Throughout the history of science, what we once held as irrefutable truth has often been overturned by new evidence and evolving perspectives. From the geocentric model of the universe to the medicinal benefits of bleeding patients, examples abound where scientific consensus crumbled under the weight of scrutiny and empirical inquiry. This phenomenon underscores a fundamental truth: certainty in science is frequently an illusion.
Take, for example, the historical belief in the geocentric model of the universe, championed by Ptolemy in ancient Greece and upheld for centuries until Copernicus and Galileo introduced the heliocentric model. What was once accepted as indisputable truth—the Earth at the center of the universe—was gradually replaced by a more accurate understanding based on empirical observation and mathematical calculation.
![An illustration contrasting two historical scientific paradigms: the geocentric model of the universe with the Earth at the center, and the heliocentric model with the Sun at the center, depicting Ptolemy, Copernicus, and Galileo. Show Ptolemy holding a model of the Earth-centered universe, while Copernicus and Galileo present the Sun-centered model. An illustration contrasting two historical scientific paradigms: the geocentric model of the universe with the Earth at the center, and the heliocentric model with the Sun at the center, depicting Ptolemy, Copernicus, and Galileo. Show Ptolemy holding a model of the Earth-centered universe, while Copernicus and Galileo present the Sun-centered model.](https://substackcdn.com/image/fetch/w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F3830cfd9-901e-4956-9873-6a856df448a2_1792x1024.webp)
Similarly, the medical practice of bleeding patients to balance bodily humours, consisting of four bodily fluids—blood, yellow bile, black bile, and phlegm persisted for centuries despite little empirical evidence of its effectiveness. It took rigorous scientific inquiry and systematic studies to debunk this practice, highlighting the dangers of adhering blindly to established dogma without empirical validation.
![An illustration of the historical practice of medical bleeding, showing a doctor from centuries past using a lancet to bleed a patient with four jars labeled 'Blood,' 'Yellow Bile,' 'Black Bile,' and 'Phlegm' next to them. In the background, show a modern laboratory setting where scientists are conducting rigorous experiments, highlighting the transition from ancient practices to modern empirical science. An illustration of the historical practice of medical bleeding, showing a doctor from centuries past using a lancet to bleed a patient with four jars labeled 'Blood,' 'Yellow Bile,' 'Black Bile,' and 'Phlegm' next to them. In the background, show a modern laboratory setting where scientists are conducting rigorous experiments, highlighting the transition from ancient practices to modern empirical science.](https://substackcdn.com/image/fetch/w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F6112a94e-4639-411d-a02b-1ac8913485bf_1792x1024.webp)
In the field of dietary science, the link between dietary fats, cholesterol intake, and cardiovascular disease once seemed incontrovertible. For decades, public health campaigns and medical advice emphasized reducing saturated fats and cholesterol to prevent heart disease, I remember them well. This consensus was based on observational studies and epidemiological data suggesting a direct correlation between high-fat diets and increased risk of cardiovascular events.
Recent research, however, challenges this entrenched belief. Studies published in reputable journals such as the National Institutes of Health's publications challenge the longstanding consensus on dietary fats and cholesterol. The study reviews current evidence and concludes that the previous belief linking high intake of saturated fats and cholesterol to cardiovascular disease is oversimplified. The study suggests that dietary guidelines advocating for low-fat diets may need reconsideration. This data contradicts the once-accepted notion that all fats and cholesterol are uniformly harmful to cardiovascular health, highlighting a shift towards a more nuanced understanding based on recent scientific findings.
In the meta-analysis conducted by Siri-Tarino et al., the association between dietary saturated fat and cardiovascular disease (CVD) was rigorously evaluated by analyzing data from 21 prospective epidemiologic studies. The study aimed to determine whether intake of saturated fat correlates with an increased risk of coronary heart disease (CHD), stroke, or overall CVD. The researchers used a random-effects model to derive composite relative risk estimates, accounting for variability both within and between the included studies.
The analysis, encompassing data from 347,747 participants over a follow-up period of 5 to 23 years, found no significant evidence linking saturated fat intake with higher risks of CHD, stroke, or CVD. The pooled relative risk estimates were 1.07 for CHD, 0.81 for stroke, and 1.00 for overall CVD, indicating no significant associations. Despite the historical belief that reducing saturated fat intake improves cardiovascular health, this meta-analysis suggests that such dietary changes may not substantially impact CVD risk.
There is evidence that the sugar industry funded research to downplay the role of sugar in heart disease and instead promote fats, especially saturated fats, as the primary dietary culprit. In the 1950s and 1960s, early evidence suggested a link between sugar consumption and coronary heart disease (CHD). To counteract this, the Sugar Research Foundation (SRF), which later became the Sugar Association, sponsored its first CHD research project in 1965, commissioning a literature review published in the New England Journal of Medicine (NEJM). This review, conducted by prominent Harvard researchers, focused on fat and cholesterol as the primary dietary culprits for CHD, minimizing the role of sugar.
The historical analysis provided by Kearns, Schmidt, and Glantz demonstrates the significant influence of the sugar industry on scientific research and public health policy. By funding and directing research to downplay the health risks of sugar, the SRF successfully shifted the blame to dietary fats, impacting dietary guidelines and public health messaging for decades. This case underscores the need for transparency in research funding and the critical evaluation of industry-sponsored studies to ensure unbiased and comprehensive public health policies.
You might be curious as to why I'm discussing diet changes, but I've recently undergone a significant shift in my eating habits. I have replaced much of the processed foods and carbohydrates with fats and proteins, adopting what could be called a "carnivore-light" diet. This change prompted me to re-evaluate long-held nutritional beliefs that have been ingrained in me throughout my life. Reflecting on this personal transformation led me to consider the broader concept of paradigm shifts and how deeply entrenched ideas can influence our choices and perceptions.
This paradigm shift in understanding dietary fats and cholesterol starkly contradicts the once-dominant dietary guidelines which I was raised with. It serves as a poignant reminder of how scientific consensus can evolve based on new evidence and rigorous scrutiny.
Under the mentorship of my advisor at UCLA, I learned firsthand the transformative impact of new evidence on long-established paradigms. Pioneering work in geochemistry, utilizing secondary ion mass spectrometry (SIMS), challenged the conventional view of a hot early Earth. Studies, particularly on ancient zircons from Western Australia, revealed isotopic evidence suggesting periods of cooler conditions conducive to liquid water—a crucial factor for the emergence of life. This paradigm shift from a hot and uninhabitable to a cool and possibly habitable early Earth model not only reshaped geological theories but also influenced broader scientific disciplines, including planetary science and astrobiology.
![Dr. Matthew Wielicki's curriculum vitae page — Dr. Matthew M. Wielicki Dr. Matthew Wielicki's curriculum vitae page — Dr. Matthew M. Wielicki](https://substackcdn.com/image/fetch/w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F2f95b13d-fd8d-4ff6-a176-cf9fb26e2c18_1790x1450.jpeg)
Drawing a parallel to climate science, where assertions of certainty often dominate public discourse, we encounter similar challenges. The narrative that human activity, particularly the burning of fossil fuels, is the primary and often sole driver of climate change has become entrenched in MSM and policy circles. Papers like this, “Consensus revisited: quantifying scientific agreement on climate change and climate expertise among Earth scientists 10 years later” are often cited as definitive evidence of anthropogenic climate change.
The paper aims to quantify the consensus on anthropogenic global warming (AGW) among Earth scientists, suggesting a high level of agreement that human activities are driving recent global temperature increases. Utilizing a survey of geoscientists from the Directory of Geoscience Departments, the study reports that 91.1% of respondents attribute global warming primarily to human activities. This percentage rises even higher among those identified as having greater expertise in climate science, reaching nearly 100% among the most prolific publishers in the field.
However, the methodology and interpretation of the findings present many critical issues. For example, the reliance on self-reported data for assessing expertise introduces significant biases. Those who are skeptical of AGW might be less likely to participate in such surveys, skewing the results towards a higher apparent consensus. With a response rate of 25%, it remains unclear whether the respondents are truly representative of the broader geoscience community.
As someone who questions prevailing narratives and explores alternative perspectives, I advocate for a skepticism that encourages rigorous scrutiny and open debate. Embracing uncertainty in climate science does not diminish the urgency of addressing environmental challenges; rather, it enhances our ability to focus our efforts, incorporate new data, and develop resilient strategies for the future.
The current ‘claimed’ consensus on AGW has become a driving force behind a multitude of political and policy decisions worldwide. Governments are implementing sweeping regulations, investing heavily in renewable energy, and committing to international agreements based on the premise that human activities are causing catastrophic climate change. This pervasive integration of climate science into policy is unprecedented. If the underlying assumptions of AGW were exaggerated or significantly flawed, driven by funds from the climate-industrial complex, the implications could be monumental, leading to massive economic and social repercussions.
Unlike past scientific errors, the current climate consensus shapes virtually every facet of modern policy, from energy production and agricultural practices to urban planning and international relations. For example, stringent emissions regulations have reshaped multiple industries and economies, often at considerable cost. The potential for misallocation of resources on such a grand scale poses significant risks to global economic stability and development.
At its core, science is about questioning, testing, and retesting hypotheses, not about adhering to a majority opinion. Consensus, by definition, implies agreement among the majority, but it does not guarantee correctness. Historical examples show that many scientific "truths" upheld by consensus were later debunked as more evidence emerged. True scientific inquiry thrives on skepticism and rigorous debate, where every idea is scrutinized, and no theory is beyond challenge.
The danger of equating consensus with the truth lies in the potential to stifle innovation and marginalize dissenting voices to continue to drive the narrative and subsequent investment and funding. As we navigate the complexities of climate science, it is crucial to remember that consensus should not be the goal; understanding should be.
This is a topic I have found relevant throughout my career as a geologist. I can give you many more examples, and what I often find most frustrating is that other scientists fail to have a sense of scientific doubt. I worked with a scientist who was near retirement, but who had found the things he could see in a scanning electron microscope to be fascinating. He began looking at samples of concretions from humans, along with sedimentary rocks, and meteors under the SEM and began to see what he believed were fossilized nanometer-size-bacteria. Of course biologists thought this was impossible as no living cell could be that small, but he persisted, and at one point suspected he had found nano-bacteria in Martian rock samples. Then it was discovered that there were relics of the gold coating process that might account for this. I don't know if it was ever resolved, the possibility remains, but the doubters who simply refuse to accept the possibility are abundant. He was probably only allowed to do this research because he had a body of past work that was so well respected.
Another example from geology is continental drift. Some geologists and many "science reporters" still use this term even though it was proven wrong 60 years ago when plate tectonics began to be confirmed.
But one of the most impactful examples is that of the shale revolution in oil and gas. It was as recently as the 1990's considered by most geoscientists that source rock intervals, like shale, had expelled their oil and gas if they had reached that stage and were impossible to get any more oil or gas out of. This was supported by well logging methods, but mostly by ignoring these intervals and not trying to produce oil from them. Then when Mitchell Energy decided to try hydraulic fracturing of the Barnett Shale, they proved the old paradigm wrong. So wrong, that a year 2000 estimate of world-wide resource of oil and gas was 3 trillion barrels (Chevron), and today that estimate stands closer to 12 trillion barrels, showing we have far more oil and gas than ever believed possible. During the same period we underwent this revolutionary rethinking, many prominent geologists were campaigning for "Peak Oil" which simply did not happen. Another example along these lines is that of Dr. Leigh Price who spent most of his career studying the Bakken Shale. He estimated the total resource to be between 270 and 530 billion barrels with recoveries as high as 50%. He died before he could get his work published, so while his draft is passed around quietly, it has never reached the public or had final peer review. Many estimates since have tried to cut this resource to as little as 4 or 5 billion barrels recoverable, but it seems these are the people who refuse to understand the new paradigm (and who refused to publish Price). Price's work has not been disproven but remains largely hidden.
The harm done by the pseudo-scientific idea that saturated fat in the diet caused heart disease is immense. It was really started by a single scientist, Ancil Keyes at the University of Minnesota. As you point out, there is accumulating evidence that it is excessive carbohydrate consumption that is behind the epidemic of obesity and diabetes.