Saarni et al.1 recently published an interesting study using Finnish twins to examine the association between adolescent smoking and adult abdominal obesity and overweight. They found that smoking was a risk for abdominal obesity in females.1 Unfortunately, they were unable to provide any explanation for the phenomenon, and did not realize that this probably affects the attractiveness of the female body.2 Here we propose why smoking may increase abdominal obesity in women and reduce attractiveness.
The study by Saarni et al.1 is consistent with previous studies that have found that smoking females have a significantly higher waist-to-hip ratio.3 It is well known that the waist-to-hip ratio is regulated by sex hormones. Previous studies have also shown that females with a lower waist-to-hip ratio and larger breasts have higher 17-β-oestradiol levels than females with a higher waist-to-hip ratio and smaller breasts.4 Likewise, women with higher testosterone levels have a higher waist-to-hip ratio,5 because testosterone causes the accumulation of fat cells around the waist and the inhibition of fat cells in the hip region.6 The effect of estrogen is the opposite.
Women who smoke have more circulating testosterone5 and lower free estradiol levels than do women who do not smoke.7 Higher testosterone levels in women have been suggested to lead to an increased risk of smoking.8 Thus, the higher testosterone levels of women who smoke probably cause the accumulation of fat cells around the waist and the inhibition of fat cells in the hip region,6 and may explain the observed pattern of increased abdominal obesity in women who smoke.3
On the other hand, it seems possible that smoking per se increases testosterone levels and reduces estrogen levels, although experimental studies on humans are lacking in this area. Saarni et al.'s study gives elegant support to this interpretation, because they found that the smoking twin was more likely to be abdominally obese.1 The change in sex hormone levels as a result of smoking probably affects females' body fat distribution, causing it to become more tubular.
In western cultures, a low waist-to-hip ratio is considered sexually more attractive in women.2 It can thus be concluded that smoking reduces the sexual attractiveness of the female body. This should be highlighted in publicizing the negative effects of smoking, especially among young women who smoke, or those who are considering starting.
References
- 1.Saarni SE, Pietiläinen K, Kantonen S, Rissanen A, Kaprio J. Association of smoking in adolescence with abdominal obesity in adulthood: a follow-up study of 5 birth cohorts of Finnish twins. Am J Public Health 2009;99(2):348–354 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Brown WM, Price ME, Kang J, Puond N, Zhao Y, Yu H. Fluctuating asymmetry and preferences for sex-typical bodily characteristics. Proc Natl Acad Sci USA 2008;105:12938–12943 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Shimokata H, Muller DC, Andres R. Studies in the distribution of body fat. III. Effects of cigarette smoking. JAMA 1989;261(8):1169–1179 [PubMed] [Google Scholar]
- 4.Janienska G, Ziomkiewicz A, Ellison PT, Lipson SF, Thune I. Large breasts and narrow waists indicate high reproductive potential in women. Proc Biol Sci 2004;271(1545):1213–1217 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Sowers MF, Beebe JL, McConell D, Randolph J, Jannausch M. Testosterone concentrations in women aged 25-50 years: Associations with lifestyle, body composition and ovarian status. Am J Epidemiol 2001;153(3):256–264 [DOI] [PubMed] [Google Scholar]
- 6.Singh D. Adaptive significance of female physical attractiveness: Role of waist-hip ratio. J Pers Soc Psychol 1993;65:293–307 [DOI] [PubMed] [Google Scholar]
- 7.Daniel M, Martin AD, Drinkwater DT. Cigarette smoking, steroid hormones, and bone mineral density in young women. Calcif Tissue Int 1992;50:300–305 [DOI] [PubMed] [Google Scholar]
- 8.Bauman KE, Foshee VA, Haley NJ. The interaction of sociological and biological factors in adolescent cigarette smoking. Addict Behav 1992;17:459–467 [DOI] [PubMed] [Google Scholar]