Current Use and What the Science Says

        There are two current uses that dominate; consumption of star anise tea and the pharmaceutical drug, Tamiflu.

        It is important to note that large clinical trials have not yet been done to prove medicinal benefits of star anise tea or its efficacy. This is mainly because it has been consumed on a folklore basis and passed down through generations by verbal dissemination. Star anise tea is believed to have carminative and sedative properties used to treat infant colic and continues to be consumed based on traditional evidence rather than based on Western evidence.  

I have therefore chosen the study by Ize-Ludlow et al as it contradicts the validity of Star anise to be used as a traditional-based medicine. Seven cases of infants aged 2-12 weeks showed signs of acute star anise intoxication over a 2 -year period after consumption. Doses ranged from 1 to 6 stars boiled in water with consumption ranging from once per day to every 4 hours. These infants exhibited neurologic episodes including seizures, jitteriness, irritability, hyperexcitability, emesis, vertical nystagmus and myoclonic movements. See Table 1 of Appendix for findings. Results also showed contamination of the commercial Star anise with toxic Illicium anisatum (Figure 7), the Japanese star anise. With the recent rise in adulteration and an increase in the number of clinical toxicities, Ize-Ludlow and the FDA has warned against drinking star anise tea. 

Figure 7- Japanese star anise.
Ref: http://bakati.com/s~q-japanese%20star%20anise.aspx

The major limitation of the study is the small sample size and its lack of being a randomly- controlled trial, however their findings are supported by an agglomeration of similar studies (Biessels, 2002; Garzo, 2002; Okuyama, 1993; Johanns, 2002). The protocols were sound since patients had already been consuming star anise tea prior to the study, thereby the symptoms were naturally occurring not induced in a clinical study, which in itself is a limitation (Ize-Ludlow, 2004).

        Shikimic acid found within the pericarp of Star anise is a main component of Tamiflu (oseltamivir), a pharmaceutical drug used to combat various strains of influenza (Figure 8). With the recent 2009 H1N1 pandemic, Tamiflu has become the only recommended antiviral drug for treating children of <5yrs. 

Figure 8- Chemical structure of oseltamivir phosphate.
Ref: http://en.wikipedia.org/wiki/Oseltamivir

According to Heinonen et al., results indicate that treating influenza with orally administered oseltamivir within 12 hours of symptom onset decreases the development of acute otitis media, a bacteria infection caused by influenza, by 85% (95% CI, P=0.2), see Figure 9. Treatment also shortened the child’s median time for recovery from influenza symptoms by 1.4 days and reduced parental absence from work by 2 days. No significant efficacy was found when oseltamivir was started within 24 hours, therefore it has been concluded to administer Tamiflu as early as possible after symptom onset. See Table 2 and 3 in Appendix for findings. 

Figure 9- Example of otitis media, which is inflammation and fluid, within middle ear caused by influenza.
Ref: http://www.nlm.nih.gov/medlineplus/ency/imagepages/19324.htm

These results show statistical significance, where its overall efficacy is supported by previous studies done on adults and maintained by the high rate of adherence to oseltamivir. Their study was a good example of a Western evidence-based clinical study where they performed randomized, double- blind, placebo- controlled trials on a fairly large sample of 408 children within 1-3 years old. Study procedures were thorough, logical and unbiased as they made certain that symptoms were caused by influenza nothing else and protocols were sound ensuring the health of the children as their priority (Heinonen, 2010).