Healthy pre-infection lifestyle linked to lower risk of long COVID in women

Older women walking

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Women who maintained a healthy weight, didn't smoke, exercised regularly, got adequate sleep, ate high-quality food, and consumed alcohol in moderate amounts were at roughly half the risk of long COVID as those who followed none of these recommended practices, concludes a prospective study today in JAMA Internal Medicine.

Harvard University researchers assessed rates of persistent COVID-19 symptoms among 1,981 women who self-reported infections from April 2020 to November 2021. The participants were among the 32,249 women included in the ongoing Nurses' Healthy Study II cohort, who reported preinfection lifestyle habits in 2015 and 2017 and COVID-19 test results during the study period. Average age of the 1,981 women was 64.7 years, 97.4% were White, and 42.8% still worked in healthcare.

Healthy lifestyle factors included healthy body mass index (BMI, 18.5 to 24.9 kilograms per square meter [kg/m2]), never smoking, at least 150 minutes per week of moderate to vigorous physical activity, moderate alcohol intake (5 to 15 grams per day), a high-quality diet (upper 40% of the Alternate Healthy Eating Index–2010 score), and adequate sleep (7 to 9 hours a night).

49% lower risk of lingering symptoms

At baseline, those with higher healthy lifestyle scores were younger and more likely to be White, with higher socioeconomic status and a lower prevalence of chronic conditions. Of the 1,981 COVID-positive women, 44.0% developed long COVID, of whom 87.0% reported symptoms lasting at least 2 months, and 56.5% reported at least occasional symptom-related daily life impairment.

Adherence to a healthy lifestyle before infection was inversely associated in a dose-dependent manner with the risk of long COVID. Relative to participants who didn't adhere to any healthy lifestyle practices, those who followed five of the six recommended practices had a 49% lower risk of lingering symptoms.

The most common symptoms were fatigue (57.1%), impaired smell or taste (40.9%), shortness of breath (25.3%), brain fog (21.6%), and memory problems (20.0%).

Relative to participants who didn't adhere to any healthy lifestyle practices, those who followed five of the six recommended practices had a 49% lower risk of lingering symptoms.

After adjustment for all lifestyle factors, those most strongly associated with a lower risk of long COVID were healthy BMI (BMI, 18.5 to 24.9 kg/m2 vs others; relative risk [RR], 0.85) and adequate sleep (7 to 9 hours per night vs others; RR, 0.83).

Women who followed a healthy lifestyle but still developed long COVID (also called post-COVID-19 condition, or PCC) had a 30% lower risk of persistent symptoms that interfered with daily life.

"If these associations were causal, 36.0% of PCC cases would have been prevented if all participants had 5 to 6 healthy lifestyle factors (population attributable risk percentage, 36.0%; 95% CI, 14.1%-52.7%)," the researchers wrote. "Results were comparable when PCC was defined as symptoms of at least 2-month duration or having ongoing symptoms at the time of PCC assessment."

Healthy BMI, sufficient sleep

The researchers noted that an unhealthy lifestyle is linked to an increased risk of chronic inflammation and immune dysfunction, both of which are associated with long COVID symptoms affecting multiple organs and their attendant public health burden. Plus, they said, an unhealthy lifestyle has been shown to predispose to blood-clotting abnormalities, another abnormal physical change seen in long COVID.

"In the past decades, scientists have accumulated evidence that healthy lifestyle is good for overall health," lead author Siwen Wang, MD, said in a Harvard press release. "However, in the U.S. for example, 70% of the population do not have a healthy body weight and 30% do not sleep enough. Findings from this study suggest that simple lifestyle changes, such as having adequate sleep, may be beneficial for the prevention of long COVID."

The authors called for future research into whether lifestyle interventions can lower the risk of long COVID or lead to milder persistent symptoms after COVID-19 infection or other postinfection syndromes. "If the associations we found were causal, among healthy lifestyle factors, maintaining a healthy weight and having adequate sleep duration may confer the greatest benefit for prevention of PCC," they wrote.

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