People who get COVID-19 are at risk for long-term health consequences, but a healthy lifestyle may protect against long COVID, a new study suggests.
Women who maintained six healthy habits — a healthy weight, didn't smoke, exercised regularly, slept and ate well, and drank alcohol in moderation — cut their risk of long COVID by about 50%, compared with women without those healthy habits, researchers found.
"If all people adhere to all six healthy lifestyle factors in our cohort, 36% of long COVID could have been avoided," said lead author Dr. Siwen Wang, a research fellow at the Harvard T.H. Chan School of Public Health.
"Also, those with a healthier pre-infection lifestyle had a 30% lower risk of having symptoms that interfere with their daily life," she added.
One possible explanation, Wang said, is that an unhealthy lifestyle increases the odds of chronic inflammation and immune system problems. Both have been tied to an increased risk of long COVID.
This study, however, can't prove that a healthy lifestyle actually lowers the odds of developing long COVID, only that there is an association between the two.
"There is also evidence that people with an unhealthy lifestyle sometimes develop autoantibodies and blood clotting issues that have been associated with increased risk of long COVID," Wang said. "But more studies are definitely needed to understand how a healthy lifestyle may lower the risk of long COVID."
As many as 23 million Americans suffer from long COVID, which causes symptoms that last for a month or more after being ill from the virus. Symptoms can include fatigue and fever, as well as respiratory, heart, neurological and digestive problems, the researchers note.
For the study, Wang's team collected data on more than 32,000 female nurses who were part of a long-term study of chronic disease risk factors. Between April 2020 and November 2021, more than 1,900 participants got COVID-19. Of these, 44% developed long COVID.
Women with five to six healthy lifestyle habits were 49% less likely to develop long COVID than women who had none of these factors, the study found.
Of the six lifestyle factors, healthy weight and adequate sleep (seven to nine hours daily) were most strongly linked with a lower long COVID risk, Wang said.
Seventy percent of the U.S. population does not have a healthy body weight and 30% don't sleep enough, she noted.
"Our study findings show that simple lifestyle changes such as having adequate sleep may be beneficial for the prevention of long COVID and from a broader context, sleep, weight, exercise and diet are all basic determinants of health and may have profound effects on our health," Wang said.
The researchers also found that women with healthier lifestyles who developed long COVID had a 30% lower risk for symptoms that interfered with their daily life.
"Long COVID is characterized by persistent inflammation," said Dr. Marc Siegel, a clinical professor of medicine at NYU Langone Medical Center in New York City. "There is a lot we still don't know but it makes sense that a healthy lifestyle decreases the risk of persistent post-COVID symptoms."
Because persistent COVID symptoms likely owe to inflammation from the virus in various organs, the findings are likely correct, said Siegel, who was not part of the study.
"Regular exercise, eating well, not smoking and limited alcohol intake would all correlate with less likelihood of long COVID and milder symptoms, because a healthy lifestyle leads to less inflammation in the body to begin with, as does maintaining a normal body weight," Siegel said.
The findings were published online Feb. 6 in JAMA Internal Medicine.