In addition to apparently causing fat loss and preventing fat deposition, resveratrol affords other health benefits as well – protection from diabetes, cardiovascular diseases and cancer – to name a few. The strong anti-oxidant ability of resveratrol has prompted some to call it the ‘anti-aging agent’.
Resveratrol has undergone much investigation in recent decades; however, not too many researchers have studied its fat-lowering abilities. Also, much of the evidence for health benefits of resveratrol comes from animal studies.
Whether resveratrol really causes weight loss or not – let us find out!
Alcohol – in excess amounts – is detrimental to human health. On the other hand, alcohol ingestion in low to moderate amounts – especially in the form of red wine – has been shown to benefit human health. Red wine has also been shown to be protective against all-cause death (de Lorimier, 2000; Brown et al., 2009). Gronbaek in 2002 suggested that the more you consume red wine, the less likely you are to die of cardiovascular causes (Gronbaek, 2002).
Called the ‘fountain of youth’, resveratrol has always been thought to possess amazing health benefits including its ability to cause weight loss. However, not many of these alleged benefits are backed up by human clinical trials.
Although animal studies proving these benefits abound, the same cannot be said for humans. There is, thus, a need for extensive human clinical trials to be conducted – the weight-loss abilities, health benefits and safety of resveratrol proved before it can be prescribed as a weight loss and health supplement.
Resveratrol is found in small quantities in plants; grapes and fermented grape fruit juice are the best sources of resveratrol; peanuts also contain small amounts of resveratrol. Red wine is more popular as a source of resveratrol because of its ready availability (Vang et al., 2011).
Commercially, resveratrol tablets are available for regular ingestion.
Resveratrol came into sudden focus when it was discovered that it had cancer preventing abilities (Jang et al., 1997). As more research began to be conducted into resveratrol, cardioprotection, prevention of neurodegenerative diseases, diabetes and cardiovascular diseases were some other benefits that were credited to resveratrol. More recently, it is also being suggested that resveratrol may cause weight loss.
Much of the initial research into resveratrol was prompted due to the French Paradox – the observation that despite high content of saturated fats in their diets, the French have always been relatively immune to coronary artery disease (compared to people from other parts of the world) (Renaud & de, 1992; Ferrieres, 2004). Initially, the French Paradox was attributed to the ethanol content in red wine, and subsequently to various other constituents (Booyse et al., 2007). However, after much research and debate, resveratrol is now thought to be the one responsible.
The mechanism by which resveratrol apparently causes weight loss is not known; the mode of action has been elucidated using data from animal studies.
Resveratrol helps fat loss by:
The evidence in favour of other health benefits of resveratrol including prevention of metabolic diseases comes mostly from animal studies. The mechanism/s responsible is/are:
The above actions translate into health benefits for humans; these can be summarized as follows (Vang et al., 2011):
Resveratrol supplements contain doses which are far lesser than those shown efficacious in human studies.
For instance, most supplements would contain 250 to 500mg of resveratrol. However, going by evidence from animal studies, to be effective in humans the dose of resveratrol needs to be somewhere in the range of 2000mg or more (WebMD, 2013).
Therefore, it always a query as to how much good a resveratrol supplement can do for you.
Generally, resveratrol is well tolerated (Vang et al., 2011). However, most of the evidence of safety of use of resveratrol comes from animal studies. Very few studies investigating the effects of short-term use of resveratrol have been performed in humans.
In a study conducted in 2010, la Porte and his colleagues found that when administered in a doses of 2g/ twice daily, subjects of the study experienced mild gastrointestinal symptoms – especially diarrhoea; one of the eight subjects presented with a rash and headache (la et al., 2010). Other similar studies which experimented with varying dosages of resveratrol and frequency of ingestion reported similar mild effects (Patel et al., 2010; Wong et al., 2011).
Similarly, animal studies have reported no adverse-effects with doses of up to 700-1000 mg/Kg of body weight per day. Furthermore, in human subjects as well, there seems to ‘no valid data on the toxicity on chronic (long-term) intake of resveratrol’ (Vang et al., 2011).
Red wine, in addition to resveratrol, is packed with other biologically active compounds – flavonols, anthocyanins and phenolic acids (Brown et al., 2009; Soleas, Diamandis, & Goldberg, 1997). These non-alcoholic ingredients of alcohol along with resveratrol have long been suspected to provide immense health benefits. However, scientific evidence in support is lacking.
Evidence in support of resveratrol as a weight-reducing agent (and as a health-promoting agent, for that matter) is not too promising either (Vang et al., 2011). Out of 218 articles indentified by Vang et al., investigating the effectiveness of resveratrol in causing weight-loss, only 19 animal studies and no human studies investigated the long-term effects of resveratrol supplementation. In contrast to animal studies, most human clinical trials on resveratrol have tended to focus on the bioavailability, pharmacokinetics and metabolic fate of resveratrol rather than investigating its effectiveness in causing fat loss or preventing diseases.
Such dearth of scientific evidence is unfortunate, especially since resveratrol, in theory (and from animal studies) does seem to posses weight-lowering abilities and deliver numerous health benefits.
Vang et al. sums it up pretty well when they conclude that the ‘published evidence is not sufficiently strong to justify a recommendation of the administration of resveratrol to humans, beyond the dose which can be obtained from dietary sources’ (Vang et al., 2011).
Resveratrol has undergone much investigation in recent decades; however, not too many researchers have studied its fat-lowering abilities.
Also, much of the evidence for health benefits of resveratrol comes from animal studies. The promising data from animals should induce researchers to conduct human studies to investigate the effectiveness (or otherwise) of resveratrol in humans.
In light of lack of conclusive evidence at the present moment, we conclude that resveratrol – although it promises a lot – fails to deliver! And, that supplementation with resveratrol is not likely to afford very many health benefits, let alone cause weight loss!