001) after covariates were controlled for. A recent study kinase inhibitor Bortezomib [14] indicates that the prevalence curve by age for positive PIB scans in cognitively normal persons overlies the prevalence of amyloid plaque measures from Braak and Braak’s [11] autopsy study in nondemented persons. Very interestingly, this curve parallels the AD prevalence by age but is 15 years earlier at each age. This 15-year window may be the opportunity to prevent AD with interventions such as exercise. 5E. Inflammatory biomarkers Whereas cross-sectional studies show that inflammatory biomarkers such as C-reactive protein are lower in persons who exercise [60,61], a randomized control trial did not show that exercise decreases C-reactive protein [62].

Conclusions There is increasing evidence from basic research, including transgenic mouse experiments, epidemiology, biomarkers, and a limited number of prospective studies, that aerobic exercise may be protective of brain health by changing chemical factors in the brain and warding off diseases and other factors related to brain disease, such as diabetes, hypertension, and inflammation. The time is ripe to do prospective studies to validate this assertion. Abbreviations AD: Alzheimer’s disease; ADAS-Cog: Alzheimer’s Disease Assessment Scale-Cognitive Subscale; BDNF: brain-derived neurotrophic factor; CBV: cerebral blood volume; CI: confidence interval; CSF: cerebrospinal fluid; LBD: Lewy body disease; MCI: mild cognitive impairment; MRI: magnetic resonance imaging; PD: Parkinson disease; PIB: Pittsburgh compound-B; VaD: vascular dementia.

Competing interests The author declares that they have no competing interests.
Alzheimer disease (AD) is the most common form of dementia, affecting 5.5 million people in the US. Progressive neurodegeneration results in relentless cognitive decline, posing a substantial public health burden, and has major implications at the individual level. AD phenotypes are divided into early-onset (EOAD) and late-onset (LOAD) AD with the arbitrary cut-off 65 years in most studies [1]. Approximately 1% to 6% of all AD is early-onset. Genetics plays a more significant role in EOAD, as this subset is enriched for familial disease in 60% of the cases [2]. Furthermore, 13% of EOAD has an autosomal dominant inheritance pattern, and three genes – the amyloid precursor protein (APP), presenilin 1 (PSEN1), and presenilin 2 (PSEN2) – have been identified as having mutations that cause EOAD.

These genes contribute to approximately Dacomitinib 80% of the autosomal dominant EOAD cases [2-4]. Although these mutations are rare and affect a small percentage of AD cases, the discovery of these selleck kinase inhibitor three genes gave molecular genetic evidence supporting the amyloid hypothesis. As the amyloid cascade is the leading hypothesis, this cohort would be ideal for proof-of-principle studies in amyloid-based drug therapy.