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Another Study Adds to the Body of Evidence that Parkinson’s Starts in the Gut


Sunday, September 3rd, 2023


This week’s core story is about: Parkinson’s may start in the gut.

Happy Labor Day!


A new analysis by the Brookings Institution found prime-age women (ages 25 to 54) have contributed the most to the post-pandemic rebound in labor force participation. The analysis found women with young children (ages 0 to 4) are driving the trend, exceeding their pre-pandemic peak participation rate by more than 1.4 percentage points.

A new study by researchers at the University of Edinburgh in Scotland found far-right accounts on Twitter/X experienced a 70% increase in retweets and a 14% increase in likes following Elon Musk’s takeover of the platform. The study found the increased engagement for far-right accounts outstrips any general engagement increase for other users. One possible explanation is unobserved changes to the Twitter/X algorithm boosting visibility for certain accounts, which would align with other research finding a modest right-wing bias in the platform’s amplification algorithm. The study didn’t include data on left-wing accounts.

A new survey by the Pew Research Center found most U.S. adults haven’t used ChatGPT and don’t think it’ll impact their jobs. The survey found that of the respondents who have heard about ChatGPT, just 24% have actually used it, amounting to around 18% of American adults overall. The survey also found just 19% of people who’ve heard of ChatGPT think it will have a “major impact” on their current job.

A new study by an international team of researchers found humans’ early ancestors nearly went extinct around 930,000 to 813,000 years ago, losing about 98.7% of its breeding population. The study found the ancestral species to Homo sapiens, Neandertals, and Denisovans weathered a prolonged, severe population bottleneck, sustaining an average of just 1,280 breeding individuals for about 117,000 years. The team found the bottleneck coincided with a period of extreme cooling.

Another Study Adds to the Body of Evidence that Parkinson’s Starts in the Gut

A new study adds to the body of evidence suggesting Parkinson’s and other neurodegenerative diseases start in the gut.

Caltech Magazine

The gut-first theory of Parkinson’s disease was originally proposed some two decades ago and has gained academic traction in recent years as scientists continue to explore one of the world’s most common neurodegenerative diseases. While the cause of the disease remains unknown, identifying where it starts could be the key to unlocking new treatments.

So, what does the research say about Parkinson’s originating in the gastrointestinal tract? And does having a healthy gut mean you’ll live Parkinson’s-free?

What’s happening:

Two hundred years ago, British pharmacist James Parkinson published An Essay on the Shaking Palsy, describing features of the disease that would come to bear his name. Ancient texts had described symptoms resembling the disease centuries earlier, though it wasn’t until Parkinson’s work and further studies in the 19th century that it became better understood.

Without getting lost in the weeds, Parkinson’s disease (PD) affects dopamine in the brain. Dopamine is a chemical messenger (a.k.a., a “neurotransmitter”) that enables coordinated physical movement, so people with PD often experience tremors, slowed movement, rigidity or stiffness, and difficulty swallowing, among other symptoms.

Today, some 10 million people worldwide live with PD, including nearly 1 million Americans (that figure is expected to grow to 1.2 million by 2030). In the U.S. alone, the yearly combined direct and indirect healthcare costs related to PD is estimated to be $52 billion, with medication itself costing an average of $2,500 per year.

Two people living with the disease are friends Steven Heller, 70, and Véronique Vienne, 79, co-authors of four books on art design. In a 2021 article for The New York Times, the duo shared an intimate 10-day email exchange between themselves that explored life with PD, with Véronique telling her friend and collaborator that the disease is “turning me into a prisoner inside my own body.”

Véronique’s account is similar to what other people living with PD say, since it changes daily life in ways one can’t comprehend until actually living with the disease. Steven’s characterization of the “despair” he feels when taking account of how the disease has impacted his life, is similarly common.

The cause of PD unfortunately remains unknown, though research in recent years has identified the body’s gastrointestinal tract as the location that the earliest stages of the disease may occur, often years before the first neurological signs appear.

Some evidence suggests the microbiome could influence the brain through circuitry that links the gut to the brain through the vagus nerve, which acts as a “superhighway” between our organs and central nervous system. Another hypothesis involves metabolites, which are produced by the microbiome to break down food, drugs, and other substances, and could be responsible for the gut-brain connection.

New research involving mice adds to the evidence that PD begins in the gut.

What the research says:

A new study by researchers at Columbia University used genetically-modified mice to further explore the gut-first theory of PD, finding a misdirected immune attack may be responsible for the gastrointestinal changes in people living with the disease.

In Parkinson’s, a protein called “alpha-synuclein” becomes misfolded, accumulating inside neurons and slowly poisoning the cells from within. Scientists also know small portions of the misfolded protein can appear on the outside of neurons, potentially making them vulnerable to attack from the body’s immune system. The attack may be doing more damage to neurons than the internal deposits of alpha-synuclein.

To examine whether an immune reaction to alpha-synuclein “kick-starts” the disease and investigate where the reactions could occur, the researchers injected genetically-altered mice with alpha-synuclein and monitored what happened inside the brain and gut.

The team found no signs resembling PD in the brain, but did observe an immune attack and damage on neurons in the gut that produced constipation and other gastrointestinal issues resembling those seen in most PD patients in the years before they’re diagnosed with the disease.

“This shows that an autoimmune reaction can lead to what appears to be the early stages of Parkinson’s and is strong support that Parkinson’s is in part an autoimmune disease,” said study author David Sulzer.

“If this is the beginning of Parkinson’s in many people, we could potentially identify who has the disease before it ever reaches the brain and hopefully stop it in its tracks,” Sulzer said.

Why it matters:

The study doesn’t necessarily mean a healthy gut prevents Parkinson’s, since it could simply be one of the places the disease originates (scientists also believe the nose could be at play), and the researchers won’t know how large of a role the immune system plays in the PD brain until they discover why the brains of their mice didn’t develop any signs of the disease.

Still, the research adds to the body of evidence suggesting an imbalance of gut microbiota is associated with some neurodegenerative conditions, including PD, Alzheimer’s disease, and multiple sclerosis.

The work may lead to future insights into the disease and potential treatments, including immunosuppressant medications and dietary recommendations that could lower the risk of developing PD. By identifying the different types of bacteria found in the gut of PD patients and comparing it with the bacteria found in people without PD, scientists hope to discover genetic diseases and mutations that may identify the gut bacteria responsible for the inflammation or genetic mutations that may cause PD.

The findings also offer hope for people living with PD, like Steven and Véronique mentioned above, many of which struggle with accepting the often debilitating reality of living with the disease.

“I figured that the new ‘me’ is someone I don’t know yet,” Véronique told Steven one day during their email exchange. “From what I can tell so far, she is less upbeat, less can-do, less energetic. I noticed that she is more tolerant of her older sibling’s meddling. She is learning to be more patient with paperwork and administrative procedures. The older ‘me’ might be someone whose company I might enjoy. I am putting a happy spin on things. Do you buy it?”

“I buy it because it is human,” Steven said in return. “If we don’t put a spin on things, how do we survive?”


A new study found just 12% of Americans consume half of all beef on a given day.


Just 12% of Americans Eat Half of All Beef Consumed on a Given Day

A new study by researchers at Tulane University found just 12% of Americans are responsible for eating half of all the beef consumed in the U.S. on a given day, with men and those aged 50 to 65 being the most likely to eat what the researchers describe as a “disproportionate amount” of beef.

  • The researchers say they focused on beef consumption because of its environmental impact and high saturated fat content, with the goal of assisting in targeting educational programs or awareness campaigns to people who eat disproportionate amounts of beef.

  • It’s not yet clear whether the findings are encouraging or discouraging for climate and sustainability advocates. “On one hand, if it’s only 12% accounting for half the beef consumption, you could make some big gains if you get those 12% on board,” said senior author Diego Rose. “On the other hand, those 12% may be most resistant to change.”



A new study by researchers transformed aggressive cancer cells into healthy cells.

Vakoc Lab/Cold Spring Harbor Laboratory

Scientists Transformed Aggressive Cancer Cells into Healthy Cells

A new study by researchers at the Cold Spring Harbor Laboratory in New York successfully induced rhabdomyosarcoma (RMS) cells to transform into normal, healthy muscle cells (pictured above), marking a breakthrough that could lead to the development of new treatments for additional types of cancers. RMS is a particularly aggressive form of childhood cancer that develops in skeletal muscle tissue.

  • The study uses what’s called “differentiation therapy,” which forces cancer cells that are yet to fully develop to continue developing and differentiate into specific mature cell types, effectively ceasing the proliferation. The researchers say, prior to their work, the use of differentiation therapy for RMS was thought to be decades away.

  • The researchers created a new genetic screening technique and used genome-editing technology to trigger the differentiation. “The cells literally turn into muscle,” said lead author Christopher Vakoc. “The tumor loses all cancer attributes. They're switching from a cell that just wants to make more of itself to cells devoted to contraction. Because all its energy and resources are now devoted to contraction, it can't go back to this multiplying state.”



A new study found alcohol may boost “liquid courage” rather than providing “beer goggles.”


Alcohol May Boost Romantic Confidence Rather than Alter Perceptions

A new study by researchers at the University of Pittsburgh found consuming alcohol makes men more likely to approach people they already find attractive but doesn’t impact how attractive they find others to be.

  • The researchers say the findings suggest alcohol might be responsible for enhancing confidence in interactions and giving men “liquid courage,” rather than altering their perceptions or acting as “beer goggles.”

  • The findings could help therapists and their patients dealing with alcohol issues. “People who drink alcohol may benefit by recognizing that valued social motivations and intentions change when drinking in ways that may be appealing in the short term but possibly harmful in the long term,” said lead author Molly Bowdring.


  • 479 - The number of mass shootings in the U.S. so far this year, according to data maintained by the Gun Violence Archive (GVA). The GVA defines a mass shooting as an incident in which four or more people are injured or killed, and includes shootings in homes and public places.

  • 39% - The share of total television usage represented by streaming in July, according to new data from Nielsen. The usage marks a new high for streaming, with Amazon Prime Video, Netflix, and YouTube each reaching new all-time highs. Traditional linear television viewing on broadcast and cable also dropped below 50% (combined 49.6%) for the first time, marking a new low.

  • 68-77°F - The optimal bedroom sleep temperature for seniors, according to a new study by researchers at Harvard Medical School. The study found sleep efficiency fell by 5% to 10% as the nighttime ambient temperature increased from 77 to 86 degrees Fahrenheit. 


Long Video. Learn why passenger train manufacturing is exploding in the U.S. (18 min)

Short Video. Africa’s $5 billion dam that will block the Nile. (9 min)

Fun Video. Why is art deco the most popular architectural style? (9 min)

Good Read. This doctor has studied over 5,000 near death experiences, and he’s convinced there’s life after death. (764 words; 4 min)

Neat List. In case we aren’t alone, here are four expert reads about potential contact with aliens.


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Written by Ryan Wittler