Grapes provide a variety of important nutrients and powerful
plant compounds that benefit your health. Although they contain sugar,
consuming them in moderation does not seem to negatively affect blood sugar
control.
People have been growing grapes for thousands of years,
including several ancient civilizations, who are revered for their use in
winemaking. Grapes are also a quick and delicious snack that you can enjoy at
home or on the go.
You may find that they come in a variety of colors,
including green, red, black, yellow, and pink. They also come in many forms,
from raisins to jelly to juice. Seeded and seedless varieties also exist.
Grapes offer a wealth of health benefits, mainly due to
their high nutrient and antioxidant content.
Here are the top 16 health benefits of grapes.
1. Rich in nutrients
Grapes are rich in a variety of important nutrients. Just
1 cup (151 g) of red or green grapes can be served (1):
- calories: 104
- carbohydrates: 27 g
- protein: 1 g
- fat: 0.2 g
- fiber: 1.4 g
- COPPER: 21% OF THE DV DAILY VALUE
- Vitamin K: 18% of DV
- Thiamine (vitamin B1): 9% of DV
- Riboflavin (vitamin B2): 8% of DV
- Vitamin B6: 8% of DV
- potassium: 6% of DV
- Vitamin C: 5% of DV
- manganese: 5% of DV
- Vitamin E: 2% of DV
As you can see, grapes are rich in copper and vitamin K. Copper
is an essential mineral involved in energy production, while vitamin K is
essential for blood clotting and healthy bones (2, 3).
Grapes also provide a large number of B vitamins such as
thiamine, riboflavin and B6. Growth and development require thiamine and
riboflavin, while protein metabolism mainly requires B6. （4, 5, 6）。
Summary: Grapes contain many important
vitamins and minerals, including copper and vitamins B and K.
2. May contribute to heart
health
Grapes can promote heart health in a number of ways.
May help lower blood pressure
One cup (151 g) of grapes contains 6% DV potassium. This
mineral is necessary to maintain healthy blood pressure levels (1, 7).
There is evidence that potassium helps lower blood
pressure primarily by helping to dilate arteries and veins. It may also help
excrete sodium and prevent narrowing of arteries and veins that would otherwise
increase blood pressure (8).
However, a review of 32 studies determined that both low
and too high potassium intake might contribute to hypertension. Researchers
recommend sticking to the current recommended daily intake of 4.7 grams (9).
May help lower cholesterol
Compounds found in grapes may help prevent high
cholesterol levels by reducing cholesterol absorption (10).
In an 8-week study of 69 patients with high cholesterol,
eating 3 cups (500 grams) of red grapes per day helped lower total cholesterol
and LDL (bad) cholesterol levels. However, white grapes do not have the same
effect (11).
In addition, diets rich in resveratrol (an antioxidant in grapes)
(such as the Mediterranean diet) have been shown to lower cholesterol levels (12).
Summary: the compounds in grapes can prevent
heart disease by lowering blood pressure and cholesterol levels.
3. High antioxidant content
Antioxidants are compounds that help repair the damage
done to cells by free radicals— harmful molecules that cause oxidative stress. Oxidative
stress has been linked to a variety of chronic health conditions, including
diabetes, cancer, and heart disease. (13）。
Grapes are rich in powerful antioxidants. The highest
concentration of antioxidants is found in the skin and seeds. However, a
variety of factors may affect its concentration, including grape variety,
ripeness, post-harvest storage, and environmental factors (14).
Interestingly, these beneficial compounds persist even
after fermentation, which is why wine is also a source of antioxidants (14, 15).
Some grape varieties contain higher levels of
anthocyanins, a class of flavonoids that give these fruits orange, red, blue,
pink and purple colors. Human and animal studies have shown that anthocyanins
may help prevent or treat brain and heart disease (14, 15).
Other important antioxidants in this fruit are resveratrol
and quercetin, which can prevent heart disease, high blood sugar and cancer. (14, 16）。
Grapes also contain vitamin C, β-carotene, lutein and
ellagic acid, which are also powerful antioxidants (14).
Summary: grapes are rich in antioxidants, and they
are beneficial plant compounds that can prevent chronic health conditions.
4. May have anti-cancer effects
Antioxidants in grapes can prevent certain types of
cancer (14).
Resveratrol is an antioxidant in this fruit that can help
reduce inflammation, act as an antioxidant, and stop cancer cells from growing
and spreading in the body. In fact, its effects on a variety of cancers have
been studied (17, 18, 19, 20).
Grapes also contain quercetin, anthocyanins, and catechin
antioxidants—all of which may have anti-cancer effects (21).
Test-tube and animal studies have shown that grape extract
may block the growth and spread of human colon cancer cells and breast cancer
cells (22, 23, 24).
In addition, a 2-week study of 30 people found that people
over the age of 50 who ate 0.3-1 pound (150-450 grams) of grapes per day had a
lower risk of developing colon cancer (25).
While research that is more human is needed, diets rich in
antioxidant foods, such as grapes, have been linked to a lower risk of cancer (26).
Summary: antioxidants in grapes can prevent
the growth and spread of many cancers, despite the lack of human research.
5. Can prevent diabetes and lower blood
sugar levels
Grapes contain 23 grams (151 grams) of sugar per cup,
which may make you wonder if they are a good choice for people with diabetes (1).
If you look at their Glycemic Index (GI) scale —, which
measures how quickly food raises blood sugar — you'll see that it ranges from
49 to 59, depending on the grape variety (27, 28).
Similarly, the definition of low GI varies depending on
the source—some consider under 55 to be low, while others consider under 50 to
be low (27, 28).
THIS MEANS THAT THE GI SCORES OF THE GRAPES MAY RANGE FROM
LOW TO MEDIUM, IN WHICH CASE THEY MAY RAISE YOUR BLOOD SUGAR LEVELS AT A SLOW
OR MODERATE RATE, BUT NOT NECESSARILY SOAR.
HOWEVER, KEEP IN MIND THAT EATING TOO MANY LOW-GI FOODS
HAS THE SAME EFFECT ON BLOOD SUGAR AS EATING HIGH-GI FOODS. THEREFORE, IT IS
BEST TO EAT GRAPES IN MODERATION.
In addition, compounds found in grapes may help improve markers
of insulin response.
In a review of 29 studies in 1,297 adults, grape and grape
supplementation significantly reduced the so-called Insulin Resistance
Homeostasis Model Assessment (HOMA-IR), a measure of insulin resistance. (29）。
In particular, the compound resveratrol can be passed
through (30, 31, 32):
- reduces
insulin resistance
- increases
insulin sensitivity
- protects
insulin-producing pancreas β cells
- improve
insulin production
- increase
the number of glucose receptors on the cell membrane
Managing blood glucose levels over time is important to reduce
diabetes risk and prevent diabetes-related complications.
Summary: Although grapes are high in
sugar, if you have diabetes, their low to moderate GI makes them safe to eat in
moderation. In addition, the compounds in grapes can prevent high blood sugar.
6. May be beneficial for eye
health
The plant compounds in grapes can prevent common eye diseases.
For example, in a study of mice, mice fed grapes showed fewer
signs of retinal damage and better retinal function than mice that did not feed
grapes. （33）。
In addition, in a test-tube study, resveratrol was found to
protect retinal cells in the human eye from ultraviolet A (UVA) light. This may
reduce your risk of age-related macular degeneration (AMD), a common eye
disease (34).
According to one review, resveratrol may also prevent glaucoma,
cataracts, and diabetic eye disease (35).
In addition, grapes contain antioxidants lutein and zeaxanthin
that have been shown to help maintain eye health, improve visual performance,
and prevent common age-related eye diseases (36, 37).
Summary: grapes contain several
compounds — such as resveratrol, lutein, and zeaxanthin — that may help prevent
common eye diseases.
7. Can improve memory,
concentration and mood
Eating grapes can enhance memory and brain health.
In a 12-week study of 111 healthy older adults, taking 250
mg of grape supplement daily significantly improved concentration, memory test
scores compared to baseline values (38).
Another study of healthy young people showed that drinking
7.8 ounces (230 ml) of grape juice improved the speed of mood and
memory-related skills after 20 minutes. （39）。
What's more, in one study in rats, ingesting 4 weeks of
resveratrol improved learning, memory, and mood. In addition, the rat's brain
showed signs of growth and increased blood flow (40).
Finally, resveratrol can prevent Alzheimer's disease by
reducing inflammation in the brain and removing β amyloid peptide, which is
associated with the accumulation of β amyloid peptide. （41, 42）。
Summary: grapes contain compounds that improve
memory, concentration and mood, as well as prevent Alzheimer's disease.
8. May support bone health
Grapes contain many minerals necessary for bone
health, including potassium, manganese and vitamins B, C and K, which help
prevent osteoporosis, which can lead to fragile bones. （1, 43）。
In addition, animal and human studies have shown that resveratrol
can improve bone density (44, 45, 46).
For example, in an 8-week study, rats fed freeze-dried
grape powder had better bone absorption and calcium retention than rats not
taking freeze-dried grape powder. （44）。
In addition, a 2-year study in postmenopausal women showed
that taking 75 mg of resveratrol twice daily improved bone mineral density and
slowed bone loss, thereby reducing the risk of severe fractures and hip
fractures. （46）。
However, there is currently a lack of human studies.
Summary: grapes contain vitamins and minerals
that are important for bone health, although more research is needed in humans.
9. Can prevent bacteria and
fungi
Several compounds in grapes protect against harmful
microorganisms (4, 7, and 48).
For example, resveratrol has antibacterial properties that
inhibit the growth of bacteria and fungi such as campylobacter jejuni and
candida albicans. (49）。
It can also prevent foodborne illness. When added to
various types of foods, resveratrol helps prevent the growth of harmful
bacteria, such as E. coli (49, 50).
Other compounds with antimicrobial activity in grapes
include anthocyanins, which may damage the bacterial cell wall (51).
Finally, grapes are a good source of vitamin C known for
their benefits to the immune system (1, 52).
Summary: grapes contain several compounds that
may be beneficial to harmful bacteria and fungi.
10. Can slow down the signs of
aging and promote longevity
The plant compounds in grapes may affect aging and
longevity.
studies have shown that resveratrol can delay signs of
aging by mimicking the beneficial effects of calorie restriction, such as
reducing oxidative stress, enhancing stress resistance, and improving the
inflammatory response. （53, 54）。
Keep in mind that these benefits have only been seen in
animal studies.
In addition, resveratrol activates the SirT1 gene, which
is activated by a low-calorie diet and is associated with longer lifespan. （55, 56）。
Resveratrol also activates sirtuin, a protein that
regulates cellular processes such as senescence and cell death. （57）。
Summary: resveratrol, found in grapes, has
been shown to activate genes associated with slower signs of aging and longer
lifespans.
11. Can reduce inflammation
While low levels of inflammation are a typical physical
response, chronic inflammation plays a key role in the development of long-term
health conditions such as cancer, heart disease, diabetes, arthritis, and
autoimmune diseases. （58）。
It is worth noting that the anthocyanin and resveratrol
compounds in grapes are associated with powerful anti-inflammatory properties. （51, 59）。
Studies have shown that both compounds can inhibit the
expression of inflammatory markers, such as tumor necrosis factor-α (TNF-α) and
interleukin-6 (IL-6) (60, 61).
However, there is a lack of research involving the grapes
themselves.
Summary: grapes contain compounds with
anti-inflammatory effects that in turn prevent chronic diseases.
12. May benefit skin and hair
health
Resveratrol may have many protective effects on your
skin and hair.
In fact, this compound is popular in cosmetics because it
penetrates the skin barrier and increases collagen concentration, and protects
against UV damage caused by sun exposure. （62, 63）。
Animal studies have shown that the effect of resveratrol on
collagen production may promote faster wound healing. （63）。
Because oxidative stress and inflammation play a role in
hair loss, research suggests that resveratrol may also promote hair growth (64).
First, resveratrol protects hair follicles from
environmental damage. It also promotes a rapid increase in important follicular
cells that promote hair growth (64).
However, there is a lack of research on the effects of
eating grapes on skin and hair.
Summary: the antioxidant resveratrol in grapes
can protect your skin from damage and promote hair growth, but more research is
needed.
13. There may be anti-obesity
effects
Obesity may increase your risk of developing a variety of
health conditions, including diabetes, heart disease, and cancer (65).
It is worth noting that the anthocyanins in grapes may
have anti-obesity effects. Studies conducted on rats fed a high-fat diet have
shown that anthocyanins can inhibit weight gain and reduce liver fat content. （60）。
In addition, studies of animals have found that
proanthocyanidin extracts in grape seeds may increase levels of the satiety
hormone GLP-1, which may reduce appetite and reduce food intake. （65）。
Still, there is a lack of human research.
Summary: antioxidants in grapes can fight
obesity by suppressing appetite and preventing weight gain. However, there is a
lack of research on humans.
14. Can relieve constipation
Constipation includes less bowel movements than usual and
feelings of incomplete bowel movements (66, 67).
Dietary changes such as increased fiber and fluid intake
are critical for treatment because dehydration is a common secondary cause of
constipation (67).
Fiber in whole fruits such as grapes can significantly
improve symptoms of constipation compared to fruit juice because it can reduce
the time it takes for stools to pass through the colon, as well as increase
fecal weight and daily bowel movements. （68）。
In addition, grapes are 81% hydrated, so they can help you
reach your hydration goals (1).
Summary: as
a good source of water and fiber, grapes may help relieve constipation.
15. Sleep may be supported
There is evidence of a direct link between diet and sleep
(69).
In fact, research has determined that grapes are a natural
source of melatonin as a sleep-promoting hormone that regulates your sleep-wake
cycle (69, 70, 71).
Interestingly, melatonin is mainly found in grape skins,
which is why it is also found in products such as grape juice and wine (69).
Since melatonin is closely related to your internal clock,
timing of intake is an important factor to consider. If you are eating grapes
to help you fall asleep, eat them in the evening.
Summary: grapes are a natural source of
melatonin, a hormone that improves sleep quality.
16. easy to add to your diet
Grapes are delicious, versatile and easy to incorporate
into a healthy diet. Here are some ways to enjoy them:
- Eat your own
grapes as a morning or afternoon snack.
- Blend with spinach, cucumber, banana,
kale and peppermint to create a nutrient-rich smoothie.
- Serve with crushed nuts and a pinch of
honey on top of your favorite yogurt.
- Enjoy frozen grapes as a refreshing
summer delicacy.
- Add chopped grapes to the salad of your
choice.
- Paired with apple slices, strawberries
and dark chocolate, it is a sweet and healthy dessert.
- Drink 100% grape juice.
- Enjoy red wine in moderation.
Summary: grapes are easy to eat as a snack or
add to your meals. Moderate amounts of grape juice and red wine may also bring
benefits.
Fresh grape fruit with grape
juice
Both grapes and grape juice have multiple health benefits,
but the whole fruit is generally healthier.
This is partly because the grape juice production process–
which includes heating the juice to avoid fermentation – may reduce its
antioxidant content by 44% (72, 73).
In addition, fruit juices are virtually fiber-free and
have a higher sugar content compared to whole fruits.
There is evidence that a diet that includes whole fruits
rather than juice is more effective for weight management for the following
reasons: (68):
- blood sugar
levels rise more slowly, preventing your blood sugar and insulin levels
from soaring and collapsing
- delays gastric emptying, increases
satiety and reduces food intake
In addition, there is evidence that only about 5% of Americans
meet the recommended fiber intake, with men and women 38 grams per day and 25
grams per day (74).
Therefore, you should eat as many fresh grapes as possible
instead of drinking grape juice.
Summary: while whole grapes and grape juice
provide multiple nutrients, eating fresh fruit ensures more fiber and
antioxidant intake while reducing sugar intake.
Are wines good for health?
Like whole grapes and grape juice, wine is a good source
of antioxidants and provides many health benefits (75).
In fact, studies have shown that moderate wine intake can
prevent heart disease, diabetes, and even cancer (75, 76, 77).
Keep in mind, however, that heavy drinking—defined as more
than four drinks a day—is associated with an increased risk of death and heart
disease (78, 79).
Current U.S. dietary guidelines recommend limiting your
alcohol intake to 1 cup per day for women and 2 cups per day for men. For
reference, every 5 ounces (150 ml) of wine equals 1 drink (79).
However, while moderate wine intake can have a positive
effect on your health, just like grape juice, it lacks the fiber content of
whole grapes.
Summary: like whole grapes, wine is a good
source of antioxidants, and it offers multiple health benefits. However,
excessive intake can lead to harmful health effects.
Bottom line
Grapes provide a variety of important nutrients and powerful plant compounds that benefit your health. Although they contain sugar, consuming them in moderation does not seem to negatively affect blood sugar control.
Antioxidants like resveratrol provide most of the benefits
of grapes, including their anti-inflammatory, anti-diabetic and anti-cancer
properties.
They are also delicious and easy to add to your diet. For
maximum benefit, choose fresh grapes instead of grape juice or wine.