Grape Seed Extract: Benefits, Usage, & Side Effects

Disclaimer: This article is a review of the various properties, studies, and potential effects of grape seed extract. The information presented is based on existing scholarship and is not a direct reflection the beliefs of Old School Labs.

Key Takeaways

1. Organic solvents are mixed with leftover grape skin and seeds to create grape seed extract. It has antibacterial, antifungal, antioxidant, and antifungal properties.
2. The extract is used as a supplement and can be found in liquid, capsule, tablet, and powder forms.
3. There are a host of potential health benefits seen from GSE usage, including bone and skin health, reducing cancer cells, weight loss, and improving blood pressure and blood flow.
4. Children and women who are pregnant or breastfeeding should avoid GSE. It’s generally considered safe otherwise, but should be avoided by those on blood thinners or taking blood pressure medicine.

Grape seed extract is made from the skin and seeds of grapes leftover from the winemaking process. Organic solvents are used to extract the polyphenols from the leftovers. 

These polyphenols contain proanthocyanidins, which is just one of the antioxidants found in grapes. Others include:

• Phenolic acids
• Anthocyanins
• Flavonoids
• Stilbenes 
• Oligomeric proanthocyanidin complexes (OPCs)

GSE can be turned into powder, liquid, or capsules for consumption as a dietary supplement. This extract has various uses and has been proven to have some health benefits.

You may see grape seed extract abbreviated to GSE, which is also the same abbreviation for grapefruit seed extract. When purchasing from retailers like Walmart or online stores, be sure you’re getting the right product before checking out.

Today, we focus on the health benefits found when supplementing with grape seed extract.

Weight Loss

If you’ve ever scrolled through weight loss supplements, you may have noticed GSE included. This is because some studies have suggested that grape seed extract can help with weight loss.

One study used mice and put them into three groups:

• Control diet
• High-fat diet
• High-fat diet plus GSE

At the end of the 12-week study, they found that the GSE group showed lower rates of weight gain than the others. The data from the study shows that grape seed extract reduces adipose tissue (body fat) mass.

It’s thought GSE reduces fat absorption in our body, allowing it to be expelled. For those who struggle with being overweight or obese because of a high-fat diet, grape seed extract might help.

A bonus to the polyphenol compounds in grape seed extract is improved gut bacteria. A healthy gut flora with beneficial bacteria is crucial for a healthy immune system. It also reduces inflammation throughout the body.

There were also other health benefits in the GSE group, which we’ll touch on in the next sections. 

Eye Health

Another benefit found when supplementing with grape seed extract is improved eye health. Inflammation can cause eye diseases such as age-related macular degeneration and diabetic retinopathy.

Researchers have shown that polyphenols from grapes can fight proinflammatory cytokines in the body. This can reduce ocular inflammation and reduce the risk of these eye diseases.

As we age, our eyesight will deteriorate. Grape seed extract can help fight free radicals and oxidative stress, improving the health of retinal cells. This could improve night vision and even lower the risk of developing cataracts.

Blood Pressure

High blood pressure is one of the leading contributors of death in the United States. HBP affects men more than women, and it’s a leading cause for stroke and heart disease. For anyone who doesn’t control their high blood pressure with medication, grape seed extract may help. 

A meta-analysis of twelve trials showed that GSE can lower both systolic and diastolic blood pressure. Participants who are young and obese or suffer from a metabolic disorder saw the greatest change.

Another study used 36 subjects who were pre-hypertensive to compare the effects of grape seed extract. The group that included GSE in juice twice daily for six weeks showed the same improvement as the meta-analysis.

If you’re already taking blood pressure medication, ask your doctor before taking GSE. It could cause spikes in blood pressure and blood flow, which could be dangerous.

Blood Flow

Increased blood flow is another suggested benefit from supplementing with grape seed extract. 

The risk of vascular disease is higher in smokers, and one study found reduced platelet activity and oxidative stress. Another study in postmenopausal women showed blood thinning, which can reduce blood clotting risks.

Living a sedentary lifestyle, which is more common in office workers, can cause leg swelling or edema. GSE was administered in a trial and women were asked to sit for six hours afterward. Water retention and swelling were minimized in those taking GSE compared to the control. 

Testosterone

While studies are recent and more will be needed, grape seed extract may help with testosterone levels. As we age, both men and women’s testosterone levels decrease. Testosterone goes through a process of aromatization where it’s converted into estrogen.

Less testosterone and more estrogen can cause an increased risk of cancer, especially breast cancer. Grape seed extract has been shown to block the aromatization process, so less testosterone is converted to estrogen.

Though dosage hasn’t been confirmed, hormone-dependent cancers could be less likely when supplementing with GSE.

Neuroprotective Properties

Brain injuries can be life-altering and sometimes cause irreparable damage. Grape seed extract has been proven to fight the effects of the trauma and suppress lipid peroxidation (cell damage).

Neurofunction is reduced when the brain is injured because of hypoxia-ischemia, or restricted blood flow. In one study, grape seed extract was shown to suppress cell damage and damaging proteins. 

A different study supports the first’s findings, showing GSE’s antioxidant power to protect from brain-damaging inflammation. 

For the neuroprotective benefits, GSE has to be administered as soon as possible once the injury has occurred. 

Alzheimer’s, memory loss, and cognitive reduction are all risk factors as we age. The same neuroprotective properties that help with brain injuries can also improve brain function in the elderly.

A study by Frontiers in Pharmacology set out to prove findings from studies in rats and mice. Patients exhibiting memory and cognitive impairments, which can lead to Alzheimer’s, were studied. 

Subjects were divided between a placebo and GSE group. Those in the grape seed extract group showed improved cognitive scores compared to their preliminary testing.

Another study done on rats suggests GSE is neuroprotective in the hippocampus, responsible for learning and memory. This one, done on mice, shows promise for polyphenols’ role in preventing and treating Alzheimer’s.

Still, more studies are needed on humans, especially those who are already suffering the neurological effects of aging. These studies can prove once and for all GSE’s ability to protect the brain.

Oxidative Damage

Oxidative damage and stress have been mentioned a few times already. Oxidation in the body can cause all sorts of damage, including:

• Plague in the arteries
• High cholesterol
• Heart disease
• Obesity

When taking grape seed extract before coronary surgery, patients had less reoxygenation injury and cellular damage compared to the control group.

High levels of LDL cholesterol can cause damage if left uncontrolled. One common consequence is atherosclerosis or plaque buildup in the arteries. GSE has been shown to reduce oxidation of LDL proteins.

Grape seed extract has also shown some benefit to those with diet-induced pancreatitis. GSE reduces oxidative stress and inflammation, reversing some effects of a high-fat diet.

Another study mentioned earlier showed some of the same results in those with pre-hypertension. 

By reducing oxidation and inflammation, grape seed extract can help the body heal from environmental and self-induced (poor eating choices) damage.

Skin & Bone Health

Another benefit from grape seed extract is improved skin health, mostly in part to the polyphenol resveratrol.

An analysis of skin disorders, grape seed extract, and resveratrol showed positive results for:

• Chloasma
• Acne vulgaris
• Skin aging
• Wound and facial redness
• Hyperpigmentation 

Grape seed extract has been used to speed up wound healing and reduce the appearance of scars. It also has anti-aging properties when used as a topical cream or powder.

When paired with a high calcium diet, grape seed extract may also improve bone density and strength.  Over time, a lack of calcium can cause brittle bones, but supplementing with GSE may reverse the damage.

In chronic rheumatoid arthritis, inflammation can degrade bone and joint density and increase cartilage loss. GSE has shown success in preventing degradation and alleviating symptoms. 

It can also prevent hydrogen peroxide production, which can destroy collagen, cartilage, and bone over time. For those suffering from chronic inflammation, skin disorders, or bone and cartilage loss, GSE may help where other therapies fall short.

Harmful Bacteria

It seems that all too frequently, we’re notified of another E. coli bacteria outbreak in food production. The antibacterial and antifungal properties of grape seed extract have proven to stop the growth of this and other harmful bacteria.

Avoiding toxins as much as possible in food growth and production is expected for the health of consumers. Grape seed extract can stop both E. coli and Campylobacter bacterias, another contributor to foodborne illness.

Some forms of Staphylococcus aureus (MRSA) are drug-resistant, but grape seed extract could be an alternative. A study found GSE to inhibit 43 different strains of the MRSA bacteria from growing.

Candida, or yeast, overgrowth can happen in both men and women, though is more common in women. The antifungal properties in GSE may control the growth, though more studies are needed.

Interacting with Cancer Growth

Most studies have been done on animals and in test tubes, but show promise for GSE’s effects on cancer cells. It’s antioxidant properties and compounds are being studied for the following cancers:

• Tongue squamous cell carcinoma
• Colorectal cancer
• Pancreatic cancer
• Liver cancer

Grape seed extract could also partner with chemotherapy, helping it target cancer cells better than chemo alone. While results are promising in animal tests, humans will need to undergo trials to see if they have the same results.

Who Should Avoid Grape Seed Extract?

Not everyone can use grape seed extract without having side effects. Grape seed extract has interactions with certain medications, especially blood thinners like warfarin and aspirin.

Anyone who has a bleeding disorder should avoid grape seed extract. If you are going to have surgery in the near future, you should also avoid it in the weeks leading up to surgery.

Those who are taking blood pressure medication should avoid GSE. The increases in blood flow could cause high blood pressure readings. Iron absorption may also be reduced when taking grape seed extract.

Long-term studies have not been done on potential side effects or contraindications of GSE. It is generally considered safe but should be avoided by children and pregnant or breastfeeding women.

If you are allergic to grapes, avoid using GSE. There are some mild side effects noted in some studies, including:

• Nausea
• Itchy scalp
• Dizziness
• Headache 

Before starting this supplement, be sure to let your doctor know our plans so you know it’s safe to use.

The Bottom Line

Grape seed extract has antioxidant power that reduces cell damage, oxidation, and inflammation in the body. It has properties that are considered antifungal, antibacterial, anti-diabetic, anti-cholesterol, and anti-platelet.

GSE can help improve skin, bone, and eye health, while also protecting the brain as we age. It also may stop some cancers from forming, protect the liver, and regulate testosterone levels. Not everyone can use grape seed extract and you should always consult your doctor before trying a new supplement. 

Speaking about boosting immunity and reducing stress, try Classic Immunity. It was formulated specifically for athletes and those who are active to support their systems in easy-to-digest capsules.

Have you tried grape seed extract? Which benefit are you hoping to get out of it, and what’s your experience with using it? Let us know how it’s working for you in the comments below.