- In 2019, science and health experts learned more about the best ways to eat, how immune cells can be programmed to fight cancer, and why vaping might be more dangerous than we thought.
- Here are 26 of the most mind-blowing health discoveries of the year, in nutrition, genetics, biology and more.
- Visit INSIDER’s homepage for more stories.
In 2019, scientists continued searching for vital clues about how people might live healthier, longer, richer lives.
Nutrition researchers learned more about the best diets for every person, cancer researchers found new ways to program immune cells to attack, vaping turned deadly as investigators zeroed in on a sticky substance of concern, and possibly, a third gene-edited baby was born.
Here are 26 of the biggest, most enlightening, and exciting health discoveries of the year.
There were major breakthroughs in genetics and biology. Scientists may have cured a man of HIV by injecting him with “superpower” cells.
This was the second time that scientists suspected they might’ve “cured” someone with HIV.
The first person thought to be cured of HIV, the virus that causes AIDS, was an American man named Timothy Brown, previously known as “the Berlin patient.” He received a bone-marrow transplant in 2007 to help treat his aggressive leukemia.
The second person who may have been cured has Hodgkin’s lymphoma and lives in the UK.
The reason these specific bone-marrow transplants seem to be capable of curing HIV is that both donors had a genetic mutation in a protein called CCR5 that made them more resistant to a common kind of HIV, which both men had.
A third gene-edited baby may have been born, using CRISPR technology.
Chinese scientist He Jiankui shocked the science world when he announced in 2018 the birth of twin girls born to be more resistant to HIV infection.
Jiankui edited a gene called CCR5 in the girls before birth, using the cut-and-paste CRISPR-cas9 DNA-modification method on their embryos. (CCR5 is the same gene that was mutated in both HIV-resistant bone-marrow donors, mentioned above.)
In 2019, Jiankui announced that another Chinese woman was pregnant with a third CRISPR gene-edited baby. It’s not clear when, or if, her baby was ever born, but the infant should have come into the world some time around mid-year if all went according to plan.
Genetically-modified people are controversial because their gene changes can be passed on to future generations, and we know little about the long-term effects of being gene-edited.
CRISPR technology also showed promise this year for helping people’s bodies fight their own cancers.
In November, The New York Times reported that doctors tested out a procedure for the first time in the US that could one day pave the way for editing genes of cancer patients, using CRISPR to help their immune systems attack cancers. (Doctors in China say they’re already doing this.)
In the US trial, doctors removed some immune cells from three cancer patients’ bodies, and essentially genetically turbocharged them to fight cancer, before infusing the cells back into the patients.
A family of people who operate soundly on less than six hours of sleep a night provided new clues into why everyone’s sleeping needs are a little different.
But if you think you have the special sleep-starving gene that allows people to operate optimally on less than six hours of sleep a night, you probably don’t.
It “shows up in about one in every 25,000 people,” according to The New York Times.
Scientists are hopeful that by studying the genes of more short sleepers, they’ll be able to develop better therapies for people who don’t get such great sleep.
The first full face transplant on an African American patient took place in July. At 68, Robert Chelsea’s is also the oldest face transplant patient.
Chelsea was hit by a drunk driver in 2013, and the accident burned over 60% of his body and face. His is the 15th full face transplant performed in the US.
European regulators approved the world’s first Ebola vaccine in November, after it tested as effective during an outbreak.
Merck’s Ervebo drug has been tried out during Ebola outbreak situations before, and is currently being trialed in the Democratic Republic of the Congo.
The vaccine is approved for use in people 18 and up, and the first doses are expected to be ready to go to market in late 2020.
Federal regulators provided the first evidence that poop transplants can be deadly.
One person died after contracting E. coli from a poop transplant, which is becoming a more popular way to treat debilitatingC. difficilegut infections.
We witnessed just how contagious the measles virus can be, in the absence of herd immunity from vaccinations.
The measles is said to be so contagious that 90% of people exposed to the virus (who are not vaccinated or immune from a previous illness) will get it.
Residents in high-income countries around the world, where more parents are hesitating to vaccinate their kids, (including England, France, and Japan) have started to witness just how virulent the measles can be.
The US, a country that had declared the measles “eliminated” from its soil in 2000, has seen more than 1,200 documented measles cases so far in 2019. The World Health Organization called the vaccine hesitancy fueling measles outbreaks around the world one of the top 10 threats to global health of the year.
“In earlier eras, it was kind of the norm to be vaccinated. It wasn’t something that people questioned,” Dr. Amesh Adalja told Business Insider earlier this year. “But in the wake of the false links to autism that occurred in the mid 1990s, that whole celebrity culture picking up these false stories, we ended up in this type of a mess.”
DNA studies of nearly half a million people in the US and UK suggested there is a handful of genetic variants that are more common in people who have same-sex partners.
This doesn’t mean that there is anything like a gay gene, or that people who have the variants will necessarily be gay.
“Genetics is less than half of this story for sexual behavior but it’s still a very important contributing factor,’ study co-author Benjamin Neale, a psychiatric geneticist at the Broad Institute in Cambridge, Massachusetts told the Associated Press in August. “It’s effectively impossible to predict an individual’s sexual behavior from their genome.”
We learned more about the limits of human performance, too. In May, runner and nutritionist Roxanne Vogel completed what just might be the fastest-ever rapid Mount Everest ascent, racing door to door from her home in California to the top of the world’s tallest peak — and back — in two weeks.
Normally, a climb like that takes at least a month (or more) for a sea-level adapted body to achieve.
“Primarily, I think I really wanted to see if it could be done,” Vogel told Insider, when reached by phone inside the oxygen-starved training chamber she sits in for a few hours at work every day. “I am a researcher and a scientist at heart, and I really wanted to be able to collect data and see what happens to the body when you actually do something like this.”
In October, Kenyan marathoner Eliud Kipchoge did what many runners had long thought impossible when he ran a marathon course in under 2 hours.
Kipchoge is the first person to ever complete a sub-2 hour marathon (at 1 hour, 59 minutes, and 40 seconds), but his run won’t count as a world record, because he did it with help from a world-class pacing crew, and laser beams guiding his way along the pavement, among other perks other marathoners don’t usually get.
“I expect more people all over the world to run under 2 hours after today,” he said.
Anthropologists who studied how many calories a group of marathoners burned may have discovered a limit to human endurance, one they suspect is bound by our body’s ability to digest and absorb nutrients.
“There’s just a limit to how many calories our guts can effectively absorb per day,” study co-author Herman Pontzer, an associate professor of evolutionary anthropology at Duke University, said in a press release. “This defines the realm of what’s possible for humans.”
The limit, they found, is that a person can only ever burn calories up to 2.5 times their resting metabolic rate. After that, a body begins to break down its own stores for sustenance.
Nutritionists also gathered new clues about the best ways to eat and drink for a long, healthy life. Science still suggests fueling up on vegetables, nuts, whole grains, and legumes tends to be a winning strategy.
In one US study that tracked health outcomes over almost three decades, people who reported eating more vegetables and other plants (about 4 to 5 servings a day), and consuming little to no processed or red meat (less than a serving per day) had an average of 18 to 25% lower risk of death than people who routinely fuel up on meat and other animal products.
The new study also found that plant-eaters tended to have healthier hearts, developing fewer heart attacks and strokes, and dying from heart issues less often.
The trendy intermittent fasting diet picked up new fans when a cancer researcher published a small but novel study that showed fasting can have positive benefits on a cellular level for otherwise healthy people.
Intermittent fasting has many different forms, but one of the most popular is a type practiced by celebrities like Terry Crews that involves fasting for 16 hours a day, and eating during a remaining 8-hour window (for Crews, that’s from 2 p.m. to 10 p.m.)
“I’m not saying food is our enemy, absolutely not, we need to eat otherwise we die,” study author and cancer researcher Dr. Miriam Merad said when her study on intermittent fasting was released in August. “But it is true that we probably eat too much … we eat too often.”
Previous lab research, though scant, also suggests that people who fast or restrict calories may have fewer heart issues, better cholesterol levels, lower stroke risk, and fewer instances of diabetes.
Other nutrition pros still maintain the fasting that we do overnight when we’re asleep is enough.
Scientists who consistently tracked the blood sugar levels of over 1,000 adults found that there’s no best diet for everyone.
Scientists had 1,100 adults in the US and UK eat the same common foods (like muffins for breakfast and sandwiches for lunch), and tracked participants’ glucose levels before and after meals. The results showed that no two individuals’ reactions were the same — more evidence that there’s no such thing as a perfect, one-size-fits-all diet.
“Even we were surprised by the results,” Tim Spector, an epidemiologist and professor at King’s College in London who led the study, told Business Insider. “Just because some diet or recommendation is out there doesn’t mean that you fit it.”
Spector still suggests most people could benefits from eating more fruit, vegetables, nuts, seeds, whole grains, and fermented foods, while skipping junk food.
New data suggested that only children may be more likely to be obese, and eat more junk foods than kids with siblings. But researchers cautioned that having more kids won’t necessarily make your family any healthier.
Research from a small study of 68 families at the University of Oklahoma suggested kids who don’t have siblings tend to be more likely to fuel up on junk food, like refined grain products and sugary drinks.
“It’s not just about the child,” study co-author Chelsea Kracht, a post-doc researcher at Pennington Biomedical Research Center, told Insider. “The child’s family situation is also what people need to think about with children’s nutrition.”
Researchers suspect that more ritualized meal times in larger families might play a role.
“What we don’t want is people to think that having more children will somehow make you healthier,” Kracht said. “There were children with siblings who were overweight and only children who were perfectly healthy, so that’s not the case.”
Regulators in California reversed course, and decided coffee isn’t that bad for you after all.
In a win for coffee lovers of the Golden State, the California Office of Environmental Health Hazard Assessment (OEHHA) ruled — after consulting over 1,000 scientific studies — that drinking coffee does “not pose a significant risk of cancer.”
“We found coffee is a complex mixture of numerous chemicals that includes both known carcinogens but also some anti-carcinogens that protect against cancer, including antioxidants,” Sam Delson, a spokesman for the OEHHA, told Business Insider. “You know, nothing is 100% risk-free, but … I’m a cancer survivor myself, and happy to drink coffee.”
There were discoveries about how technology and regulations (or a lack thereof) are impacting our health, too. Scientists learned we may inhale hundreds of microplastics — tiny plastic particles swimming in our waters and wafting through the air — every day.
A study published in June suggests that microplastics — tiny, often invisible pieces of plastic — are in our water, food, air, and stomachs at alarming rates. Scientists have evidence that the average American woman may ingest around 98,000 tiny plastic particles every year, while the average man consumes 121,000.
There’s no good evidence yet that any of this plastic detritus is having a major effect on our bodies, but it’s definitely trashing the planet.
“If you are a concerned citizen that is worried about plastic pollution, and you have access to a well-managed pipe supply, a water supply, why not drink from that? You know, why not reduce pollution,” said Bruce Gorden, De France’s colleague.
The results of a blockbuster heart health study of more than 400,000 people with Apple Watches showed that the device might help detect rare heart problems.
The Apple Heart Study, a collaboration between the tech giant and Stanford University, was designed to measure whether the Apple Watch can detect irregular heartbeat issues.
The results of the study, which tracked more than 400,000 watch-wearers over an average of about four months per person, suggests that the devices perform pretty well at alerting people when they have irregular heartbeats.
The watches, which used flashing LED lights to detect heart rates, weren’t perfect though. They missed diagnosing some heart issues, and also alerted some other people who don’t have heart conditions at all with false positives, which could lead to more “healthy people flocking to healthcare providers for care they don’t need,” as Business Insider’s Erin Brodwin noted when the study was released.
Cancer-causing toxins were found lurking in consumer beauty products, including concealer and eye shadow.
Trace amounts of asbestos — a known cancer causer — were found in concealer and sparkly makeup marketed to kids at Claire’s.
The find underscores a larger contamination issue across the beauty industry, one that isn’t limited to asbestos contamination.
“It wasn’t surprising to me, because there’s no regulation,” gynecologist Shruthi Mahalingaiah told Business Insider in June.
The FDA also recently warned consumers about dangerous bacteria in a no-rinse cleansing foam used by hospital patients, alerted tattoo artists about ink contaminated with microorganisms, and found yeast in Young Living essential oils moisturizer.
Scientists discovered it isn’t just adults who take advantage of more legal marijuana. In November, researchers released a study that showed a 25% jump in problematic marijuana use in teens in states with legal weed shops.
“While these findings are concerning, our results in no way imply that we shouldn’t be legalizing marijuana,” lead study author Magdalena Cerdá, an associate professor and director of the Center for Opioid Epidemiology and Policy at NYU Langone Health, told Business Insider. “If use is increasing, states need to be able to understand what’s going on so they can respond appropriately.”
Finally, we got fresh evidence that optimism is a life-giving quality. People who consider the glass half full tend to live lives of “exceptional longevity,” making it past age 85 more often than curmudgeons.
The results, from a study of more than 70,000 people (mostly women) published in September from researchers at Harvard and Boston University, found that optimistic people tend to live, on average, 11 to 15% longer than others who are more grumpy.
This held true regardless of a person’s socioeconomic status, smoking status, diet, or health condition, suggesting there may be something about the optimism that’s keeping people alive.
“Other research suggests that more optimistic people may be able to regulate emotions and behavior as well as bounce back from stressors and difficulties more effectively,” senior study author Laura Kubzansky said in a press release.