Grapeseed oil contains compounds such as vitamin E and proanthocyanidins (a type of polyphenol), which have been studied for their potential vascular benefits. Research has focused more specifically on grapeseed extract (not the oil itself), which is rich in oligomeric proanthocyanidin complexes (OPCs). Some clinical studies suggest that grapeseed extract may help improve symptoms of chronic venous insufficiency (CVI), such as leg swelling and heaviness, likely through antioxidant activity that protects blood vessel walls and improves microcirculation.

However, grapeseed oil is not as concentrated in these beneficial polyphenols as the extract, since many of these compounds are water-soluble and remain in the seed after pressing for oil. The oil is primarily valued as a source of vitamin E and healthy fats, with only limited evidence suggesting a direct impact on the veins. While some animal and in vitro research suggests antioxidant and anti-inflammatory effects of grapeseed oil, there is a lack of substantial human clinical trials directly linking grapeseed oil consumption to improved venous health.

Therefore, while there is a scientific rationale and some indirect evidence related to components found in grapeseed, the evidence supporting grapeseed oil specifically for vein health is limited and rated as moderate to low (2 out of 5).