7 benefits and side effects of resveratrol

Veratrum became famous around the world when it was mentioned in a discussion about the French paradox in the 1990s. As we all know, the French diet is mostly high-fat food, which usually makes them prone to cardiovascular diseases. But in fact, the elegant French do not have this problem. Later we learned that it is because the French are accustomed to drinking red wine, which contains our protagonist today, resveratrol. So what are the beneficial effects of resveratrol on the human body, and what are its side effects? Let’s find out together.

Since then, resveratrol has been continuously discovered to have potential health benefits, including anti-aging, anti-diabetes, anti-cancer, anti-dementia, etc., but most of them are still animal studies, and relevant human verification is still insufficient.

Resveratrol is generally divided into cis and trans isomers, but the trans isomer is more stable (Trans-resveratrol is the most common in nature), and many of its effects are only seen in the trans isomer (such as regulating inflammatory pathways and anti-proliferation). Therefore, it has become the mainstream of current health care ingredients and a major research target.

What are the scientifically proven benefits of resveratrol that are recommended?

1. Regulates blood sugar, beneficial for diabetic patients

Diabetes is the most common chronic disease, but also the easiest to prevent. However, because of this, people often take it lightly. The biggest problem with diabetes is arteriosclerosis, which not only greatly increases the risk of myocardial infarction and stroke, but also further causes renal failure if it affects the kidney microvessels. Therefore, how to control blood sugar is a matter of life and death (in the United States alone, 70,000 people die from diabetes complications each year).

In a small study, resveratrol (150 mg daily for 30 days, patented by DSM, resVida) improved blood sugar levels (down 4.2%) and insulin concentrations (down 13.7%) in overweight people.

A recent meta-analysis also found (including 11 studies with a total of 388 people) that resveratrol can improve fasting blood sugar, insulin, and glycosylated hemoglobin in patients with diabetes. The study also mentioned that the improvements in these blood sugar markers were not found in non-diabetic patients.

2. Resveratrol and weight loss

According to the World Health Organization, 2.3 billion people in the world are overweight (people over 15 years old) and 700 million people are obese.

The risks of obesity include type 2 diabetes, cardiovascular disease, high blood pressure, high blood lipids and increased incidence of various cancers.

A large-scale observational study (follow-up period of 10 years, subjects included 500,000 men and women) found that being overweight increases the mortality rate by 20% to 40%, which is 2 to 3 times that of people with normal weight.

A systematic review (7 studies with 208 participants) found that oral resveratrol had no significant effect on weight management, reduction of adipose tissue, or abdominal obesity in overweight subjects (however, the only positive result was that resveratrol could reduce inflammatory markers (IL-6)).

The researchers believe that weight loss is a gradual process. Considering the limitations of small sample size, heterogeneity, and short experimental period (mostly less than 90 days), further confirmation is needed in the future.

3. Reduces risk of cardiovascular disease

Cardiovascular disease, generally known as heart disease, is mainly caused by insufficient blood flow leading to hypoxia of heart tissue. The reason why cardiovascular disease is so scary is that most of the time there are no symptoms, but once it occurs, the mortality rate is as high as 30%, which is very unprepared.

Among them, coronary heart disease (i.e. angina pectoris and myocardial infarction) is the most common one, which is common in men aged 40 to 60 and mostly occurs in women after the age of 50. It is the main cause of sudden death (accounting for about 70% of the total deaths from heart disease).

In a 6-month study of 34 patients with metabolic syndrome, it was found that taking resveratrol (100 mg daily) improved endothelial cell relaxation, an indicator of vascular health, compared with a placebo group, but other blood values ​​did not change.

In addition, a double-blind controlled study (sample size 75 people, experimental period of one year) found that taking resveratrol can not only significantly improve a variety of inflammatory factors, including C-reactive protein (CRP) and tumor necrosis factor (TNF-α), but also reduce the factor that causes blood clots: plasminogen activator inhibitor type 1 (PAI-1), which may be used as a golden ingredient for preventing cardiovascular disease.

4. Improves cognitive function (may help with dementia)

Generally, the brain will have more than one aging path. As we enter old age, if our physical and mental conditions are normal, cognitive function usually begins to decline after the age of 80 under normal aging. The other pathway is related to dementia, which is characterized by the destruction of brain cells. Over time, it can easily lead to memory and cognitive impairment, and even inability to take care of oneself.

The most common dementia in the elderly is: The main pathological feature of Alzheimer's disease is the accumulation of beta-amyloid protein outside nerve cells, which causes abnormal cell function and necrosis, and the other is the tangle of nerve fibers formed by excessive aggregation of tau protein.

Animal experiments have found that giving mice resveratrol can not only prolong their average lifespan, but also reduce the aggregation of beta-amyloid protein and tau protein, and has the effect of protecting nerve cells and slowing down cognitive degeneration, but relevant human research has yet to be confirmed.

In a small study of overweight adults aged 50 to 75, taking resveratrol (200 mg daily for 26 weeks) not only improved blood sugar metabolism and body fat, but also helped improve memory performance (more words were recalled after hearing them 30 minutes earlier) and hippocampal connectivity, an important area for forming long-term memories.

5. Good for age-related macular degeneration

Choroidal neovascularization is the most complex complication of macular degeneration (wet lesions). These newly formed abnormal blood vessels often lead to macular edema, retinal pigment epithelial cell degeneration and even retinal detachment. If not treated in time, it may cause blindness in the worst case.

Vascular endothelial growth factor (VEGF) inhibitors are currently the main treatment for wet macular degeneration, which can slow down abnormal angiogenesis and vision deterioration.

A preliminary study found that resveratrol has the ability to inhibit vascular endothelial growth factor VEGF, thereby slowing down choroidal neovascularization (induced by the inflammatory hormone TGF-β or tissue hypoxia), which may improve the progression of macular degeneration.

Additionally, other small studies have found that resveratrol (one hour after taking it) helps increase choroidal thickness (which increases blood flow and can slow the risk of macular degeneration) compared to a placebo.

However, to date, no research has directly confirmed the relationship between resveratrol and age-related macular degeneration, so further confirmation is needed.

6. Extending animal lifespan

So far, the scientific community believes that the most effective way to extend human life is through calorie restriction, that is, limiting daily calorie intake by 20-40%. However, under the condition of balanced nutrition, in many studies, restricting calorie intake in various species has also been shown to significantly extend lifespan (up to 60%). Although long-term studies on humans have not yet been released, preliminary evidence can determine that the results should be close to the truth.

A six-month human study found that following a calorie-restricted diet lowered several values ​​related to longevity, including insulin levels, body temperature, and DNA damage, helping to reduce the incidence of metabolic syndrome, cardiovascular disease, and cancer.

Some studies have found that resveratrol has disease-fighting and life-extending mechanisms similar to those of calorie restriction (it can activate the sirtuin 1 longevity gene).

Therefore, in an animal control study (both groups were fed high-calorie food), the experimental mice that took resveratrol could significantly increase their survival rate and reduce their mortality rate by 31% (in addition, it also increased insulin sensitivity, lowered blood sugar, increased mitochondrial production capacity, improved activity, etc.)

However, the longevity effect of resveratrol on humans has not yet been determined, so it still needs to be confirmed by more large-scale and precisely designed studies in the future.

7. Ulcerative colitis

Ulcerative colitis is a type of inflammatory bowel disease. Its main clinical symptoms include bloody diarrhea, abdominal cramps, etc. It is a chronic inflammation caused by immune dysfunction (the intestinal mucosa is the main affected area), and patients also have a higher incidence of colorectal cancer.

It is currently believed that oxidative stress and free radicals play an important role in the cause and aggravation of diseases, and resveratrol has become the target of many studies due to its excellent ability to scavenge reactive oxygen species.

A double-blind controlled study (6 weeks, subjects included 56 patients with mild to moderate ulcerative colitis) found that taking resveratrol (500 mg per day) not only helped reduce the concentration of malondialdehyde (MDA, a product of free radical attack in the organism, the higher the MDA, the greater the oxidative stress), but also increased the body's total antioxidant capacity and superoxide dismutase (SOD, a type of antioxidant) concentration.

In addition, the resveratrol treatment group also had significant improvements in disease activity and quality of life (compared to the placebo control group).

What are the side effects of resveratrol?

Resveratrol is still an emerging health ingredient. So far, there are still few large-scale human trials, so the exact effective dose and safety concerns (side effects) have not yet been established.

In a 29-day human study, high doses of resveratrol, between 2.5 g and 5.0 g per day, may produce mild gastrointestinal symptoms (including nausea, flatulence, abdominal discomfort, and diarrhea) (symptoms appear 2 to 4 days after the start of use and occur half an hour to an hour after ingestion).

Precautions

Pregnant women, breastfeeding mothers, children, and people with liver and kidney dysfunction should not use (because its safety is unknown).

It may have an anticoagulant effect, so do not take it together with related anticoagulant drugs (such as warfarin, heparin), antiplatelet drugs (dipyridamole, clopidogrel), and non-steroidal anti-inflammatory drugs (NSAIDs).

Resveratrol may interfere with enzymes in the liver that are involved in drug metabolism (such as cytochrome P450, CYP1A2), thereby interfering with the effects of many common drugs and possibly causing unknown risks to the patients taking the drugs. Therefore, it should be avoided from use with other drugs or herbal medicines, or a qualified physician or doctor should be consulted before use.

It may have a mild estrogenic effect (found in animal studies, but not yet confirmed in human studies). For safety reasons, people with estrogen-sensitive diseases (such as breast cancer, ovarian cancer, and uterine cancer) should avoid taking it.