COVID-19 is undoubtedly a global crisis. Aside from the apparent challenges our country has been facing, a lurking crisis not fully realized is the poor baseline metabolic health of many Americans that makes them immensely more vulnerable to severe illness or death from COVID-19. While it is widely known that a majority of Americans have pre-existing health conditions and metabolic disease, it is less apparent, but indeed true, that these conditions are also common among young or even normal-weight individuals assumed to be healthy.
At the outset of the pandemic, many of my colleagues and I knew we would see disproportionate suffering in the elderly and those with pre-existing conditions. Still, we were not surprised to see middle-aged groups affected beyond expectations. In the clinic, we have seen unprecedented rates of metabolic dysfunction in younger Americans.
Sadly, many young and middle-aged individuals rarely interact with the health care system under the pretenses that they are healthy when, in fact, they may have pre-existing conditions not yet diagnosed.
A recent meta-analysis, including over 40,000 patients in China underscored the most prevalent comorbidities in COVID-19 were hypertension, diabetes, and cardiovascular disease followed by respiratory illnesses. These findings were supported by Italian cohort studies showing that the majority of those who died from COVID-19 had either underlying ischemic heart disease (30 percent) or diabetes (35.5 percent).
Notably, these illnesses are often downstream from metabolic syndrome and insulin resistance, which appear much earlier, before heart disease or diabetes are clinically apparent. Patients with diabetes and metabolic syndrome have up to ten times greater risk of death when they contract COVID-19, according to recent information from the Centers for Disease Control and Prevention (CDC) and Nature, stressing the need for doctors to tighten glucose control earlier to improve outcomes.
Data from the National Health and Nutrition Examination Survey (NHANES) shows that the number of U.S. adults at ideal metabolic health is alarmingly low. After recent guideline changes, expert consensus reveals the proportion of healthy Americans is currently an abysmal 12.2 percent, down from 19.9 percent—this our nation’s Achilles’ heel.
There are myriad reasons why underlying conditions lead to worse outcomes in COVID-19, emphasizing the critical links between metabolism and viral disease. Overweight/obesity and Type 2 diabetes are associated with delayed or reduced natural antiviral responses, leading to more severe viral infections.
Researchers have shown that excess body fat, especially “sick fat” (visceral fat built up around abdominal organs and in arteries that leak inflammatory molecules called cytokines), can lead to harmful immunological changes and pathogenic inflammation. Also, elevated blood sugar levels independently disrupt the proper functioning of immune cells, which simultaneously hinders healthy immune responses and over activates others, leading to inflammation and cytokine storms that are characteristic of severe COVID-19 illness.
While metabolic disease certainly affects immunity and organ systems such as the heart, liver, kidneys, and the pancreas, it also negatively affects an overlooked organ: the brain.
Mental illnesses such as depression, bipolar illness, and psychosis are strongly associated with increased inflammation, and individuals with these conditions suffer from even higher rates of metabolic disease than the general population.
Currently, one in five Americans live with a mental illness, and the rates of mental illness have been tracking alongside increases in metabolic disease. Yet, conventional psychiatric care does not include a discussion of food or an assessment of metabolic dysfunction, obesity, or insulin resistance in the evaluation or treatment of mental health conditions.
Metabolic psychiatry is a subfield our group conceived of at Stanford several years ago to describe the assessment and treatment of metabolic dysfunction as a critical means of improving mental health. Our program investigates the influences of nutrition, inflammation, obesity, hyperlipidemia, hyperglycemia and insulin resistance on a variety of mental health conditions, including mood, psychosis, and unhealthy eating patterns. The Stanford Metabolic Psychiatry Clinic, founded in 2019, integrates an assessment of an individual’s cardiovascular, metabolic, nutritional, and lifestyle factors to improve, and in some cases reverse, mental health conditions that can be debilitating. A much needed clinical and research focus in this area is emerging, and we work alongside the small but growing group of experts to characterize and communicate our clinical and research findings to benefit public guidance and patient care.
There has perhaps never been a better time to re-evaluate nutrition strategies and new evidence and to have frank conversations about weight, diet, alcohol intake, smoking, and exercise. Regardless of the times — in fact, because of them — we should be encouraging improvements in health and immunity in every possible way.
Changing lifestyle habits can improve well-being tremendously, and even on a budget, we can consume the right foods and make better choices. If we continually strive for a healthier nation with less chronic conditions, we could weather the current pandemic and be better prepared for the next one, physically, metabolically, and mentally.
Shebani Sethi Dalai, M.D. M.S., is the founding director of Metabolic Psychiatry at Stanford University School of Medicine, Director of Silicon Valley Metabolic Psychiatry, and creator of metabolicpsychiatry.com. Follow her on Twitter @ShebaniMD.