New research reveals that pairing brain stimulation with daily exercise can curb cigarette cravings and inspire smokers to quit, offering fresh hope in the fight against nicotine addiction.

Study: Transcranial direct current stimulation associated with physical exercise can help smokers to quit smoking: a randomized controlled trial. Image Credit: Yiistocking / Shutterstock

In a recent study published in the journal Scientific Reports, researchers investigated the potential of combined transcranial direct current stimulation (tDCS) and aerobic exercise (AE) in helping chronic smokers curb cigarette cravings. They carried out a randomized controlled trial comprising 41 participants (39% women) assigned to one of four intervention cohorts: tDCS alone (G1; n=10), AE alone (G2; n=9), tDCS in combination with AE (G3; n=12), and sham tDCS in combination with AE (G4; n=10).

Study findings revealed that the G3 cohort (tDCS+AE) experienced significantly reduced cigarette cravings, consumption, and smoking-associated brain reactivity (gamma wave activity in prefrontal and temporal regions) compared to other cohorts. Simultaneously, G3 participants and G4 (sham tDCS+AE) experienced enhanced motivation to change smoking behavior (MCSB), though only G3 showed reduced cravings, highlighting this combination therapy as a promising means to curb chronic smoking, pending confirmation in larger, long-term studies.

Background

Smoking, the practice of inhaling smoke produced through the burning of plant (mainly tobacco) material, has been identified as the most prevalent cause of preventable mortality worldwide (World Health Organization [WHO], 2021). Smoking is a highly harmful habit linked to several chronic diseases, including cancers, lung diseases, heart diseases, and neurological conditions. Unfortunately, it is also one of the most challenging habits to quit—nicotine, a stimulatory alkaloid found in tobacco products, is one of the most addictive drugs known to man.

Prolonged nicotine exposure is medically validated to be correlated with smoking cravings and high impulsivity, primarily due to the substance’s effects on the prefrontal cortex (PFC). Several studies have investigated means to curb these cravings and promote smoking cessation, with PFC-targeting transcranial direct current stimulation (tDCS, via electrodes placed at F4 and T3) and aerobic exercise (AE) emerging as likely candidates for pharmacological and nonpharmacological smoking interventions, respectively.

About the Study

The present study aims to address current knowledge gaps by evaluating the combined effects of tDCS therapy and AE on smoking addiction. It evaluated four main metrics: 1. craving, 2. brain reactivity (gamma wave responses in specific regions like the left anterior and posterior cortex), 3. cigarette consumption, and 4. motivation to change smoking behavior (MCSB).

Study participants were recruited via bulletin boards and social network posts from Maceió/Alagoas. Potential participants who demonstrated nicotine addiction of at least 2 years, were adults between the ages of 25 and 55, and were not addicted to any other substances were included. Participants with mental disorders or contraindications for electrical brain therapy were excluded.

The participants underwent five daily sessions of their assigned intervention. The first and last visits involved questionnaires (Fagerström, QSU-B, and URICA for all 41 participants), carbon monoxide (CO) checks, electroencephalogram (EEG) evaluations, and self-reported cigarette consumption via diaries.

The active tDCS involved fixing electrodes to participants’ heads (anode at F4 targeting the prefrontal cortex, cathode at T3 targeting the temporal region) via elastic bands, following which a 2 mA current was supplied for 20 minutes. The ‘sham’ tDCS protocol followed the same electrode arrangement but delivered no sustained current. AE sessions were treadmill walks of moderate intensity (40-59% of heart rate) lasting 40 minutes daily.

Study Findings

CO Levels: By the end of the five-day intervention, CO levels decreased in all AE groups—G2 (-56.3%), G3 (-61.3%), and G4 (-71.5%, from 21.8 ppm to 15.6 ppm). However, researchers noted that these CO reductions in AE groups may reflect increased CO elimination due to exercise rather than solely reduced smoking.

Cigarette Consumption: Linear regression showed reductions in G1, G3, and G4 but not in G2 (AE alone). However, there was no statistically significant difference in cigarette consumption reduction between groups, suggesting the combination therapy, while promising, requires further investigation.

Craving: Only G3 (tDCS+AE) showed a significant reduction (-50.4%, p

Brain Reactivity: EEG revealed increased gamma activity in G1 (tDCS alone) and G4 (sham tDCS+AE) during cigarette cue exposure but decreased activity in G3, suggesting reduced craving-related brain responses. No significant changes were observed in alpha wave activity across groups, indicating that cortical deactivation patterns remained stable during cigarette cue exposure.

MCSB: Both G3 and G4 reported significant increases (~15% improvement), though only G3’s craving reduction was statistically significant.

Conclusions

The study identifies combination therapy (tDCS+AE) as a promising short-term means of promoting smoking cessation. Nonetheless, no statistically significant differences in smoking reduction were found between groups, and caution is warranted when interpreting these early results.

Longer clinical trials are needed to confirm long-term efficacy, as the study’s five-day duration and small sample size limit generalizability. Additionally, the reliance on self-reported cigarette consumption and the absence of biochemical verification, such as urine cotinine levels, may affect the reliability of reported outcomes.