Table 1.

Internal and External Exposures That Influence Telomere Length.

	Modifiable	Nonmodifiable
Internal   exposures	Oxidative stress Inflammation Body morphology Physiologic   comorbidities Physical activity Psychological and mental   health Perceived stress	Chronological age Endogenous circulating   hormones Genetic predisposition
External   exposures	Lifestyle factors Dietary intake Smoking Alcohol consumption Occupation Sleep deprivation	Environmental pollutants Chemical contaminants Radiation Infectious agents Climate