Although the long term stability of
Although the long-term stability of childhood intelligence during the life course has been shown in longitudinal studies, studies of the long-term effects of breastfeeding are important. With age, the effects of early developmental factors might either be diluted, because of the effects of later environmental factors, or be enhanced, because cognitive ability affects educational attainment and occupational achievements. Birthweight is an example of a developmental factor that has often been associated with intelligence in childhood, but this effect might not persist into midlife. By contrast, Victora and colleagues\' study suggests that the effects of breastfeeding on cognitive development persist into adulthood, and this has important public health implications.
Previous studies with long-term follow-up have investigated effects on intelligence and education, but no studies seem to be available for associations between breastfeeding and income in adult life. Many studies have shown associations between intelligence, education, and occupation. Thus, studies that show the effects of breastfeeding on educational achievement in adolescence would be expected to show the association of breastfeeding with education and income. Victora and colleagues show that children who were breastfed maintain this cognitive and educational advantage until at least their early 30s, and this advantage is associated with increased income. The results of Victora and colleagues\' mediation analysis suggest that the crucial developmental path is the effect of breastfeeding on cognitive development. However, a model that only incorporates intelligence and income seems too simple, since much evidence suggests that intelligence affects education, which is an important determinant of occupation and income.
The findings from this Brazilian cohort suggest that breastfeeding might have long-term effects on intelligence in a check details without strong social patterning of breastfeeding, and this effect might mediate effects on life outcomes, such as educational attainment and income. However, these findings need to be corroborated by future studies designed to focus on long-term effects and important life outcomes associated with breastfeeding.
China is home to more than 300 million smokers, a substantial proportion of whom are male and low-income, and who consume more than a third of the world\'s cigarettes. More than 1 million premature deaths each year in China are attributable to smoking, and the economic cost of smoking amounts to billions of dollars. Studies consistently show that raising tax on tobacco is the most cost-effective way to reduce tobacco use, yet China has so far hesitated to use such strategies in its bid to reduce tobacco use and its consequences. One of the concerns raised by the Chinese State Tobacco Monopoly Administration (STMA) is that a tax increase would lead to an unfair burden on the poor. Under the influence of the STMA, the Chinese government has kept tied tax rates on cigarettes—ie, lower rates on low-end cigarettes so as to keep them affordable for the poor, while generating revenues by taxing premium products at higher rates. However, in many countries, studies have disclosed that a tax increase along with raised tobacco product prices leads to the largest declines in smoking among the lowest-income people, and that the burden of tax increase falls more heavily on higher-income consumers whose smoking behaviour changes little in response to the tax increase. It is in this context that the findings of a study in have important implications for the tobacco tax and price policies in China, a country that has ratified WHO\'s Framework Convention on Tobacco Control but has not significantly increased its tobacco excise taxes since 2009. Stéphane Verguet and colleagues attempted to simulate the effect, across income quintiles, of a hypothetical tobacco price increase in China. Specifically, they estimated the health benefits (years of life gained), the additional tax revenues raised, the net financial consequences for households, and the financial risk protection provided to households caused by a 50% increase in cigarette prices through raising cigarette excise tax. Their goal is ambitious given the complex, yet not-well-understood, mechanisms that link cigarette excise tax and various outcomes examined in this study, and the paucity of evidence to demonstrate the effectiveness of such a strategy in a rapidly changing economy like China\'s, which is also the world\'s largest tobacco producer and consumer.