Doctors in one study said Pycnogenol, an extract of pine bark, promotes healthy blood pressure. They wanted to see if it could also improve kidney function. Fifty-five people with high blood pressure and early signs of impaired kidney function took the anti-hypertension drug Ramipril with or without 150 mg of Pycnogenol per day.
After six months, protein in the urine—a sign of impaired kidney function—had nearly returned to normal in the Pycnogenol group while remaining elevated in the Ramipril-only group. Blood pressure and inflammation were also much lower with Pycnogenol and blood flow to the kidneys had improved.