Besides distributing the contraceptive, the leaders have also been telling explorer scouts, boys and girls aged 14 to 18, about the sexual health clinics so that they know the risk involved.
The new advice has been issued by The Scouting Association, with its motto "Dyb, Dyb, Dyb, Dob, Dob, Dob", meaning "Do Your Best, Do Our Best".
"We must be realistic and accept that around a third of young people are sexually active before 16 and many more start relationships at 16 and 17," the Sun quoted Chief Scout Peter Duncan, 54, as saying.
"Adults in scouting have a duty to promote safe and responsible relationships. We have a responsibility to provide sound advice about how to do that," the former Blue Peter host added.
Even though leaders are distributing the condoms to explorer scouts, whose "physical or mental health is likely to suffer" without them, they have also been told to urge scouts to resist having sex too young.
Minister for Young People, Beverley Hughes, welcomed the idea that information should be given to scouts aged 10-14 if they requested it.
Professor Clive Ballard, director of Research at the Alzheimer's Society, said the work was "robust and exciting".
"This is a novel and potentially exciting area of research, but it is still at a very early stage," he said.
"Much more research is needed to see if fatty acids could lead to a treatment for those living with the devastating effects of Alzheimer's disease," he added.