by Sanjay Gupta
Throughout the pandemic, we’ve been hearing a lot about the risk factors for the most severe effects from COVID. The list of chronic underlying medical conditions for severe COVID and death is quite long and includes conditions as complex as cancer and as common as asthma. Historically, chronic health conditions have been attributed to older adults, or at least we often think of chronic ailments that way. But they increasingly strike younger and younger generations, with new studies showing that older millennials, those born between 1981 and 1988, report having been diagnosed with at least one chronic health condition.4 These are people who just started to turn forty in 2021. Among the most common troubles reported are migraines, major depression, and asthma, followed by type 2 diabetes and hypertension. And experts agree that obesity is a primary driver for general unhealthiness.
In the United States, obesity is an epic problem, with nearly 40 percent of adults and 20 percent of kids living with it.5 That’s one in three adults and nearly one in five kids. I use the word obesity delicately but with good intention. The whole subject of obesity is shrouded in feelings of discomfort, and even shame, but now dangerous obesity raises the risk for all kinds of disorders and disease—among them COVID. It should be no surprise that wealthy nations, often insulated from the worst of infectious disease outbreaks, were hit disproportionately hard and some have blamed this partly on our obesity rates. This is a complex problem because obesity rates are not only higher in many rich countries, but they are also attributed to poor communities within those nations whose access to healthy nutritional choices is limited. As much as the obesity epidemic is a product of wealth and abundance, it’s also the result of the absolute opposite—food deserts where bad calories dominate.
Obese patients who contract COVID are 74 percent more likely to end up in an intensive care unit and 48 percent more likely to die.6 Among the more than 900,000 adult COVID hospitalizations that occurred in the United States between the beginning of the pandemic and November 18, 2020, nearly a third have been attributed to obesity. That’s significant. Imagine those 271,800 people avoiding hospitalization entirely by not having been obese when they got infected. Have you ever wondered why obesity is such a risk factor? It’s one of the questions I’ve probably answered the most this past year: What explains the relationship between weight and the chance of survival from infection? It’s partly due to how our bodies are built.
The diaphragm is one of the major muscles that helps with breathing. Breathe in and the diaphragm contracts and the lungs expand to take in oxygen. But if you’re carrying excess fat in the abdomen, it can place pressure on the diaphragm, forcing that large muscle to restrict the airflow in the lungs. After a short time, the airways in the lower lobes of the lungs collapse, making it increasingly difficult for the body to adequately oxygenate the blood coming through. Also, let’s not forget that obesity is a precursor to other health conditions that add risk, including heart disease, lung disease, diabetes, an impaired immune system, chronic inflammation, and blood that’s more likely to clot. Now toss in a COVID infection, and the risk increases. The mechanics of the coronavirus in the body make it especially harmful to people with a lot of extra weight. The cells that line your blood vessels and regulate blood flow, endothelial cells, can become damaged when you’re infected with this virus. And the fat cells themselves may also be more susceptible to coronavirus. Remember: This virus attaches to cells in the body through the ACE2 receptor, which is a protein on the surface of many cells. It turns out that fat tissue has a high level of ACE2 receptors, thus functioning as a reservoir for the virus. In essence, the more fat you carry, the more “infected” you can become. You’re more magnetic toward the virus.
All of us have a role to play in reversing the obesity trends, especially when it comes to its disproportionate impact on racial and ethnic minority groups (more on this later; at last count, Black and Latinx adults have a higher prevalence of obesity and are more likely to suffer worse outcomes from COVID). But if there’s one silver lining to this pandemic, it is the intense attention shining on our general unhealthiness, forcing us to consider what we can do about it before another virus arrives. In my conversations with Dr. Bob Redfield, the former head of the CDC, he repeatedly lamented our challenges with obesity as a driving force in our dismal COVID outcomes. He brought up an interesting insight about the relationship between weight and a body’s reaction to a virus like COVID: set points. It came up when I asked him about people who can’t seem to shake the illness and go on to become long-haulers—patients with chronic symptoms that remain after the initial infection runs its course. Redfield discussed the idea that each person has a unique internal setting for managing the body’s metabolism and its degree of inflammation.
Set point theory is often evoked in weight loss circles: There is a biological control method in each of us that actively regulates our weight toward a predetermined set number for each person.7 The body prefers to stay within a certain range of weight, but if that set point becomes dysregulated or tinkered with because of overeating or undereating, the results are evident in weight gain or loss—and potentially create a new set point. Similarly, we each carry a baseline level of inflammation. Inflammation is the body’s defense system for taking care of potential insults and injury, but when that system is constantly deploying chemical substances and keying up the immune system, it starts to go a bit haywire. Fire hoses are good for extinguishing blazes, but you wouldn’t want a fire hose to stay on indefinitely.
It helps to think of your set point as a built-in thermostat that is programmed to a particular temperature. If your set point is high, such as a thermostat fixed at 80 degrees Fahrenheit, your general level of inflammation is higher than someone whose set point is lower. Although there may be some variations, a higher set point means a higher degree of temperature (inflammation). Now toss in a virus that wreaks havoc on the body’s internal systems and self-regulatory processes. During the acute phase of infection, the virus first attacks organs and tissues, directly triggering a cascade of inflammation. After the virus leaves, however, the body may be left in the throes of an ongoing cytokine storm that can dial up one’s inflammation set point indefinitely. This scenario has kept a lot of doctors up at night, worried their seriously ill patients would seemingly improve after the virus cleared, only to crash and die a few days later. We learned months later that President Trump’s doctors had feared that might happen to him when he returned to the White House just days after being admitted for the infection.
Redfield is among many doctors who think our inflammatory set points can be adversely affected and reprogrammed by an infection like COVID, which may help explain the ongoing inflammatory storm that some infected patients suffer. The next question is: How can one deprogram and dial back that thermostat to a healthier setting? How do we prime our bodies to be ready for the next infection? Here’s a good place to start: Remake your metabolism and nurture your microbiome.
Remake Your Metabolism
Diet is a confusing topic. I don’t even like to use the word diet and much prefer nutrition. For my previous book, Keep Sharp: Build a Better Brain at Any Age, I spent an enormous amount of time researching and talking to nutrition experts all over the world about the “best diet” for the brain (knowing full well that what’s good for the brain is good for everything else). I was surprised by a lack of consensus, with some experts promoting ketogenic diets or intermittent fasting, with others talking about the benefits of going gluten free. But one common denominator rang true across the board: Good nutrition and other lifestyle habits like regular movement (I also try to avoid the word exercise) and restful sleep have the power to drive down the risk of the major chronic diseases in the United States. And when it comes to good nutrition, there are styles of eating that do not have to conform to any single, restrictive “diet.” In other words, you can find an ideal approach to nutrition that works with your preferences and personal needs.
We have enough evidence bet
ween outcomes in animal models, human clinical trials, and large epidemiological studies to make certain assertions with confidence. And I know that deep down, you already understand that eating muffins or doughnuts with a mochaccino every morning for breakfast probably isn’t going to get you where you really need to go. Diets may seem confusing, but food isn’t. Part of the solution is figuring out what really fuels you in the best way without producing digestive issues or food allergies. If you focus more on what you should eat instead of what you shouldn’t eat, you will find yourself fueling up with good calories and naturally avoiding the bad ones. Food should be a source of nutrition, yes, but it should also be a source of pleasure. I go out of my dietary lane from time to time and have no guilt when I do.
The key to remaking your metabolism involves changing how you think about food in the first place. Food is at the center of a grand intersection: it can hurt, and it can heal. When we choose what to eat, we are determining what information to give our body—information for our cells and tissues all the way down to their molecular structure. For most of my life, I simply thought of food as fuel, just calories for energy, made up of micronutrients and macronutrients (“building blocks”). Over the past decade, though, I have come to understand and appreciate food as a tool for so-called epigenetic expression, or how your diet and genome interact. Of course, it matters what you eat, and your genes play a role in how you use and metabolize what you eat. This is why underlying genetics can factor into risk for certain conditions, like obesity and metabolic dysfunction. But rather than the chemical conversion of food to energy and body matter of classic metabolism, food is also a conditioning environment that can shape the activity of the genome and the physiology of the body.
You probably have not thought about food from that perspective before, but the foods you consume send signals from your environment to your genes. Those signals have the power to change how your genes behave, how your DNA is turned into messages for your body, and how your resulting biology and physiology operate. Because food is the one piece of information we all have to give our body every day, we have to be sure we send the right information that works with it and supports healthy pathways—not harmful or self-destructive ones.
Given the diversity in cultural practices and lifestyle habits around the world, there are many ways to approach dietary choices. It should come as no surprise that the typical Western diet—high in salt, sugar, calories, and saturated fats—is not friendly to our physiology when it’s in excess. As the research concludes, a plant-based diet that is rich in a variety of fresh whole fruits and vegetables, particularly berries and green leafy vegetables, is associated with better health. I know you have heard this countless times, and you may be numb to it. I am too. But there are a few simple statistics I often share with my patients to make the point—for example, increasing fruit intake by just one serving a day has the estimated potential to reduce your risk of dying from a cardiovascular event by 8 percent, the equivalent of 60,000 fewer deaths annually in the United States and 1.6 million fewer deaths globally. And I’ll add that if a mere handful of berries or a juicy apple reduces your risk of having a cardiac event by that much, it can also reduce your risk of experiencing a bad reaction to an infection like COVID. While no single food is the key to good health, a combination of healthy foods will help secure the body against assault, and it is never too early to begin. Think about it. The food you eat today can lay the groundwork for protecting your body in the future. Only 10 percent of Americans get the recommended number of fruits and vegetables a day.8 More than a third of us eat fast food daily, and at least one meal a day comes from a pizza box or a drive-through.
So in the age of pandemic preparedness, what does eating well look like? It’s focused, and with renewed purpose. Make no mistake: Every smart microdecision you make to nourish yourself is part of the plan to make you pandemic proof. From a fundamental standpoint, it means eating real food—not popping pills and supplements. Not to my surprise, supplement sales surged during the pandemic, with multivitamin sales increasing by double digits as people prioritized health and wellness. By fall 2020, vitamin and supplement use had increased by 28 percent in the United States and by 25 percent worldwide since the start of the pandemic. The demand for vitamins D and C and zinc also spiked when news hit that these ingredients might help fight a COVID infection and “boost” immunity. Trouble is, we don’t have evidence that any specific supplement or vitamin fortifies the immune system or offers an advantage when fighting an infection like COVID. That doesn’t mean they aren’t helpful; it’s just that we don’t have the evidence. In the interim, remember the old adage: Absence of evidence is not evidence of absence. Maybe these nutrients are helpful, but we just aren’t sure.
One thing that researchers do agree on is that the best way to obtain these nutrients is through food, when you get the active ingredient and the constellation of micronutrients that help the active ingredients do their job. While we all like the idea of a pill with the micronutrients neatly packaged in one swallow, that approach is not effective and not really possible. That bottle with broccoli on the label doesn’t really have broccoli in a pill. The evidence shows that micronutrients such as vitamins and minerals offer the greatest benefit when consumed as part of a balanced diet because all those other components in healthy food work with the micronutrients to do their job better. Think of this as an entourage effect. While there may be some star players, they don’t work as well without the entourage of other ingredients. For example, getting your B vitamins from eggs and your omega-3 fatty acids from fish always beats taking vitamins and supplements alone.
While effectiveness is challenging to prove when it comes to supplements, I believe we do have an obligation to make certain something is safe. And for the record, the supplement colloidal silver, which has been marketed as a COVID treatment, is neither safe nor effective for treating any disease. From the last day of January in 2020, the day the White House declared a public health emergency, until the end of July, the FDA and the Federal Trade Commission (FTC) sent 106 joint warning letters to supplement producers for selling products with fraudulent claims of treating or preventing COVID.9 During the same period, the FTC separately issued 62 warning letters, and the Department of Justice obtained injunctions against three supplement producers for selling products that made claims of treating serious diseases like COVID.
I realize that changing your diet in an effort to optimize your health will take some time—and it should. Most of us have a general idea of what’s good for us, what we like and don’t like, and even what our own superfoods are. I kept a food journal a few years ago to figure out what worked best for me. Turns out fermented foods like pickles are my secret weapon. I snack on them to boost my productivity and energy. Find what works for you, and make it part of your routine. Reducing your intake of refined sugars and flours, artificially sweetened foods and beverages, fast food meals, processed meats, highly salty foods, and sweets is no longer a gentle suggestion; it is a mandate. Watch your portions. Prepare more meals at home where you’re in control over the salt, sugar, and fat content that can hide stealthily in packaged meals or in restaurant food. (For a list of basic guidelines to follow, see Keep Sharp.)
In the wake of this pandemic, we will need to analyze how we nourish ourselves at a deeper level than we have ever done in the past. This past year has reminded us that we shouldn’t only focus on avoiding heart disease or diabetes. We should instead have a thorough understanding of how our food can minimize our vulnerability to pathogens we haven’t even yet identified.
In preparing for the next pandemic, we also need to consider the role of the microbiome—the gut’s internal “friendly” germ factory that actually plays mightily into our immunity. Let’s go there next.
Immune Boosters Do Not Exist
Despite slick advertising by marketers of “immune booster” products, such as those that fill the largely unregulated vitamin and supplement industry, there’s
no such thing as an immune-boosting pill, powder, bar, shake, juice, herb, spice, elixir, potion, or food. The best immune boosters are the habits we keep to support the body’s innate defenses: a nutritious, diverse diet; regular exercise; restful sleep; and managed stress.
Nurture Your Microbiome
A lot has been written about the human microbiome, and it’s all the more relevant now in the world of COVID. The microbiome is the link—the biological hinge, if you will—that connects your interactions with your environment (and potential infectious agents) to your immune system.10 The term microbiome comes from the combination of micro, for supersmall or microscopic, and biome, which refers to a naturally occurring community of life forms occupying a large habitat—in this case, the human body. When I began to study immunology and microbiology as a medical student, the term microbiome was not yet on my exams, at least not in the way we talk about it today. Although Joshua Lederberg, a Nobel laureate and microbiologist, is sometimes credited with having coined the term microbiome in 2001, the underlying concept and importance of microbiome work hearken back to the beginning of microbial ecology and to Sergei Winogradsky in the 1800s. Lederberg’s forte was understanding microbial genetics, and he’d be dazzled by how far we’ve come since his death in 2008. Roughly 95 percent of the published microbiome scholarship has come in just the past decade, and two-thirds of it only in the past five years.
