Who Qualifies as an “Expert” And How Can We Decide Who Is Trustworthy?
This article is part of the magazine, "The Future of Science In America: The Election Issue," co-published by LeapsMag, the Aspen Institute Science & Society Program, and GOOD.
Expertise is a slippery concept. Who has it, who claims it, and who attributes or yields it to whom is a culturally specific, sociological process. During the COVID-19 pandemic, we have witnessed a remarkable emergence of legitimate and not-so-legitimate scientists publicly claiming or being attributed to have academic expertise in precisely my field: infectious disease epidemiology. From any vantage point, it is clear that charlatans abound out there, garnering TV coverage and hundreds of thousands of Twitter followers based on loud opinions despite flimsy credentials. What is more interesting as an insider is the gradient of expertise beyond these obvious fakers.
A person's expertise is not a fixed attribute; it is a hierarchical trait defined relative to others. Despite my protestations, I am the go-to expert on every aspect of the pandemic to my family. To a reporter, I might do my best to answer a question about the immune response to SARS-CoV-2, noting that I'm not an immunologist. Among other academic scientists, my expertise is more well-defined as a subfield of epidemiology, and within that as a particular area within infectious disease epidemiology. There's a fractal quality to it; as you zoom in on a particular subject, a differentiation of expertise emerges among scientists who, from farther out, appear to be interchangeable.
We all have our scientific domain and are less knowledgeable outside it, of course, and we are often asked to comment on a broad range of topics. But many scientists without a track record in the field have become favorites among university administrators, senior faculty in unrelated fields, policymakers, and science journalists, using institutional prestige or social connections to promote themselves. This phenomenon leads to a distorted representation of science—and of academic scientists—in the public realm.
Trustworthy experts will direct you to others in their field who know more about particular topics, and will tend to be honest about what is and what isn't "in their lane."
Predictably, white male voices have been disproportionately amplified, and men are certainly over-represented in the category of those who use their connections to inappropriately claim expertise. Generally speaking, we are missing women, racial minorities, and global perspectives. This is not only important because it misrepresents who scientists are and reinforces outdated stereotypes that place white men in the Global North at the top of a credibility hierarchy. It also matters because it can promote bad science, and it passes over scientists who can lend nuance to the scientific discourse and give global perspectives on this quintessentially global crisis.
Also at work, in my opinion, are two biases within academia: the conflation of institutional prestige with individual expertise, and the bizarre hierarchy among scientists that attributes greater credibility to those in quantitative fields like physics. Regardless of mathematical expertise or institutional affiliation, lack of experience working with epidemiological data can lead to over-confidence in the deceptively simple mathematical models that we use to understand epidemics, as well as the inappropriate use of uncertain data to inform them. Prominent and vocal scientists from different quantitative fields have misapplied the methods of infectious disease epidemiology during the COVID-19 pandemic so far, creating enormous confusion among policymakers and the public. Early forecasts that predicted the epidemic would be over by now, for example, led to a sense that epidemiological models were all unreliable.
Meanwhile, legitimate scientific uncertainties and differences of opinion, as well as fundamentally different epidemic dynamics arising in diverse global contexts and in different demographic groups, appear in the press as an indistinguishable part of this general chaos. This leads many people to question whether the field has anything worthwhile to contribute, and muddies the facts about COVID-19 policies for reducing transmission that most experts agree on, like wearing masks and avoiding large indoor gatherings.
So how do we distinguish an expert from a charlatan? I believe a willingness to say "I don't know" and to openly describe uncertainties, nuances, and limitations of science are all good signs. Thoughtful engagement with questions and new ideas is also an indication of expertise, as opposed to arrogant bluster or a bullish insistence on a particular policy strategy regardless of context (which is almost always an attempt to hide a lack of depth of understanding). Trustworthy experts will direct you to others in their field who know more about particular topics, and will tend to be honest about what is and what isn't "in their lane." For example, some expertise is quite specific to a given subfield: epidemiologists who study non-infectious conditions or nutrition, for example, use different methods from those of infectious disease experts, because they generally don't need to account for the exponential growth that is inherent to a contagion process.
Academic scientists have a specific, technical contribution to make in containing the COVID-19 pandemic and in communicating research findings as they emerge. But the liminal space between scientists and the public is subject to the same undercurrents of sexism, racism, and opportunism that society and the academy have always suffered from. Although none of the proxies for expertise described above are fool-proof, they are at least indicative of integrity and humility—two traits the world is in dire need of at this moment in history.
[Editor's Note: To read other articles in this special magazine issue, visit the beautifully designed e-reader version.]
Too much of this ingredient leads to autoimmune diseases, new research shows. Here's how to cut back.
For more than a century, doctors have warned that too much salt in your diet can lead to high blood pressure, heart disease and stroke - and many of the reasons for these effects are well known. But recently scientists have been looking deeper, into the cellular level, and they are finding additional reasons to minimize sodium intake; it is bad for immune cells, creating patterns of gene expression and activity seen in a variety of autoimmune diseases such as multiple sclerosis, lupus, rheumatoid arthritis, and type-1 diabetes.
Salt is a major part of the ocean from which life evolved on this planet. We carry that legacy in our blood, which tastes salty. It is an important element for conducting electrical signals along nerves and balancing water and metabolites transported throughout our bodies. We need to consume about 500 milligrams of salt each day to maintain these functions, more with exercise and heavy sweating as that is a major way the body loses salt. The problem is that most Americans eating a modern western diet consume about 3400 milligrams, 1.5 teaspoons per day.
Evidence has been accumulating over the last few years that elevated levels of sodium can be harmful to at least some types of immune cells. The first signal came in monocytes, which are immune cells that travel to various tissues in the body, where some of them turn into macrophages, a subset of white blood cells that can directly kill microorganisms and make chemical signals that bring other types of immune cells into play.
Two years ago, Dominik N. Müller from the Max-Delbrueck-Center in Berlin, Germany and Markus Kleinewietfeld, an immunologist at Hasselt University in Belgium, ran a study where they fed people pizza and then measured their immune cell function. “We saw that in any monocytes, metabolic function was down, even after a single salty meal,” Kleinewietfeld says. It seemed to be the cellular equivalent of the sluggish feeling we get after eating too much. The cells were able to recover but more research is needed to answer questions about what dose of sodium causes impairment, how long the damage lasts, and whether there is a cumulative effect of salt toxicity.
Kleinewietfeld and his colleagues have hypothesized that too much salt could be a significant factor in the increased number of autoimmune diseases and allergies over the last few generations.
The latest series of experiments focused on a type of T cell called T regulatory cells, or Tregs. Most T cells release inflammatory mediators to fight pathogens and, once that job is done, Tregs come along to calm down their hyperactive brethren. Failure to do so can result in continued inflammation and possibly autoimmune diseases.
In the lab, Kleinewietfeld and his large team of international collaborators saw that high levels of sodium had a huge effect on Tregs, upregulating 1250 genes and downregulating an additional 1380 genes so that they looked similar to patterns of gene expression seen in autoimmune diseases.
Digging deeper, they found that sodium affected mitochondria, the tiny organelles inside of cells that produce much of its energy. The sodium was interfering with how the mitochondria use oxygen, which resulted in increased levels of an unstable form of oxygen that can damage cell function. The researchers injected those damaged Tregs into mice and found that they impaired the animals' immune function, allowing the inflammation to continue rather than shutting it down.
That finding dovetailed nicely with a 2019 paper in Nature from Navdeep Chandel's lab at Northwestern University, which showed in mice that inhibiting the mitochondrial use of oxygen reduced the ability of Tregs to regulate other T cells. “Mitochondria were controlling directly the immunosuppressive program, they were this master regulator tuning the right amount of genes to give you proper immunosuppression,” Chandel said. “And if you lose that function, then you get autoimmunity.”
Kleinewietfeld's team studied the Treg cells of humans and found that sodium can similarly decrease mitochondrial use of oxygen and immunosuppressive activity. “I would have never predicted that myself,” Chandel says, but now researchers can look at the mitochondria of patients with autoimmune disease and see if their gene expression also changes under high salt conditions. He sees the link between the patterns of gene expression in Tregs generated by high salt exposure and those patterns seen in autoimmune diseases, but he is cautious about claiming a causal effect.
Kleinewietfeld and his colleagues have hypothesized that too much salt could be a significant factor in the increased number of autoimmune diseases and allergies over the last few generations. He says a high salt diet could also have an indirect effect on immune function through the way it affects the gut microbiome and the molecules made by microbes when they break down food. But the research results are too preliminary to say that for sure, much less parse out the role of salt compared with other possible factors. “It is still an exciting journey to try to understand this field,” he says.
Additionally, it is difficult to say precisely how this research in animals and human cell cultures will translate into a whole human body. Individual differences in genetics can affect how the body absorbs, transports, and gets rid of sodium, such that some people are more sensitive to salt than are others.
So how should people apply these research findings to daily life?
Salt is obvious when we sprinkle it on at the table or eat tasty things like potato chips, but we may be unaware of sodium hidden in packaged foods. That's because salt is an easy and cheap way to boost the flavor of foods. And if we do read the labeled salt content on a package, we focus on the number for a single serving, but then eat more than that.
Last September, the U.S. Food and Drug Administration (FDA) began a process to update labels on the content of food, including what is meant by the word “healthy” and how food manufacturers can use the term. Many in the food industry are resisting those proposed changes.
Chandel cautions against trying to counter the effects of salt by reaching for foods or supplements full of antioxidants, which, in theory, could reduce the harmful effects on mitochondria caused by a heavy hand with the salt shaker.
Until labels are updated, it would be prudent to try to reduce sodium intake by cutting down on packaged foods while making your own food at home, where you know just how much salt has been added. The Mayo Clinic offers guidance on how to become more aware of the sodium in your diet and eat less of it.
Chandel thinks many people will struggle with minimizing salt in their diets. It’s similar to the challenge of eating less sugar, in that the body craves both, and it is difficult to fight that. He cautions against trying to counter the effects of salt by reaching for foods or supplements full of antioxidants, which, in theory, could reduce the harmful effects on mitochondria caused by a heavy hand with the salt shaker. “Dietary antioxidants have failed in just about every clinical trial, yet the public continues to take them,” Chandel says. But he is optimistic that research will lead us to a better understanding of how Tregs function, and uncover new targets for treating autoimmune diseases.
The Friday Five covers five stories in research that you may have missed this week. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on scientific creativity and progress to give you a therapeutic dose of inspiration headed into the weekend.
Here are the promising studies covered in this week's Friday Five, featuring interviews with Dr. Christopher Martens, director of the Delaware Center for Cogntiive Aging Research and professor of kinesiology and applied physiology at the University of Delaware, and Dr. Ilona Matysiak, visiting scholar at Iowa State University and associate professor of sociology at Maria Grzegorzewska University.
Listen on Apple | Listen on Spotify | Listen on Stitcher | Listen on Amazon | Listen on Google
- Could this supplement help prevent Alzheimer's?
- Why you should care about smart senior towns
- Here's how to reverse being drunk
- Money can make you happy - if you're this type of person
- Personalized anxiety medicine