поискала в гугле по русски и ничего на эту тему не нашла...
набрала "citral prostate" нашлись некие труды об экспериментах на крысах .. пишут что воздействие цитрала возможно связано с его эстрогенными свойствами. Получается любые фитоэстрогены мужчинам нельзя
С другой стороны есть исследование, которое утверждает, что цитрал способен убивать раковые клетки, так что вот

Citral is the lemon-scented substance found in a number of herbs, such as lemongrass (Cymbopogon citratus), citronella (Cymbopogon nardus, a blue-green perennial grass), lemon balm or melissa (Melissa officinalis), and lemon verbena (Verbena officinalis). It is also present in eucalyptus. Citral is used extensively as the lemon scent in household products such as insect repellants, washing-up liquid etc.
In research conducted at the University of Negev, published in May 2005, citral has also been shown to cause the self-destruction (apoptosis) of cancer cells in a cell culture. It is therefore likely to be a possible cancer preventative agent. However, citral has also been shown to cause benign prostate enlargement (in rats), and to inhibit the binding of oestrogen to oestrogen receptors in cell cultures. Its use may therefore be something of a mixed blessing.
http://www.self-helpcancer.org/cancertreatment2_1.htm