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Humans Have Been Perfecting Avocados for 7,500 Years

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Humans Have Been Perfecting Avocados for 7,500 Years

Avocados are true superfoods: dense, buttery scoops of vitamins, fat and fiber, all in a hand-size package.

We worked for a long time to make them this way. According to a paper published Monday in the Proceedings of the National Academy of Sciences, people in what we today call Honduras made avocados a part of their diets at least 10,000 years ago and purposefully improved them starting more than 7,500 years ago — first by managing wild trees, and then by selectively planting new ones, to encourage thicker rinds and larger fruit.

This means fruit domestication at this site began thousands of years before the arrival of more commonly studied plants like maize.

“People were domesticating and cultivating their forests” long before they were planting crops in fields, said Amber VanDerwarker, a professor of anthropology at the University of California, Santa Barbara and an author of the paper.

Avocados first arose in central Mexico about 400,000 years ago. They were originally dispersed by megafauna: Giant ground sloths, elephantine gompotheres and burly toxodons all regularly gulped them down, choking-hazard-size pits and all. By the end of the Pleistocene epoch, around 13,000 years ago, megafauna had spread the oily fruits throughout Central and northern South America, and helped them diversify into at least three different species.

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But the mass megafaunal extinction that ended the Pleistocene left the avocados stranded: Without animals big enough to eat them whole and spread their seeds, their range began to shrink. At this point, “humans stepped in,” said Doug Kennett, a professor of environmental archaeology also at the University of California, Santa Barbara and an author of the paper. These humans — who, without the megafauna, now needed new food sources — began cultivating the fruit, “saving avocados,” Dr. Kennett said.

For the new study, researchers focused on a site in western Honduras called El Gigante, an elevated cave that people began frequenting 11,000 years ago. Over generations of living and working there, humans left heaps of discarded squash seeds, maize kernels, agave leaves and much more. Archaeologists have been sifting through it all for about 20 years.

To learn about how people at El Gigante enjoyed avocados, researchers looked at dozens of their seeds found in this “long-term trash pile,” as well as thousands of rind fragments, Dr. VanDerwarker said. They used radiocarbon dating to put these scraps in chronological order, and measured the thicknesses of the rinds and the dimensions of the seeds.

Comparing seed and rind sizes over time allowed the team to trace how humans shaped the fruit. Early on, people were “just picking wild fruits from their trees as they need to,” and the trash was littered with cherry-size seeds and thin bits of rind, Dr. VanDerwarker said.

In layers from about 7,500 years ago, the seeds had become larger and the rinds more robust. This suggests that people were managing existing trees, pruning some branches and new fruits in order to encourage the remaining ones to grow bigger.

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In layers from 4,500 years ago, seeds had reached apricot size and rind thickness had pushed beyond the plant’s natural variation — “an indicator that people had started saving seeds and planting their own trees,” Dr. VanDerwarker said. The arborculturalists favored large fruits, as well as hefty skins that helped with preservation and transport.

The study gives “new evidence for 10,000 years plus, probably, of avocado use,” said Tom Dillehay, a research professor at Vanderbilt University who was not involved with this particular study. He said he had found similar signs of longstanding avocado enjoyment in northern Peru; other evidence has been found in Mexico, Colombia and Panama. Dr. Dillehay predicts that as research continues, more sites, and more types of manipulated food plants, will be discovered.

The finding also continues an ongoing shake-up of the notion that food domestication began with animals and cereal grains. That early avocado growers were putting so much effort into their plants is “different than what was imagined even 10 or 15 years ago,” Dr. Kennett said.

While our concepts of plant husbandry come and go, some things are more timeless. One reason to want to cultivate a thick avocado rind is for ease of scooping, said Dr. VanDerwarker, inspiring other tasty imaginings: “I think people have probably been eating guacamole now for a good 10,000 years.”

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Not everyone is leaving California. A new commercial battery maker just landed in Sacramento

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Not everyone is leaving California. A new commercial battery maker just landed in Sacramento

The lithium-ion batteries that supply much of today’s clean energy come with some infamous drawbacks, from fire risk to reliance on foreign mining.

Alternatives have been slow to get off the ground.

But California startup Peak Energy announced Wednesday it’s building a factory in Sacramento that will be the first in the U.S. to make sodium-ion battery packs at commercial scale.

Sodium-ion batteries have long held promise. They are made from cheap and abundant sodium ash deposits. The materials are less prone to overheating, so they don’t have the fire risk of lithium.

But they also store less energy per cubic inch. That means they have to be bigger and heavier, which makes them harder to fit into electric vehicles. So far, they’ve struggled to compete.

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Peak Energy thinks it has an edge. The company focuses on storage systems big enough to power large data centers, factories and whole segments of the grid, where battery size matters less.

The company already delivers battery packs out of a small pilot project in San Francisco, but it has gotten $1.1 billion in preorders and now needs more space.

CEO and co-founder Landon Mossburg said its first products, each about the size of a shipping container, will begin rolling out in early 2027.

“We’re a 3-year-old company with over a billion in deposit-backed customer contracts, we’ve got grid deployment already, and all those products are exceeding expectations on the grid,” Mossburg said. “Those are really great signals.”

He founded Peak after working at Tesla and the now-folded Swedish battery company Northvolt. The battery cells, which make up the systems, will come from China.

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Customers for Peak who have put down a deposit include independent power providers Jupiter Power, Energy Vault and RWE Americas, who are connecting utilities, and increasingly data centers, with batteries. Peak also works with utilities directly including one unnamed customer in California, and is “in fairly advanced discussions with two of the major hyperscalers,” Mossburg said.

Not everyone is so optimistic about the technology. Lithium-ion batteries are still cheaper, at least up front.

“Sodium-ion batteries attracted considerable interest when lithium-ion battery prices surged in 2022,” said Isshu Kikuma, an energy storage analyst at BloombergNEF. Since then, he noted, those prices have come down.

And as with lithium-ion battery chemistry, Asian manufacturers already have an edge.

“Sodium-ion cells are currently exclusively manufactured on a commercial scale within China,” said Evan Hartley, a research manager at the Benchmark Minerals consulting firm. Large producers such as BYD and CATL are spending enormous amounts to research and develop new products, he said.

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Other U.S.-based sodium-ion startups have floundered of late. Natron Energy canceled plans to produce sodium-ion battery cells in North Carolina last year after funding difficulties. Bedrock Materials, which was making sodium-ion batteries for EVs, also closed up shop, citing a bet on a lithium supply shortage that hadn’t panned out.

But Peak Energy’s model is different, Mossburg said. Unlike Natron, it won’t be trying to make the batteries that go into their systems at first. They’ll import them, initially from China and later from other countries in Asia.

“While working at Tesla, I saw the advantage of focusing on a great end product that customers want before you try to bite off more of the scope,” Mossburg said.

Last month, Peak announced a partnership with General Motors to develop their own cells.

Once up and running, Peak Energy’s Sacramento factory will make three to four battery systems per day, each filled with almost 8,000 battery cells. One system can power hundreds of homes for four hours, Mossburg said. Customers will deploy tens or hundreds in a single project, “basically creating a power-plant sized battery” that can store power and supply the grid when energy is expensive, or directly serve facilities like data centers.

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Although sodium-ion batteries cost more than lithium ones, Mossburg said Peak Energy’s battery systems still save customers money: The technology does not heat up like lithium, so it eliminates the need for expensive cooling technology.

“Because lithium-ion needs to actively cool, you’re basically paying to refrigerate your batteries or using energy to refrigerate your batteries, and we don’t need any of that stuff,” said Mossburg.

The upshot is a battery that’s cheaper, quieter, and safer.

“Safety is a major advantage for sodium-ion batteries,” Kikuma said.

That could matter in California, where battery opposition has surged after a fire at a Moss Landing energy storage facility drove the evacuation of 1,200 residents and contaminated nearby wetlands.

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California has typically been a hub of battery research and development, not manufacturing. Mossburg said Peak Energy, which also has offices in Colorado, chose Sacramento for its proximity to a talented workforce, a growing energy storage market and the company’s engineering teams in Burlingame. He said the factory would create 239 new jobs.

The company hasn’t received any federal clean energy tax credits, but it got a $10.5-million tax credit from the state of California.

While sodium-ion is likely to remain a small fraction of the global battery market, Kikuma said stationary energy storage is one of the fastest growing applications for sodium-ion batteries.

Mossburg sees Peak as being ahead in this corner of the market.

“Everybody from CATL to GM have sort of validated now what we’re doing,” he said. “The market is trying to catch up.”

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What’s the deal with … coffee enemas?

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What’s the deal with … coffee enemas?

It seems like nothing is off limits these days in L.A.’s most woo-woo wellness scenes. From ayahuasca circles and mail-order ketamine lozenges to off-label peptide injections, IV drips and longevity treatments, there’s a seemingly infinite number of ways to look and feel better that people will swear by in this town. Coffee enemas — mostly for digestive issues, but also for a host of other emotional and physiological conditions — is on that alleged miracle menu, and far more common than I even realized before I started writing this article.

“Oh, I have a friend who does that,” “Oh, my cousin swears by it,” I began hearing from people as soon as I started looking for interviewees.

Reddit contains hundreds of anecdotes — both enthusiastic and cautionary — about coffee enemas, which involve a person, often on their own, but sometimes with the assistance of an alternative health practitioner, filling a bag with coffee fluid, inserting a tube into their rectum, and slowly allowing the liquid to be absorbed. “Beware of coffee enemas,” reads the subject line of a post from a woman who did them regularly for a decade and reports feelings of exhaustion, spaciness and cravings when she tries to stop. “Caffeine in any form only (temporarily) masks and provides salve toward bigger, unaddressed issue(s),” she writes.

In response, another user — a person with Stage 4 ovarian cancer — jumps in to defend the practice. “Let’s respect what we are all doing, whether we agree or not,” they write. “I am doing conventional [treatment] in conjunction with alternative (I believe there is a place for both). I haven’t felt this good since my diagnosis. I feel light, have never felt jittery and chemotherapy had me so constipated I would cry.”

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Over the last couple of decades, the interest in digestive health has grown exponentially, prompted by research on the gut-brain connection. According to a report by Grand View Research, the global gut health market was valued at $60.31 billion in 2025 and is projected to reach $114.83 billion by 2033. The growing number of people who are quietly (and often devoutly) doing coffee enemas is a part of this larger trend, which also includes fasting, cleanses, colonics, probiotics, food allergy and stool tests, and a number of other products and services intended to address everything from irregular or uncomfortable bowel movements to energy levels and mood. But what’s the deal with coffee enemas? And are they actually good for you? We talked to a wide range of people with an equally wide range of opinions.

Five enemas a day? Inside the controversial Gerson therapy

The pro-enema Reddit user coping with Stage 4 cancer posted that they do three coffee enemas daily. They discovered the practice through Gerson, an institute founded in 1978 to promote a treatment plan initially developed for tuberculosis, and later for cancer, migraines and other chronic conditions, by German American physician Dr. Max Gerson in the 1930s. If you visit the Gerson Institute website, the supplies for a coffee enema — organic therapy blend coffee ($9.75) and the complete enema bucket kit with catheter ($19) — are listed in its store. It has clinics in Tijuana, Budapest and Shangri-La, China.

Nicole Ferrer-Clement, executive director of the Gerson Institute, says the treatment plan, referred to as the Gerson therapy, has four parts, with five coffee enemas per day being the first part and an essential component of the protocol. The other parts include a vegetarian, fat-free diet, three juices (carrot, carrot and apple, and a green juice) and supplements. The idea behind the coffee enemas, she says, is that compounds (theobromine, theophylline, caffeine) in coffee stimulate the liver to produce more bile, which helps carry toxins out of the body through the digestive tract. Ferrer-Clement says this is important for cancer patients, whose livers may already be compromised while processing toxins released during treatment. Even though many people reach out to Gerson about coffee enemas for general health and wellness and constipation, she says that’s not generally something they recommend. The therapy remains controversial among mainstream oncologists, in part because there are few rigorous clinical studies evaluating its efficacy.

“We want research on [coffee enemas], we’re happy and open to do that, if someone is going to fund it,” Ferrer-Clement says, estimating the institute has treated thousands of patients over the years.

In addition to using coffee enemas to treat cancer, the majority of users online report turning to them for constipation. Many anecdotes are from people who tried more conventional medicine for digestive issues and, from a place of desperation, decided to look elsewhere for solutions. Others, like Chevanni Davids, a 33-year-old South African man living in Bali, use them to maintain a general sense of well-being. Davids — who grew up in South Africa, where culturally it’s common for grandmothers to administer enemas to children in rural areas — does a coffee enema twice per month. He was introduced to the practice of enemas with coffee by someone he describes as a Brazilian grandmother or elder. He swears by the practice, saying it’s kept his bowel movements regular and his emotional state at an equilibrium. Davids warns against doing them too frequently, however. “The addiction is a thing,” he says, “because it feels so, so good. After you do it once, you’re going to say, ‘I’m going to do that tomorrow.’”

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A doctor’s take

Unsurprisingly, given that most people tend to find coffee enemas after reports of being failed by Western medicine, mainstream gastroenterology is not on board with this practice. “Coffee enemas are based on the ill-conceived idea that you’re washing toxins out of your colon, but your colon is not an organ that clears toxins like the liver,” says Dr. Barry Zamost, a gastroenterologist who was in private practice in Long Beach for more than 40 years. “This just flies in the face of all logic and physiology that any doctor has learned for 100 years.”

Zamost remembers first hearing of coffee enemas decades ago when Michael Landon, an actor best known for his roles on “Little House on the Prairie” and “Bonanza,” decided to reject chemotherapy in favor of alternative treatments following a pancreatic cancer diagnosis in 1991. Over his four decades in private practice, Zamost says he frequently saw patients with constipation who were frustrated and trying alternate methods, but that oral therapies such as laxatives, supplements and prescription medications remain the most safe and effective treatments.

A review of case reports from nine people who self-administered coffee enemas also concluded that there’s insufficient evidence to prove that the practice is helpful, and that it could be harmful, to the colon. Zamost says he thinks it’s unlikely for someone to cause themselves serious harm by doing coffee enemas, although it’s happened. He also says that in rare cases that enemas — not with coffee — are appropriate for patients who are severely constipated to provide temporary relief. But, generally, he doesn’t see any benefit to using coffee. As for why people report loving them? That’s easy enough to explain, he says. “Everybody feels better after a bowel movement. So if you gave yourself an enema that really made you feel like you were emptied, you’ll feel good. It doesn’t mean your health is better.”

The takeaway

Coffee enemas are likely not harmful when done in moderation, but we don’t have much more than anecdotal evidence at this point to indicate that they’re helpful either.

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Contributor: The crucial medical question that AI can’t ever answer

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Contributor: The crucial medical question that AI can’t ever answer

One of us got a call last spring from a longtime friend. The story was familiar: two doctors, an MRI, an online AI tool, a stack of articles — and one anxious question. “Everything tells me something different. The AI says I might need surgery. What should I do?”

We believe there’s one key response to anyone in this all-too-common conundrum: “What matters most to you?”

There was a long pause.

That pause is one of the most important moments in modern healthcare — and it is exactly the question artificial intelligence is unable to address.

In our careers as physicians and researchers, we have found, clearly and repeatedly, that for many common conditions the medical evidence does not point to a single “right” answer. The biology is often close. What determines the success of an outcome is whether the choice fits the person making it.

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Some patients with back pain want the fastest possible return to physically demanding work, even if it means surgery. Others want to avoid an operation at almost any cost, even if recovery takes longer. The scan may look the same. The lives behind the scan are not.

That insight is becoming critically important as artificial intelligence moves deeper into everyday health decisions.

In our research on AI and clinical decision-making, we’ve studied what happens when systems are trained to optimize medical outcomes but are blind to human values. In plain English, today’s AI is very good at telling you what usually works for people like you with similar demographics and medical histories. It is far less capable of understanding what you are trying to protect, avoid or prioritize.

This matters because some of the most common and most expensive medical decisions are not purely biological. Should someone with low-risk prostate cancer choose surgery, radiation or careful monitoring? Should a person with atrial fibrillation undergo a procedure or manage the condition with medication? Should a patient with chronic knee or back pain operate now or try months of physical therapy to see whether surgery can be avoided?

In these situations, the medical differences between options are often small or uncertain. What makes the biggest difference is whether the treatment aligns with the patient’s goals: tolerance for risk, willingness to undergo recovery, ability to adhere to long-term therapy or simply what kind of life they want to live.
AI systems can calculate probabilities. They cannot determine what those probabilities mean to a particular person.

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In some respects, artificial intelligence may know more medicine than any individual physician. It can synthesize millions of scientific papers, clinical studies and patient records in seconds. Yet it knows remarkably little about the person sitting across from it. AI does not know a patient’s goals, fears, obligations, tolerance for risk or personal definition of a good outcome. And because it knows little about either the patient or the physician, it knows even less about the conversation between them — the place where facts, values and trust come together to produce the right decision for a particular person.

A second patient story brought this home. A retired teacher was referred after an AI-based symptom checker flagged a heart rhythm abnormality and “favored” an invasive procedure. The patient arrived frightened, convinced there was one correct path. When we talked, it became clear that what mattered most was avoiding a long recovery and staying healthy enough to travel to see grandchildren.

Medication and monitoring — less dramatic, but well-supported by evidence — fit those goals better. The AI wasn’t wrong. It just didn’t know what mattered.
This blind spot is not trivial. Roughly a quarter of U.S. healthcare spending flows through decisions in which patient preferences meaningfully affect outcomes. When those preferences are ignored — by people or by algorithms — care becomes misaligned. That can mean unnecessary procedures, poor adherence, regret and rising costs without better health.

So what should consumers do when an app, portal or “smart” tool recommends a course of action?

Start with three questions.

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First: “Best for whom?” If a tool says one option is best, ask whether it means best on average — or best for someone with your priorities.

Second: “What does this system not know about me?”
AI can see lab values and imaging results. It cannot see your job, your family responsibilities, your fears or what you are trying to get back to.

Third: “What happens if I wait or choose differently?”
Many important medical decisions are not emergencies. When options are close, taking time to reflect is often part of good care.

Artificial intelligence is becoming a powerful partner in medicine. It can help explain options, surface evidence and reduce confusion. But it should inform human decisions, not replace them.

AI may know more medicine than any physician.

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It knows far less about any patient.

And it knows least about the conversation between them.

The most important variable in your healthcare is not in any algorithm. It is you.

James N. Weinstein is a surgeon and former chief executive of Dartmouth Health. He is a clinical professor at Northwestern University’s Kellogg School of Management and global head of Health Futures at Microsoft, which develops AI systems. Ogan Gurel is a physician and assistant professor at the University of Texas at Arlington, where he researches AI, causal inference and patient decision-making.

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