The health claims for grapeseed oil are based on its supposedly high amounts of nutrients, antioxidants and polyunsaturated fats. t’s very high in polyunsaturated fats, mainly omega-6. Scientists have speculated that a high intake of omega-6 fats, relative to omega-3s, may increase inflammation in the body. It also seems to have anti-platelet effects, meaning it reduces your blood’s tendency to clot.