Oranges and lemons have always been considered the fruits with an antitumor action par excellence. But for an even more powerful effect it is also important to use the peel, as it is rich in precious substances that fight cancer, the terpenes, as emerges from a very interesting scientific research published in the journal Cancer Prevention Research by an American team from the University of Arizona ( Miller et al, Cancer Prevention Research, 2013).
The anticancer properties of limonene
The study investigated the properties of limonene, which is a particularly abundant terpene in the peel of citrus fruits, such as lemons, oranges and grapefruits. Previous studies performed in vitro and on animals had already had the opportunity to show the anticancer action of limonene. In addition, limonene is fat-soluble. Therefore, this substance is absorbed by the adipose tissues of the body thus allowing its accumulation and ready use when needed. However, there was still no proof of its effectiveness on humans. This is therefore the reason why American scientists at the University of Arizona have developed the research we are talking about today.
Limonene counteracts the proliferation of breast cancer
Scientists have decided to focus attention on the action of limonene on breast cancer. 43 women with this cellular degeneration and awaiting surgery were then recruited. The volunteers took 2 grams of limonene every day for a month and a half before the surgery. At the end of the study, further analyzes revealed that limonene had accumulated mainly in the breast tissue. Not only that, the intake of limonene had reduced some tumor markers. In particular, following the intake of limonene, the cyclin D1 of breast cancer was reduced by 22%, a fact which indicates how this substance contributes to the arrest of the cell cycle and the reduction of the proliferation of diseased cells.
Research has yet to continue and shed light on some aspects that have remained in the shade, such as a slight increase in a substance, IGF-1, or similar insulin growth factor. As admitted by the study authors themselves, the significance of this variation, albeit small, has not yet found an explanation and it is not possible to evaluate its clinical effect. However, this refers to the intake of pure limonene in the form of a supplement, not to the quantities taken with food. While waiting for science to clarify, we can certainly include citrus peel in our diet. We can, for example, add a grated lemon peel to fruit salads, salads and side dishes, or orange peel to morning yogurt. But remember not to overdo it because it is always necessary to pay attention to that the diet is varied and balanced, without excess.