A healthy diet delays memory decline in the elderly, even with the Alzheimer’s gene
A healthy lifestyle, in particular a healthy diet is associated with a slower decline in memoryaccording to a decade-long study of older adults in China, published in ‘The BMJ’.
Even in the case of carriers of the apolipoprotein E (APOE) gene, The most important risk factor for Alzheimer’s disease and other related dementias, a healthy lifestyle slows memory loss.
Memory declines as you age
Memory declines continuously as one ages, but data from existing studies are insufficient to assess the effect of a healthy lifestyle on memory in later life and, given the many possible causes of memory impairment, it could A combination of healthy behaviors may be necessary for optimal effect.
Study with 29,000 adults over 60 years of age
To delve deeper into this question, the researchers analyzed data from 29,000 adults aged 60 or older (mean age 72 years; 49% women) with normal cognitive function who were part of the China Study of Cognition and Aging.
At the start of the study in 2009, memory function was measured using the Auditory Verbal Learning Test (AVLT) and participants were tested for the APOE gene (20% were found to be carriers). Follow-up evaluations were then carried out over the next 10 years, in 2012, 2014, 2016 and 2019.
Healthy diet, regular exercise and not smoking and drinking
A healthy lifestyle score was then calculated that combined six factors: healthy diet, regular exercise, active social contact (eg, seeing friends and family), cognitive activity (eg, writing, reading, playing mahjong) Don’t smoke and never drink alcohol.
Based on their score, which ranged from 0 to 6, participants were categorized into favorable lifestyle groups (4 to 6 healthy factors), medium (2 to 3 healthy factors) or unfavorable (0 to 1 healthy factors) and in groups of APOE carriers and non-carriers.
After accounting for other health, economic, and social factors, the researchers found that each individual healthy behavior was associated with slower-than-average memory decline over 10 years.
The healthy diet slowed down the deterioration
The healthy diet was the one that contributed the most to slow down the deterioration of memory, followed by cognitive activity and physical exercise.
Compared with the unfavorable lifestyle group, memory decline in the favorable lifestyle group was 0.28 points slower over 10 years based on the standardized score (z-score) of the AVLT, and memory decline in the medium lifestyle group was 0.16 points slower.
Participants with the APOE gene with favorable and medium lifestyles also experienced a slower rate of memory decline than those with an unfavorable lifestyle (0.027 and 0.014 point per year slower, respectively).
Lower risk of dementia
In addition, people with favorable or average lifestyles had almost 90% to 30% less likely to develop dementia or mild cognitive impairment than those with an unfavorable lifestyle, and the APOE group had similar results.
This is an observational study, so it cannot establish cause, and the researchers acknowledge some limitations, such as the possibility of measurement errors due to self-reported lifestyle factors, and the possibility of selection bias, as some participants did not return for follow-up assessments.
But this is a large study with a long follow-up period, allowing individual lifestyle factors to assess memory function over time. Furthermore, the results remained significant after subsequent analyses, suggesting that they are robust.
For this reason, the researchers state that the results provide reliable evidence that the observance of a healthy lifestyle, with a combination of positive behaviors, is associated with less memory impairment, even in people genetically susceptible to it.
They suggest that future research could focus on the effects of a healthy lifestyle on memory decline throughout life, acknowledging that memory problems may also affect younger people, not included in this study.
“These results could offer important information for public health initiatives aimed at protecting older adults against the memory impairment,” conclude.
“Prevention is important, given the absence of effective treatments for Alzheimer disease and other related dementias,” the researchers state in a linked editorial.
Doubts about the study
However, they note that these results do not help determine which of the six healthy behaviors included in the score (or a specific combination) is the best target for dementia prevention, or at what point in life to focus efforts. of prevention. More data is also needed to determine if the differences in memory impairment seen in this study are clinically meaningful, they add.
They suggest that an approach similar to the one that led to a substantial reduction in cardiovascular diseases should be adopted with dementia prevention, “identifying not only the factors that matter most, but also the threshold at which they matter, and the age at which the intervention is likely to be most effective.”