Nutrient-dense eating patterns during a limited daily “eating window” can encourage more effective immunometabolic, cardiovascular, neurocognitive, and autophagic function over time, with considerable scope on what these eating patterns may look like in a given person’s life. These effects are bolstered by regular and sometimes intense physical activity, mind-body practices, avoiding toxic exposures, limiting alcohol intake, and solid sleep. But genetics and epigenetics also impact these aspects of health, in equally individualized fashion. Is it possible to tease out the overlapping effects of genes and lifestyle on overall risk for dementia? Recent research highlighted in the July 2019 issue of JAMA aimed to find out.
This retrospective study included almost 200,000 older individuals of European origin without cognitive impairment who had been evaluated for ancestry and genetic point mutations associated with these conditions, and tracked them for an average of about 8 years. Genetic risk was determined as low, intermediate, or high according to polygenic evaluation for the presence of single-nucleotide polymorphisms (SNPs) identified by previous genome-wide association study (GWAS) as both common among those with European ancestry and related to dementia risk in this population. With available lifestyle information on study participants, researchers scored contributions according to a simple 0- or 1-point scale for four variables (resulting in an overall 0-4 score):
moderate alcohol consumption (0-1 drink daily for women and 0-2 drinks daily for men)
healthy diet (eating at least 4 of 7 food groups linked to better cardiometabolic health)
sufficiency of physical activity (75 weekly minutes’ vigorous, 150 weekly minutes’ moderate, 5 days per week moderate, 1 day per week intense, or any equivalent combination)
The researchers found that individuals with combined increased risk from both lifestyle and genetics showed almost tripled the risk for dementia, compared to those with low lifestyle as well as genetic risk. High genetic risk alone resulted in almost doubling of dementia risk, yet persons with high lifestyle risk alone showed about 1.5 times the dementia risk of those with high genetic risk alone. Persons with intermediate genetic risk but a favorable lifestyle showed a lower dementia risk than persons with low genetic risk but high lifestyle risk.
The final conclusion? A healthier lifestyle significantly reduces dementia risk regardless of whether genetic risk is high, intermediate, or low.