I have been using a mayonnaise substitute made from grapeseed oil. (I like it on celery and with leftover grilled salmon.) I read an entry in the forum that indicated it may not be Paleo. Is it a pro-inflammatory oil?
When I'm making a decision about a new oil I always look at the fatty acid composition.
In grapessed that would be
Acid / Type / Percentage
Linoleic acid / ω−6 unsaturated / 72%
Oleic acid / ω−9 unsaturated / 16%
Palmitic acid / Saturated / 7%
Stearic acid / Saturated / 4%
Alpha-linolenic acid / ω−3 unsaturated / less than 1%
Palmitoleic acid / ω−7 unsaturated / less than 1%
If you decide to keep your Omega-6 intake below 4%, which should lower your risk for having a heart attack I would recommend that, due to very high (72%, only safflower ranks higher) Omega-6 content, you do not use grapessed oil.
"Characteristics and composition of melon and grape seed oils and cakes" via secondary source (Wikipedia)
"Biochemistry and physiology of n-3 fatty acids"
It's a good idea not to trust seeds to be good sources of food. Seeds are the plant's children and the plants will put in toxic protection to try to deter predators from eating their children. Humans are typically not well adapted to disarming these toxins. SOme animals have adapted to it, but humans apparently did not eat much of these in the paleo and so we have not evolved much in that direction.