[FALSE] Does a study prove eating mangoes can treat Alzheimer’s disease?

Screenshot of the Facebook post.

The Claim and Our Verdict

The claim: A Facebook post published Aug. 9, 2021, claims a study proves eating mangoes can treat Alzheimer’s disease.

Fact-checking:

• The claim is based on a paper published in September 2021 in the Journal of Functional Foods. The research and findings were based on an in vitro (an artificial environment) experiment conducted outside the normal biological context, rather than an in vivo (the living body of a plant, animal or human) experiment, which observes the effects of eating mangoes on the human body.
• The co-authors of the paper, professor He Xiangjiu and associate professor Wang Yihai in the school of pharmacy at Guangdong Pharmaceutical University, responded to our inquiry and emphasized the current study do not prove that eating mangoes in daily life will treat Alzheimer’s disease, because the study conducted only in vitro experiments. The anti-neuroinflammatory components in mangoes may not affect the same activity inside the human body, and daily consumption of mangoes cannot guarantee the relevant bioactive components take effect. Thus, based on the results of the current study, we cannot conclude eating mangoes can treat Alzheimer’s disease.

Our ruling: Therefore, we rate the claim as FALSE.

News Brief

A Facebook post published Aug. 9, 2021, claims that mangoes are not only tasty, but also rich in various vitamins and can treat Alzheimer’s disease.

As of the issuance of this report, the post had been shared 18 times, and had received 3 comments and 76 likes or reactions.

A TVBS news programme also reported this issue on July 18, 2021. TVBS is a Taiwanese commercial television broadcaster.

Fact-checking

Keyword searches found the following relevant information. A website post published by Hong Kong’s Department of Health claims that Alzheimer’s disease is the most common cause of dementia. Patients experience a decline in brain function due to neurological pathology, affecting memory, comprehension, language, learning capacity, calculation, and judgement. Some people also suffer from emotional, behavioural or sensory problems. According to the United Kingdom’s National Health Service (NHS) website, the exact cause of Alzheimer’s disease is not yet fully understood, and academia generally consider it as a progressive neurodegenerative disease.

Screenshot of Alzheimer’s disease overview on the official NHS website.

A further keyword search found a research paper published in September 2021 in the Journal of Functional Foods, titled “Potential in vitro anti-neuroinflammatory sterols from mango fruits (Mangifera indica L.).” The journal’s name and the paper’s publishing date are identical to those mentioned in the claim. The paper claims, “However, long duration of neuroinflammation can cause neurodegenerative diseases, such as Alzheimer’s disease (AD) and Parkinson’s disease (PD). Inhibition of neuroinflammation is considered to be one of the important means to alleviate neurodegenerative diseases.” Thus, it indicates that this paper is the source of the Facebook claim.

It is determined the research in this paper only conducted an in vitro experiment – outside the normal biological context – rather than an in vivo experiment, which observes the effects of eating mangoes on the human body. Though results of the in vitro experiment show that some compounds in mangoes can help inhibit neuroinflammation, it cannot be concluded that eating mangoes can treat Alzheimer’s disease.

HKBU FactCheck Service also sent inquiries to co-authors of the paper. Professor He Xiangjiu and associate professor Wang Yihai in the school of pharmacy at Guangdong Pharmaceutical University replied via email on Sept. 1, 2021, and Aug. 31, 2021, respectively. He wrote, “The study cannot conclude eating mangoes in daily life can treat Alzheimer’s disease due to two reasons: (1) the current research on relevant bioactive components was only based on in vitro experiments, and anti-neuroinflammatory components that are active in vitro may not possess the same activity in vivo; (2) a certain level of plasma concentration is needed for any drug to take effect in human body, and daily consumption of mangoes cannot guarantee the concentration reaches that level. Therefore, the current study cannot conclude that eating mangoes in daily life can treat Alzheimer’s disease. Consumers should be alert to such misinformation.”

Screenshot of the email reply by professor He Xiangjiu.

Wang wrote, “Our research results show some of the compounds possess a certain level of in vitro anti-neuroinflammatory activity (though not very high). Further research is needed to confirm whether these compounds will be active in vivo anti-neuroinflammatory activity. Based on the research’s results, we cannot draw the conclusion that eating mangoes can treat Alzheimer’s disease.”

Screenshot of the email reply by associate professor Wang Yihai.

Further keyword searches cannot find any other relevant research.