Grape seed extract is a supplement made from grape seeds. The supplement is produced by removing the seeds, drying and pulverizing them.
Grape seeds are loaded with antioxidants, such as phenolic acids, flavonoids, anthocyanins, oligomeric proanthocyanidin complexes.
Grape seed extract has a lot of antioxidants, and so, it can help with the prevention of diseases. It can also offer protection against tissue damage, oxidative stress, and inflammation (3).
Many marketers of grapefruit seed extract and grape seed extract sell it as supplements under the acronym GSE. In this article, we will discuss the health benefits of grape seed extract. All health benefits are based on scientific studies.
It helps with the reduction of blood pressure
Several pieces of research have examined the effects of grape seed extract on high blood pressure.
A review of 16 studies in 810 high blood pressure patients or people with a high risk of it found that a daily administration of 100-2000 mg of grape seed extract caused a significant reduction in diastolic and systolic blood pressure by 2.8mmHg and 6.08 mmHg respectively.
Obese people under 50 years of age or people with metabolic disorders experienced very significant improvements.
The most significant results came from doses of 100-800mg per day for 8-16 weeks, instead of just one dose of 800mg or higher (4).
Another study involving 29 adults suffering high blood pressure found that a daily dose of 300mg of GSE caused a 5.6% reduction in systolic blood pressure, and a 4.7% reduction in diastolic blood pressure after a 6-week timeline (5).
Grape seed extract improves the circulation of blood
Several pieces of research have suggested that GSE can improve the circulation of blood.
In a 2-month study involving 17 healthy women past menopause, it was discovered that daily administration of 400mg of grape seed extract had thinning effects on the women’s blood, thus minimizing the risk of blood clots (6).
Another study involving 8 healthy young ladies examined the effects of a single 400mg dose of proanthocyanidin from grape seed extract. Results from the study showed that it reduced swelling of the leg and edema by over 70%, compared to those who did not take grape seed extract.
Still, in the same study, another 8 healthy young women treated with GSE-based proanthocyanidins at a dose of 133mg for 14 days experienced a reduction in leg swelling by 40% after sitting for 6 hours (7).
It reduces oxidative damage
One of the major risk factors for heart disease is an increase in the blood level of LDL. LDL is basically, the bad cholesterol.
When LDL cholesterol is oxidized, its risk of elevation is increased. Of course, this, in turn, contributes to atherosclerosis, or the accumulation of fatty plaque in your arteries (8).
A study examined 8 healthy people who took a fatty meal. The 8 subjects also took 300mg of GSE. The GSE inhibited fat oxidation in the blood. On the other hand, those who did not take the grape seed extract experienced a 150% increase in fat oxidation (14).
In another study involving 61 healthy adults, a 400g dose of GSE caused a 13.9% reduction in oxidized low-density lipoprotein. It is worth noting that these results were not replicated by a similar study (5, 12).
Also, another study involving 87 heart surgery patients found that the administration of 400mg of grape seed extract before the surgery caused a significant reduction in oxidative stress. Thus, GSE protects against further damage to the heart (15).
Improves bone strength & collagen levels
Boosting your intake of flavonoids may improve bone formation and collagen synthesis.
The grape seed extract is loaded with flavonoids, and thus can boost your bone strength and density.
However, these are all animal-based studies. None has been conducted on humans.
Grape seed extract supports the aging brain
Flavonoids have both anti-inflammatory and antioxidant properties. Clinical research has shown that the anti-inflammatory and antioxidant properties of flavonoids reduce or delays the onset of Alzheimer’s disease (22).
Gallic acid is one of the major components of GSE. Animal studies have shown that gallic acid can inhibit the production of fibrils by beta-amyloid peptides (23).
The presence of beta-amyloid proteins in the brain is a major feature of Alzheimer’s disease (23).
Results from animal studies show that GSE has the potential to prevent loss of memory, boost antioxidant levels in the brain, improve a person’s cognitive status, and reduce lesions and amyloid clusters in the brain (24, 25, 26, 27).
A 12-week study involving 111 healthy adults found that daily intake of 150mg of GSE caused a significant improvement in language, attention, and memory (28).
It is important to note that there are not many human studies on the effects of grape seed extract on cognitive or memory deficits.
Grape seed extract can improve kidney health
Human kidneys can be affected by oxidative damage. And the damage is in many cases irreversible.
Studies conducted on animals have shown that grape seed extract does have the potential to reduce damage to kidneys, and also improve kidney function by minimizing oxidative stress & inflammatory damage (29, 30, 31).
In a study involving 23 people with chronic renal failure, daily administration of 2g of grape seed extract for 6 months decreased urinary protein by 3%. Kidney filtration was improved by 9%.
What this means is that GSE improved the filtration function of the kidneys compared to the kidneys of subjects in the placebo group (32).
Grape seed extract inhibits infectious growth
GSE has very potent antifungal and antibacterial properties.
Research has shown that the antibacterial properties of grape seed extract are so potent that they can inhibit the growth of E. coli and Campylobacter. Both can cause abdominal upset and severe food poisoning (33, 34).
In laboratory studies, grape seed extract has been found to inhibit up to 43 strains of Staphylococcus aureus (35).
Candida is a fungus that causes thrush or candida overgrowth. GSE is a common remedy for candida.
In a particular study, mice infected with vaginal candidiasis received an intravaginal solution of grape seed extract every 2-8 days. The infection slowed down after 5 days and resolved after 8 days (36).
However, there are no human studies on GSE’s ability to treat infections.
Other benefits include:
- Anti-cancer effects
- Protection of the liver against drug-induced damage and toxicity
- Enhances the appearance and healing of wounds
Does grape seed extract have any side effects?
Generally, GSE is safe. It has very few side effects.
Studies have shown that humans can tolerate the dosages of 300-800mg for 8-16 weeks (4).
However, people who are breastfeeding or pregnant should avoid GSE, as there is not much data on its effect on these populations.
A grape seed extract has blood-thinning effects, and blood pressure reducing effects, so you should be cautious when taking blood pressure medications or blood-thinning medications (4, 6, 7). Also, it reduces iron absorption and also improves drug metabolism and liver function. You must seek the consent of your healthcare provider before you take grape seed extract supplements (37, 38).