Apple (Malus domestica Borkh) is the most cultivated fruit in the world and although it is not very nutritious, it provides the human body with a whole series of benefits due to its content:
- Chlorogenic acid
- Epicatechin
- Flavonoids
- Polyphenols
- Vitamin C
Studies
Apple has antioxidant properties (1) especially on the fats of the cell membrane and therefore helps to combat vascular diseases such as atherosclerosis and other forms of cardiovascular problems.
Another important function is to regulate the balance of blood sugar, stimulating the cells of the pancreas to produce the right dose of insulin (2).
Other studies have shown the effectiveness of apples in reducing the risks of asthma and aging.
Raw or cooked apples are also an excellent digestive aid.
Phlorizin , a glucoside compound found in the bark of apples, in quantities of 100ug/ml has demonstrated a protective antioxidant effect on DNA damage and cellular apoptosis (3).
Among the polyphenols present, cyanidin-3-galactoside, catechin, epicatechin and proanthocyanidin in an apple extract reduced free radicals by inducing apoptosis of cancer cells. Among the apples varieties, red apples were most effective against BGC-803 cancer cells (4).
Phldz (phloretin 2′-O-glucose), a phenylpropanoid found only in apples, and Phlor, a direct derivative thereof, exert an anti-inflammatory function in the intestine, improving the symptoms of intestinal inflammation (5).
In a crossover study involving 30 participants, a high intake of apples improved endothelial function, blood pressure and arterial rigidity both acutely and chronically (6). The cardioprotective role of the apple can therefore be confirmed.
Apple studies
References_____________________________________________________________________
(1) Snyder SM, Zhao B, Luo T, Kaiser C, Cavender G, Hamilton-Reeves J, Sullivan DK, Shay NF. Consumption of Quercetin and Quercetin-Containing Apple and Cherry Extracts Affects Blood Glucose Concentration, Hepatic Metabolism, and Gene Expression Patterns in Obese C57BL/6J High Fat-Fed Mice. J Nutr. 2016 May;146(5):1001-7. doi: 10.3945/jn.115.228817.
(2) Fathy SM, Drees EA. Protective effects of Egyptian cloudy apple juice and apple peel extract on lipid peroxidation, antioxidant enzymes and inflammatory status in diabetic rat pancreas. BMC Complement Altern Med. 2016 Jan 11;16:8. doi: 10.1186/s12906-015-0957-0.
Abstract. Background: Apples possess rich content of varied polyphenolic compounds showing a variety of biological activities that may ascribe to worthy effects against some chronic diseases. The present study was designed to assess the protective effects of the cloudy apple juice (CAJ) and apple peel extract (APE) of Egyptian Anna apple on the complications in experimental diabetes.... Conclusions: The results indicate that Egyptian CAJ and APE supplementation may have protective effects against deleterious complications of diabetes mellitus.
(3) Wang H, Cheng J, Wang H, Wang M, Zhao J, Wu Z. Protective effect of apple phlorizin on hydrogen peroxide-induced cell damage in HepG2 cells. J Food Biochem. 2019 Dec;43(12):e13052. doi: 10.1111/jfbc.13052.
(4) Han M, Li A, Shen T, Meng J, Lei Y, Zhang X, Liu P, Gan L, Ao L, Li H. Phenolic compounds present in fruit extracts of Malus spp. show antioxidative and pro-apoptotic effects on human gastric cancer cell lines. J Food Biochem. 2019 Nov;43(11):e13028. doi: 10.1111/jfbc.13028.
(5) Zielinska D, Laparra-Llopis JM, Zielinski H, Szawara-Nowak D, Giménez-Bastida JA. Role of Apple Phytochemicals, Phloretin and Phloridzin, in Modulating Processes Related to Intestinal Inflammation. Nutrients. 2019 May 25;11(5):1173. doi: 10.3390/nu11051173.
Abstract. Plant-derived food consumption has gained attention as potential intervention for the improvement of intestinal inflammatory diseases. Apple consumption has been shown to be effective at ameliorating intestinal inflammation symptoms. These beneficial effects have been related to (poly)phenols, including phloretin (Phlor) and its glycoside named phloridzin (Phldz). To deepen the modulatory effects of these molecules we studied: i) their influence on the synthesis of proinflammatory molecules (PGE2, IL-8, IL-6, MCP-1, and ICAM-1) in IL-1β-treated myofibroblasts of the colon CCD-18Co cell line, and ii) the inhibitory potential of the formation of advanced glycation end products (AGEs). The results showed that Phlor (10-50 μM) decreased the synthesis of PGE2 and IL-8 and the formation of AGEs by different mechanisms. It is concluded that Phlor and Phldz, compounds found exclusively in apples, are positively associated with potential beneficial effects of apple consumption.
(6) Bondonno NP, Bondonno CP, Blekkenhorst LC, Considine MJ, Maghzal G, Stocker R, Woodman RJ, Ward NC, Hodgson JM, Croft KD. Flavonoid-Rich Apple Improves Endothelial Function in Individuals at Risk for Cardiovascular Disease: A Randomized Controlled Clinical Trial. Mol Nutr Food Res. 2018 Feb;62(3). doi: 10.1002/mnfr.201700674.
Apple 
Catechin
