Acute effect of Snus on physical performance and perceived cognitive load on amateur footballers

Smokeless tobacco (Snus) is a substance that contains nicotine, which has been placed on World Anti‐Doping Agency's 2014 Monitoring Program. A proliferation of nicotine use in sport has been observed in recent years, but little is known regarding its effects, especially on football players' performance. Therefore, the aim of this study was to assess the effect of Snus on physical performance, heart rate variability, subjective activation, mental fatigue, and perceived readiness before a physical test in non‐smoker, non‐Snus user, amateur football players. Participants were administered either Snus or placebo 40 min prior to a fitness test battery (handgrip test, countermovement jump, agility test, and Yo‐Yo intermittent recovery test). Results showed that Snus intake (compared with placebo) increased perceived mental fatigue level and mental load, and reduced perceived readiness level and heart rate variability. No significant differences between the two experimental conditions were found in either performance in the physical tests or perceived physical fatigue levels. In light of these results, Snus could not be considered an ergogenic substance. On the contrary, based on the extant evidence linking mental load and fatigue with physical performance, we argue that the observed negative effects on mental fatigue, perceived readiness, and heart rate variability should be considered.     

Free-base nicotine in tobacco products. Part II. Determination of free-base nicotine in the aqueous extracts of smokeless tobacco products and the relevance of these findings to product design parameters

Reports in the peer-reviewed literature and popular press have alleged that smokeless tobacco product (STP) manufacturers increase the addictiveness of their products by adjusting formulae to increase the relative percentage of nicotine in STP that is not protonated. Such nicotine is more popularly, but incorrectly, known as free-base nicotine (“FBN”) as it is a calculated amount as opposed to a real chemical species in the STP. Some regulators have mandated reporting of FBN as estimated by Henderson–Hasselbalch equation (“HHE”) using the pH-value of an aqueous suspension (or extract) of STP. This is technically incorrect because the HHE is only valid in pure dilute aqueous solution of a single base and its conjugate acid. The aqueous suspensions (or extracts) of STP often contain high concentrations of salts and polymeric anions such as pectate and many other compounds, and there is a molar excess of ammonia over nicotine in some products. These are heretofore-unrecognized sources of error in use of the HHE to estimate relative amount of nicotine that is not protonated results in inaccurate FBN-values. Thus, it is not surprising that attempts to show the relevance of estimated value of FBN in STP to human physiology have failed.     

An epidemiologic review of smokeless tobacco health effects and harm reduction potential

A systematic review of the epidemiologic literature on the health effects of smokeless tobacco (ST) and its relevance to the harm reduction model for smoking was undertaken. Published epidemiologic studies, from the US and European countries, meeting defined inclusion criteria and assessing the health effects of smokeless tobacco products were examined. ST use showed evidence of a slightly increased risk for all-cause mortality. Little evidence was found to support a causal relationship between ST use and risk of oral, pancreatic or lung cancer. ST use was not associated with an increased risk of cardiovascular disease or stroke incidence, but evidence suggested ST use was associated with increased mortality from these diseases. Clinical trials evaluating the effectiveness of ST products in smoking cessation have been sparse, and no standardized method for measuring ST dependence has been used, limiting the assessment of their relationship to ST use. Several studies have examined if ST use increases the risk of smoking initiation, but few have modeled this complex behavior appropriately. Overall, epidemiologic studies have not shown strong evidence of elevated tobacco-related disease risks with ST use. More research is necessary to assess the smoking behavioral consequences of ST use prior to its consideration as a harm reduction tool.     

Exercise performance increase in smokeless tobacco‐user athletes after overnight nicotine abstinence

The use of nicotine administered through smokeless tobacco (snus) has increased among athletes. The purpose of this study was to investigate the ergogenic effects of snus on aerobic performance during exercise until exhaustion in athletes after abstinence or satiety nicotine conditions. The study utilized a randomized, controlled, within‐subject design experiment. Sixteen male snus‐user athletes completed an exercise until exhaustion at a constant load of their 80% of (calculated by a maximal incremental test) in two separate sessions, corresponding to nicotine conditions: 12‐hour overnight abstinence and satiety. A portion of 1 g of snus (~8 mg/g of nicotine) was administered 25 minutes before each experimental test. In each session, time to exhaustion (TTE), global rating of perceived exertion, cardiovascular and metabolic responses, and muscle and cerebral oxygenation were measured. Nicotine and cotinine analysis confirmed session conditions (abstinence or satiety). Snus induced a significant increase (+13.1%) of TTE following abstinence (24.1 ± 10.7 minutes) compared to satiety condition (20.9 ± 8.0 minutes; P = 0.0131). The baseline values revealed that abstinence of snus induced significant increase in the oxygenation of the muscular tissues (+4%), in metabolic values and in cardiovascular parameters, when compared to satiety condition. Our results indicate an increase of exercise performance (+13.1% TTE) due to snus administration in an abstinence condition. Considering that twelve hours of abstinence from snus‐contained nicotine affected metabolic, cardiovascular and muscular tissue oxygenation, we suggest that snus administration at test time might relieve these withdrawal changes and yield an increase in time to exhaustion.     

Inhibition by blueberries (bilberries) and extract from milk thistle of rat forestomach hyperplasia induced by oral smokeless tobacco (Swedish snus)

The aim of this study was to identify palatable additives which have a significant protective action against soft tissue changes in the oral cavity caused by Swedish smokeless tobacco (“snus”), and that satisfy existing legal requirements.Although the cancer risk from snus is extremely low, long term use may result in highly undesirable keratotic lesions and associated epithelial abnormalities in the oral cavity.The rat forestomach, which is vulnerable to the irritative action of non-genotoxic compounds like butylated hydroxyanisole, propionic acid as well as snus, was chosen as an experimental model. Studied toxicological endpoints included histopathology and cellular proliferation based on DNA incorporation of bromodeoxyuridine.After 6 weeks' exposure, blueberries (bilberries) and an extract from the common milk thistle were found to exert a highly significant inhibition of cell proliferation induced by snus in the rat forestomach epithelium, indicating a potential protection with respect soft tissue changes in the human oral cavity.     

Risk and protective factors of adolescent exclusive snus users compared to non-users of tobacco,exclusive smokers and dual users of snus and cigarettes

The use of snus is increasing in Norway. In this study we examined differences between adolescents who were exclusive snus users, and adolescent non-users, smokers and dual users of snus and cigarettes on a number of psychosocial factors, categorized as risk variables and protective variables associated with involvement in health compromising behavior. We applied separate logistic regression models, where exclusive snus users (n = 740) were compared with non-users (n = 904), smokers (n = 219), and dual users (n = 367). Compared to non-users, the group of exclusive snus users was associated with variables traditionally predicting health risk behavior, such as smoking friends (OR = 1.74, SD 1.27–2.38) and truancy (OR = 2.12, SD 1.65–2.78). Compared to smokers, exclusive snus users were related to variables traditionally associated with protection against involvement in health risk behavior, e.g. higher academic orientation (OR = 1.66, SD 1.12–2.45). Associations with protective factors were also observed when exclusive snus users were compared with dual users. While the group of exclusive snus users was associated with a pattern of psychosocial risk compared to non-users, they showed a more conventional pattern when compared to smokers and dual users. The group of exclusive snus users may be described on a continuum varying from psychosocial risk factors to protective factors of risk involvement depending on the group of comparison.