Life-long risk reduction could cut late dementia by a third

(First of two parts)

As many as a third of dementia cases could be prevented worldwide if society could adopt a life course-focused approach of supporting brain health with mostly common sense measures.

Improving childhood education, controlling blood pressure and cholesterol, keeping socially and intellectually active, exercising, and ceasing tobacco use are among the recommendations to reduce the incidence of dementia made by a worldwide panel of expert clinicians and researchers.

The findings are part of an exhaustive report commission by The Lancet and released at the Alzheimer’s Association International Conference. The report has concluded that nine lifestyle factors, most of which are modifiable from childhood though middle age, account for 35 percent of dementia that strikes elderly persons, as mentioned during the conference. The report was simultaneously published.

Together, these factors, which also impact many other areas of health and well-being, dwarf the genetic risk compared by the high-risk ApoE4 allele according to the University College London and the paper’s lead author.

Being homozygous for the ApoE4 allele confers about immutable seven percent increase chance of developing Alzheimer’s disease. But two of the other factors identified in the Lancet report, low education in childhood and hearing lost in middle age, confer even higher individual risks of eight percent and nine percent. And when combined with other mid-life risks of hypertension and obesity, and late-life risks imposed by smoking, depression, inactivity, social isolation, and diabetes, these factors not only dwarf the potential impact of ApoE4, but offer a life-long chance to forestall or even prevent dementia.

The findings, all gathered from an exhaustive literature review, bolster the notion that public health intervention could block the tsunami of dementia cases that threatened to overwhelm the world’s health care resources by 2050 , a doctor said at the conference.

While public health intervention won’t prevent or cure all potentially modifiable dementia, intervention for cardiovascular risk factors, mental health, and hearing may push back the onset on many people for years. Even if only some of these promise is realized, it could make a huge difference. We have, in fact, already seen that in some populations dementia is being delayed for years. If we could achieve an overall delay of onset by five years, we could cut the global prevalence by half.

The Lancet commissioned the panel of global dementia experts to review the extant literature and construct a lifespan-focused risk model. In addition to examining risk and making recommendations to ameliorate it, the panel issued recommendations about treating cognition and psychiatric and behavioral problems; protecting dementia patients in both home and long-term care settings; supporting the family members who provide most of the care for dementia patients; and helping patients and families navigate end-of-life situations.

The literature review identified nine modifiable risk factors that account for 35 percent of dementia risk worldwide.

• Education in youth – less education in childhood, which the commission identified as a lack of secondary schooling, increased the risk of dementia by eight percent. Improving education at this age would remove this portion of the population attributable risk factor (PAF).

This finding represents an enormous opportunity for improvement. The decline in dementia incidence seen in some populations occurs mostly among the better-educated.

The mechanism of prevention here appears to be increasing brain resilience, said by one of the members of the Lancet panel. (To be continued)