory test scores being observed in the favourable lifestyle group and the lowest being observed in the unfavourable lifestyle group.
A healthy diet was found to have the greatest impact on memory, followed by engaging in cognitive activity, engaging in regular physical exercise, actively maintaining social connections, never or formerly smoking, and abstaining from alcohol.
Memory loss-altering mechanisms were not discovered in this study. “reduced cerebrovascular risk,” “enhanced cognitive reserve,” “inhibition of oxidative stress and inflammation,” and “promotion of neurotrophic factors” were all proposed as possibilities by the researchers.
To MNT, Dr. Caselli said, “whether directly or indirectly [beneficial to memory], these findings seem credible and consistent with other well conducted studies,” adding that the “findings echo heart healthy behaviours (diet, exercise, no smoking in particular),” with the addition of active social and cognitive activity.
Non-participating epidemiologist Dorly J.H. Deeg, Ph.D., of the Amsterdam University Medical Center, likewise lauded the study for its extensive sample size and variety of analyses.
Alzheimer’s disease susceptibility: the role of healthy habits versus genetics
Twenty-three percent of the study population carried the APOE 4 allele, a genetic variant strongly associated with increased vulnerability to developing Alzheimer’s disease.
This study found that healthy lifestyle habits improved memory in all participants, regardless of whether or not they carried the APOE 4 allele.
Some people are discouraged to learn they are a 4 carrier, and we’ve found that’s okay, too,” Dr. Caselli hopes that the study’s findings will give those affected confidence that they can take steps to lessen the impact of their genetic predisposition to risk.
Potential Future Directions and Restrictions of the Current Study
Dr. Jia and colleagues point out in their paper that the self-reported nature of lifestyle factors introduces measurement error into the study. In addition, only one neuropsychological test was used to evaluate memory. They also admit the study design didn’t look at whether or not healthy habits started having an effect on memory before age 60.
The possibility that some participants had Alzheimer’s disease in its preclinical stages was not ruled out, according to Dr. Caselli’s comments to MNT. Though this required a 10-year follow-up, the preclinical phase of Alzheimer’s disease is closer to 20 years, so things like social and cognitive activity may already start to decline in subtle ways before a person with preclinical stage disease develops overt symptoms and is diagnosed with MCI [mild cognitive impairment].
Dr. Deeg noted that the researchers “excluded a huge number of participants” (30 percent of eligible people) in comments to MNT.
” This is labelled as “younger than 60 years, refused to participate, etc” in the study’s official documentation. She said, “As a reviewer, I do not find this to be a convincing explanation.
Observational studies like this one, Dr. Deeg told MNT, “should be replicated in randomised controlled trials.”
These randomised controlled trials have been conducted, though typically they focus on just one lifestyle factor, such as exercise. Sadly, she continued, “the findings are not unambiguous, and a recent JAMA articleTrusted Source showed no effects. “Therefore, we need to know what the underlying mechanisms in the brain are in order to find out what intervention would work, and why.”
Séverine Sabia, PhD, of Université Paris Cité in France, and Archana Singh-Manoux, PhD, of University College London, wrote in an editorialTrusted Source linked to this study that future research should focus on “identifying not only the factors that matter most but also the threshold at which they matter, and the age when intervention is likely to be most effective.”