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VOA's weekly science and technology radio magazine
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This week on Our World: All fats are not created equal ... A new way of making salt water drinkable ... and the gender gap in American science ...
JEMISON: "They are really derailed from their track to becoming professional scientists by academic systems and societies that are neither color blind nor gender blind. There is a bias that makes them fall out "
Barriers to women and girls in science careers ... a traditional medicine cures a reporter's headache, and more.
I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."
Polyunsaturated Fats Reduce Risk of Heart Disease, Study Finds
For years, doctors have been telling patients to cut their consumption of saturated fats — the kinds of fats in meats and milk, for example. Reducing fat in the diet, especially saturated fat, was believed to be an important strategy for lowering the risk of heart disease.
Now, a new study says reducing fat intake isn't enough. Maybe it's the kinds of fats we eat.
MOZAFFARIAN: "And we wanted to look at whether replacing saturated fat with polyunsaturated fat, with a healthy fat rather than, for example, with carbohydrates or protein or other things, was beneficial."
Dariush Mozaffarian of the Harvard School of Public Health thought the answer might lie in the numerous studies over the years that looked at diet and heart disease.
MOZAFFARIAN: "And we wanted to do a systematic review of all the literature, find all of the appropriate studies and pool them to see if together, there's a benefit for replacing saturated fat specifically with polyunsaturated fat."
So Mozaffarian and his colleagues studied the studies in which some participants ate less saturated fat and more polyunsaturated fats, the kind of fats that are in fish, nuts, and vegetable oils. They were compared with a control group that had more saturated fat in their diets. Thirteen thousand people were enrolled in the eight studies they reviewed.
The studies showed that while cutting down on saturated fats may lower potentially dangerous levels of artery-clogging cholesterol in the blood stream, low-fat diets alone didn't do much to actually open up clogged arteries and reduce the risk of heart attacks.
MOZAFFARIAN: "There's actually, in the last several years, been convincing evidence that replacing saturated fat in one's diet with carbohydrates has very little effect on heart disease. And so if that's not going to produce benefit, what sorts of replacements [for saturated fats] might?"
Mozaffarian's study found that people who replaced saturated fat with polyunsaturated fat had about a 20 percent lower risk of heart attack or other heart disease.
It's still not exactly clear how the polyunsaturated fats confer this benefit. The effect on cholesterol may be part of the answer.
MOZAFFARIAN: "So for example, dietary fats also actually in many cases improve HDL cholesterol, the good cholesterol, compared to carbohydrates, and they actually lower triglycerides, a type of blood lipid which is associated with harm."
But Mozaffarian said dietary fats may also affect blood pressure and inflammation of the blood vessels; they may even have an impact on the heart's electrical function.
Whatever the mechanism, the study does suggest some guidance for people who want to lower their risk of heart disease.
MOZAFFARIAN: "They can't just look at a product that says 'low grams of saturated fat' or 'low saturated fat' and assume that it's healthy. If you're taking out the saturated fat, what are you replacing it with?"
And it doesn't mean we have to spend a lot of time parsing the nutritional labels that are now on packaged foods in many countries.
MOZAFFARIAN: "If someone says I should eat fruits, vegetables, whole grains, fish, nuts, and avoid processed foods, sugary beverages, and foods with trans fats or high in salt, that's actually much simpler, I think, than chasing all of these numbers."
I reached Professor Dariush Mozaffarian at his office at the Harvard School of Public Health. His study was published this week in the journal PLoS Medicine.
Diabetes in China on the Rise Along with Prosperity
In China, the booming economy has led to changes in how people live ... and eat. A new national study has found that diabetes — a disease associated with obesity and lack of physical activity — is now on the rise. Philip Graitcer reports.
GRAITCER: Diabetes is a chronic disease that's common in the Western world. Now, a new study shows it has reached epidemic proportions in China.
HE: "Diabetes is very prevalent in China's general population."
GRAITCER: Dr. Jiang He is an epidemiologist at Tulane University's School of Public Health and Tropical Medicine and one of the authors of the study published in the New England Journal of Medicine.
HE: "Our study reported the prevalence of diabetes was 9.7 percent."
GRAITCER: In other words, about 93 million Chinese adults have diabetes; that's triple the rate of diabetes seen in 1980.
The rapid rise in diabetes concerns Dr. He because it is a risk factor for heart disease.
Cardiovascular disease is already the leading cause of death in China.
Older people, obese people, and those living in cities have the highest rates of diabetes in China. Dr. He says that's because diabetes is a lifestyle disease.
HE: "This is a lifestyle issue. People eat more food, and they eat more calories, and they eat more fatty food, and do less physical activity."
GRAITCER: But diabetes is preventable, and the Tulane researcher says a public health initiative is needed.
HE: "Our study indicates there is an epidemic of obesity and diabetes in the Chinese general population. The government and the health professions should pay attention to this problem and develop a national policy and a strategy to prevent this problem."
GRAITCER: And it's not just the government and health officials in China that need to pay attention and take action. As long ago as 2004, the World Health Organization projected that the percentage of people with diabetes in developing countries would rise by one-third by 2025, approaching the rate in developed countries.
I'm Philip Graitcer.
Researchers Demonstrate Nanotech-based Desalination Device
U.S. and South Korean researchers have demonstrated a nanotechnology-based method for converting seawater into drinking water. So far, the invention only purifies tiny amounts of water, but scientists say it paves the way for low-power facilities that will be able to remove salt and other contaminants from enough seawater to provide entire communities with drinkable water. VOA's Jessica Berman reports.
BERMAN: The desalination process was tested on a postage stamp-size chip, which uses an electric current to help separate electrically charged salt particles and other impurities from water to make it drinkable.
Conventional, industrial-size desalination facilities use a process called reverse osmosis to filter salt and other contaminants out of sea water. But they are expensive to run and require a lot of power, which makes them a poor fit for many low-income countries, says Massachusetts Institute of Technology biotechnology professor Jongyoon Han.
HAN: "Many countries that suffer from the water shortages also [do not] have the water delivery infrastructure, [do not] have electricity infrastructure to power these large scale plants. I think that's the combined challenges that we need to address."
Han and his colleagues have developed ion concentration polarization, which improves the efficiency of the filtering process by adding a small electrical charge to the salt and other impurities.
The chip removed 99 percent of the salt and other contaminants from samples of undrinkable water.
Han says the technology might one day be available as a personal water purification appliance or used to bring drinking water to communities by scaling up the technology to create plates containing thousands of chips.
HAN: "And then run all of these little devices at the same time to get the flow rate at the levels of perhaps a hundred milliliters per minute. That flow rate is the typical flow rate you can get from the household water filtration devices."
BERMAN: Han would like to develop a way to power the devices so they can provide water in the wake of natural disasters, such as this year's devastating earthquake in Haiti.
HAN: "It needs to be run without the need for continuous power supply because some of these countries or disaster zones [do not] have working power or electricity. So, we think the power efficiency of this device is good enough so we can run this small unit with the solar power."
BERMAN: Han describes the desalination-on-a-chip technology this week online in the journal Nature Nanotechnology.
Jessica Berman, VOA News, Washington.
Website of the Week Features Unedited Videos of US Political Events
Time again for our Website of the Week, when we showcase interesting and innovative online destinations.
This time, it's a source for records of more than two decades of Congressional debates, Washington press conferences, newsmaker interviews, policy forums, and all the other machinations of government -- all captured live and unedited by the cameras of America's leading public affairs television network.
BROWNING: "The C-SPAN video library is an online digital collection of all material that's aired on C-SPAN since 1987
Robert Browning is the director of the C-SPAN archives at c-spanvideo.org. C-SPAN is the Cable-Satellite Public Affairs Network, which broadcasts live the proceedings of the U.S. Senate and House of Representatives, and fills the rest of its schedule with the policy conversations that drive decision-making here in Washington.
What's different about C-SPAN is that while a news report may give you a 10-second sound bite from a lawmaker or analyst, on C-SPAN you get the whole thing.
BROWNING: "We don't do edits; we don't cut out portions. We air the entire event. And so it really makes this programming that is airing every day usable for historians, for educators, and just for public citizens."
C-SPAN's archive includes 160,000 hours of tape, fully indexed and often transcribed to help you find what you're looking for.
And if you just want to browse, the C-SPAN Video Library blog has links to some memorable and historic moments, such as the 1987 Reagan-Gorbachev summit and George W. Bush announcing the capture of Saddam Hussein. That and much, much more uncut and unedited history at c-spanvideo.org, or get the link from our site, VOAnews.com.
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It's Our World, the weekly science and technology magazine from VOA News. I'm Art Chimes in Washington.
Reports Cite Barries to Women & Minorities in Science Careers
Women and minorities in the United States are under-represented in careers in science, technology, engineering, and mathematics. According to two reports released this week, poor schools, stereotypes, cultural bias, and workplace barriers are holding these students back. Researchers hope a better understanding of the trend can help reverse it.
VOA's Rosanne Skirble has the details.
SKIRBLE: Mae Jemison has accomplished many things in life. She's a chemical engineer, a medical doctor, a college professor, and in 1992, was the first African American woman astronaut to go into space.
Jemison is also a spokesperson for a Bayer Corporation science outreach program. Every year since 1995, the company commissions the Bayer Facts of Science Education survey on science literacy and workplace issues. This year, Jemison says, it polled 1,200 women and minority chemists and chemical engineers. Careers in science, technology, engineering and math are collectively known as STEM.
JEMISON: "And I think that survey shows that as minorities and women pursue a STEM career, they have to face a number of barriers along the [education] pipeline and they achieve in spite of [those barriers] many times. What we need to do as a society is really understand what these road blocks are."
SKIRBLE: While women and minorities make up two-thirds of the American workforce, they represent less than 25 percent of STEM careers. The survey cites poor schools and a lack of quality science and math programs, persistent negative stereotypes, financial cost, and school and workplace bias.
Jemison says the survey also finds an early interest in science in children younger than 11.
JEMISON: "What that means is that kids come out of the chute [are young], they are excited about the world around them. They are interested in what is going one, but many children hit roadblocks. They are really derailed from their track to becoming professional scientists by academic systems and societies that are neither color blind nor gender blind. There is a bias that makes them fall out [from career track].
SKIRBLE: Despite a gradual increase in women graduating with undergraduate and graduate degrees in science fields, the gap between men and women remains significant in the U.S. workplace. That's according to a second report released this week by the American Association of University Women.
Why So Few? compiles academic research from the last fifteen years, and its findings underscore the social and cultural bias and barriers in higher education reported by the chemists and engineers in the Bayer survey.
Co-author Andresse St. Rose says, for example, while girls earn high-school math credits at the same rate as boys, the myth that girls aren't good at math is persistent and powerful.
But St. Rose is hopeful that that situation can be reversed.
ST. ROSE: "Although cultural biases and beliefs like these are very strong and they are hard to change, it is possible to change. And we belief that people can reset their biases by taking a proactive step, [such as] by choosing to educate themselves more about women in these fields, by putting up positive images of women in science in their classrooms and in their homes."
SKIRBLE: The AAUW report recommends steps to raise awareness about girls' achievement and interest in science, and to get colleges to attract and keep more female students and faculty. St. Rose says all sectors of the community must implement these initiatives in order for them to be successful.
Former astronaut Mae Jemison agrees and adds that stronger science programs in schools and colleges will not only put more women and minorities in science fields, but also fuel a more literate democracy.
Rosanne Skirble, VOA News, Washington.
Traditional Plant-Based Peruvian Medicine, Ayahuasca, Interests Western Scientists
And finally this week ... the World Health Organization has said that medicines derived from plants play a major role in the health care of 80 percent of the world's population. Western medicine has synthesized many of these natural drugs — from the painkillers in willow bark (that would be aspirin) to anti-cancer compounds in the neem tree — and is constantly searching for more pharmaceuticals in the biodiversity of the world's jungles. Erika Celeste visited the Onanyan Shobo spiritual retreat center in the rainforest near Iquitos, Peru, to learn more about a traditional plant-based medicine with the potential to treat a variety of modern ailments.
CELESTE: In the South American jungles, ayahuasca is used in religious ceremonies to induce visions and also as a medicine to cure ills.
ALFREDO: "The ayahuasca, it's a vine. What ayahuasca means is vine of the dead. Some people call it [the] soul vine."
CELESTE: With the help of an interpreter, shaman Alfredo Kayruna Canayo explains that ayahuasca is known as a master plant: a very powerful remedy that treats the whole person-body, mind, and soul.
ALFREDO: "The ayahuasca [can] cure anything you have. Start with simple things. For example, it's very simple to cure or repel the bad energies from your insides. What is the bad energy? One of them could be the fears, then some wound or injury you have."
CELESTE: Whether the plant is being used for religious or medicinal purposes, ayahuasca is taken only in a ceremonial setting under the direction of an experienced shaman. To turn it into a drink, also called ayahuasca, pieces of the twisting, leafy vine are pounded into a pulp and combined with several other plants, then brewed down for eight or more hours into a thick orange liquid.
White-hot, head-splitting pain turned me from an interested reporter into a willing patient on the second day of my visit to the Peruvian jungle, when one of the unpredictable migraines I have suffered from since adolescence blindsided me. I downed the vile brew as quickly as I could. The taste was so bitter and the smell so pungent that my head immediately began to swim and my stomach churned. Shaman Alfredo said that meant it was working.
ALFREDO: "Only by [it]self, this plant doesn't work good, you have to add this with the other plant — the chacruna — which is the help to the ayahuasca. In the Shipibo culture, they believe the chacruna is the wife of ayahuasca, because they help and work together."
CELESTE: An international research team is investigating the pharmaceutical potential of ayahuasca, known scientifically as Banisteriopsis caapi. Principal investigator, Dr. Charles Grob, is Professor of Psychiatry and Pediatrics at the UCLA School of Medicine. His team has done a chemical analysis of the medicinal drink. While the shaman's characterization of the herbal interaction may be whimsical, Grob says science confirms that the ayahuasca brew is a potent medication:
GROB: "It's a very sophisticated form of pharmacology, which somehow the native peoples of the Amazon region have figured out. Ayahuasca is generally a decoction of two plants. Each plant if taken separately has no effects on the human central nervous system, but when taken together there's a very powerful synergy."
Grob says ayahuasca has anti-parasitic properties, which can help prevent malaria. There is also some evidence that it diminishes the symptoms of Parkinson's disease. The researcher says one of ayahuasca's most promising uses is in treating drug and alcohol addiction.
GROB: "Number one it does not appear to be addictive and the individuals do not develop a tolerance, they do not go through withdrawals, and generally speaking, it is very unusual for people to take it on consecutive days over an extended period of time."
CELESTE: The U.S. Food and Drug Administration classifies the principal active ingredient in ayahuasca as a Schedule 1 controlled substance, which is not considered to have any legitimate medical use. As a result, the ayahuasca brew is illegal in the United States, and most of the pharmaceutical studies are being conducted in South America.
GROB: "There's great potential to learn about the range of ayahuasca and to explore its therapeutic value, but first steps first, and I think first we need to fully understand how it's utilized in South America and then do trials in the U.S. and Europe."
CELESTE: Because many Shamans claim ayahuasca cures a variety of cancers, tumors, and other diseases, the Peruvian jungle has become a popular destination for the medical tourism industry. Most of the visitors at Onaynan Shobo, where Shaman Alfredo practices, are European, with the remainder from the United States, Australia and Asia.
By the way, the ayahuasca brew did wipe out my migraine, so that I could enjoy the rest of my jungle stay. But as long as its use in western medicine is illegal, anyone wishing to explore its medical benefits will have to come to its source in South America.
For VOA News, I'm Erika Celeste in Onanyan Shobo, Iquitos, Peru.
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