Two apples a day reduce levels of ‘bad’ cholesterol in the blood and the incidence of cardiovascular disease. This is the finding of a clinical study just published in The American Journal of Clinical Nutrition. (1) The work is carried out by the University of Reading (UK) in collaboration with the Edmund Mach Foundation, using an Italian apple variety particularly rich in polyphenols.
Apple and sweetened apple juice drink compared, the clinical study
British researchers recruited 43 healthy individuals-25 women and 18 men, aged 29 to 69 years-with mild hypercholesterolemia. The volunteers underwent a preliminary diet period to standardize the sample. (2) Which was divided into two groups:
– the first group added to their daily diet two apples per day (340g), with skin but no seeds, of the Renetta Canada variety, grown in Trentino and provided by the Melinda Consortium of cooperatives,
– In contrast, the control group took 500ml of a drink with apple juice from concentrate (50%), water and sugar every day as an alternative to apples. With a total amount of sugar equal to that of the two apples.
After 8 weeks, there was improvement in cardiovascular disease risk factors in the group treated with the two apples, with reduced LDL cholesterol levels and increased microvascular vasodilation.
The benefits of the apple
A nutritional gulf runs between apples and fruit drinks , which the study under review summarizes well. The two rents consumed by the volunteers provided 8.5g of fiber, compared with 0.5g in the juice drink. As for polyphenols, the apples used in the study provided 990mg, the drink 2.5mg. But there is also more.
‘Studies […]are needed to explore potential mechanisms, which are likely to involve BA (bile acid, ed.) signaling and/or small phenolic acids derived from apple polyphenols, both of which are linked to gut microbiota metabolism,’ the British researchers conclude.
Apple and microbiome
The gut microbiome-that is, the community of microorganisms that interacts with the central nervous system through the gut (also called the‘second brain‘) to regulate various functions of the body-appears once again to be the key that activates health benefits.
Comparison with organic rennet apples would have been interesting. Indeed, the scientific evidence associating apple consumption with protection against cardiovascular disease (3) is compounded by the greater microbiome richness of organic apples in comparison with conventional apples.
Notes
(1) Athanasios Koutsos, Samantha Riccadonna, Maria M Ulaszewska, Pietro Franceschi, Kajetan Trošt, Amanda Galvin, Tanya Braune, Francesca Fava, Daniele Perenzoni, Fulvio Mattivi, Kieran M Tuohy, Julie A Lovegrove. Two apples a day lower serum cholesterol and improve cardiometabolic biomarkers in mildly hypercholesterolemic adults: a randomized, controlled, crossover trial. The American Journal of Clinical Nutrition, 2019, https://doi.org/10.1093/ajcn/nqz282
(2) In the two weeks prior to the start of the research, volunteers eliminated any food traceable to apple from their diet, as well as probiotics and prebiotics
(3) Epidemiological studies suggest that frequent apple intake is inversely associated with acute coronary syndrome, mortality from total cardiovascular disease, and mortality from any cause. V.
– Hansen L., Dragsted L., Olsen A., Christensen J., Tjønneland A., Schmidt E., & Overvad K. (2010). Fruit and vegetable intake and risk of acute coronary syndrome. British Journal of Nutrition, 104(2), 248-255. doi:10.1017/S0007114510000462
– Hodgson J., Prince R., Woodman R., Bondonno C., Ivey K., Bondonno N., Lewis J. (2016). Apple intake is inversely associated with all-cause and disease-specific mortality in elderly women. British Journal of Nutrition, 115(5), 860-867. doi:10.1017/S0007114515005231
Professional journalist since January 1995, he has worked for newspapers (Il Messaggero, Paese Sera, La Stampa) and periodicals (NumeroUno, Il Salvagente). She is the author of journalistic surveys on food, she has published the book "Reading labels to know what we eat".