Anxious about cervical screening? What you need to know

 Many people put off cervical screenings due to feelings of anxiety or embarrassment. In this feature, we spoke to two obstetrician-gynecologists to find out what you should know and do to feel prepared and let go of the anxiety.

Cervical screening — also known as a smear test or Pap smear — is an important part of looking after the health of female bodies.

This is because it can detect abnormal cells, human papillomavirus (HPV), and cervical cancer, allowing doctors to come up with the best, timeliest treatments and care plans.

However, many people are anxious about schedulingTrusted Source and attending cervical screenings, sometimes due to concerns about what the test entails. Will it hurt? Will it cause discomfort or bleeding?

Other causes of anxiety relate to body image and the psychological discomfort of being in a vulnerable position in front of a stranger.

Medical News Today spoke with Dr. Zahra Ameen, a consultant obstetrician-gynecologist (OB-GYN) at the Cadogan Clinic, and Dr. Apurva Shah, an OB-GYN at Women’s Wellness Associates at Saint Vincent Hospital and a member of the Mira medical advisory board, to learn more about what goes on during a screening and how to prepare for one with confidence.

“Fear and anxiety of having a pelvic exam is probably the single most common reason that people avoid cervical screenings,” Dr. Shah told us. “Other reasons are lack of knowledge of the purpose of screening, lack of resources, past history of physical abuse. It is a very intimate exam and can feel like an invasion of privacy for many.”

Yet it is crucial to overcome the anxiety to minimize the risks of cervical cancer and other gynecological health problems.

“The most important thing for women to understand is that cervical screening is a potentially life saving test and is the very best protection against developing cancer,” Dr. Ameen emphasized.

“The test detects infection with HPV and whether there are any abnormal, precancerous cells in the cervix, at an early stage, before it develops into cancer. If everybody attended their regular tests, 83% of cervical cancers could be prevented. It’s over very quickly, and 93% of cervical smears are normal,” she noted.

What happens during cervical screening?

During the appointment, you undress from the waist down behind a screen and use a disposable sheet to cover your pelvic area.

The medical professional conducting the screening then asks you to lie on an examination table in a position that allows access to your vagina — usually with your knees apart, though this may vary, depending on what is most comfortable for you.

They then use a tool called a speculum to gently open the vaginal walls and gain access to the cervix. Many people worry about the size of the speculum, but this should not be a concern, Dr. Ameen told MNT.

“The size of the speculum differs from person to person and is dependent on your age and the size of your vaginal opening,” she explained. “It will usually only need to be opened to 2.0 to 2.5 centimeters wide in order to perform a smear test.”

The healthcare professional conducting the screening then uses a soft brush to collect cell samples from the cervix. They send the samples to a laboratory for analysis.

The entire process should only last a few minutes.

Remember: The health professional is an expert

“It’s also very important to remember that the medical professionals conducting the smear tests are experts and have conducted numerous cervical screening tests before,” said Dr. Ameen.

It is only natural to feel discomfort at the thought of having your intimate parts checked by a stranger. But it is worth keeping in mind that this person knows what they are doing — and they are not there to judge your body.

Moreover, since they have conducted this procedure so many times, the health professional will understand any worries you may have, so it is worth communicating openly about any anxiety or discomfort.

“If you are really concerned or anxious about any part of the test, it’s advisable to speak with the doctor or nurse in advance, as they can help make the test more comfortable for you and talk through any of your concerns,” Dr. Ameen also suggested.

How much discomfort to expect

“Smear tests should not be painful. You may experience a little discomfort in your pelvic area and some pressure, but this [is] momentary,” Dr. Ameen explained.

She recommended asking to change positions on the consultation table to see if it helps ease any discomfort:

“Using a lubricant can also help with the insertion of the speculum,” she added.

Dr. Shah noted that it is important to find a healthcare professional whom you trust, in order to prevent physical as well as emotional discomfort during a cervical screening.

“Feeling in control and seeing a provider you can trust is key,” he told MNT, explaining that “Once you are in a position of trust, it really impacts how your body and your pelvic floor responds to an exam.”

The more relaxed and in control you feel, the less likely it is to have discomfort during the screening, he said, because, “The pelvic floor which would otherwise resist the speculum will relax and allow for a much gentler exam and an overall better experience.”

Part of establishing trust with the healthcare professional, Dr. Shah added, involves communicating openly with them about what the screening entails and your own worries about it.

You could also ask to take a more hand-on approach. “If you feel more comfortable inserting the speculum yourself, go ahead and ask to do that. You would be surprised how much easier it is for you,” he suggested.

Bringing a friend for moral support could also help, said Dr. Shah.

How to stay calm during the appointment

Both Dr. Ameen and Dr. Shah shared some tips for keeping calm during the appointment, if anxiety feels like it is starting to take over.

Ahead of their first smear test, many people wonder what is best to wear. Dr. Shah suggested wearing whatever makes you feel most comfortable, not just to make it easier to undress and dress, but also to help you feel more confident and relaxed.

“I believe much of our confidence and control emanates from our image, and whatever attire provides comfort and confidence is the way to go,” he said.

During the appointment, Dr. Ameen said, “Remember to take deep breaths, which will help calm you — don’t hold your breath, as this will make your muscles tense and increase discomfort.”

If it is difficult to clear your mind, you may want to use something distracting to help shift your focus. “I have had patients play music, some watch Netflix, others talk about their hobbies,” said Dr. Shah.

Dr. Ameen also noted that, for people who are really sensitive to physical discomfort, taking over-the-counter pain relief medication, such as acetaminophen (Tylenol) half an hour before the appointment might help prevent any painful sensations.

What happens after the appointment

MNT also asked the OB-GYNs if it is likely for pain or bleeding to develop after a smear test. Usually, they said, smear tests do not induce any further discomfort or bleeding, though occasionally light spotting may occur, as the brush used to collect cell samples may sometimes irritate the cervix.

“Some people may experience spotting or very light bleeding following a smear test as the blood vessels of the cervix are irritated, and this is not uncommon and not usually any cause for concern,” Dr. Ameen told us.

Heavy bleeding after a smear test is not common, and anyone who experiences this or other symptoms should seek a doctor’s advice as soon as possible.

“If you experience heavy bleeding which is not your period, severe cramps, or blood clots following a smear test, it’s important to speak with your doctor to rule out other health conditions. You know your own body, and it’s important to listen to it,” said Dr. Ameen.

It usually takes 1–3 weeks to process a smear test sample and receive the results. In most cases, the results come back clear, but sometimes the laboratory analysis picks up on abnormalities in the cells. Still, this is not a reason to worry, explained Dr. Ameen.

“If the smear test comes back as positive for HPV or abnormal cells on the cervix, it is important to remember that this does not mean that you have cervical cancer,” she noted. “It means that you would need a review with a specialist gynecologist, where they will carry out a colposcopy to get a closer look at your cervix, and they may need to take targeted biopsies.”

Also, in some cases, the lab finds the sample unclear. You should avoid scheduling a smear test on a day when you are likely to have your period, as blood cells could interfere with the sample, making it unreadable, and you may need to reschedule the test.

For the same reason, you should avoid using any creams on your vagina for 2–3 days before the test.

Take control of your health

Perhaps the most important thing to remember about cervical screenings is that by scheduling and attending them regularly as advised, you are taking control of your own health.

“It is not uncommon to feel the anxiety [about smear tests], but you can fight the anxiety with knowledge,” said Dr. Shah.

“Educate yourself as to what to expect, communicate your feelings with your provider, develop situational awareness while in the exam room, and feel free to speak up,” he urged.

Source: Medical News Today

Epstein-Barr virus may be leading cause of multiple sclerosis

 Multiple sclerosis (MS), a progressive disease that affects 2.8 million people worldwide and for which there is no definitive cure, is likely caused by infection with the Epstein-Barr virus (EBV), according to a study led by Harvard T.H. Chan School of Public Health researchers.

Their findings will be published online in Science on January 13, 2022.

"The hypothesis that EBV causes MS has been investigated by our group and others for several years, but this is the first study providing compelling evidence of causality," said Alberto Ascherio, professor of epidemiology and nutrition at Harvard Chan School and senior author of the study. "This is a big step because it suggests that most MS cases could be prevented by stopping EBV infection, and that targeting EBV could lead to the discovery of a cure for MS."

MS is a chronic inflammatory disease of the central nervous system that attacks the myelin sheaths protecting neurons in the brain and spinal cord. Its cause is not known, yet one of the top suspects is EBV, a herpes virus that can cause infectious mononucleosis and establishes a latent, lifelong infection of the host. Establishing a causal relationship between the virus and the disease has been difficult because EBV infects approximately 95% of adults, MS is a relatively rare disease, and the onset of MS symptoms begins about ten years after EBV infection. To determine the connection between EBV and MS, the researchers conducted a study among more than 10 million young adults on active duty in the U.S. military and identified 955 who were diagnosed with MS during their period of service.

The team analyzed serum samples taken biennially by the military and determined the soldiers' EBV status at time of first sample and the relationship between EBV infection and MS onset during the period of active duty. In this cohort, the risk of MS increased 32-fold after infection with EBV but was unchanged after infection with other viruses. Serum levels of neurofilament light chain, a biomarker of the nerve degeneration typical in MS, increased only after EBV infection. The findings cannot be explained by any known risk factor for MS and suggest EBV as the leading cause of MS.

Ascherio says that the delay between EBV infection and the onset of MS may be partially due the disease's symptoms being undetected during the earliest stages and partially due to the evolving relationship between EBV and the host's immune system, which is repeatedly stimulated whenever latent virus reactivates.

"Currently there is no way to effectively prevent or treat EBV infection, but an EBV vaccine or targeting the virus with EBV-specific antiviral drugs could ultimately prevent or cure MS," said Ascherio.

Other Harvard Chan School researchers who contributed to this study include Kjetil Bjornevik, Marianna Cortese, Michael Mina, and Kassandra Munger.

Source: ScienceDaily

Fastest DNA sequencing technique helps undiagnosed patients find answers in mere hours

 A new ultra-rapid genome sequencing approach developed by Stanford Medicine scientists and their collaborators was used to diagnose rare genetic diseases in an average of eight hours -- a feat that's nearly unheard of in standard clinical care.

"A few weeks is what most clinicians call 'rapid' when it comes to sequencing a patient's genome and returning results," said Euan Ashley, MB ChB, DPhil, professor of medicine, of genetics and of biomedical data science at Stanford.

Genome sequencing allows scientists to see a patient's complete DNA makeup, which contains information about everything from eye color to inherited diseases. Genome sequencing is vital for diagnosing patients with diseases rooted in their DNA: Once doctors know the specific genetic mutation, they can tailor treatments accordingly.

Now, a mega-sequencing approach devised by Ashley and his colleagues has redefined "rapid" for genetic diagnostics: Their fastest diagnosis was made in just over seven hours. Fast diagnoses mean patients may spend less time in critical care units, require fewer tests, recover more quickly and spend less on care. Notably, the faster sequencing does not sacrifice accuracy.

A paper describing the researchers' work will publish Jan.12 in The New England Journal of Medicine. Ashley, associate dean of the Stanford School of Medicine and the Roger and Joelle Burnell Professor in Genomics and Precision Health, is the senior author of the paper. Postdoctoral scholar John Gorzynski, DVM, PhD, is the lead author.

Setting out to set a record

Over the span of less than six months, the team enrolled and sequenced the genomes of 12 patients, five of whom received a genetic diagnosis from the sequencing information in about the time it takes to round out a day at the office. (Not all ailments are genetically based, which is likely the reason some of the patients did not receive a diagnosis after their sequencing information was returned, Ashley said.) The team's diagnostic rate, roughly 42%, is about 12% higher than the average rate for diagnosing mystery diseases.

In one of the cases, it took a snappy 5 hours and 2 minutes to sequence a patient's genome, which set the first Guinness World Records title for fastest DNA sequencing technique. The record was certified by the National Institute of Science and Technology's Genome in a Bottle group and is documented by Guinness World Records.

"It was just one of those amazing moments where the right people suddenly came together to achieve something amazing," Ashley said. "It really felt like we were approaching a new frontier."

The time it took to diagnose that case was 7 hours and 18 minutes, which, to Ashley's knowledge, is about twice as fast as the previous record for a genome sequencing-based diagnosis (14 hours) held by the Rady Children's Institute. Fourteen hours is still an impressively quick turnaround, Ashley said. Stanford scientists plan to offer a sub-10-hour turnaround to patients in intensive care units at Stanford Hospital and Lucile Packard Children's Hospital Stanford -- and, over time, to other hospitals too.

Speeding up

To achieve super-fast sequencing speeds, the researchers needed new hardware. So Ashley contacted colleagues at Oxford Nanopore Technologies who had built a machine composed of 48 sequencing units known as flow cells. The idea was to sequence just one person's genome using all flow cells simultaneously. The mega-machine approach was a success -- almost too much. Genomic data overwhelmed the lab's computational systems.

"We weren't able to process the data fast enough," Ashley said. "We had to completely rethink and revamp our data pipelines and storage systems." Graduate student Sneha Goenka found a way to funnel the data straight to a cloud-based storage system where computational power could be amplified enough to sift through the data in real time. Algorithms then independently scanned the incoming genetic code for errors that might cause disease, and, in the final step, the scientists conducted a comparison of the patient's gene variants against publicly documented variants known to cause disease.

From start to finish, the team sought to hasten every aspect of sequencing a patient's genome. Researchers literally ran samples by foot to the lab, new machines were rigged to support simultaneous genome sequencing, and computing power was escalated to efficiently crunch massive data sets. Now, the team is optimizing its system to reduce the time even further. "I think we can halve it again," Ashley said. "If we're able to do that, we're talking about being able to get an answer before the end of a hospital ward round. That's a dramatic jump."

Long-read sequencing

Perhaps the most important feature of the diagnostic approach's ability to quickly spot suspicious fragments of DNA is its use of something called long-read sequencing. Traditional genome-sequencing techniques chop the genome into small bits, spell out the exact order of the DNA base pairs in each chunk, then piece the whole thing back together using a standard human genome as a reference. But that approach doesn't always capture the entirety of our genome, and the information it provides can sometimes omit variations in genes that point to a diagnosis. Long-read sequencing preserves long stretches of DNA composed of tens of thousands of base pairs, providing similar accuracy and more detail for scientists scouring the sequence for errors.

"Mutations that occur over a large chunk of the genome are easier to detect using long-read sequencing. There are variants that would be almost impossible to detect without some kind of long-read approach," Ashley said. It's also much faster: "That was one of the big reasons we went for this approach."

Only recently have companies and researchers honed the accuracy of the long-read approach enough to rely on it for diagnostics. That and a drop from its once-hefty price tag created an opportunity for Ashley's team. To his knowledge, this study is the first to demonstrate the feasibility of this type of long-read sequencing as a staple of diagnostic medicine.

During the study, Ashley's team offered the accelerated genome sequencing technique to undiagnosed patients in Stanford hospitals' intensive care units. They provided established standard of care testing to the study patients along with the experimental rapid gene sequencing, with which they sought answers to two important questions: Are genetics to blame for the patient's ailment? If so, what specific DNA errors are stirring up trouble?

Standard tests screen a patient's blood for markers associated with disease, but they only scan for a handful of well-documented genes. Commercial labs, which often run these tests, are slow to update the molecules for which they screen, meaning it can take a long time before newly discovered disease-causing mutations are integrated into the test. And that can lead to missed diagnoses.

That's why rapid genome sequencing could be such a game-changer for patients ailing from rare genetic disease, Ashley said. Scientists can scan a patient's entire genome for any and all gene variants suggested by the scientific literature, even if that gene is only discovered the day before. Furthermore, if a patient doesn't initially receive a genetic diagnosis, there's still hope that scientists will find a new gene variant linked to the patient's disease down the line.

Interest from other clinicians is already starting to pour in. "I know people at Stanford have heard we can make a genetic diagnosis in a few hours, and they're excited about it," Ashley said. "Genetic tests just aren't thought of as tests that come back quickly. But we're changing that perception."That's why rapid genome sequencing could be such a game-changer for patients ailing from rare genetic disease, Ashley said. Scientists can scan a patient's entire genome for any and all gene variants suggested by the scientific literature, even if that gene was discovered the day before. Furthermore, if a patient doesn't initially receive a genetic diagnosis, there's still hope that scientists will find a new gene variant linked to the patient's disease down the line.

Other Stanford authors of the study are clinical data scientist Dianna Fisk, PhD; graduate student Tanner Jensen; Jonathan Bernstein, MD, PhD, professor of pediatrics; clinical exercise physiologist Jeffrey Christle, PhD; software engineer Karen Dalton; genetic counselor Megan Grove; Maura Ruzhnikov, MD, clinical assistant professor of neurology and neurological sciences; Elizabeth Spiteri, MD, clinical assistant professor of pathology; and pediatric resident Katherine Xiong, MD.

Source:ScienceDaily

Regrowing knee cartilage with an electric kick

 UConn bioengineers successfully regrew cartilage in a rabbit's knee, a promising hop toward healing joints in humans, they report in the 12 January issue of Science Translational Medicine.

Arthritis is a common and painful disease caused by damage to our joints. Normally pads of cartilage cushion those spots. But injuries or age can wear it away. As cartilage deteriorates, bone begins to hit bone, and everyday activities like walking become terribly painful.

The best treatments available try to replace the damaged cartilage with a healthy piece taken from elsewhere in the body or a donor. But healthy cartilage is in limited supply. If it's your own, transplanting it could injure the place it was taken from; if it's from someone else, your immune system is likely to reject it.

The best possible treatment would be to regrow healthy cartilage in the damaged joint itself. Some researchers have tried amplifying chemical growth factors to induce the body to grow cartilage on its own; other attempts rely on a bioengineered scaffold to give the body a template for the fresh tissue. But neither of these approaches works, even in combination.

"The regrown cartilage doesn't behave like native cartilage. It breaks, under the normal stresses of the joint," says UConn bioengineer Thanh Nguyen.

Nguyen's lab has also been working on cartilage regeneration, and they've discovered that electrical signals are key to normal growth. They designed a tissue scaffold made out of nanofibers of poly-L lactic acid (PLLA), a biodegradable polymer often used to stitch up surgical wounds. The nanomaterial has a neat property called piezo-electricity. When it is squeezed, it produces a little burst of electrical current. The regular movement of a joint, such as a person walking, can cause the PLLA scaffold to generate a weak but steady electrical field that encourages cells to colonize it and grow into cartilage. No outside growth factors or stem cells (which are potentially toxic or risk undesired adverse events) are necessary, and crucially, the cartilage that grows is mechanically robust.

The team recently tested the scaffold in the knee of an injured rabbit. The rabbit was allowed to hop on a treadmill to exercise after the scaffold was implanted, and just as predicted, the cartilage grew back normally. "Piezoelectricity is a phenomenon that also exists in the human body. Bone, cartilage, collagen, DNA and various proteins have a piezoelectric response. Our approach to healing cartilage is highly clinically translational, and we will look into the related healing mechanism," says Dr. Yang Liu, a postdoctoral fellow in Nguyen's group and the lead author of the published work.

The results are exciting, but Nguyen is cautious.

"This is a fascinating result, but we need to test this in a larger animal," one with a size and weight closer to a human, Nguyen says. His lab would want to observe the animals treated for at least a year, probably two, to make sure the cartilage is durable. And it would be ideal to test the PLLA scaffolds in older animals, too. Arthritis is normally a disease of old age in humans. Young animals heal more easily than old -- if the piezoelectric scaffolding helps older animals heal as well, it truly could be a bioengineering breakthrough.

Source: ScienceDaily

Remembering faces and names can be improved during sleep

 For those who rarely forget a face, but struggle with names, the remedy for boosting learning may as near as your pillow.

New research by Northwestern University is the first to document the effect reactivating memory during sleep has on face-name learning.

The researchers found that people's name recall improved significantly when memories of newly learned face-name associations were reactivated while they were napping. Key to this improvement was uninterrupted deep sleep.

"It's a new and exciting finding about sleep, because it tells us that the way information is reactivated during sleep to improve memory storage is linked with high-quality sleep," said lead author Nathan Whitmore, a Ph.D. candidate in the Interdepartmental Neuroscience Program at Northwestern.

The paper, "Targeted memory reactivation of face-name learning depends on ample and undisturbed slow-wave sleep," will publish Jan. 12 in the Nature partner journal NPJ: Science of Learning.

The paper's senior author is Ken Paller, professor of psychology and director of the Cognitive Neuroscience Program at Weinberg College of Arts and Sciences at Northwestern. The paper was also co-authored by Adrianna Bassard, Ph.D. candidate in psychology at Northwestern.

The research team found that for study participants with EEG measures (a recording of electrical activity of the brain picked up by electrodes on the scalp) that indicated disrupted sleep, the memory reactivation didn't help and may even be detrimental. But in those with uninterrupted sleep during the specific times of sound presentations, the reactivation led to a relative improvement averaging just over 1.5 more names recalled.

The study was conducted on 24 participants, aged 18-31 years old, who were asked to memorize the faces and names of 40 pupils from a hypothetical Latin American history class and another 40 from a Japanese history class. When each face was shown again, they were asked to produce the name that went with it. After the learning exercise, participants took a nap while the researchers carefully monitored brain activity using EEG measurements. When participants reached the N3 "deep sleep" state, some of the names were softly played on a speaker with music that was associated with one of the classes.

When participants woke up, they were retested on recognizing the faces and recalling the name that went with each face.

The researchers say the finding on the relationship between sleep disruption and memory accuracy is noteworthy for several reasons.

"We already know that some sleep disorders like apnea can impair memory," said Whitmore. "Our research suggests a potential explanation for this -- frequent sleep interruptions at night might be degrading memory."

The lab is in the midst of a follow-up study to reactivate memories and deliberately disrupt sleep in order to learn more about the relevant brain mechanisms.

"This new line of research will let us address many interesting questions -- like whether sleep disruption is always harmful or whether it could be used to weaken unwanted memories," said Paller, who also holds the James Padilla Chair in Arts & Sciences at Northwestern. "At any rate, we are increasingly finding good reasons to value high-quality sleep."

Source: ScienceDaily

Unusual team finds gigantic planet hidden in plain sight

 A UC Riverside astronomer and a group of eagle-eyed citizen scientists have discovered a giant gas planet hidden from view by typical stargazing tools.

The planet, TOI-2180 b, has the same diameter as Jupiter, but is nearly three times more massive. Researchers also believe it contains 105 times the mass of Earth in elements heavier than helium and hydrogen. Nothing quite like it exists in our solar system.

Details of the finding have been published in the Astronomical Journal and presented at the American Astronomical Society virtual press event on Jan. 13.

"TOI-2180 b is such an exciting planet to have found," said UCR astronomer Paul Dalba, who helped confirm the planet's existence. "It hits the trifecta of 1) having a several-hundred-day orbit, 2) being relatively close to Earth (379 lightyears is considered close for an exoplanet), and 3) us being able to see it transit in front of its star. It is very rare for astronomers to discover a planet that checks all three of these boxes."

Dalba also explained that the planet is special because it takes 261 days to complete a journey around its star, a relatively long time compared to many known gas giants outside our solar system. Its relative proximity to Earth and the brightness of the star it orbits also make it likely astronomers will be able to learn more about it.

In order to locate exoplanets, which orbit stars other than our sun, NASA's TESS satellite looks at one part of the sky for a month, then moves on. It is searching for dips in brightness that occur when a planet crosses in front of a star.

"The rule of thumb is that we need to see three 'dips' or transits before we believe we've found a planet," Dalba said. A single transit event could be caused by a telescope with a jitter, or a star masquerading as a planet. For these reasons, TESS isn't focused on these single transit events. However, a small group of citizen scientists is.

Looking over TESS data, Tom Jacobs, a group member and former U.S. naval officer, saw light dim from the TOI-2180 star, just once. His group alerted Dalba, who specializes in studying planets that take a long time to orbit their stars.

Using the Lick Observatory's Automated Planet Finder Telescope, Dalba and his colleagues observed the planet's gravitational tug on the star, which allowed them to calculate the mass of TOI-2180 b and estimate a range of possibilities for its orbit.

Hoping to observe a second transit event, Dalba organized a campaign using 14 different telescopes across three continents in the northern hemisphere. Over the course of 11 days in August 2021, the effort resulted in 20,000 images of the TOI-2180 star, though none of them detected the planet with confidence.

However, the campaign did lead the group to estimate that TESS will see the planet transit its star again in February, when they're planning a follow up study. Funding for Dalba's research is provided by the National Science Foundation's Astronomy and Astrophysics Postdoctoral Fellowship Program.

The citizen planet hunters' group takes publicly available data from NASA satellites like TESS and looks for single transit events. While professional astronomers use algorithms to scan a lot of data automatically, the Visual Survey Group uses a program they created to inspect telescope data by eye.

"The effort they put in is really important and impressive, because it's hard to write code that can identify single transit events reliably," Dalba said. "This is one area where humans are still beating code."

Source: ScienceDaily

Risky food-finding strategy could be the key to human success

 It's a cold and rainy Sunday afternoon: would you rather be running after tasteless wild berries, or curled up on your couch with fuzzy socks and a good book?

You might not have had that choice if our ancestors had not taken a big gamble with their food.

A new study published in Science on December 24 shows that early human foragers and farmers adopted an inefficient high-risk, high-reward strategy to find food. They spent more energy in pursuit of food than their great ape cousins, but brought home much more calorie-rich meals that could be shared with the rest of their group. This strategy allowed some to rest or tackle other tasks while food was being acquired.

"Hunting and gathering is risky and inefficient, but the rate of return is enormous," said study co-leader, Herman Pontzer, an associate professor of Evolutionary Anthropology at Duke University. "We can share our food, and because we got so many calories before noon, we can hang out around each other in this new space, a free-time space."

Humans spend a lot more energy than great apes. We have big brains that eat up a lot of calories, we live a long time, we can have long pregnancies that produce big babies, and these babies rely on adults for a long time.

To find out how humans obtained this extra energy, a group of researchers led by Thomas Kraft, a postdoctoral researcher at the University of California Santa Barbara, and Pontzer compared the energy budgets of wild gorillas, chimpanzees and orangutans with that of populations of Tanzanian hunter-gatherers (Hadza) and Bolivian forager-horticulturalists (Tsimane).

Hunter-gatherers and forager-horticulturalists both gather food from wild plants and animals, but the Tsimane also produce small-scale crops.

Energy budgets depend on how much food energy is absorbed, and how much time and energy are spent obtaining food. Humans were thought to maintain their energetically costly lifestyle in one of two ways: they could be super-efficient, spending little time and energy finding food -- in part due to the use of tools and technological advances, or they could spend a lot of energy to quickly bring home a lot of food, sacrificing energy efficiency.

The researchers found that hunter-gatherers and forager-horticulturalists are inefficient, high-intensity foragers. Like a gas-guzzling pick-up truck bringing home a ton of donuts, they spend a lot more energy obtaining food than great apes, but they do it faster and the food they obtain is high in calories. Rather than minimizing their costs, they take a risk to maximize their rewards.

Chimpanzees, gorillas and orangutans, on the other hand, are like an electric car bringing home a head of lettuce and some apples. They are essentially herbivores and frugivores who eat very little, if any, meat. Their strategy is one of low risk, low rewards: their food is easy to find, but it's fibrous, low in energy, and it takes a lot of time to get enough of it.

The Hadza hunter-gatherers and the Tsimane forager-horticulturalists both eat high-calorie foods that are harder to get. They spend a lot of energy hunting, gathering, planting and harvesting, but can quickly bring home a nutritious lunch. What's more, they bring enough to share.

Pontzer said sharing provides a safety net, enabling some group members to take risks, targeting big game and other high-risk, high-reward foods. If they come home empty-handed, which they often do, they know others will have something to share. The possibility of sharing food also means some group members can even stay at the camp on occasion, enjoying one of our most precious commodities: free time.

"This slight shift in the way that we go about getting our food has fundamentally made everything else possible," Pontzer said. Free time allows group members to communicate about things other than food. It allows for experimentation, for learning, for creativity, for play, for culture.

Being wired to finding and sharing energy bombs was, and still is, a winning strategy for hunter-gatherers and foragers-horticulturalists, Pontzer said. But it also can be treacherous for those of us with a pantry full of delicious highly caloric food.

"We are built to try and get a lot of food," Pontzer said. "We are hugely ravenous and inefficient, and that's how we've evolved for 2 million years."

"That doesn't mean we can be careless with our energy today, and it doesn't mean that we have to say, 'well there's nothing we can do about it'," Pontzer said. "We have to be aware of ourselves and our evolutionary history."

Source:ScienceDaily