Processed Meat Associated with Greater COPD Risk

Middle-aged women may be at an increased risk of developing chronic obstructive pulmonary disease (COPD) when they have a greater intake of processed meat.

In a new international study assessing the 87,000-plus registrant Nurses’ Health Study II data, a team of France- and Boston-based investigators found that processed meat—along with other known risk factors including smoking habit and obesity—significantly increase the risk of developing COPD in middle-aged women.

Led by Raphaelle Varraso, PhD, of the French Institute of Health and Medical Research, investigators sought to interpret the associated increased risk of COPD with processed meat, as well as the significance of increased risk factors in COPD-susceptible women.

Their research comes recently following the classification of processed meat as a carcinogenic by the International Agency for Research on Cancer (WHO-IARC). Previous research has linked processed meat intake to greater risks of chronic diseases and all-cause mortality, investigators noted.

“Regarding lung health, 8 studies have reported that frequent processed meat intake was associated with decreased lung function, and greater COPD symptoms, exacerbations, or incidence,” they wrote.

That said, all 8 studies were conducted in cross-sectional or longitudinal fashion, in different countries, and among men or women with a mean age greater than 65 years old.

The team used 2,296,894 person-years’ worth of data from the nurses database to create a multivariable-adjusted Cox proportional hazards model for positive associations between processed meat, smoking habits, and unhealthy diet on COPD risk. They identified 634 incident cases of COPD, while separating cumulative average processed meat intake into intervals of ‘never/almost never;’ <1 servings per week; or ≥1 servings per week.

After adjusting for smoking and unhealthy diets, investigators found a positive association between processed meat intake of ≥1 serving per week and COPD risk versus never/almost never intake (HR 1.29; 95% CI: 1.00 — 1.65).

When stratified according to smoking or unhealthy diet, only ever smokers (HR 1.37; 95% CI: 1.01 — 1.86) and women with unhealthy diets (HR 1.39; 95% CI: 1.04 – 1.85) were at an associated increased risk of COPD.

When adjusted for age, the risk for COPD was nearly doubled in middle-aged women with 2 of the 3 observed unhealthy lifestyle habits (HR 1.93; 95% CI: 1.12 — 3.32). Among women with all 3 observed habits, COPD risk was raised nearly seven-fold (HR 7.77; 95% CI: 4.55 – 13.27).

Investigators believe their findings carry major public health implications, as the only currently understood metric for primary COPD prevention is avoidance of exposure to tobacco smoke.

“To our knowledge, only one cross-sectional study has assessed the modifying effects of antioxidant and oxidant intake in the association between processed meat and lung function, but without including the combined effect of unhealthy/healthy diet and smoking,” they observed.

Though the actual role of processed meat in COPD pathogenesis is unclear, without many mechanistic studies assessing the correlation in existence, Varraso and colleagues prosed its likely due to the nitrites added to meat products which can play a role in an increased inflammatory process.

“In addition to the antioxidant/anti-inflammatory hypothesis in the diet-COPD association, it is reasonable to posit that an imbalance in the gut microbiome caused by changes in the diet over the last decades, may lead to the development of COPD,” they wrote. “Tobacco smoke is another source of nitrites as well as oxidants.”

Investigators concluded processed meat intake is associated with increased COPD risk, and advised clinicians assess dietary interventions as part of their approach to promoting proper lung health.

The study, “Processed Meat Intake and Risk of Chronic Obstructive Pulmonary Disease among Middle-aged Women,” was published online in The Lancet.