If you are looking for real data then the only place to look is in actual research Journal articles. I am a researcher and the only online sources I use are PubMed and NCBI, they major online hubs for anything to do with research. If something legit is to be found it will be there. Everything else is going to be majority of uneducated bloggers trying to sell a basement cancer cure concoction, if it looks like a poorly made website of information than you can quickly summarize it as no good simply based on common sense. You need to be careful as to what you buy, especially from online sources. There is no cure for any cancer. You can eat foods that are thought to prevent cancer but absolutely nothing is going to without a doubt prevent cancer. Everyone already has cancer cells in them whether they like it or not, prevention can be brought on simply by not eating a poor diet like sodas, fast food, or junk foods. Eat all the grapes you want they are healthy for you, but many people who have eaten a ton of fruit still get cancer. Top athletes eating perfectly with great exercise get cancer, no one is immune. The thing with grape seed oil is that science has yet to prove anything without a doubt. There are a ton of theories sure, but absolutely nothing is concrete. Right now the theory is that grapes contain a thing called Resveratrol. Now simply typing "resveratrol" into PubMed I get 4047 peer reviewed published research articles spanning 10's of years all on resveratrol, typing resveratrol cancer prevention I still get 315 published articles. So obviously a lot of information. Read through a handful and they will be split, some say yay we saw some potential results from resveratrol preventing cancer cell growth, and other papers saying no we saw nothing that shows proof. Basically if you want to have the best prevention of anything, go with the actual product. Eat a bunch of grapes in a week if you believe it would help, keep up with other fruits, the worst thing that could happen is you get a good dose of vitamin C and other minerals to keep you going.Are there scientific studies to prove this?