Coronavirus
What Do We Know About The Role of Ketones?

Could Ketones Have Beneficial Effects?

Ketones could possibly protect against COVID-19 in at least two ways. First, a mouse study, published this past December in Science Immunology, found that a ketogenic diet protects mice against the influenza flu virus, which is like COVID-19's cousin. The mechanism by which the ketogenic diet protected the mice is the same mechanism by which infants are protected against the influenza ( 1). Since we know infants are also protected against COVID-19, although we aren't yet sure why, it's possible that it's the babies' ketones that protect them.

Second, it's important to note that it's not the COVID-19 virus that kills people, it's the body's response to the virus. When the body is overwhelmed (more likely in elderly and immunocompromised people), it overreacts with what is known as a "cytokine storm." This is a fancy way of saying, the body releases tons of inflammatory factors that can lead to "acute respiratory distress syndrome" (ARDS) in COVID-19, the need for ventilator support, and ultimately, death.

Ketones are known to be potent inhibitors of inflammation by increasing levels of an important molecule called NADPH ( 2), inhibiting the NLRP3 inflammasome ( 3), and other mechanisms. Therefore, ketones may protect against the cytokine storm that leads to death in severe cases of COVID-19.

At this time, the relationship between ketones and COVID-19 is still within the realm of speculation although researchers are hard at work to change that. However, it's notable that there have been numerous clinical reports of individuals (including the elderly and those with chronic diseases) who are in ketosis and have presented with mild respiratory symptoms — runny noses, scratchy throats, and mild coughs — as well as other COVID-19-associated symptoms — conjunctivitis ( 4) and diarrhea ( 5) — but who are otherwise fine.

Is it possible that they are infected and that their diets are blunting the impact of the virus? Possibly. In any case, we'd argue that you're better off simply trying to eat healthily than chugging orange juice while hidden inside your fortress made of toilet paper.

It's not the COVID-19 virus that kills people, it's the body's response to the virus. When the body is overwhelmed, more likely in elderly & immunocompromised people, it overreacts with what is known as a "cytokine storm."

February 2021 Update

Earlier this month (February 8, 2021), the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) published a perspectives piece in the prestigious journal, Cell Metabolism, highlighting the relationship between COVID-19 and metabolic diseases, including diabetes and obesity. (William T. Cefalu et at, 2021)

The ketogenic diet is a means to achieve metabolic health. In fact, randomized controlled crossover trial in individuals with metabolic syndrome demonstrated that a low-carb diet is better than a low-fat diet for improving metabolic syndrome, even when calories and weight are controlled. Therefore, this piece was relevant to what we do here at KetoDiet.

Personally, I couldn’t be more pleased that a government body and top scientific journal are willing to call out that metabolic health matters when it comes to saving lives from the viral pandemic, and in particular minority lives.

Metabolic Diseases & COVID-19

Diabetes and obesity unequivocally increase COVID-19 severity, including a two-fold increase in mortality. So, how many lives have metabolic diseases contributed to the COVID-19 death toll this past year? Well, as the NIDDK is an American group, we will focus on United States statistics.

Over half-a-million people have been taken by the virus at the time of this writing in March 2021. Given that more than one third of Americans have diabetes or pre-diabetes, 42.4% are obese, and 88% have at least one marker of metabolic syndrome, the number is not one I’m keen to quantify.

Minority Burden

The authors rightly point out that minorities carry a disproportionate burden of metabolic diseases and COVID-19-related deaths. These observations are inseparable. For example, Black Americans have a prevalence of diabetes that two-fold that of white Americans, the highest prevalence of obesity among any minority group, and a corresponding 3.5-fold increase in COVID-19-related mortality as compared to non-Hispanic whites.

The racial disparities in COVID-19-related do not appear to be attributable to differences in genetics or immune disposition, or by a difference in the of certain medication that interact with SARS-CoV-2 virus. Instead, multiple studies referenced in the perspectives article demonstrate that COVID-19-realted mortality was not increased in minorities after adjusting for sociodemographic factors and co-morbidities.

The conclusion is evident — metabolic diseases contribute to COVID-19 severity and mortality — but what about the solution?

Therapeutic Carbohydrate Reduction (TCR) as a Solution

There are obviously tremendous gaps between minorities and white Americans with respect to important environmental factors, including food availability and affordability. We can and should close the gaps, but this will not happen overnight. By contrast, therapeutic carbohydrate reduction (TCR) is a tool we do have at our fingertips to address the epidemic of obesity and diabetes, and thereby save American and minority lives from COVID-19.

TCR is effective at reversing obesity and type II diabetes. ( Athinarayanan et al, 2019) For example, the Virta health trial found that over two-years individuals who practiced TCR lost 30 pounds and 60% were able to come off of insulin. By contrast, the standard of care control group gained weight and most had to increase their medications. In this study, TCR was shown to be 11-times as effective as standard of care at reversing diabetes, based on markers of glycemic control. And, not surprisingly, better glycemic control in diabetes has been associated with lower COVID-19-related mortality. What’s more, a randomized crossover trial including 16 people with metabolic syndrome showed that, even independent of weight loss, TCR was able to reverses metabolic syndrome in 9/16 subjects in just four weeks, as compared to 1/16 subjects on an isocaloric lower fat, higher carb diet. ( Parker N Hyde et al, 2019)

Where Are We Now?

The issue with generating any content on this topic is that the field is rapidly changing. However, when I look back at the principles, I wrote one-year ago at the start of the pandemic in March 2020 (above) I personally feel the principles still apply.

Masks matter but so does metabolic health. Again, personally, I want to do all I can to protect myself and my loved ones and the community at large. That means being a responsibly cautious — not paranoid — citizen. For now, mask up (it keeps your face warm in Boston winters anyway), get your vaccine when you have the opportunity (I know it’s a controversial topic but the bigger gamble is with the virus [you’re even gambling on your brain!]), and eat healthy. Personally, I think a well-formulated ketogenic diet is a fantastic option for metabolic health. But, honestly, so long as you’re eating a whole foods diets that’s low in sugar you’re doing pretty well.

Related video: COVID19, metabolic disease, race

References & COVID-19 Resources

1. Goldberg EL et al.,  Ketogenic diet activates protective γδ T cell responses against influenza virus infection, Sci Immunol. (2019 Nov 15).
2. Richard L. Veech et al.,  The "great" controlling nucleotide coenzymes, IUBMB Life. (2019 May).
3. Youm YH et al.,  The ketone metabolite β-hydroxybutyrate blocks NLRP3 inflammasome-mediated inflammatory disease. Nat Med. (2015 Mar).
4. CDC, WHO,  Important coronavirus updates for ophthalmologists (Updated March 28, 2020)
5. Lei Pan, MD, PhD et al.,  Clinical characteristics of COVID-19 patients with digestive symptoms in Hubei, China: a descriptive, cross-sectional, multicenter study (March 18, 2020)
6. William T. Cefalu et at., COVID-19 and metabolic diseases: a heightened awareness of health inequities and a renewed focus for research priorities, Cell Metabolism (February 8, 2021)
7. Parker N Hyde et al.,  Dietary carbohydrate restriction improves metabolic syndrome independent of weight loss, JCI Insight (Jun 20, 2019)

For information and latest updates on COVID-19, please visit:

•  CDC
•  WHO
•  NHS (UK)