When the summer hits, my face begins to tan more quickly than the rest of my body (because it is more exposed). I usually do not have a problem with this tanning variation except when it comes to matching foundation or wearing low-cut tops that reveal a less tanned complexion from the neck down. I've learned to deal with it since it is only temporary, and during some summers, the tan does balance out over time.
Nevertheless, I stumbled upon this interesting study (while researching grapeseed oil) that demonstrated lightening effects on UV-induced hyperpigmentation (i.e., a tan) after topical application of linoleic acid. Since grapeseed oil contains a large amount of linoleic acid, it makes you wonder if it would have that effect? Maybe you can do your own personal experiment or research.
SOURCE:
ABSTRACT ON LINOLEIC ACID LIGHTENS UV-INDUCE HYPERPIGMENTATION (1998)