Esteban Parra

Small image of Parra
Wednesday, July 12, 2006 - 1:41pm
Carla DeMarco
This Early Researcher Award winner is exploring skin pigmentation

Image of Parra

Esteban Parra is remarkably humble when the Early Researcher Award (ERA) he recently won is mentioned. “I applied before and I didn’t get it, so I applied again,” says Parra, an assistant professor in the department of anthropology. “You have to apply and persist. Sometimes you’re lucky, sometimes you’re not.”


Parra also points out that his winning the award was down to the wire, since it is given by the province to promising researchers who are within the first five years of an independent academic career. Parra, who came to the University of Toronto Mississauga campus in 2002 to work in molecular anthropology, says it was his last chance to apply. He is relieved to have received the award that will allow him to build his research team of graduate students, post-doctoral fellows and research associates to further study skin pigmentation and its relationship with vitamin D synthesis.


Skin pigmentation is of particular interest for Parra, although he says that there are some misunderstandings in this area. “Some people are not comfortable with anybody working in skin pigmentation research, maybe because of the wrong use of pigmentation in the past, or because it is regarded as classifying people in races,” Parra explains. But Parra’s approach is to examine the unique situation of a trait, such as skin pigmentation, that shows a remarkable variation between populations. This contrasts to most other human traits, which typically show small populations differences. What factors have been involved in the evolution of skin pigmentation? How many genes are responsible for normal pigmentation variation?. “It is really amazing that we are in the 21st century, and we know so much – the human genome has been sequenced, and there are all kinds of technological and theoretical advances – but we still do not know why people have different colours of the skin, the iris, or the hair,” Parra says, and he further explains that natural selection has been acting in promoting light skin away from the tropics, and dark skin in the tropics. “This is not only to understand evolution, which is interesting on its own, but also its influence in terms of health.”

Some people are not comfortable with anybody working in skin pigmentation research..

One main focus for Parra’s work with regards to health is vitamin D, which has long been regarded as an essential nutrient for bone growth and development. “But there is recent research that shows that vitamin D goes well beyond that,” Parra states. “It is very important for autoimmune diseases, like multiple sclerosis, several forms of cancer – breast cancer and prostate cancer, for example – and defends against pathogens, too.” However vitamin D synthesis, which is particularly varied in such a diverse population as is found in Canada, has been found to be affected by the amount of the skin’s melanin, a complex mixture of pigments formed in skin cells (known as melanocytes) that helps to protect skin against the harmful effects of ultraviolet radiation (UVR).

For their upcoming vitamin-D project, Parra and his associates will be measuring test subjects’ skin pigmentation through a machine called a reflectometer, which measures the reflectance of the skin and relates the amount of melanin. The pigmentation readings will take place at two key times: in February or March, when people have not been able to synthesize vitamin D naturally throughout the long winter, and then again at end of the summer, when there is enough UVR to synthesize vitamin D. Blood samples will also be collected at both times, so they can measure vitamin D levels, and they will be able to note the correlation between the amount of melanin in the skin and vitamin D synthesis. The vitamin D analysis for the project will be conducted by Dr. Reinhold Vieth, a world-renowned expert on vitamin D metabolism, from nutritional sciences and laboratory medicine and pathobiology at University of Toronto. Parra says that studies of this nature have been conducted before, but they mostly focused on people of European ancestry. This project will target a diverse group of people, including a large sample from South and East Asia, Africa and the Middle East, as well as Europe.

Parra, who is also interested in admixture – a mixing of people from different areas, and a particular trait of the Americas since the 15th century – feels that Toronto is the ideal setting for his research. “Being in Toronto for an anthropologist is paradise,” says Parra. “Of all the places that I have been Toronto is the most cosmopolitan by far. You basically have the whole world in one place, and you can try to study variation.”
 "You basically have teh whole world in one place and you can try to study variation

And Parra has many cities with which to compare Toronto. Since he received his PhD in 1993 from the University of Santiago in Spain, his homeland, Parra was a postdoctoral fellow in Rome and Spain, before coming to North America where he has lived for the past ten years. He worked at two separate institutions in Pittsburgh, and then on to Penn State, before relocating to Toronto, where his fiancée, Heather MacLean, was already working as an assistant professor in civil engineering on the St. George campus. Parra has also travelled extensively, and has collaborated on several different projects with people from around the world.

Although Parra misses Spain, he has been enjoying the range of activities that Toronto has to offer. True to his Spanish roots, he is a great soccer enthusiast. He plays “just for fun” with a group from the Swansea Soccer Association year-round, and he also plays with an informal group, comprised of University of Toronto Mississauga faculty members and students from various disciplines, who play on the field at noon when weather permits. Parra has also been learning to salsa dance with his fiancée, and music in general – from jazz festivals to classical concerts – is a big part of their time spent outside of their respective labs.

While he wishes that he had more time to engage in extracurricular activities, Parra feels very fortunate to be pursuing his research projects in anthropology, a field he was drawn to as an undergraduate, and to have his position on the Mississauga campus, which includes two labs – one for pre- PCR (polymerase chain reaction) work, such as DNA purification and quantitation, and one for post-PCR work, including gel analysis and DNA sequencing. “I was lucky. I came here for an interview, and they were interested in my research,” Parra says. “Now this is more than enough. I cannot complain.”