A new study, that suggests a different way to measure how humans age, may provide an answer to why Latinos live longer compared to non-Latino Caucasians. The study says that this is due to Latinos sharing a link with their Native American ancestors.
The new research provides insight into a question that a lot of researchers have been asking. Why do U.S Latinos averagely live longer than non-Latino whites even though they have higher rates of chronic diseases (obesity and diabetes) and inflammation?
The effort of the study was to develop a biological clock meant to be a better standard to measure age than walking speed, birthdays, twinkly eyes or wrinkled skin. Through the new standard researchers hoped to find out why some people live longer while others die young, and to understand how aging is linked to chronic disease, and predict as well as increase a person’s life spans. The effectiveness of anti-aging therapies can also be determined through the use of such a measure.
In the study, Steve Horvath, a bioinformatician at the University of California, created a measure of aging that reflected the epigenome’s activity level. Epigenome can be described as a set of signals that urges the genes to change their function throughout a person’s lifespan in response to new demands. The ‘epigenetic clock’ by Horvath covers how predictable and complex changes occur in the rate at which genes are switched off and on as individual’s grow older due to DNA Methylation. A total of 353 sites present in a person’s genome were observed to measure the biological age of a person and then to access their speed of aging.
Previous studies have also tried to make an epigenetic clock. These studies suggested that the speed of aging and the biological age is different in each individual. This means that the tissues present in all human beings may age at different rates. This observation may explain why some tissues and organs might be more vulnerable to cancer and other diseases related to age.
The new study was published in the journal Genome Biology. The researchers wanted to refine as well as test the epigenetic clock. Blood, saliva and lymphoblastoid samples were collected from a total of 5,162 volunteers and were analyzed for this study. The volunteers covered race and ethnicities including white, black and Latino American, Han Chinese, members of the Tsimané Amerindian tribe in South America, and also two separate groups of Central Africans (agrarians living in open savannas and grasslands and rain-forest-dwelling hunter-gatherers).
The Tsimané were included because they offered a good test of the epigenetic clock. The members of the tribe were constantly facing viral, parasitic and bacterial infections. A high rate of inflammation (a marker for aging) is also experienced by them. However, risk factors for type-2 diabetes and heart disease are rarely shown as they age. Other diseases such as obesity, high blood pressure and problematic cholesterol are nonexistent in the tribe.
The study observed that members of the Tsimané tribe aged even more slowly than Latinos. According to the results the age of their blood was two years younger when compared to Latinos of the same age. Also the age of their blood was shown to be four years younger compared to Caucasians. This was a surprising observation as the rate of inflammation found in a 35 year old Tsimané’s immune system made him comparatively close to a 90 year old. “This result sheds light on what is frequently called the Hispanic paradox,” said Horvath. “It suggests that what gives Hispanics their advantage is really their Native American ancestry, because they share ancestry with these indigenous Americans.”
Horvath was also quick to state that rate of slow aging in Latinos couldn’t be explained by their lifestyle factors as the researchers had adjusted for diet, education, socioeconomic status or obesity during the study.
The study also observed that women aged more slowly compared to men. Also aging accelerated in individuals with less education, however, it slowed down in individuals who had acquired more education. These results might explain why women, even though they experience more diseases, statistically live longer than men. It might also explain why a longer lifespan is linked to more education.