I came across many studies showing the benefits of healthy lifestyle, but there is one in particular I always feel compelled to share with anybody starting their healthy lifestyle journey because it shows that a healthy lifestyle benefits everybody, including people who had their genetic dice cast against them:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8484773/#:~:text=While%20APOE*E4%20carriers%20were,associated%20with%20slower%20cognitive%20decline.
One of the well-known genes influencing the risk of getting Alzheimer's disease is APOE. Each person inherits 2 copies of APOE called alleles. The alleles can have several forms: ε2, ε3 and ε4. Having at least one APOE ε4 gene doubles the risk of getting Alzheimer's disease. The study looked at the cognitive decline of 3886 individuals over 9 years. The conclusion was that the cognitive decline could be slowed down considerably if scoring high for a healthy lifestyle, defined as 1) MIND diet score (without alcohol) in the top 40% of the cohort distribution; 2) cognitive activities in the top 40% of the cohort distribution; 3) not being a current smoker; 4) moderate or vigorous exercise for at least 150 minutes per week; and 5) light-to-moderate alcohol consumption (1–15 g/day for women and 1–30 g/day for men—that is, up to approximately 1 drink per day for women and 2 drinks per day for men). By contrast, have a look at the people who have no increase in genetic risk but do not pay attention to lifestyle:
Rate of change in global cognitive score over 17 years among carriers of the ε4 allele of the apolipoprotein E gene (APOE*E4) (A) and APOE*E4 noncarriers (B) according to their adherence to healthy lifestyle factors, Chicago Health and Aging Project, 1993–2012.
Dhana K, Aggarwal NT, Rajan KB, Barnes LL, Evans DA, Morris MC. Impact of the Apolipoprotein E ε4 Allele on the Relationship Between Healthy Lifestyle and Cognitive Decline: A Population-Based Study. Am J Epidemiol. 2021 Jul 1;190(7):1225-1233. doi: 10.1093/aje/kwab033. PMID: 33585904; PMCID: PMC8484773.
