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Despite meat-heavy diet, indigenous tribe has world’s healthiest hearts — but why?

ASU prof: Tsimane people have lowest levels of plaque in their hearts ever seen
Study reveals new details about relationship between inflammation, heart disease
March 17, 2017

ASU professor helps lead study that shows low levels of arterial plaque in group with low good cholesterol, high inflammation

Researchers have discovered that despite meat-heavy diets, low levels of good cholesterol and high levels of inflammation, an indigenous South American tribe has the healthiest hearts ever examined — and it might have something to do with parasites in the gut.  

“It’s kind of an exciting paper,” said Ben Trumble, co-director of the study and an assistant professor in the School of Human Evolution and Social Change at Arizona State University and affiliated faculty in the Center for Evolution and Medicine, “because for a long time we thought pre-industrial groups had lower levels of heart disease. The Tsimane have the lowest levels of plaque in their coronary arteries that we’ve ever seen.”

An 80-year-old Tsimane has heart arteries equal to a 50-year-old American, scientists discovered.

“One of the key things about this study is we’ve always thought populations living these traditional lifestyles had low risk factors,” Trumble said, “but we were never able to show before that they actually did have these very low levels of atherosclerosis. This is the first time it’s been shown.”

About 90 percent of the Tsimane people’s food comes from hunting, fishing, foraging, and farming. Until two years ago, none of their communities had electricity. None have running water. They live in the Bolivian Amazon with relatively low contact with the rest of Bolivia. Most still speak their traditional language. It takes days to get from villages to towns.

They eat about the same amount of meat that Americans do, but it’s much leaner, coming from wild animals. The average hunt for a Tsimane man takes five to six hours and ranges up to 10 miles.

But another potential factor for a healthy heart is perhaps surprising: Tsimane have a high parasite -pathogen load.

More than two thirds of Tsimane adults have intestinal ailments, according to Trumble. About 30 percent also have giardia on top of that.

fish being smoked outside
Smoking fish over a fire. Ninety percent of the Tsimane people’s food comes from hunting, fishing, foraging, and farming. Photo by Ben Trumble

“That creates a really big burden because intestinal parasites eat the food we eat before we can absorb it, or they’re tapping into our blood streams, stealing the (fats) from our blood, stealing calories,” he said.

Some combination of diet, physical activity and the immune system are working together to prevent heart disease, but researchers aren’t sure how they connect.

The Tsimane have high rates of inflammation, stemming from high exposure to the pathogens and parasites, but not obesity.

“That’s what makes this population really interesting to study,” Trumble said. “You could say, ‘Oh, they get four to seven hours of activity per day, and they’re not eating cheeseburgers, so of course they’re not going to get heart disease.’ But the thing that makes this population really interesting is that they have such levels of inflammation. We’ve always thought of inflammation as this major cause of heart disease. They’re just getting it from a different source, and it’s not having any effect at all.”

If you’re reading this with a kale smoothie before your morning run and wondering if it all makes a difference, co-author Michael Gurven of the University of California - Santa Barbara Anthropology Department said you’re doing the right thing — but the Tsimane still have medical issues.

“While the active lifestyle, lean diet, minimal obesity and smoking are all consistent with having a healthy heart, (the) Tsimane also experience high levels of inflammation and low levels of 'good cholesterol,’” Gurven said in an email interview. “Given this combination of factors consistent with both low and high risk, it is remarkable that the Tsimane have such low levels of coronary artery disease.”

Gurven said researchers compared the “arterial age” between Tsimane and Americans using coronary artery calcium scores, revealing the gap between Tsimane and American hearts.

“Curiously, prior work measuring biological age based on immune cell parameters showed that Tsimane were biologically "older" than their age — that their immune systems are not up to par,” Gurven said. “This is fascinating because it shows that different biological systems may age at different rates — and indeed, the majority of older adult deaths are due to infectious disease, and rarely (if at all) from coronary artery disease.”

There are 16,000 Tsimane living in 95 communities, with between 30 to 500 in each village. The population is mainly children. Tsimane women average about nine children each.

“One thing I think a lot of people get confused is that there’s this idea that life was nasty, brutish and short, and with life expectancies in the 40s and 50s, people were going to die before they got heart disease anyway,” Trumble said.

There’s a big problem with that, however: the way life expectancies are calculated. Life expectancy at birth in a hunter-gatherer population is in the 30- to 40-year range, because of high infant mortality.

“For the average Tsimane who makes it to age 15, the modal age of death is 70,” Trumble said. “They’re living just as long as we are,” but their rates of heart disease are far, far lower.

The study was published Friday in The Lancet.


Top photo: Tsimane man crossing the Maniqui River. Photo by Ben Trumble.

Scott Seckel

Reporter , ASU Now


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Black Lives Matter figure DeRay Mckesson speaks at ASU about activism

Black Lives Matter figure stresses power of activism to ASU crowd.
March 20, 2017

Movement organizer praises the power of social media, urges students to enact positive social change in their community

A message posted outside the Memorial Union Ventana Ballroom on Monday night forbade the presence of posters and signs at a student-organized talk being given by DeRay Mckesson, one of the most outspoken members of the Black Lives Matter movement.

The international activist movement that began in 2013 with a Twitter hashtag in response to the acquittal of George Zimmerman in the shooting death of African-American teen Trayvon Martin has been at the center of a politically and socially charged conversation concerning violence and perceived systemic racism toward black people in the U.S. criminal justice system since.

But the event on ASU’s Tempe campus where Mckesson spoke to a group of roughly 350 students, faculty, staff and members of the community was peaceful and informative, covering topics from the power of social media, to the importance of engaging others in the cause, to productive next moves. 

“As organizers, we give you the language and the tools” to enact positive change, Mckesson told the crowd, referring to himself and other influential activists associated with Black Lives Matter. “But you have to carry this stuff with you every day, at work, at home” and everywhere else.

The event was organized by students from various groups including Undergraduate Student Government, Rainbow Coalition and Black African Coalition.

Geography and urban planning undergrad and president of Rainbow Coalition Gabriel Leon said having someone speak to students about activism has “the power to deepen and broaden their perspective of the world.”

Mckesson began his talk with images from the 2014 protests in Ferguson, Missouri, that followed the shooting death of another young black man, Michael Brown, by white police officer Darren Wilson. If it weren’t for social media, Mckesson said, nobody would have known Brown’s body lay in the street for four hours before being removed by medical personnel.

Mckesson himself has more than 750,000 Twitter followers. He praised social media in general for its ability to allow everyday people to tell the story of what’s really going on around them — “telling the truth in public,” as he calls it.

In April 2015, Mckesson and fellow activists Johnetta Elzie, Samuel Sinyangwe and Brittany Packnett launched Mapping Police Violence, which collected data on people killed by police during 2014. In August 2015, the same group launched Campaign Zero, a 10-point policy plan for police reform.

He addressed the issue Monday night, saying, “There’s very little data on police.” He added that most of that data comes from an aggregate of newspaper reports, which is a problem because it can be inaccurate.

Although he preferred to avoid commenting too much about President Donald Trump (“because he’s stressing me out right now,” he said), Mckesson did speak about having met with former presidential hopefuls Hillary Clinton and Bernie Sanders, as well as former President Barack Obama, to advance the mission of Black Lives Matter.

He stressed the importance of activists having a presence and voicing their concerns both amongst each other and to people in power. 

“We have to be on the inside as well as the outside,” Mckesson said. “Us being present at the table is our attempt to make truth present at the table.”

He proved that conviction in 2016 when he ran for mayor of his hometown, Baltimore. Though he lost, the experience — during which he sometimes spoke to neighborhood crowds in living room gatherings — served as “a deep reminder of the power of organizing at the local level.”

At the close of his talk, Mckesson told the audience that they have “the power to stand up right now and do something beautiful” through protest, and that the most compelling data they have to back up their cause is their own lives.


Top photo: Educator and civil rights activist DeRay Mckesson speaks to a group of students Monday in the Memorial Union on ASU's Tempe campus. Mckesson is a leading voice in the Black Lives Matter movement, and his speech focused on campaign strategies, the origins of Black Lives Matter and the role of activism in the current political climate. Photo by Anya Magnuson/ASU Now

Emma Greguska

Reporter , ASU Now

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