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A statin a day keeps the doctor away: comparative proverb assessment modelling study

BMJ 2013; 347 doi: (Published 17 December 2013) Cite this as: BMJ 2013;347:f7267

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Re: A statin a day keeps the doctor away: comparative proverb assessment modelling study

What kind of apple?

The study by Briggs and colleagues shows that prescribing either an apple a day or a statin a day to everyone over 50 years old is likely to have a similar effect on population vascular mortality. The authors considered the side effects of statins, while excluded adverse events for increased apple consumption. This is right and I agree, together with thousands of consumers who are increasingly interested in health-promoting properties of plant foods. Notwithstanding, the question as to why apples have such beneficial effect has not been discussed. Table 1 reports the nutritional composition of 100 g of apple listing some components (fat, cholesterol and fibre), without mentioning phytochemicals, i.e. plant secondary metabolites, which play a key role in promoting human health by reducing oxidative damages, preventing chronic diseases and decreasing the risk of mortality from cancer and cardiovascular diseases. Pytochemicals such as polyphenols, flavonols, flavonoids, anthocyanins, tocopherol, ascorbic acid, and carotenoids can be constitutively expressed, but they can also be induced by a range of factors, including plant genotype, ripening stage, harvest season, industrial processing, soil quality, beneficial root symbionts and agronomic and environmental conditions. Just as an example, a comprehensive study aimed at establishing an antioxidant capacity database in USA provided different data on apple fruits, depending on the variety: Total Antioxidant Capacity per serving (138 g = 1 fruit) ranged from 3578 to 5381 in Fuji and Granny Smith varieties, respectively.
In conclusion, while a statin is a statin, the nutraceutical value of an apple may change in relation to diverse variables. Thus, the proverb “An apple a day keeps the doctor away” needs more precise information: what kind of apple? When, where and how was it grown? Knowledge of the food production chain would improve the awareness of consumers and medical doctors on health-promoting activity of fruits and vegetables.
Thank you for your attention,
Manuela Giovannetti
Full Professor in Agricultural Microbiology
Director of the Research Center Nutraceuticals and Food for Health - Nutrafood, University of Pisa, Italy.

Giovannetti et al. (2012). Nutraceutical value and safety of tomato fruits produced by mycorrhizal plants. British Journal of Nutrition, 107: 242-251.

Thomasset et al. (2006) Dietary polyphenolic phytochemicals – promising cancer chemopreventive agents in humans? A review of their clinical properties. Int J Cancer 120, 451–458.

Wu et al. (2004). Lipophilic and Hydrophilic Antioxidant Capacities of Common Foods in the United States. J Agric Food Chem 52, 4026−4037.

Competing interests: No competing interests

01 January 2014
Manuela Giovannetti
Full Professor, Agricultural Microbiology
Dep. Agricutlure, Food and Environment, University of Pisa, Italy
Via del Borghetto 80