Telomeres are repetitive sequences of DNA capping the ends of chromosomes and protecting them from deterioration or from fusion with neighboring chromosomes. Telomeres shorten progressively over time -- at an average rate of approximately 50-100 base pairs annually. Telomere length is variable, shortening more rapidly under conditions of high psychosocial and physiological stress. Shorter telomere length is associated with increased risk of premature death and chronic diseases such as diabetes, dementia, stroke and heart disease. Among African American men with stronger anti-Black attitudes, investigators found that average telomere length was approximately 140 base pairs shorter in those reporting high vs. low levels of racial discrimination; this difference may equate to 1.4 to 2.8 years chronologically.