Alcohol use is the seventh leading risk factor for both deaths and disability-adjusted life years globally—this new study could help with improving global public health by broadening the array of effective non-stigmatizing treatments available for people with alcohol use disorder.
Common barriers to help seeking
Most of those with alcohol use disorder (AUD) never seek or receive treatment despite negative consequences for mental and physical health. According to the researchers, perceived stigma and dissatisfaction with available treatments are common barriers to help seeking. Thus, more effective and non-stigmatizing treatments are needed for treating alcohol use disorder.
“To address this, we investigated the effects on alcohol consumption of aerobic exercise—which is recommended for general health—and yoga, an increasingly popular form of exercise which may be suitable for people with AUD,” says Mats Hallgren, Project leader, Department of Global Public Health.
Yoga and aerobic exercise reduce alcohol consumption
The studies show that aerobic exercise and yoga were equally effective in reducing alcohol consumption, compared to usual care. The participants were 140 non-treatment seeking, physically inactive, adults diagnosed with AUD.
Participants in the two physical activity groups were supported to exercise 3 times/week for 12 weeks. Assessments were taken at baseline and 12-weeks—90% completed the ‘blinded’ follow-up assessment.
They also took blood samples to assess markers of somatic health, and objectively measured changes in physical activity using accelerometers. Within the randomized controlled trial (RCT), they conducted an acute exercise study, where participants cycled intensely for 12 minutes. Changes in cravings for alcohol, mood states, and anxiety were assessed before and after cycling.
“Alcohol consumption reduced approximately equally in all three groups, with the largest absolute reduction seen among yoga participants—6.9 standard drinks/week. The reductions were statistically significant and clinically meaningful.
“This is great news; it means there are potentially effective treatment options available for people who do not wish to seek treatment through specialist clinics.”
The researchers also found that single sessions of aerobic exercise reduced cravings for alcohol, lowered anxiety, and improved mood states.
“This suggests that the optimal time to exercise is when cravings are high—typically in the afternoon or evening. Repeatedly replacing alcohol with a brief session of exercise may ‘re-wire’ the brain to respond positively to the rewards associated with exercise, resulting in less craving.
“Finally, we found that both forms of exercise reduced symptoms of depression and anxiety, with the largest reductions seen among yoga participants. Feeling anxious or sad increases the likelihood of alcohol use, so it’s promising that exercise was shown to reduce these symptoms.”
The dopaminergic (reward) system
There are multiple mechanisms that could explain the benefits of exercise on alcohol consumption. Exercise tends to make us feel good; it reduces stress and anxiety through neurophysiological effects, which could indirectly affect alcohol consumption by reducing cravings, improving cognition, and making behavior change more likely.
“Exercise can improve self-esteem and the belief in one’s ability to control drinking. The anxiolytic effects of exercise are powerful, and anxiety is a known ‘trigger’ for drinking.
“Alcohol dependence is associated with dysregulation of the dopaminergic (reward) system, and exercise is shown to adjust dopamine synthesis in ways that may reduce cravings for alcohol.
“Our yoga classes emphasized physical postures, but relaxation and breathing exercises may confer additional health benefits relevant to those with AUD.”
Interventions for improving physical activity
According to Mats Hallgren, the next step forward is to determine whether these benefits of exercising are maintained over time. And also to study the effects of exercise on cognition in those with AUD, as this is often impaired and may affect recovery. The dopamine hypothesis is biologically plausible, but no studies have examined this mechanism in humans using an exercise intervention.
“Encouraging people to exercise is challenging, but it can be done. To help people initiate and maintain new exercise regimes, interventions should include a parallel behavior change program. Another challenge is implementing these knowledge gains in clinical practice.
“Currently, primary and specialist healthcare is not set up to implement exercise interventions on a wide scale. We need to employ physical therapists to assess, prescribe, and monitor physical activity interventions in healthcare settings.”
Dopamine is a monoamine neurotransmitter that is known to be modulated by physical activity (PA) and exercise [1]. The physiological roles of dopamine were first described in 1957 [2]. Dopamine is synthesized in both the central and peripheral nervous systems, acting as a signalling molecule. Dopamine has essential roles in regulating motor neurons [3], spatial memory function [4], motivation, and reinforcement learning [5]. In addition, dopamine plays a crucial role in maintaining chemical balance within the central nervous system [6]. Concerning vulnerability, an excess or lack of dopamine can cause mental disorders, such as depression [6,7].
Dopamine is critical for the motor system [8], and it has a well-established role in motor functioning [9,10]. Dopamine synthesis seems to affect the will to practice PA [11,12] and plays an important role in cognitive–motivational reward mechanisms for pursuing a certain behaviour such as PA [13]. This is because dopamine is a key neurotransmitter in the neural system, supporting cognitive control [14]. In turn, successful cognitive control is relevant for continuing PA engagement [15]. This mechanism is emphasized due to the association between the amount of striatal dopamine depletion and motor deficits observed in Parkinson’s disease [16].
On the other hand, PA seems to influence the central dopaminergic, noradrenergic, and serotonergic systems [17]. In this regard, it has been observed that an increase in PA seems to result in a corresponding increase in neurotransmitter activity [1,18,19,20]. PA is known to change the dopamine system in the central nervous system [1], increasing dopamine receptor availability [21]. This association may have positive consequences, such as reducing the severity of symptoms of anxiety, depression, and other mental-related issues [22,23,24]. Studies in patients with Parkinson’s disease also suggest that exercise may provide a preventive and non-pharmaceutical therapeutic approach [25,26,27]. However, the studies that examined the influence of PA on dopamine were mostly conducted in animals [28,29,30], and they either used PA as a stress model or compared exercise with other stressors [28].
The mechanism that increases dopaminergic activity during exercise is mostly related to fatigue [31,32,33]. A decrease in dopamine neurotransmission during PA would hasten the onset of fatigue, while an increase in dopamine neurotransmission might delay the onset of fatigue [31]. Studies that manipulated the increase of dopamine synthesis [34], stimulated extracellular dopamine release [35], inhibited dopamine reuptake [36], or directly activated dopamine neurons and/or dopamine receptors [37] were performed to better understand the role of dopamine in exercise-induced fatigue. Some of these manipulations have been successful in impacting exercise-induced fatigue.
These two different lines of research suggest that there is a bidirectional relationship between the practice of PA and dopamine [7,11,12,38]. Yet, so far, the underlying mechanisms are highly debated. Moreover, the existing empirical research investigating this reciprocal association showed high heterogeneity across multiple study parameters and provided mixed and, thus far, inconclusive results [39]. Therefore, to advance the understanding regarding the reciprocal relationship between PA and dopamine synthesis, we conducted a systematic review of the existing evidence concerning the potential PA and exercise effects on dopamine, and vice versa, across adulthood
reference link :https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8301978/
Source: Karolinska Institute
