Guest Post by John Fawkes
This next guest post includes an awesome assemblage of research on a confusing health topic--the sort of post Crabby has given up even trying to write since she got so
Is Resveratrol just an excuse to get drunk, or will it turn you into the highlander?
Resveratrol. By now, you’ve probably read about five different articles about how it might just allow us to turn back the clock on aging, so we can live long enough to see the first Mars colony. You’ve probably read about how it can cure cancer, burn fat, build muscle, and make you smarter. Or maybe you’ve just heard about it from some wine snob you know, bragging about how damn healthy he is while getting drunk on a bottle of 2002 Douchenozzle Reserve.
Resveratrol is a chemical produced by a variety of plants as an immune response against fungi, but the highest concentrations are found in the skins of wine grapes, and by extension, in red wine. It naturally occurs in two forms, cis-resveratrol and trans-resveratrol, with trans-resveratrol being the bioactive form that produces all of the alleged health benefits. A glass of red wine might contain anywhere from .15 to 1.5 mg of trans-resveratrol per glass.
For a while in the 2000’s, it really looked like resveratrol was some kind of miracle drug. Every year, a few more studies would come out demonstrating benefits to longevity, cardiovascular fitness, and brain health. But then two funny things happened.
First, a 2011 resveratrol meta-analysis concluded that the evidence for resveratrol’s effectiveness just wasn’t sufficiently strong to justify recommending it for human use at that time. The study did however say that resveratrol seemed promising, and suggest several avenues for further research.
Second, in 2012 an investigation found that the author of dozens of resveratrol studies, cardiovascular researcher Dr. Dipak Das was a massive fraud. He had apparently been falsifying lab tests and misrepresenting the data in almost every study he was involved in since at least 2005. Funny enough, he was also a co-author in the 2011 meta-analysis which had suggested spending more money on resveratrol research. Following this revelation, most of the most positive studies on resveratrol had to be retracted. Also, Dr. Das died of undisclosed causes-- I’m going to go ahead and guess heart disease.
Since then, more (apparently legit) research has been done on resveratrol by other (apparently honest) scientists. So what’s the deal? Is resveratrol bullshit? No. Is it a miracle drug? No. Is it worth looking at? Yes, so let’s go over its purported benefits one by one.
This may come as a surprise to you, but no study has ever taken young adult humans, given them resveratrol, and followed them until they die to see how long they live. Human longevity is damned hard to study, which is why most longevity studies look at shorter-lived animals and then try to generalize those results to humans. A lot of skepticism is warranted here.
First off, resveratrol has been studied on drosophilia, better known as fruit flies. Seriously. Fruit flies. Resveratrol prolonged the lifespans of fruit flies, but the effect varied a lot depending on the diet and gender of the flies. It’s hard to say what to make of this, since flies have very different diets and hormonal profiles than we do.
And then of course we have mice. Studies have shown that resveratrol provides substantial health benefits as mice age, helping to preserve the mice’s motor functions, energy metabolism, and insulin sensitivity, and increasing median lifespan. The effects seem particularly strong when the mice are on a high-calorie diet, and in fact mimic the effects calorie-restricted diets.
In human resveratrol studies, evidence suggests that resveratrol doesn’t increase life span per se, but does protect against many age-related health problems, such as osteoporosis, heart disease, and cognitive decline. There’s no evidence that resveratrol directly fights aging itself, although it might-- might-- increase median age somewhat by reducing some of the causes of premature death. In other words, resveratrol probably won’t let you live to 200, but it might keep you out of the nursing home.
There are strong indications that resveratrol can fight atherosclerosis, reduce blood pressure, and scavenge free radicals from your heart, preventing oxidative damage. Again though, most of this comes from rat studies, and it’s also extremely dense reading.
Human studies have had to use population data rather than the experimental method to investigate the relationship between wine/resveratrol intake and heart health. A meta-analysis of resveratrol and heart health studies provides great news: consuming 2 glasses of red wine a day is associated with a 61% reduced risk of cardiovascular disease. Before you get too excited, remember that this is based on uncontrolled population studies. It’s a good reason to switch from beer to red wine, but not a good reason to cancel your gym membership and start eating at McDonald’s.
Insulin Sensitivity and Fat Loss
There’s tremendous evidence, in human, mouse and lemur studies, that resveratrol can aid glucose metabolism and insulin sensitivity- in other words, it can make more of the food you eat go to your lean tissues or get burned off for energy, and less of it go to fat. One study even showed that resveratrol protected rats’ pancreatic beta cells from dying, meaning that it might protect against type 1 diabetes. However, the dosage in this study was so high as to likely produce dangerous side effects.
In humans, 150 mg/day has been demonstrated to improve energy metabolism in obese humans. The benefits don’t seem to apply to non-obese humans, however, and they also disappear a few months after people stop taking resveratrol.
In other words, resveratrol can probably help you lose weight, but you’d better actually be losing some weight when you’re on it. It’s not an excuse to stay fat and tell yourself that you’re actually healthy, as the benefits don’t last and don’t compare to not being fat in any case. If you do lose weight though, the resveratrol may wear off, but the benefits of having gotten leaner will remain.
Effects on Brain Health and Alzheimer’s
Based on over a dozen studies, resveratrol appears to help brains stay healthy as they age. It can cross the blood-brain barrier, and has been shown to boost cerebral blood flow, but this wasn’t shown to lead to improved cognitive performance. In mice, resveratrol prevented some of the biomarkers associated with Alzheimer’s disease. In humans, at least one study has demonstrated a neuroprotective effect, synergistic with melatonin.
Athletic Performance Enhancement
Resveratrol shows some very mixed effects on athletic performance. On the one hand, some studies suggest an increase in muscular power and aerobic endurance, as well as glucose absorption. On the other hand, other research found resveratrol failed to aid performance adaptations over time. Worse still, another study actually found that resveratrol reduced the long-term benefits of exercise, although the effect wasn’t very large in practical terms.
So what’s going on here? The issue likely stems from resveratrol’s anti-oxidative effects. You see, exercises actually damages your body; the benefits occur when your body recovers from that damage, becoming even stronger than before. By protecting your body from exercise-induced damage, resveratrol may help you perform better at the time, but hinder your long-term results because the exercise is effectively less intense and provides less growth stimulus for your body.
Effects on Testosterone and Estrogen
Resveratrol is similar in structure to estrogen, and thus can activate some of the same receptors that estrogen activates. Higher doses of resveratrol have been found to increase testosterone production in both mouse ovaries) and mouse testicles and testicular tumors. Man, imagine being the person who has to study cancerous mouse balls. That’d make for some fun cocktail party conversations.
In humans, higher doses of resveratrol (around 500 mg a day) have been shown to inhibit aromatase. Aromatase is the enzyme that converts testosterone into estrogen, so aromatase inhibition means more testosterone but less estrogen. Really high doses of resveratrol- one gram or more per day- also appear to act as an aromatase inhibitor for one week, but then increase aromatization after the first week.
Why would it have one effect for one week, and the opposite effect after? There are two possibilities: first off, the high dosage might desensitize your receptors, causing them to eventually stop responding both to resveratrol as well as your body’s natural estrogen. Second, testosterone levels could build up to the point where they overcome the aromatase inhibiting effect, cascading over into estrogen.
Effects on Cancer
The same aromatase-inhibiting properties that make resveratrol a potential testosterone booster also make it potentially useful for fighting breast cancer. Topical resveratrol is being investigated as a skin cancer drug. Resveratrol also shows promise in fighting esophageal cancer; this is actually also a topical effect, is it seems to work by coming into contact with the cancer while being swallowed, rather than by being absorbed into the bloodstream. Finally, resveratrol appears to help prevent liver cancers from metastasizing. All of this cancer research is in the early stage, and will probably take years to prove resveratrol’s usefulness as an anti-cancer drug, but it is promising.
So as you can see, resveratrol isn’t some kind of miracle drug, and has been really overhyped over the years. A lot of the studies about it were actually done on mice and fruit flies- freaking fruit flies! That said, it does have some health benefits that make it worth using, but how you should use it depends on your goals.
If you have cancer and think some resveratrol from Walgreens will help you, FOR CHRIST’S SAKE STOP! Don’t take it without talking to your doctor first, as it may have interaction effects with whatever else you’re taking. Not to mention the supplement industry is so unregulated, you can’t always be sure how much is actually in the pills you’re taking. I’m not a doctor and don’t play one on the internet, so ask your real doctor.
For longevity, cardiovascular and neuroprotective benefits, 5-10 mg per day is the way to go. Take it in the evening with .3 mg of melatonin, and a glass of dry red wine if you’re so inclined.
For fat loss, take 100-200 mg while on a diet and exercise program geared towards fat loss. That means cut the carbs, and get your heart rate up a few times a week- resveratrol is NOT a magic weight loss pill and won’t make you lose fat on its own, but does work well in conjunction with diet, exercise, and other fat loss supplements like green tea and caffeine. I recommend using this dosage for only 3-4 months at a time, then taking at least a month off to avoid the estrogen-increasing effects.
If you want to use it to boost testosterone, that takes 500 mg a day. At that dosage, you should use resveratrol for no more than 8 weeks at a time before taking a few weeks off- again, to avoid the increase in estrogen that comes from long-term, high-dosage use.
Finally, for athletic performance, you can take anywhere from 150 to 500 mg a day- however, I wouldn’t use this long-term since it seems to reduce adaptations to exercise. If you’re training for a competition, consider taking resveratrol only for the last two weeks before the competition.
Okay, so does this mean your wine snob “friend” is right and red wine is actually good for you? Well, sort of. Even a 5 mg dose of resveratrol is equivalent to between one and three bottles of red wine, depending on which varietal you’re drinking, so you should probably take pills if you’re really interested in resveratrol. There seem to be non-trivial effects even at one or two glasses of wine a day though, and beer is terrible for you, so this is certainly a great reason to switch to red wine if that’s not already your drink of choice.
And as for the wine snobs, here’s what to do next time you’re stuck at a party with them. Get a blender, a bottle of wine, and one of your resveratrol capsules. Making sure said wine snob is in the room, pour the wine and the contents of the capsule into the blender and blend them up- this has the added bonus of aerating your wine. Now pour the wine into the glass, lock eyes with your now-horrified wine snob acquaintance, and begin drinking. Sip slowly, maintaining eye contact the whole time.
Science 2 - Wine Snobs 0
John used to be an out of shape guy who drank too much beer, didn’t get any exercise, and felt like shit all the time. Now he feels awesome, loves exercise, and prefers wine, but hates wine snobs. Also, he’s a fitness coach. Through his blog and free fitness course, John helps people to make healthy choices, get into shape, and re-energize their minds and bodies. When he’s not getting drunk and singing karaoke, anyway.