Black grapes are small, sweet fruits — famous for their intense blueish-purple color that makes them look almost black.
Their unique color comes from their high concentration of anthocyanins, an antioxidant responsible for the color of other black, purple, and blue fruits and veggies. Anthocyanins also give color to foods like blackberries, blueberries, eggplant, and purple cauliflower.
Multiple varieties are available, including seeded and seedless types, most of which are primarily used to make red wine.
However, black grapes can also make a nutritious snack or dessert.
The first obvious health benefit from black grapes is their nutrition profile. A one-cup serving (138 grams) of seedless black grapes provides:
- Calories: 90
- Carbs: 24 grams
- Fiber: 1 gram
- Protein: 1 gram
- Fat: 1 gram
- Vitamin C: 17% of the Daily Value (DV)
- Vitamin A: 11% of the DV
- Iron: 2% of the DV
Like most fruits, black grapes are primarily a source of carbs and provide virtually no fat and protein. Yet they are good sources of vitamins C and A.
Vitamin C is a water-soluble vitamin that your body uses to improve iron absorption, produce collagen, and boost your immune system. It is also a potent antioxidant that may help prevent some chronic diseases.
On the other hand, vitamin A is a fat-soluble vitamin involved in your body’s immune function, cell growth and development, and eye health.
Black grapes are primarily a source of carbs. They provide a good amount of vitamins C and A as well.
Aside from their high vitamin C content, black grapes are packed with multiple antioxidants.
Antioxidants are compounds that help fight oxidative stress, which occurs when there’s an excessive amount of free radicals in your body. Oxidative stress plays a major role in the promotion of chronic illnesses like diabetes, heart disease, and cancer.
Black grapes contain considerable amounts of polyphenols, a category of compounds with strong antioxidant capacities.
As mentioned before, the characteristic color of black grapes comes from their anthocyanin content — the main type of polyphenols present in the fruit.
Another essential antioxidant found in black grapes is resveratrol, which is known for its purported anti-cancer, anti-inflammatory, and anti-aging benefits.
As you can imagine, most of black grapes’ antioxidants are concentrated in their peels, which contain significant amounts of other antioxidants, including catechins and epicatechins, caffeic acid, catechin gallate epicatechin, and gallic acid.
Grape seeds are also rich in these beneficial compounds.
Black grapes are rich in polyphenols, namely anthocyanins and resveratrol, which provide strong antioxidant properties that may help fight oxidative stress and prevent chronic diseases.
The antioxidant properties of anthocyanins and resveratrol have been associated with a reduced risk of heart disease. Therefore, adding black grapes to your diet may support the health of your heart .
For instance, anthocyanins may protect you against atherosclerosis — the buildup of plaque in your arteries — by reducing oxidative stress and inflammation.
In addition, they may reduce arterial stiffness, leading to improved blood flow and reduced blood pressure. Anthocyanins may also reduce both total and bad — LDL — cholesterol levels.
As for resveratrol, test-tube and animal studies suggest it may also improve your blood vessels’ functioning. Moreover, resveratrol may prevent inflammation and inhibit plaque buildup, potentially reducing your risk of atherosclerosis and stroke as well.
Anthocyanins and resveratrol in black grapes may reduce the risk of heart disease by protecting against atherosclerosis and lowering blood cholesterol levels.
Polyphenols in black grapes may also provide anti-diabetic effects that may help manage your blood sugar levels.
Diabetes is characterized by constant high blood sugar levels and an impairment in your ability to regulate insulin production.
Test-tube studies show that resveratrol may activate a protein called sirtuin 1 (SIRT1), which reduces insulin resistance.
Additionally, animal studies suggest that resveratrol may also decrease insulin resistance and improve your body’s insulin secretion. This may help alleviate your diabetic-related complications.
Furthermore, human studies reveal that resveratrol may also improve your ability to regulate your blood sugar control and reduce insulin resistance if you live with type 2 diabetes.
However, more clinical studies are needed to fully understand the effects of resveratrol on blood sugar control as the evidence from current studies is inconsistent.
Resveratrol in black grapes may help improve blood sugar control and reduce insulin resistance, but more research is needed.
Again, resveratrol and anthocyanins may provide black grapes with cancer-fighting properties.
Research shows that both antioxidants may help fight cancerous cells by preventing tumor growth and spread, which affects how cancer develops.
These antioxidants may also induce cell apoptosis — the programmed death of cancerous cells.
Test-tube studies show resveratrol’s anticancer effect against various cancers, including stomach, breast, liver, thyroid, ovarian, and prostate cancers.
Similarly, test-tube and animal studies support the cancer-fighting effects of anthocyanins against gastric, skin, colorectal, cervical, and breast cancers.
However, large human studies do not show a lower risk of most human cancers after taking anthocyanins. Therefore, further research is still needed to determine whether consuming black grapes can prevent cancer.
Black grapes’ antioxidants may prevent the growth and spread of various cancers. Yet more research on humans is still needed.
Again, antioxidants in black grapes may deliver a couple more health benefits, such as improving your hair and skin and offering some antimicrobial properties.
However, these benefits have not been as extensively researched as those mentioned throughout this article.
Nevertheless, here’s what science has to say:
May boost skin health
Research suggests that antioxidants such as anthocyanins in black grapes may not only be efficient against skin cancer but also in the treatment of minor skin problems such as acne.
In addition, black grape antioxidants may also protect against the damaging effects of which often include sunburn, edema or water retention, hyperpigmentation, and skin cancer .
UV radiation also leads to the production of free radicals and oxidative stress, UV radiation exposure, which may lead to premature skin aging — marked by wrinkling, skin dryness, or the appearance of fine lines.
While grapes and their by-products are considered for herbal cosmetic formulations, most of their effects rely on their direct application onto the skin instead of eating the fruit.
Simply, eating black grapes may not show the same potential as topical creams when it comes to improving your skin health.
May provide antimicrobial properties
Antioxidants present in black grapes’ skin may act as antimicrobial agents that can fight the growth of antibiotic-resistant harmful bacteria and toxin-producing molds.
Test-tube studies show that the antibacterial activity significantly inhibited the growth of bacteria responsible for foodborne illnesses, such as Staphylococcus aureus, Enterococcus faecalis, and Enterobacter aerogenes.
Similarly, their antifungal activity seems to be effective against toxin-producing molds such as Penicillium chrysogenum, Penicillium expansum, Aspergillus niger, and Aspergillus versicolor .
However, studies on whether eating the fruit would lead to the same effects are lacking.
May promote hair growth
Test-tube, animal, and human studies suggest that resveratrol may promote hair growth.
Evidence shows that the antioxidant may stimulate the transition of the hair cycle from the telogen phase — also known as the resting phase — into the anagen phase, or the active growth phase, thus inducing hair growth.
It may also protect your hair follicles from oxidative stress and increase your hair density.
Animal studies even show that resveratrol may increase the number of hair follicles in young rodents’ skin.
Nevertheless, these effects also rely on resveratrol being applied directly onto the skin. Therefore, research on the direct impact of eating black grapes on hair growth is still needed.
Test-tube, animal, and some human studies support the effects of black grapes’ antioxidants on skin and hair health and their antimicrobial properties. However, further research on the direct impact of eating black grapes is still needed.
Like most grapes, black grapes’ benefits almost exclusively come from their high antioxidant content, namely anthocyanins and resveratrol.
Some of the most widely studied benefits of these compounds in black grapes include their beneficial effects on your heart’s health, your ability to regulate your blood sugar, and perhaps even your ability to combat cancer cell growth.
While some research supports their benefits on skin, hair, and antimicrobial properties, more research is still needed.