Coffee and Veggies May Help Protect Against COVID-19

Less processed meat and breastfeeding also provide protection.

Drink a Venti dark roast and eat a salad. A new Northwestern Medicine study shows that coffee consumption and eating plenty of vegetables may offer some protection against COVID-19.

The authors believe this is the first study to use population data to examine the role of specific dietary intakes in the prevention of COVID-19.

“A person’s diet affects immunity,” said senior author Marilyn Cornelis, an associate professor of preventive medicine at Northwestern University Feinberg School of Medicine. “And the immune system plays a key role in susceptibility and response to infectious diseases, including COVID-19.”

Breastfeeding can also provide protection and eat less processed meat, the study finds.

A person’s diet affects immunity. And the immune system plays a key role in susceptibility and response to infectious diseases, including COVID-19.”

— Marilyn Cornelis, Feinberg School of Medicine

“In addition to following guidelines currently in place to slow the spread of the virus, we provide support for other relatively simple ways individuals can reduce their risk and that is through diet and nutrition,” Cornelis said.

The article on nutrition and COVID-19 protection was recently published in the journal Nutrients.

One or more cups of coffee per day was associated with about a 10% reduction in the risk of COVID-19 compared to less than one cup per day. Consumption of at least 0.67 servings per day of vegetables (cooked or raw, excluding potatoes) was associated with a lower risk of COVID-19 infection. Processed meat consumption of just 0.43 servings per day was associated with a higher risk of COVID-19. If baby was breastfed, the risk was reduced by 10% compared to not being breastfed.

While the study shows that diet appears to reduce disease risk to some extent, the Centers for Disease Control and Prevention recommends vaccines as the most effective way to prevent COVID-19, especially serious illness and death. COVID-19 vaccines also reduce the risk of people spreading the virus that causes COVID-19.

To date, most COVID-19 research has focused on individual factors assessed after a positive COVID-19 test. Individuals with suppressed immune systems, such as the elderly and those with existing co-morbidities, including cardiovascular disease, hypertension, diabetes, and obesity, are more likely to experience severe impacts from COVID-19.

But other than weight management, less attention has been paid to other modifiable risk factors prior to COVID-19 infection, said Cornelis, who studies how diet and nutrition contribute to chronic disease.

dr. Thanh-Huyen Vu, the study’s lead author and an associate professor of medicine at Northwestern, is now leading analyzes to determine whether these protective feeding behaviors are specific to COVID or respiratory infections in general.

Exact mechanisms linking these dietary factors to COVID are unknown.

“Coffee is an important source of caffeine, but there are also dozens of other compounds that may underlie the protective associations we observed,” Cornelius said. “Associations with processed meat, but not red meat, point to non-meat factors.”

Using data from the UK Biobank, researchers examined the associations between feeding behavior measured in 2006-2010 and COVID-19 infections in March to December 2020, before vaccines were available. They focused on 1) dietary factors for which data was available and previously implicated in immunity based on human and animal studies; 2) self-reported intakes of coffee, tea, vegetables, fruit, fatty fish, processed meat and red meat. Early exposure to breast milk was also analyzed.

Of the 37,988 participants who were tested for COVID-19 and included in the study, 17% tested positive.

The observational nature of the UK Biobank study limits the extent to which protection mechanisms can be tested, Cornelis said. However, much of her nutritional research uses genetics, and with all of the UK Biobank participants currently genotyped, she hopes to use this information to better understand how diet and nutrition protect against the disease.

Reference: “Dietary behavior and COVID-19 incident in the UK biobank” by Thanh-Huyen T. Vu, Kelsey J. Rydland, Chad J. Achenbach, Linda Van Horn and Marilyn C. Cornelis, June 20, 2021, Nutrients.
DOI: 10.3390 / nu13062114

Other Northwestern authors include Kelsey Rydland, Dr. Chad Achenbach and Linda Van Horn.

The research was supported by grant K01AG053477 from the National Institute on Aging of the National Institutes of Health.