Higher dietary niacin intake linked to lower risk of COPD, study finds

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

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

What causes COPD?

COPD is characterized by airflow obstruction due to abnormalities in the airways and alveoli. As a result, some of the more common symptoms associated with COPD include shortness of breath, coughing, and sputum production. In addition to the lungs, COPD can also affect the muscles, bones, and cardiovascular system, thus creating a significant public health burden.

Despite recent advances in the treatment and management of COPD, the disease remains fatal, with over three million deaths attributable to COPD each year. Several factors can increase the risk of COPD, the most notable of which include smoking and aging. However, there is still a lack of data on how consuming certain vitamins, either through supplements or through a well-balanced diet, may affect COPD risk.

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

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

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

About the study

In the current study, researchers pulled data from the National Health and Nutrition Examination Survey (NHANES) between 2003 and 2018, focusing on people with dietary niacin intake and COPD. Dietary information was obtained from two 24-hour dietary recall questionnaires three to ten days apart. Participants’ 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) 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 with 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 plasma glucose measurements.

Study findings

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

Study participants who reported the highest intake of niacin had 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 steady decrease in COPD prevalence.

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

conclusions

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