The story goes something like this: humans evolved in hunter-gatherer settings, facing acute, intermittent stressors like predator encounters that triggered intense fight-or-flight responses followed by recovery. These environments fostered physiological adaptations suited to natural rhythms, physical activity, and periodic challenges.

In contrast, today’s industrialized, urbanized world—home to over 4.5 billion people, projected to reach 6.5 billion by 2050—imposes a constant stream of low-level stressors, from traffic noise to relentless digital stimulation. Evolutionary anthropologist Colin Shaw of the University of Zurich argues this “mismatch” places a chronic stress load on our bodies, as our nervous systems react to modern pressures “as though all these stressors were lions… you have this very powerful response… but no comedown.”

This mismatch manifests in widespread health declines. Physically, it likely contributes to elevated blood pressure, weakened immune function, rising autoimmune diseases, and plummeting fertility rates, with sperm counts and motility dropping since the 1950s. Mentally, constant stimulation impairs cognitive function and sustains tension.

Shaw and his colleagues speculate that environmental factors like pesticides and microplastics are overlooked drivers of these harms, though they wrongly exaggerate the risks posed by these technologies and, more importantly, the higher living standards they enable—including free time to explore nature.

However, many harmful effects attributed to modern environments are probably amplified by the erosion of traditional social bonds and community structures. The rise of our modern, globalized civilization hasn’t just altered our environment but rapidly weakened intermediate associations—such as family, neighborhood, church, and community groups—that once provided meaning, security, and mutual support.

This complementary thesis suggests that our hardwired need for community remains vital to our well-being, and its increasing absence in contemporary society compounds health declines far beyond environmental factors alone.

Join Dr. Liza Lockwood and Cam English on this episode of Facts and Fallacies as they take a closer look at the risks and benefits of industrialized society:

Dr. Liza Lockwood is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Follow him on X @camjenglish

While preliminary studies suggest ketamine could reduce—or perhaps even eliminate—depressive symptoms in some patients, critics emphasize its significant risks. As a powerful anesthetic with a history of recreational abuse, ketamine carries high addiction potential, especially for those with substance use histories. Side effects include dissociation, elevated blood pressure and potential long-term issues like bladder damage.

Its benefits may be short-lived, necessitating repeated infusions of IV ketamine therapy, and long-term safety data remains limited, raising concerns about unknown effects from prolonged use. While it reduces suicidal thoughts acutely, evidence for sustained protection is unclear. Accessibility is another hurdle: treatments are costly, require clinic supervision and are not universally licensed for depression.

Proponents rebuff these criticisms, noting that traditional medications can also have serious side effects and often take weeks or even months to relieve depression, if they work at all. If ketamine can help even a relatively small group of people, including those at greatest risk for suicide, then why not allow them to use it? Some patients report life-transforming outcomes, including reduced anxiety and PTSD symptoms after just a few sessions. For individuals unresponsive to standard therapies, ketamine could offer relief where few other treatment options exist, proponents say.

The controversy underscores the tenuous balance between innovation and caution. Advocates push for expanded research and access, viewing ketamine as a breakthrough for TRD, while skeptics call for rigorous studies on risks and ethical guidelines to prevent misuse. As of today, ongoing trials aim to clarify its role, but the debate persists on whether benefits outweigh hazards for vulnerable populations.

Join Dr. Liza Lockwood and Cam English on this episode of Facts and Fallacies as they take a closer look at ketamine’s promising benefits and alarming risks:

Dr. Liza Lockwood is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Follow him on X @camjenglish

Weiser spoke with KFF Health News on the evening before World AIDS Day, which the U.S. government, for the first time since 1988, didn’t acknowledge this year. That was only the latest blow to efforts to combat HIV. The Trump administration has cut funds to provide lifesaving HIV care abroad, withheld money to prevent and treat HIV in the U.S., and fired HIV experts at the Centers for Disease Control and Prevention.

Weiser was fired from the CDC during mass layoffs in April, was rehired in June, and then resigned. He continues to treat patients at Grady Memorial Hospital in Atlanta. In November, he published an article that warns against complying with presidential orders to censor data about transgender people.

The following conversation has been condensed and edited for clarity.

LISTEN: Former CDC official John Weiser speaks with KFF Health News correspondent Amy Maxmen about his resignation from the agency and why he thinks complying with President Donald Trump’s orders to erase transgender people is bad for science and society.

In the first weeks of his presidency, Donald Trump issued several executive orders with implications for HIV programs. One directed federal employees to exclude gender identities that didn’t correspond to a person’s biological sex assigned at birth.

On how this played out at the CDC:

We were told to scrub any mention of gender or transgender people from dozens of research papers and surveillance reports that had already been published or were going to be published, and to stop collecting information from participants about their gender identity. For example, we had to recalculate our numbers on HIV among men who have sex with men, or MSM, a category that the CDC changed to “males who have sex with males.”

The CDC had no director at the time. The order came from on high. And there was no discussion about whether we wanted to comply with the directive.

On how this directive has affected his research:

Using data from the Medical Monitoring Project, we found that people with HIV who misused opioids were more likely to engage in behaviors that could pass on HIV to another person — through unprotected sex or shared injection. And we found that very few people who misused opioids were receiving treatments for substance misuse. This information could have been useful to change clinical practice and boost funding to treat people with HIV who misuse opioids.

We were getting ready to publish this study, but when I put the paper through CDC’s clearance process, I was told to remove data about the prevalence of opioid misuse among transgender people.

I thought carefully about that, and I decided not to do that, because it’s bad science to suppress data for ideologic reasons and because erasing people from the story harms actual people. I thought about my transgender patients and how I would face them, and what I would say to them while I’m sitting with them in the exam room, knowing that I had erased their existence from CDC.

I withdrew the paper. It remains unpublished.

On how removing data harms people:

Purging data about transgender people has the effect of erasing them from the real world, pretending that they don’t exist. This group of people is heavily affected by HIV, and this type of information informs improvements in treatment. My transgender patients struggle with poverty, with unstable housing, with food insecurity, with mental health disorders, with substance misuse, and face a huge amount of stigma and discrimination in their daily lives.

My transgender patients are trying to get by, day by day. They’re trying to survive. I think it’s important to realize that somebody who is transgender needs to feel comfortable in their own body to be healthy — and denying them recognition compounds their challenges.

After the executive order came down, one of my patients said she felt even more afraid of being in public and not passing, and so she was considering having additional surgical treatment to feel safer. Her concern was not about politics. It was about survival.

On why the CDC went along with orders to remove transgender data:

I think the hope was that by complying with the directive, other work at the CDC would be spared. And unfortunately, that hasn’t proved to be the case. Funding for the Medical Monitoring Project was terminated after 20 years, and the concern within CDC is that the president will eliminate all HIV prevention and surveillance funding.

One of my concerns while there was that if it’s OK to comply with a directive to remove information about gender, what if the next demand is that we don’t report about people who emigrated from other countries, or on people who are experiencing homelessness? What if there’s a directive to suppress data about a particular racial or ethnic group that’s unpopular? How far would we go?

Some HIV clinics and organizations have considered curtailing their work with transgender people and undocumented immigrants, or on equity initiatives, because they fear the loss of federal funds.

His advice on these decisions:

People making these decisions are in a really tough spot. They want to do what’s best for their programs. They want to do what’s best for their employees. They want to do what’s best for the people they’re charged with taking care of. Those are careful decisions that need to be made weighing all of the considerations. What I want these leaders to do is also consider how a decision to essentially throw one group of people under the bus undermines scientific integrity and harms everyone.

 And I think that it’s also necessary for the rise of autocracy to go along, to compromise, to acquiesce. While all of this was going on, I heard an interview with Masha Gessen, who is a Russian American journalist who writes about the rise of autocracy. Gessen explained that decisions to go along are not made because people are unethical or heartless. They’re rational choices. They’re made in order to protect something that’s important — institutions, families, jobs — even if it means sacrificing principles. Gessen’s point is that this gradual process of compromising ultimately is what solidifies an autocrat’s power.

On why he resigned from the CDC:

As a physician working at the CDC, numbers have always described individual people, people whose suffering I witness. When you know somebody, they’re no longer just a concept that you make a judgment about.

I realized that I could do more good by spending more time with my patients than I could working for the CDC under this administration.

Amy Maxmen is a science journalist in New York City who covers the entanglements of health, climate, policy and the people behind research. Find Amy on X @amymaxmen

A version of this article was originally posted at Kaiser Family Foundation Health News and is reposted here with permission. Any reposting should credit both the GLP and original article. Find Kaiser Health News on X @KFFHealthNews

The science is settled: biological sex is not a spectrum but a binary, and the evidence is undeniable to anyone willing to fairly consider it. So argues evolutionary biologist Colin Wright in a new peer-reviewed article simply titled Why There Are Exactly Two Sexes. Grounding his argument in Darwinian evolution—a theory universally endorsed by the science community—Wright outlines a few basic facts that no serious person disputed until just a few years ago.

In anisogamous species, including humans, sex is strictly defined by the type of gamete an organism’s reproductive system is designed to produce, small sperm for males and large ova for females. This gametic dimorphism, evolved over a billion years ago from isogamous ancestors through disruptive selection, forms the universal basis for the two sexes. “As with the fact of evolution itself,” Wright notes, “contemporary scientific debates have long moved on from questioning whether the sex binary is a fact to questions about how anisogamy evolved, why it persists, and what its evolutionary consequences are.”

Of course, challenges to this consensus are widespread today; even some major science journals have declared their opposition to the sex binary. “The idea of two sexes is simplistic,” Nature famously asserted in 2015, for example. “Biologists now think there is a wider spectrum than that.” The problem with this and similar counterarguments, Wright adds, is that they’re “seemingly driven by cultural and political debates surrounding the concept of ‘gender identity’ and transgender rights.” They don’t introduce new evidence that improves our understanding of sex, they merely try to redefine it to facilitate certain policy outcomes.

This biased methodology introduces an even greater problem beyond its factual mistakes: lawmakers, physicians and individuals begin making decisions that cause real harm. As Wright puts it:

Join Dr. Liza Lockwood and Cam English on this episode of Facts and Fallacies as they take a closer look at Wright’s defense of the sex binary.

Dr. Liza Lockwood is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Follow him on X @camjenglish

Critics aren’t convinced, however. They contend that obesity is a behavioral abnormality and a risk factor for real diseases, not a discrete pathology. Writing in the journal Nature in 2014, Dr. David Katz summed up this perspective. “Our bodies, physiologies and genes are the same as they ever were,” he argued. “What has changed while obesity has gone from rare to pandemic is not within, but all around us.” In short, an abundant food supply and marked decrease in physical labor over recent decades have turned a normal physiological response—storing excess calories for later use—into a public health threat. Humans are wired for an environment characterized by energy scarcity, where intense exertion is required to gather the calories necessary for survival, a dynamic that persisted well into the 20th century.

Proponents of the disease model of obesity, including the American Medical Association (AMA), which classified obesity as a disease in 2013, emphasize its complex etiology: genetic predispositions, hormonal dysregulation (e.g., leptin resistance) and socioeconomic barriers contribute to energy imbalance, akin to hypertension or diabetes. Advocates also say recognizing obesity as a disease destigmatizes patients, enhances insurance reimbursement for treatments and spurs research funding—vital as obesity drives comorbidities like cardiovascular disease and type 2 diabetes.

So, is obesity a disease or a harmful lifestyle choice? Are those two definitions mutually exclusive? Join Cam English on this episode of Facts and Fallacies as he examines the obesity-disease hypothesis.

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Follow him on X @camjenglish

Americans across the political spectrum embrace this rights-based rhetoric, even people who are generally hostile to Kennedy’s agenda; for instance, scientists who advocate for universal health care often frame access to medicine as a human right. Nevertheless, critics of the MAHA campaign argue that health freedom is merely a smokescreen masking an insidious agenda. Kennedy and his compatriots cloak their policy goals in the language of liberty, the argument goes, but they have no problem imposing their preferences on Americans when they can get away with it.

For example, the FDA under Kennedy’s leadership recently changed federal recommendations for COVID-19 vaccines, a move that could limit access to the shots even if people want them and could benefit from the protection they provide. And earlier in his career, RFK, Jr. was caught on camera advocating for the imprisonment of prominent businessmen he deemed proponents of climate change misinformation. The man clearly has an authoritarian streak, in other words.

These observations invite some important questions: is health freedom a legitimate concept that has been abused by cynical MAHA activists? Is the very idea of “health freedom” a fiction? Join Dr. Liza Lockwood and Cam English on this episode of Facts and Fallacies as they scrutinize “health freedom.”

Dr. Liza Lockwood is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Follow him on X @camjenglish

This crisis is a serious threat to scientific progress. Dubious results fuel skepticism of mainstream medicine, legitimizing radicals like RFK, Jr. who claim academic publishing is corrupt to its core—merely a vehicle for boosting Big Pharma’s profits. Addressing the problem requires systemic changes: punishing bad behavior in the academy, promoting open data sharing, enforcing rigorous peer review and incentivizing replication studies. Journals and funding agencies must prioritize negative results, and institutions should reward transparency over sensationalism.

Without these reforms, the scientific method’s foundation—reliable, verifiable evidence—could crumble, slowing progress and risking additional harmful policies or applications. By fostering a culture of integrity, science can regain credibility and advance more efficiently, ensuring discoveries are robust and trustworthy for future generations.

But the question remains: will the science community consistently implement these critical solutions? Join Dr. Liza Lockwood and Cam English on this episode of Facts and Fallacies as they tackle the replication crisis with GLP contributor Dr. Kevin Folta.

Kevin M. Folta is a professor in the Horticultural Sciences Department at the University of Florida and host of the Talking Biotech podcast. Follow Professor Folta on Twitter @kevinfolta

Dr. Liza Lockwood is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Follow him on X @camjenglish

While Purdue Pharma did indeed oversell OxyContin and many people used the drug recreationally, these were almost always individuals with long histories of substance abuse. The vast majority of patients prescribed OxyContin for legitimate medical purposes did not misuse it. Moreover, by 2001, this widely maligned pain reliever accounted for less than 10 percent of nonmedical opioid use. In reality, there is a large body of research showing that OxyContin poses minimal addiction risk when used as prescribed by a physician.

By the early 2010s, as addiction rates soared and prescription opioids became harder to obtain due to regulatory crackdowns, many users transitioned to cheaper, illicit alternatives like heroin. This second wave, peaking around 2010–2013, saw heroin overdose deaths triple. The crisis evolved further with the third wave starting in 2013, dominated by synthetic opioids such as fentanyl, often laced into other drugs by cartels. Fentanyl-related deaths skyrocketed, accounting for over 70% of opioid fatalities by 2022. Fortunately, this trend has slowed in recent years.

Overlooked amid all this controversy are patients afflicted by painful chronic diseases, who have been denied access to prescription opioids in the name of fighting drug abuse. This severe response to the overdose epidemic often forces sick people with no history of substance abuse to drink alcohol daily or seek out illicit opioids for pain relief—or just commit suicide.

Is there a way to resolve this tragic state of affairs without actively encouraging recreational drug use?

Join Dr. Liza Lockwood and Cam English on this episode of Facts and Fallacies as they break down America’s overdose epidemic with patient advocate Bev Schechtman

Bev Schechtman is vice president of the Doctor-Patient Forum, a non-partisan, community-based organization that works to support pain patients and their physicians with access to lifesaving pain relief. Follow her on X @ibdgirl76.

Dr. Liza Lockwood is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Follow him on X @camjenglish

There was a critical problem, however: the internal company documents explicitly refuted a causal association between Tylenol use and autism. Johnson & Johnson’s experts, tasked with evaluating the possible link between acetaminophen and the neurodevelopmental disorder, panned the low-quality evidence cited by critics. “There is no proven link between the two [our emphasis],” a 2012 email from one company scientist plainly stated. A second email in the same chain of messages explained why: “Review of the cases identified confounders or lack of information which preclude a causal assessment.”

Kopp excluded these clear refutations of the Tylenol-autism link from her story, though she implied that the company’s tone had shifted by 2018, quoting one J&J scientist as saying “The weight of the evidence is starting to feel heavy to me.” But an internal evidence review prepared for company executives the same year confirmed that its experts remained skeptical of the association. Evaluating all the evidence available at the time, they noted that studies linking Tylenol to autism were hampered by confounding, meaning another factor beyond acetaminophen exposure was the likely cause of autism. “There are limitations of the individual studies that make it challenging to conduct a meta-analysis,” the presentation concluded.

Meta-analysis is a method of combining and analyzing data from multiple studies on the same topic to reach a more conclusive answer than any one study could provide. The individual studies linking acetaminophen and autism were so limited—so hampered by confounding—they couldn’t be combined for a meta-analysis, J&J scientists found.

The most recent evidence review, published in August 2025, purporting to show a link between Tylenol and autism didn’t include a meta-analysis for the same reason. “[W]e did not conduct [a meta-analysis] due to significant heterogeneity across studies in exposure assessment…” the authors wrote. In sum, the advocates of the acetaminophen-autism association were forced to concede publicly the same point J&J’s scientists made privately.

What do we make of all this? The best evidence to date indicates that the risk of autism is heavily influenced by a variety of genetic factors. For example, multiple studies have shown that pregnant women with neurodevelopmental disorders experience more pain during pregnancy and thus tend to use more Tylenol, explaining the association between the drug and subsequent autism diagnosis in their children. “So let’s be clear,” GLP contributor Dr. Andrea Love observed in a recent story, “autism is overwhelmingly genetic, sometimes influenced by biological and developmental factors like maternal fever, but not acetaminophen.”

Bottom line: The Daily Caller report is fundamentally flawed. It selectively cited private communications and scientific research to support a predetermined conclusion. There is no evidence showing that Tylenol causes autism.

Join Cam English on this episode of Facts and Fallacies as he examines Daily Caller’s allegation in more detail.

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Follow him on X @camjenglish

In reality, no such epidemic exists. Childhood cancer (ages 0-14) remains rare, with about 9,550 new U.S. cases projected for 2025—stable at roughly 15 per 100,000 children annually. Incidence rates have slightly declined by 0.8% per year from 2015-2021, driven by drops in brain tumors. For adolescents (15-19), rates rose modestly by 0.7% annually, and for young adults (15-39), by just 0.3% from 2013-2022—far from “soaring.”

Cancer mortality tells an even clearer success story: Death rates have plummeted 70% in children and 63% in adolescents since 1970 (p 11), thanks to better treatments—now at approximately 1% of all cancer deaths. Survival exceeds 86% for young patients. While specific cancers like colorectal and breast show slight upticks in people under 50 (1-2% annually), these are tiny increases, and they aren’t occurring in an age group anybody typically describes as young.

Scapegoating chemical exposure for these rare cancer cases lacks evidence and obscures the fact that child health has improved dramatically, with overall mortality halved since the 1960s. It’s time for reporters, social media influencers and public health officials to focus on evidence and quit exaggerating risk.

Join Dr. Liza Lockwood and Cam English on this episode of Facts and Fallacies as they debunk the media-driven “youth” cancer scare.

Dr. Liza Lockwood is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Follow him on X @camjenglish