Grape Seed Extract

Introduction

This fact sheet provides basic information about grape seed extract, including its uses, potential side effects, and resources for further information. Grape seeds used to produce grape seed extract are generally obtained from wine manufacturers. The leaves and fruit of the grape have been used medicinally since ancient Greece.

Common Names

• Grape Seed Extract

Latin Names

• Vitis vinifera

What It Is Used For

• Grape seed extract is used for conditions related to the heart and blood vessels, such as:
  • Atherosclerosis (hardening of the arteries)
  • High blood pressure
  • High cholesterol
  • Poor circulation
• It is also used for diabetes-related complications, such as nerve and eye damage, and for vision problems like macular degeneration, which can cause blindness.
• Other uses include cancer prevention and wound healing.

How It Is Used

• Grape seed extract is prepared from the seeds of grapes and is available in capsule and tablet forms.

What the Science Says

• Laboratory studies have shown that grape seed contains antioxidants, which prevent cell damage caused by free radicals—highly reactive molecules that can harm cell function. However, the effects of grape seed on human health remain unclear.
• Preliminary clinical trials have indicated some beneficial antioxidant effects of grape seed extract, but few studies have focused on specific diseases or conditions, resulting in limited scientific evidence.
• A study funded by the National Cancer Institute (NCI) found that grape seed extract did not reduce the hardening of breast tissue that can occur after radiation therapy for breast cancer.
• NCI is currently funding studies to evaluate the effectiveness of grape seed extract in preventing breast and prostate cancers.
• The National Center for Complementary and Integrative Health (NCCIH) studies whether grape seed extract and its components may benefit heart health or provide protective effects in the brain.

Side Effects and Cautions

• Grape seed extract is generally well tolerated when taken by mouth and has been used safely for up to 8 weeks in clinical trials.
• Common side effects include:
  • Headache
  • Dry, itchy scalp
  • Dizziness
  • Nausea
• The interactions between grape seed extract and medications or other supplements have not been thoroughly studied.
• You must inform your healthcare providers about any complementary and alternative practices you use to ensure coordinated and safe care.

Sources

• Brooker S, Martin S, Pearson A, et al. Double-blind, placebo-controlled, randomized phase II trial of IH636 grape seed proanthocyanidin extract (GSPE) in patients with radiation-induced breast induration. Radiotherapy and Oncology. 2006;79(1):45-51.
• Clouatre DL, Kandaswami C. Grape seed extract. In: Coates P, Blackman M, Cragg G, et al., eds. Encyclopedia of Dietary Supplements. New York, NY: Marcel Dekker; 2005:309-325.
• Grape. Natural Medicines Comprehensive Database Web site. Accessed on March 13, 2007.
• Grape seed (Vitis vinifera, Vitis coignetiae). Natural Standard Database Web site. Accessed on March 13, 2007.
• NCCAM National Institutes of Health