For many of those counselors running an addiction program that takes a holistic approach to recovery, there’s no question of the importance of a suitably-tailored accompanying nutritional therapy program. Such beliefs are further affirmed by a recent study supported by the National Institute on Drug Abuse (NIDA), buttressing the hypothesis of obesity and nicotine addiction having shared genetic and biological roots.
The research found that some gene variants with an influence on body mass index (BMI) also had a role in smoking behaviors. Associations between 32 BMI-influencing gene variants – known as single nucleotide polymorphisms or SNPs – and smoking were scrutinized by a team led by Dr. Thorgeir E. Thorgeirsson at deCODE genetics/Amgen in Reykjavik, Iceland. DNA was contributed to the study by some 50,000 Icelanders, and when the SNPs were taken as a group, they accounted for a modest, but significant fraction of individual differences in two smoking behaviors.
The behaviors in question were initiation – whether someone had ever smoked – and the number of cigarettes that were smoked per day, or CPD. The researchers found that the likelihood of a person initiating smoking was increased for SNPs that genome-wide association studies linked with higher BMI. These results were confirmed by the researchers’ use of DNA data collected by three genomics consortia (ENGAGE, Tobacco and Genetics and Oxford-GSK) from a further 127,000 non-Icelandic individuals.
11 of the 32 BMI-associated SNPs, when considered individually, were found to correlate with smoking at the p < 0.05 level of statistical significance. 9 of these were linked to smoking initiation, 2 to CPD and 2 to both initiation and CPD. Also observed by Dr. Thorgeirsson and colleagues was that most of the SNPs associated with heightened BMI were also positively linked to smoking initiation or higher CPD, with both food intake and nicotine consumption potentially influenced by them.
The study does not merely shed light on the potential common origins of obesity and nicotine addiction, but also covers an apparent paradox in how smoking and BMI relate, with smokers generally having a lower BMI than nonsmokers, despite the BMI of heavier smokers being higher than more occasional smokers.
The first observation can be accounted for by the appetite-suppressing and metabolism-accelerating effects of nicotine, while the second may be partly explained by the study’s finding that increased nicotine consumption and BMI may be simultaneously promoted by some SNPs. Whatever the situation, there’s no doubt that the study has provided plenty of food for thought for many of those overseeing a nutritional therapy and experiential program.