Researchers from McMaster University suggest that human beings are wired to emulate people they admire. This act called the "self-esteem motive" is often seen in purchasing products that celebrities endorse because they match how we want to perceive ourselves, according to Steven Hoffman, assistant professor of clinical epidemiology and biostatistics in the Michael G. DeGroote school of medicine at McMaster.

This tendency extends to health. Celebrity status causes a “halo effect” that gives celebrities “a cloak of generalised trustworthiness which extends well beyond their industry of expertise,” Hoffman says. Humans are social creatures who have evolved a tendency to follow the herd. So the vast social networks that celebrities keep, contribute to that considerable influence.

Mental shortcuts to minimise cognitive dissonance

This can be seen in the case of reality TV star Kim Kardashian - a woman that many love to love or hate, with at least 64 million followers on Instagram alone. Then pregnant, she raved about morning sickness medication Diclegis.

The Food and Drug Administration (FDA) took issue with the drug’s maker, Duchesnay, for allowing her to tout the drug’s benefits on social media without mentioning limitations and risks associated with the drug. Kardashian later bowed to FDA’s intervention and presented a more well-rounded endorsement of Diclegis.

Hers is a reminder of the power that celebrities have in affecting individual health behaviours - experts say that passionate support and compelling personal narratives, especially by celebrities, may overshadow the nuance involved in individual decision-making, or overstate a case for a particular prevention.

Psychologically, humans prefer to minimise cognitive dissonance, which could “cause psychological stress”, and following celebrities’ advice does so. Also, majority of the public rarely have enough health literacy and coupled with the increasing complexity of medicine, there is a tendency to take mental shortcuts - or heuristics. It is easier to listen to words coming from the lips of someone trusted (whether with good reason or not) rather than attempt to make complex health decisions.

Celebrities do not always know better

The trust we put into our idols may be sorely misplaced. An up-and-coming young Chinese actress chose to reject chemotherapy treatment in favour of traditional Chinese medicine (TCM).

“I know that chemotherapy is extremely painful, and is a process that can even speed up my death,” she said to her 300,000 followers on the Chinese social media site Weibo. “I don’t want to let chemotherapy torment me to the point where there’s no beauty and talent left.”

However, her condition only continued to worsen after going through different TCM treatment techniques. A month later, she finally turned to chemotherapy for treatment, but it was too late - Xu Ting, 26, passed away due to lymphoma.

Could her the attitude that led her to eschew chemotherapy to her detriment have influenced those of her 300, 000 followers?

Celebrity influence can help sometimes

The influence of celebrities is not always a bad thing. Health care organisations and professionals could partner with celebrities in productive ways, such as in raising awareness, or in public education.

A prominent example is that of Chinese actor Pu Cun Xin, Chairman of China Theatre Association, as well as one of China’s most publicised AIDS heroes for his persistent promotion of HIV education and social acceptance of China’s HIV positive.

Pu’s fame positions him as an authoritative voice on the topic of AIDS, to the extent where he educates state leaders about HIV /AIDS, endorses official campaigns and serves as an advisor on HIV publications. Yet, Pu has no relevant educational credentials to offer advice on health.

Pu attends and gives speeches at HIV/AIDS events, attracting fans and journalists. According to staff members involved in Beijing’s HIV organisations, “the degree of Pu’s impact on popularising HIV as an issue is unquestionable”.

In a roundabout way, health professionals can also take advantage when celebrity advice flops - especially when a patient heeds celebrity advice - taking the moment to educate, as in Kim Kardashian’s case. For good or for ill, the influence of celebrities is virtually unavoidable.

“People need to always be thinking about what evidence underpins whatever health claim we hear,” Hoffman says. “We have to think about who we trust for health advice and why they might be trusting them." MIMS

Read more:
The ’Angelina Jolie effect’ and the downside of mammography
Actress dies of cancer after choosing traditional Chinese medicine over chemotherapy

Sources:
http://www.huffingtonpost.com/entry/celebrities-vs-science-where-do-you-get-your-health-advice_us_579a211de4b0d3568f86480d
http://www.cbc.ca/news/canada/hamilton/news/why-we-listen-to-health-care-advice-from-celebrities-1.2468022
http://today.mims.com/topic/actress-dies-of-cancer-after-choosing-traditional-chinese-medicine-over-chemotherapy?country=malaysia&channel=gn-health-wellness
https://books.google.com.my/books?id=OKngKF0TkcsC&pg=PA85&source=gbs_toc_r&cad=2#v=onepage&q&f=false http://www.medicalnewstoday.com/articles/298404.php