Maritime Pine (Pinus pinaster), specifically its bark extract known as Pycnogenol®, has been the subject of several clinical studies exploring its effects on circulation, including cerebral (brain) blood flow. The extract is rich in procyanidins, a type of flavonoid with antioxidant and endothelial-supporting properties. Research suggests that Pycnogenol may improve endothelial function, which in turn can enhance overall vascular health and circulation. Some double-blind, placebo-controlled trials have indicated that Pycnogenol supplementation can increase cerebral blood flow and improve cognitive function in certain populations, such as older adults or those with cognitive decline. For example, a 2008 study published in "Nutritional Neuroscience" found improved cognitive function and attention in elderly subjects after Pycnogenol supplementation, possibly as a result of better microcirculation. Other studies have reported improvements in subjective memory and reduced symptoms of chronic venous insufficiency.

However, while these findings are promising, the quality and size of the available studies are moderate, and more large-scale trials are needed to confirm the benefits and understand the mechanisms fully. The current scientific evidence supports the potential use of maritime pine bark extract for improving circulation, including to the brain, but it is not yet robust enough to warrant a higher rating.