ABSTRACT
Apples are known as a major source of polyphenols, dietary fiber, carotenoids, and other nutrients. There are many documents and studies that show fruit polyphenols likely promote anti-obesity effects and exert their beneficial effects via scavenging free radicals, regulating gene expression, and altering signal transduction in target cells and tissues, especially fat tissues.The goal of this review is to presenti the major components of apple and the evidence that indicates its potential to diminution weight gain risk from in vitro, animal, and epidemiological and clinical studies. This review summarizes data about the apple and apple products that been have reported to reduce weight gain by various mechanisms, including antioxidant, antiproliferative, and cell signaling pathways. An extensive search was performed in PubMed, Science Direct, Scopus, and Google Scholar to identify human, animal, and cell culture studies on the association between weight loss and apple consumption, published from inception up to journey 15, 2017. The feeding of apples rats (7–10 mg/kg/d) in different forms in 8 experiments have shown that this caused weight loss during 3 to 28 weeks. In agreement with this, the obtained results from 5 experiments on humans have revealed that consumption of the whole apple or apple juice (240–720 mg/d) in 4–12 weeks by fat people can cause weight loss. Experiments on animals and humans have shown that the consumption of apples in different forms can cause weight loss in overweight ones. However, the main questions are which kind of apple, which part of it, how much, and how long overweight persons should consume them to reduce their body fat and body mass index (BMI). Then, it is necessary to do a meta-analysis to show how these factors affect the body fat percentage and whether this weight-lowering effect is statistically significant or not.
Transparency statement
The lead author affirms that this article is an honest, accurate, and transparent account of the study being reported. The lead author affirms that no important aspects of the study have been omitted and that any discrepancies from the study as planned have been explained.
Conflict of interest, source of funding, and authorship
We confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome. This research received no specific grant from any funding agency or commercial or not-for-profit sectors.
All authors contributed to the design of the study. MK led the article preparation with assistance from all authors. MK, AR, and SA added to the intellectual content of the article and approved the final version submitted for publication.