Evening Primrose Oil is commonly used as a vegetarian source for essential fatty acids (EFAs): omega 3's, omega 6's, gamma linoleic acid (GLA) & linoleic acid (LA). This used to be commonly be recommended by those in the supplementation world of DS, but then after more current research, the recommendation was reversed.
Dr. Leichtman used to recommend the use of EPO as well (as his website states, but that is out of date), but presently does not recommend it.
When we first started supplementing with TNI, Omega 3's, etc, I remember all the talk of how people used to use EPO and switched to another source. Recently I've been seeing a lot of families starting to use EPO again and it's raised questions and concerns in my mind. Because I recall there being a concern back in the day, but I couldn't remember the exact reason for why.
Well, because my research side of me wants to be informed, I looked up the use of EPO again.
It is true that there are benefits that EPO can give. Andi over at Down Syndrome: A Day to Day Guide shares some good info on her blog here. Since Andi has all the good info on EPO on her blog, I won't explain it all here :).
But, there are also risks involved with giving EPO. Omega 6's are essential fatty acids, but they must be given in moderation, as they can increase oxidative stress.
The two main fatty acids EPO converts to is GLA & LA. Both of these, but particularly, LA have been shown to induce oxidative stress & damage, as well as programmed cell death (apoptosis). While, certain amounts of LA and GLA can have some antioxidant states, they more commonly increase oxidative stress.
There is so much extra oxidative stress in people with Down syndrome due to the overexpressed genes on the 3rd chromosome. In DS, there is not enough antioxidants to battle this already highly oxidant state.
I am hesitant to supplement with a product that is known to increase oxidative stress, however mild it may be. While EPO isn't a very high pro-oxidant vegetable origin of omega 3's, it does still encourage a pro-oxidant state.
While there are no studies, as usual, on EPO in people with DS, you can see a couple studies here and here.
One quote from the discussion of the second study is below,
The possibility arose by in vitro experiments that a high intake of LA would increase oxidative stress in the body is supported by the results of our strictly controlled human experiment... ...although the intake of antioxidants and plasma levels of a-tocopherol of our subjects were well above recommendations.Flax seeds that are freshly ground are a much better source of vegetarian omega-3's & 6's, but it is harder to quantify. EPO may be okay to give, if it is given in small amounts. I do not feel comfortable giving it at all, therefore we stick with fish oils for our essential fatty acids.