Unlike normal cocoa, which has a minimum percentage of Cocoa Butter of 22/24%, low-fat cocoa has a lower percentage of it, which is around 10/12%.
This is the only difference between cocoa and low-fat cocoa.
See Cocoa
As for the positive properties, from a health point of view, cocoa beans contain a significant amount of antioxidants: flavonoids, proanthocyanidins, catechins, epicatechins and in particular a phytosterol, beta-sitosterol to which are attributed protective actions on the development of cancer.
This study warns about the risk of high chocolate intake, which is positively associated with the risk of prostate cancer as total, advanced, localized and low-grade disease. However, the authors also pointed out that although high intake of antioxidants from supplements was associated with an increased risk for all prostate cancer subgroups except fatal cancer, this finding must be interpreted with caution because of the possibility of reverse causality (1). Which, if we interpret the study correctly, means that small amounts of cocoa have anti-inflammatory activity in our bodies, whereas excessive amounts may cause an adverse effect.
References____________________________________________________________________
(1) Russnes KM, Möller E, Wilson KM, Carlsen M, Blomhoff R, Smeland S, Adami HO, Grönberg H, Mucci LA, Bälter K. Total antioxidant intake and prostate cancer in the Cancer of the Prostate in Sweden (CAPS) study. A case control study. BMC Cancer. 2016 Jul 11;16:438. doi: 10.1186/s12885-016-2486-8.