Resveratrol: Benefits, Side Effects, Dosage

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What is Resveratrol?

Resveratrol is a naturally occurring chemical mostly present in grape products such as red wine, purple grape juice, red grape juice and grape skin. It is also present in small quantities in peanuts, blueberries, mulberries and raspberries. Resveratrol is mainly present in the skins and seeds of grapes and berries.

The chemical, classified as a polyphenol, is the plant’s natural defensive response to damage or invasion by pathogens and disease-causing microorganisms. The consumption of resveratrol as a dietary supplement offers many benefits, such as boosting overall health and promoting longevity.

How It Works

Discovered only a century ago, resveratrol still earned a significant role in traditional medicine for many ancient tribes, including the Chinese and other African and Asian colonies.

Wine, specifically from rich red grapes, was not just a drink, but also a medicinal beverage. This is one reason why it was only available to the royals and wealthy merchants of the past. The chemical was also present in the roots of the Japanese knotweed, which often treated different conditions and ailments including liver and heart diseases.

The first modern-day discovery and mention of resveratrol came in 1939 by Japanese scientist Michio Takaoka. Takaoka managed to isolate it from the roots of the Japanese white hellebore. The discovery of knotweed occurred later around 1963. Resveratrol has since been studied, and several attempts to extract it and commercialize it as a polyphenol supplement have been made over the years.

The French Paradox

As the studies on resveratrol advanced, scientists observed that French people consumed significant amounts of saturated fats in their traditional cuisines, yet they still managed to stay very fit and slim. This stereotype was propagated and one Dr. Serge Renaud quickly coined it as the French Paradox.

In that regard, scientists and doctors directed some attention to their general lifestyle and discovered that they consumed a lot of alcohol. Red wine was found to be the prevalent type, and from that, the belief that resveratrol wine could help in weight loss was born (x).

Types of Resveratrol

There are two types or resveratrol; trans-resveratrol and cis-resveratrol. This article will be referring to the former for the most part.

Trans-resveratrol is the beneficial kind that comes from the skins of grapes and berries. When in contact with oxygen, it transforms into cis-resveratrol. In this form, it may not have any use to the body. There is, however, more research pending to distinguish one over the other in terms of benefits as well as efficiency (x).

How Resveratrol Works

Most animals, including humans, have a gene referred to as Sirt 1. It usually becomes activated when the body is undergoing a calorie-restricted diet. In such circumstances, many free radicals may oxidize — a process that may cause significant levels of inflammation in the body. Sirt 1 comes into play to protect the DNA and the body cells from this oxidation and minimize inflammation. This helps the body cells live for longer; a concept believed to promote longevity.

Resveratrol works by boosting the levels of the gene and helping them do their work. It also interacts with mitochondria (the cell organelles that provide energy) to increase the aerobic capacity and boost the process of oxidative phosphorylation. This could potentially protect the body from diet-induced obesity as well as insulin resistance (x).

Resveratrol Benefits

Lowers Blood Pressure

Resveratrol has very high antioxidant properties, which makes it an ideal solution for reducing blood pressure. As one ages, their arteries tend to become stiffer. This makes them more narrow, which increases the force exerted on the vessels as blood flows to and from the heart. Needless to say, this has adverse effects on the circulatory health of the individual, including stroke and, in extreme cases, death.

An analysis in 2015 found that high doses of the chemical could help to reduce this pressure (x). This occurs through the production of nitric oxide, which causes relaxation of blood vessels. It minimizes the stiffening and widens the arteries, which consequently leads to lower blood pressure.

More research, however, is necessary to establish the correct amounts of the chemicals needed to produce the desired effects.

Reduces Joint Pains

One of the major causes of joint pain is the breakdown of bone cartilage. In some extreme cases, the pain can be crippling and even lead to a loss of mobility in patients.

A study conducted on rabbits with arthritis showed that by injecting resveratrol into their knee joints, they suffered less deterioration of the cartilage (x). This suggests that the plant supplement could help in reducing inflammation to the joints while preventing further damage.

Positively Impacts the Blood Fats

In 2016, a study was conducted on healthy mice. The mice were fed diets with high amounts of proteins and unsaturated fats. They were also given resveratrol supplements and observed. After some time, the researchers found that the mice displayed a significant reduction in total amount of cholesterol as well as their body weight — this made resveratrol weight loss a good possibility (x).

Their levels of high-density cholesterol, often referred to as the ‘good cholesterol’ also increased (x).

In that regard, resveratrol may be one of the best polyphenols supplements for reducing the levels of ‘bad’ cholesterol. It does this by regulating both the production and functioning of the enzyme responsible for producing cholesterol. It also reduces the oxidation of the cholesterol that builds up to form plaque of artery walls.

Helps Manage Diabetes

People with diabetes often suffer the effects of sorbitol, a sugar alcohol which, in excess, causes oxidation in the cells. This damages them gradually. Resveratrol may relieve this by slowing down and stopping the enzyme responsible for the conversion from glucose to sorbitol (x).

Promotes Longevity

As mentioned above, resveratrol may be accountable for activating SIRT 1, the gene that protects the DNA and body cells from harmful oxidation and inflammation. This helps them live longer, increasing the age of the animal or person (x).

This research, however, was conducted on animals like rats, and the results showed that the lifespan increased in about 60 percent of the organisms studied. The effect only got stronger in organisms less related to humans, so there is no concrete evidence that resveratrol would have similar results in people (x).

Helps to Prevent Alzheimer’s

According to a number of studies, resveratrol may be beneficial in protecting the brain from Alzheimer’s. Researchers suspect that the supplement plays a significant role in interfering with the production and functioning of beta-amyloid. These protein fragments play an active part in the formation of the dreaded plaques that cause Alzheimer’s (x).

Also, the anti-inflammatory, as well as the anti-oxidation activities of resveratrol, are crucial in protecting the brain cells.

Resveratrol as Cancer Treatment

Studies have revealed that resveratrol has the potential to fight the growth of cancer cells, which is useful in preventing types such as colon and gastric cancer. Mainly, the supplement may help in battling cancer by inhibiting the growth and replication of the cells.

It can also alter the expression of genes and the production of hormones that spread cancer in the body. These studies, however, have not been carried out in humans, which shows that more research is required to establish the potential of resveratrol in fighting cancer (x).

resveratrol benefits

Resveratrol Side Effects

Generally, resveratrol is safe if taken in small amounts, particularly in those found naturally in foods. Some side effects that may result from too much resveratrol include:

  • Itchiness or a mild rash that may reduce after discontinuation
  • Increased frequency of bowel movements
  • Diarrhea
  • Weight loss
  • Nausea

While there are no special risks associated with taking resveratrol, it is important to note that there are no standard doses recommended to attain any health benefits. Take proper precautions when administering the supplement, particularly for someone who is also taking other medicines.

  1. Anti-coagulants and anti-clotting drugs: Test-tube studies have found that resveratrol reduces blood clotting. If you are on any anti-clotting medication, you should consider taking it in small doses or avoiding it altogether as it could increase bleeding or bruising.
  2. Medicines such as blood-pressure prescriptions and anti-depressants: Resveratrol may also slow down or stop the functioning of certain hormones in the body. These could be the ones responsible for removing certain chemicals and compounds from the body. It is, therefore, wise to avoid it if on medication as the drugs could build up to dangerous levels (x).


It is best to take resveratrol in small amounts before and after surgery as it prevents blood from clotting, which increases bleeding. It should also be taken in controlled amounts by people suffering from any bleeding disorders for the same reasons.

When taken in small amounts during pregnancy and breastfeeding, resveratrol is safe. Of course, wine should not be the source. It has been observed to act like the hormone estrogen, which makes it unsafe for people with conditions sensitive to it, such as breast and uterine cancer.


It is best to take 250mg (rounded 1/8 tsp) of resveratrol two times daily. However, if your health professional suggest different dosage instructions, it is key to follow their orders.

Scientists are still working to establish a more appropriate dosage for the supplement. They are also working on a way of delivering more resveratrol in the available supplements than the current amount.

Bottom Line

Resveratrol is a chemical largely present in the skins of grapes and some berries. It offers many health benefits to those who use it as a supplement, including longevity, reduced blood pressure, preventing and reducing the spread of cancer cells as well as reducing the effects of diabetes. There is no specific dosage for the supplement. It is best to seek advice from a health professional to clarify dosage and interactions with other drugs.

About the author

Ryan Quigley

Graduate of Longwood University in Virginia. Part-time sports journalist covering the Vegas Golden Knights.

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