Science Facts & Fallacies

Though still widely maligned today, pesticides played a pivotal role in this progression, enabling HYVs to thrive and contributing to yield surges of up to 44% from 1965 to 2010. The benefits were staggering in economic terms. A 2021 study in the Journal of Political Economy quantified that HYVs boosted incomes and curbed population growth via reduced fertility. Cumulatively, the Green Revolution saved the world trillions of dollars over 45 years—equivalent to one year of global GDP.

In risk-benefit terms, the Green Revolution’s gains—saving multitudes from starvation, reducing poverty and sparing 18-27 million hectares from conversion to cropland, primarily in developing countries—far outweighed drawbacks, especially given the annual welfare gains from related technologies by 2020. Yet, Borlaug’s work remains controversial today, with many environmental activists and some scholars alleging that his work was harmful on balance, despite the documented increases in food production.

Join Dr. Liza Lockwood and Cam English on this episode of Facts and Fallacies as they examine the Green Revolution and address criticisms of Borlaug’s work.

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

“Along with the possibility of the extinction of mankind by nuclear war, the central problem of our age has therefore become the contamination of man’s total environment with such substances of incredible potential for harm … How could intelligent beings seek to control a few unwanted species by a method that contaminated the entire environment and brought the threat of disease and death even to their own kind? Yet this is precisely what we have done” (Silent Spring p 14-15 Kindle Edition).

Although Carson is remembered fondly for her colorful prose that helped to launch the modern environmental movement, her criticisms of pesticides were flawed in important ways. “Silent Spring was replete with gross misrepresentations and atrocious scholarship,” says former FDA scientist Dr. Henry Miller. While she was broadly correct that pesticides can be harmful to off-target organisms (e.g. DDT causing eggshell thinning in some bird species), Carson’s claim that the insecticide was driving many birds to extinction was contradicted by multiple studies published before and after Silent Spring hit bookstores.

Strikingly, annual data from the North American Breeding Bird Survey from 1966, a study launched in response to concerns Carson popularized, showed “through the end of the 1970s … no obvious pattern of overall increasing bird populations as would be expected to follow the 1972 banning of DDT if it were truly harming bird populations,” science writer Robert Zubrin noted in 2012.

But of particular note was Carson’s allegation that DDT caused a variety of illnesses, including cancer: it was speculative at the time and subsequently refuted by additional research. “…[S]tudies in Europe, Canada, and the United States have since shown that DDT didn’t cause the human diseases Carson had claimed,” Dr. Paul Offit observed in 2017:

“Indeed, the only type of cancer that had increased in the United States during the DDT era was lung cancer, which was caused by cigarette smoking. DDT was arguably one of the safer insect repellents ever invented—far safer than many of the pesticides that have taken its place.”

But the story of highly toxic DDT persists to this day, and mainstream accounts of Carson’s work maintain that her claims about pesticides were vindicated.

Join Dr. Liza Lockwood and Cam English on this episode of Facts and Fallacies as they take a closer look at the risks of benefits of DDT use, and challenge some common misunderstandings along the way.

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

The guidelines aren’t perfect; they call out harmless additives and processing that have no bearing on the nutritional content of food, for example. But the media, always eager to publicly chastise RFK, Jr., has exaggerated the changes, portraying the updates as fully endorsing unrestricted meat and dairy consumption. For instance, NPR described them as going “all in on meat and dairy,” suggesting a complete reversal of prior cautions. In reality, the guidelines do not eliminate established limits on saturated fats, a common (though arguably unjustified) concern with red meat and full-fat dairy.

In fact, the guidelines explicitly retain the longstanding recommendation to cap saturated fat intake at less than 10% of daily calories, consistent with previous editions and recognizing the ongoing debate over the risks and benefits of meat and milk consumption.

Bottom line: everyone is wrong about the new dietary guidelines to one degree or another. Reporters rushed in to amplify a scandal when they should have been calling balls and strikes. Kennedy doubled down on his quasi-religious devotion to “whole foods,” and the public was left to discern the new recommendations for themselves.

Join Dr. Liza Lockwood and Cam English on this episode of Facts and Fallacies as they take a closer look at the new dietary guidelines:

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

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

But fluoride phobia was suddenly mainstreamed after the Journal of the American Medical Association (JAMA) amplified concerns about fluoridated drinking water, publishing a federally funded study in January claiming that “Accumulating evidence suggests that fluoride exposure may affect brain development.” The concern intensified after health and human services secretary RFK, Jr. announced plans in April to tell the Centers for Disease Control and Prevention to stop recommending fluoridation in communities nationwide. CDC has yet to update its guidelines on water fluoridation, and just-published research has confirmed that exposure to trace amounts of fluoride in drinking poses no risk of neurological damage.

Nevertheless, two states have already removed the chemical from their municipal water supplies, and the broader policy debate over fluoridated water continues despite clear evidence exonerating it as a beneficial public health intervention. Skepticism today typically correlates strongly with political identity but spans the ideological spectrum, with left-wing anti-chemical activists and MAHA conservatives finding common cause on this and other alternative health issues.

The question worth exploring is: why are so many people from opposite ends of the political spectrum, who disagree about almost everything, willing to lock arms on these alternative health causes? More importantly, what can scientists do to neutralize this campaign before it gains further traction and causes more harm to public health?

Join Dr. Liza Lockwood and Cam English on this episode of Facts and Fallacies as they take a closer look at the anti-fluoride crusade:

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

On the surface, food addiction makes sense. America remains in the throes of an obesity crisis, and heart disease—a condition heavily influenced by poor dietary choices—still kills more Americans than any other cause. Against that backdrop, the addictive nature of our favorite foods seems to explain our ongoing willingness to overindulge despite the often-fatal consequences.

But the food addiction narrative begins to unravel the more experts scrutinize it, raising questions proponents of the hypothesis don’t have good answers for. For example, only a minority of obese people fit the definition for food addiction while a larger share of patients diagnosed with anorexia do. This paradox badly undermines food addiction and goes to a broader point: the diagnostic criteria are not distinct from existing disorders. Indeed, large-scale studies show that food addiction symptoms almost perfectly overlap with binge-eating disorder and normal overeating driven by stress or restriction.

Once those factors are controlled for, an independent “food addiction” syndrome disappears. “Collectively, the present findings support the view that [food addiction] reflects a cluster of preexisting psychological constructs—such as craving, guilt, and disordered eating attitudes—rather than a clearly delineated disorder,” the authors of a July 2025 review concluded.

Perhaps more importantly, no unique addictive agent has been identified. Decades of searching for a “food drug” (sugar, fat, palatability) have failed. While some mental health experts insist there is an “emerging consensus” about the validity of food addiction, they can’t seem to settle on exactly what quality makes a certain dietary choice addictive. This seriously undercuts any attempt to analogize food addiction to a well-established substance use disorder like alcoholism.

In short, “food addiction” is a metaphor stretched into a diagnosis. It pathologizes common human struggles and distracts from evidence-based drivers of overeating: sleep deprivation, emotional distress, and the modern food environment’s relentless cue exposure. The science has moved on; the label should too.

Join Dr. Liza Lockwood and Cam English on this episode of Facts and Fallacies as they take a closer look at “food addiction.”

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

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