Healthy lifestyle habits dramatically cut long-term COVID-19 risks

By Priyanjana Pramanik, MSc.Reviewed by Susha Cheriyedath, M.Sc.Jul 30 2024

In a recent study published in the journal Nature Communications, researchers investigated the association between alterable lifestyle factors and complications after having coronavirus disease 2019 (COVID-19).

Their findings indicate that maintaining healthy lifestyle habits significantly reduces the danger of developing long-term COVID-19 complications, underscoring the importance of healthy living in mitigating adverse outcomes and preparing for future pandemics.

Study: Modifiable lifestyle factors and the risk of post-COVID-19 multisystem sequelae, hospitalization, and death. Image Credit: p.ill.i / Shutterstock

Background

The long-term effects of COVID-19 on health, known as long COVID, continue to be a public health issue despite a decrease in cases and deaths. Long COVID affects a range of systemic diseases or symptoms across 10 organ systems, including cardiovascular, coagulation, metabolic, gastrointestinal, kidney, mental health, musculoskeletal, neurologic, and respiratory disorders, as well as general symptoms of fatigue and malaise, severely impacting the quality of life and daily life.

While vaccination and certain medications have been explored for prevention, their effectiveness is only partial. There is a lack of strategies that are effective for preventing or treating long COVID, especially non-pharmaceutical approaches. Long COVID affects a range of systemic diseases or symptoms across ten organ systems, including cardiovascular, coagulation, metabolic, gastrointestinal, kidney, mental health, musculoskeletal, neurologic, and respiratory disorders, as well as general symptoms of fatigue and malaise, severely impacting the quality of life and daily life.

About the study

Researchers aimed to fill a critical knowledge gap by examining how a combination of healthy lifestyle factors, particularly regular physical activity, a healthy diet, and avoiding smoking, might reduce the risk of developing long COVID symptoms across various organ systems. The study considered factors like infection severity, vaccination status, and different COVID-19 variants.

The study used data from the UK Biobank, which includes health and lifestyle information from over 500,000 people. Researchers focused on participants who had tested positive for COVID-19 from March 1, 2020, to March 1, 2022.

They analyzed lifestyle factors, including alcohol use, smoking, body mass index (BMI), physical activity, and diet, to assess their impact on COVID-19 outcomes.

Lifestyle data were collected at baseline, and participants were categorized into three groups based on their lifestyle score: unfavorable, intermediate, and favorable. Outcomes, such as a range of long-term complications or health issues termed multisystem sequelae, hospital admission, and death, were tracked through medical records and national registries.

The study used a statistical method called the Cox proportional hazards model adjusted for multiple covariates to understand how lifestyle factors affect health outcomes. They adjusted the analysis to account for age and whether participants had been vaccinated. To ensure their results were reliable, they ran several tests to check their findings. They also looked into how existing health conditions might impact the results.

Blue square represents risk estimates from models fully adjusted for age, sex, education level, ethnicity, IMD, and mutually for all lifestyle factors. The purple square represents risk estimates from models partially adjusted for age, sex, education level, ethnicity, and IMD. The horizontal lines indicate 95% CIs, with black line representing statistically significant results and the gray line representing non-significant results. The sample sizes were 60,561 for any sequela (4792 events), 55,106 for hospitalization (6958 events), and 68,887 for death (1203 events). The HR for each lifestyle factor was calculated by comparing the healthy category with the unhealthy category (e.g., past or never smoker versus current smoker).

Findings

The study analyzed 68,896 participants in the UK Biobank project who tested positive for COVID-19 during the included period (2020-2022). Participants had an average age of 66.6 years; 53.4% of the sample were male and 82.1% White.

Based on their pre-infection lifestyle, they were categorized into unfavorable (12.3%), intermediate (41.3%), and favorable (46.4%). During the study period, 5.5% experienced multisystem sequelae during the acute phase of their infection and 7.8% during the post-acute phase.

The study found that individuals with a favorable lifestyle had a significantly lower risk of developing multisystem sequelae, with a 36% reduction in risk compared to those with unfavorable lifestyle habits.

This was true for both infection phases. Furthermore, those with a favorable lifestyle also had lower risks of death (41% reduction) and hospitalization (22% reduction) related to COVID-19.

Each healthy lifestyle factor, such as physical activity and sleep duration, contributed to this reduced risk. These benefits were consistent across different COVID-19 variants and vaccination statuses, highlighting the importance of maintaining a healthy lifestyle in mitigating long-term COVID-19 effects.

Conclusions

The study reveals that maintaining a healthy lifestyle before contracting COVID-19 significantly lowers the risk of severe outcomes, including multisystem sequelae, hospitalization, and death, during both phases (acute and post-acute) of the disease.

Participants who followed a favorable lifestyle had a 36% lower risk of multisystem complications, a 41% lower risk of death, and a 22% lower risk of hospitalization compared to those with an unfavorable lifestyle. This reduction in risk was consistent across different variants, including the dominant Omicron variants, regardless of vaccination status.

The study's strengths include its large, diverse cohort and its comprehensive assessment of multiple lifestyle factors. It highlights that a healthy lifestyle is associated with reduced risk across various organ systems, which is more impactful than some pharmaceutical interventions.

However, limitations include the study's reliance on self-reported lifestyle data and its predominantly older European ancestry population, which may affect generalizability. Additionally, the study's observational nature means that causation cannot be firmly established, and some outcomes might be missed due to reliance on hospital records.

Future research should explore the specific mechanisms by which lifestyle factors contribute to these benefits and evaluate the impact of lifestyle interventions on long COVID. Overall, the findings support integrating healthy lifestyle recommendations into public health strategies to mitigate the long-term effects of COVID-19 and improve preparedness for future pandemics.