By Christopher Tack |
Clinical Specialist Physiotherapist
Resveratrol is the reason behind the notion that drinking red wine can be positive for your health!
This polyphenol compound found in the skin of grapes has the science world in a tizzy as researchers from Harvard University have shown that mice fed with resveratrol amazingly had a 25% greater life expectancy than similar mice, and did not gain weight when given a high fat and high calorie diet (compared to controls) (1).
If you are interested in the secret behind a longer life or perhaps a magical weight loss cure, read on and learn about resveratrol.
Polyphenols are a specific group of plant compounds which have been deemed to have positive health benefits. There are approximately 8,000 types in nature, of which resveratrol is one (2).
These molecules are generally found in the skin of plants and work to protect them from environmental stress. Through a concept of xenohormesis, plants respond to stress by changing at a molecular level (such as the accumulation of resveratrol in the plants skin), which then leads to induction of a biologically beneficial and protective response in the animals which have consumed the plant (3-6).
What Is Trans Resveratrol?
Trans-resveratrol is one of the isomers (molecule structures) of resveratrol, with cis-resveratrol being the other. Simply put, trans-resveratrol occurs with hydroxide atoms on opposite sides of the molecule, where cis- resveratrol has the hydroxide atoms on the same side.
Trans- resveratrol is deemed to have the greater biological activity of the two isomers (7).
Interest in resveratrol stems partially from the cardio protective effects of drinking red wine. This subject has been labelled the “French Paradox” and is based upon the observation that the French population has a diet high in saturated fat but a low incidence of heart disease (8).
Researchers postulate that a higher than average wine consumption in this population may protect them from having cardiology issues (9), and informs the extensive research into the components of wine to discover which elements provide this protective effect.
In 1992, resveratrol was examined more closely and identified as a key component of grape skin for this function (10-11).
Since this discovery, further research has been undertaken showing that resveratrol also shows anti-inflammatory, anti-oxidant and anti-cancer effects; as well as an amazing ability to extend the lifespan in various animals (12).
What does Trans Resveratrol do? Benefits?
The health benefits of resveratrol are widespread and through various mechanisms this compound has been shown to affect a number of illnesses.
These include cancer (14) and heart disease (15); as well as a variety of other functions. We will investigate some of the more established benefits further.
#1 Anti-oxidant/ Anti-inflammatory
Firstly, a number of the systemic effects which resveratrol provides are through its capacity as an anti-oxidant and anti-inflammatory agent (16).
For example, resveratrol has the ability to induce activity of a key protein (PGC-1α) which results in greater mitochondrial development in our body’s tissue (e.g. muscle, brain, heart) to reduce oxidative stress (17-18).
With more mitochondria available in muscle more oxygen can be delivered to aid oxidative phosphorylation, which can assist exercise endurance performance.
For example: in animal studies, resveratrol has been shown to increase treadmill running time to exhaustion (17). Similarly, in healthy humans resveratrol supplementation has been seen to increase cardiovascular efficiency during exercise (19-20).
Resveratrol also has the ability to reduce activation of a particular protein complex (nuclear factor kappa B) which induces a number of pro-inflammatory genes (2, 21). This also has the added benefit of suppressing expression of nitric oxide synthase and cyclooxygenase-1 (COX-1) and COX-2 (pro inflammatory enzymes), indicating a multi-faceted anti-inflammatory effect (13).
A number of chronic diseases are associated with both nuclear factor kappa B and the proliferation of such pro-inflammatory enzymes, and these include diabetes (22) and insulin resistance (23). It goes without saying then, that anything which may reduce these factors, is likely to provide benefits for chronic disease. This is the same mechanism that anti-inflammatory drugs work (such as COX-2 inhibitors).
These anti-inflammatory effects of resveratrol has been seen to reduce lipid peroxidation in healthy people following exercise (22); as well as reducing chronic inflammation in arthritis
#2 Heart disease
As described previously epidemiological studies have shown that red wine can provide cardioprotective benefits (24-25).
For example: it can decrease the excessive clotting of platelets (blood cells) (26-27); reduce the formation of fatty plaques in blood vessels (atherosclerosis) (28); and increases blood vessel dilation (29-30).
It is thought that these heart and vascular system benefits could involve its inhibition of COX-1 in order to regulate our blood vessel homeostasis (14). Amazingly, in some conditions this inhibition of COX-1 is irreversible, meaning even brief exposure to resveratrol may have long term, lasting effects (31).
Additionally, the vessel dilation abilities of resveratrol are attributed to the stimulation of potassium channels via calcium, and leading to an increase in nitric oxide signalling (32-33).
The fascinating effects of resveratrol do not however stop there, as there is good evidence indicating that this compound has the ability to inhibit cancer development.
In 1997 a group of researchers found that a topical application of resveratrol (as a gel) reduced the number of skin tumours in mice by up to 98% (14).
In another study on mice with a neuroblastoma tumour a daily dose of 40mg per kg of body weight increased survival from 0% to 70% (35).
The physiological effects of resveratrol for chemoprevention include its inhibition of cyclooxygenase-1 and COX-2 (36-40); reduction of blood supply to tumours (41-42); and prevention of cancer cell proliferation (43).
Alongside the benefits to the cardiovascular system, resveratrol has also been seen to have a protective effect on the nervous system.
For a number of degenerative neurological conditions resveratrol seems to have a benefit in preventing degenerative changes.
For example: in the case of Alzheimer’s disease protein plaques accumulate in the brain tissue and inhibit the production of endothelial nitric oxide synthase (34). These plaques of protein sheets then promote the activity of a specific gene called p53 which can lead to neural tissue cell death.
Resveratrol influences a variety of metabolic pathways to reduce the number and size of these protein plaque deposits by repressing p53 activity and the aforementioned changes to nuclear factor kappa B activation- the net result of which decreases neurodegenerative toxins to protect nerve and brain cells (34).
Probably one of the most amazing physiological mechanisms provided by resveratrol is related to its remarkable effect on the aging process. This mechanism revolves around a distinct group of enzymes called sirtuins.
It is thought that the main function of these enzymes is in the promotion of survival and resistance to stress (44), and in some lower animal forms (yeast, worms and flies) the genes which encode sirtuins are associated with longer life (45-47). Incredibly this association is also seen in mammals (7).
Sources of Trans Resveratrol?
As already stated wine is a common source of resveratrol, however in this sense not all wine is created equally.
Red wine (e.g. Pinot Noir) has a concentration of resveratrol up to 14mg per litre (7), whilst white wine has less than 0.1mg per litre. This would indicate the importance of grape colour when choosing a source of this compound.
However, even a red grape juice only contains 0.5mg per litre and a whole grape contains 3.54μg per gram, thus indicating the importance of the concentration of resveratrol within the skin which is accentuated and accumulated in the wine making process.
Other sources of resveratrol are peanuts (maximum 1.92μg per gram) and the herb Japanese Knotweed which has a concentration of 0.524mg per gram (13).
Side Effects and Safety
In laboratory studies with animals, excessive SIRT1 activation has been associated with heart failure (51), however it is likely the large concentrations of resveratrol used in such models are unlikely to be achieved through oral supplementation.
In fact studies examining the pharmacological mechanisms and effects of resveratrol show that supplementation is very safe for humans. For example, one particularly study (52) showed that 5g of resveratrol daily showed no adverse effects.
Similar results were seen in another study (53) which supported the use of 4g per day for a period of 3 months with no side effects.
Take Home Message
Admittedly, the purpose of this article is not to convince you of the potential for resveratrol to boost your chances to achieve eternal life.
Instead it’s biological mechanisms are presented to highlight the sophisticated and astonishing benefits this compound can provide to aid your cardiovascular, metabolic and neurological health. I think these are all good reasons for why everyone should consider trying resveratrol.