In a recent study published in Scientific Reports, researchers examine the association between the prevalence of chronic obstructive pulmonary disease (COPD) and dietary niacin intake.

Study: Association of dietary niacin intake with the prevalence and incidence of chronic obstructive pulmonary disease. Image Credit: monticello / Shutterstock.com

What causes COPD?

COPD is characterized by obstructed airflow due to abnormalities in the airways and alveoli. As a result, some of the most common symptoms associated with COPD include dyspnea, cough, and sputum production. In addition to the lungs, COPD can also affect the muscles, bones, and cardiovascular system, thus posing a significant public health burden.

Despite recent advancements in the treatment and management of COPD, the disease remains deadly, with over three million deaths attributed to COPD each year. Several factors can increase the risk of COPD, the most notable of which include smoking and aging; however, there remains a lack of data on how the consumption of certain vitamins, either through supplementation or a well-balanced diet, may impact the risk of COPD.

Vitamins are crucial components of normal physiological processes. For example, vitamins B3, C, E, and D effectively reduce oxidative stress by limiting lipid peroxidation, protein carbonylation, and the glycation of end-products. Likewise, several vitamins are also associated with antioxidant properties that support cellular repair processes and mitigate inflammatory responses.

Niacin, otherwise known as vitamin B3, is found in various food products, including meat, fish, and nuts. It is involved in numerous cellular processes, including metabolism, DNA repair, and nervous system function.

Previous studies have found that niacin and other nutrients like vitamin A, fiber, carbohydrates, protein, riboflavin, and vitamin C are associated with reduced severity of damage in COPD patients. However, few studies have investigated niacin’s role in COPD.

About the study

In the present study, researchers retrieved National Health and Nutrition Examination Survey (NHANES) data between 2003 and 2018 while focusing on individuals with dietary niacin intake and COPD. Dietary information was obtained from two 24-hour dietary recall questionnaires three to ten days apart. Participant responses to these surveys were used to determine niacin, energy, alcohol, and macronutrient intake.

Study participants were considered to have COPD if they self-reported a physician diagnosis, had a forced expiratory volume in one second (FEV₁) to forced vital capacity (FVC) ratio below 0.7, or were over 40 years of age with a history of smoking or chronic bronchitis and were being treated by certain medications, including selective phosphodiesterase-4 inhibitors, mast cell stabilizers, leukotriene modifiers, and inhaled corticosteroids.

Demographic data on the participant’s gender, age, body mass index (BMI), race, family income, education level, smoking status, drinking habits, and history of diabetes or hypertension were also recorded. Blood samples were also collected for baseline plasma glucose measurements.

Study findings

After excluding individuals for missing COPD, dietary niacin intake, and demographic data, 7,055 participants constituted the final analytical sample set, 243 of whom had COPD. Participants with COPD were more likely to be older, with a mean age of 60.8 years as compared to 46.7 years of age in the non-COPD group. Lower incomes, a higher incidence of smoking and alcohol consumption, diabetes, and hypertension were also more frequently reported in the COPD group.

Study participants who reported the highest niacin intake were at a significantly lower risk of COPD than those with the lowest intake. In fact, a clear dose-response relationship was observed between dietary niacin intake and COPD prevalence, in which increasing levels of dietary niacin intake were associated with a consistent reduction in COPD prevalence.

The protective effect of dietary niacin intake on COPD incidence was independent of age, income, smoking, drinking habits, marital status, race, hypertension, and diabetes.

Conclusions

The current study established a dose-response relationship between dietary niacin intake and COPD prevalence using a representative sample of adults residing in the United States. Niacin may mitigate oxidative stress in COPD by improving the antioxidant capacity of both endogenous and exogenous antioxidants, thereby reducing inflammation in the airways and improving pulmonary function. Nevertheless, further studies are needed to elucidate the precise mechanisms by which niacin intake affects COPD.