Pine Bark (2015, 2007, 2009) Helps Diabetic Retinopathy


Learn more about diabetic retinopathy.

A number of diseases involve inflammation and impairment of endothelial layers (that line blood vessels): these include not only heart disease but diabetic retinopathy. The endothelium is the inner lining of blood vessels. Such dysfunction is generally defined as there being an imbalance between the ability of blood vessels' ability to contract and expand.

Various studies have determined that the relationship between obesity, inflammation and other risk factors is a critical factor in such endothelial dysfunction which causes diabetic retinopathy.1


Drawing on earlier research demonstrating that pycnogenol supports vision improvement in diabetic retinopathy by improving microcirculation and reducing swelling, researchers investigated combining this nutrient with other antioxidants as a therapeutic approach.

In patients with nonproliferative diabetic retinopathy, scientists evaluated treatment with 50mg pycnogenol, 30mg vitamin E and 20mg CoQ10. Sixty eight patients were divided into two groups, one receiving the supplement and one receiving placebo. The researchers evaluated levels of free radicals and macular thickness at the beginning of the study period, after three months, and after six months.

In the test group both measures improved; in the placebo group the free radicals level worsened, and macular thickness did not change.

The researchers report that this is the first study to find that free radical levels are reduced, and that retinal thickness is also affected.

Researchers: D. Domanico, S. Fragiotta, et al
Published: Circulating levels of reactive oxygen species in patients with nonproliferative diabetic retinopathy and the influence of antioxidant supplementation: 6-month follow-up, Indian Journal of Ophthalmology, January, 2015.


Researchers have been investigating alternative means of alleviating diabetic retinopathy as diabetes becomes more widespread in the world. Earlier studies have found that pine bark can be effective in very early stages of diabetic retinopathy. This study looks at effectiveness a little later in development when retinal edema begins to appear but before bleeding or other changes occur in the macula.

In a small study 24 patients were assessed as to the degree of retinal swelling and thickness of the retina layer. They were treated with pycnogenol (maritime pine bark) for 3 months and then the measurements were repeated.

The 24 patients were compared to 22 controls with similar conditions who were treated with placebo. The patients given pine bark showed statistically significant improvement in degree of retinal swelling compared to placebo patients (very little change). Likewise, they experienced a marked increase in microcirculation compared to placebo.

The researchers reported that the primary positive result was that visual acuity (sharpness) improved in 18 out of 24 patients receiving treatment from 14/20 to 17/20 after only two months of treatment. There was no change in the placebo group.

The researchers concluded that pine bark, taken early, may improve microcirculation and reduce swelling - both of which help to improve vision.

Researchers: R. Steigerwalt, G. Belcaro, et al
Published: Pycnogenol improves microcirculation, retinal edema, and visual acuity in early diabetic retinopathy, Journal of Ocular Pharmacology and Therapeutics, December, 2009.


A two week study found that extract of French maritime pine bark (pycnogenol supported the ability of blood vessels to appropriately dilate for adequate blood supply. However, placebo used in the study did not affect vasodilation.

The researchers concluded that pycnogenol would be useful in treating diseases involving endothelial dysfunction.

K. Nishioka, T. Hidaka, et al. (2007). Pycnogenol, French maritime pine bark extract, augments endothelium-dependent vasodilation in humans, Hypertension Research, September.

1. M. Tomic, S. Ljubic, et al, The role of inflammation and endothelial dysfunction in the pathogenesis of diabetic retinopathy, Collegium Antropologicum, April, 2013.