Tag: supplements

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My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

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Another development in the continuing saga of confusion about the benefits and hazards of antioxidant supplements. Despite recent suggestions that certain antioxidant supplements may slow or counteract some of the benefits of exercise, there’s still great interest in whether plant-based antioxidants like quercetin can boost endurance. A new study in the Journal of Agricultural and Food Sciences should make you think twice about whether you really want to pursue that avenue.

Kuan-Chou Chen, Robert Peng, and colleagues note that vegetables, fruits, and other plant-based foods are rich in antioxidants that appear to fight cancer, diabetes, heart disease, and other disorders. Among those antioxidants is quercetin, especially abundant in onions and black tea, and ferulic acid, found in corn, tomatoes, and rice bran…

They found that diabetic laboratory rats fed either quercetin or ferulic acid developed more advanced forms of kidney cancer, and concluded the two antioxidants appear to aggravate or possibly cause kidney cancer.

I generally try to avoid putting too much emphasis on single studies like this one (especially when they’re conducted on “diabetic laboratory rats” instead of humans), since it’s very frustrating to be bombarded by messages that bounce back and forth between “X is great for you” and “X is bad for you” and “No wait, X will make you stronger” and “Oops, sorry, X will kill you.” I definitely don’t view this as anywhere near definitive evidence that quercetin will kill you.

That being said, this study does fit into a larger pattern of research over the past few years that leaves me with the conclusion that we’re much better off getting our micronutrients from whole foods than from supplements. I know, I know, that’s difficult. In fact, after I blogged about Juice Plus+ last month, I got an e-mail from a promoter of the product who made that argument:

If you are like me, you probably love eating the real thing, and nothing beats the flavour of fresh produce. I just had some corn, peaches and grapes! But it’s practically impossible to eat 13-17 servings every day, especially fresh, vine ripened and raw.

I don’t know — “impossible” seems like a bit of an overstatement. And I’m not sure where “fresh, vine ripened and raw” came from. Frozen and canned fruit and vegetables still seem like a far better option to me than supplements. Here’s what Lauren and I picked up in two trips to the fruit and vegetable market in Sydney last summer, for ridiculously low prices ($5 for 12 baskets of strawberries, $5 for that entire crate of plums, etc.). Most of it ended up in our freezer — which was pretty awesome over the winter!

THANK YOU FOR VISITING SWEATSCIENCE.COM!

My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

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Andrew Jones, the man behind the beet juice fad of 2009, has more performance-enhancing revelations in a study just released online in the Journal of Applied Physiology. He found that taking the supplement L-arginine produced very similar effects to beet juice: by reducing the “oxygen cost of exercise,” it allowed subjects to last 20% longer in a ~10-minute cycle to exhaustion (11:47 versus 9:22 for controls) in a placebo-controlled double-blind trial. They estimate that’s equivalent to a boost of 1-2% in a fixed-distance race. (Abstract here, press release here.)

What’s significant here is that L-arginine acts in basically the same way as beet juice. Beet juice contains nitrate, which the body converts to nitric oxide, which has a number of effects such as dilating blood vessels and lowering blood pressure, ultimately allowing the body to perform more work from the same amount of oxygen. L-arginine is also converted by an enzyme to nitric oxide, producing the same cascade of effects — and, as the researchers note, the performance boosts observed in the two studies are very similar, giving them confidence that they really do understand what’s happening inside the body.

This is by no means the first L-arginine study — there have been a number of attempts to use it for performance enhancement, with conflicting results. Previous studies have generally given the supplement on a chronic basis — a little bit each day, or even several times a day. In this case, the researchers opted for one big dose, taken an hour before exercise, to make sure that nitric oxide availability really was elevated during the exercise bout. (They used 500mL of a drink called Ark 1, containing 6 g of L-arginine. There are no disclosures in the paper about who paid for the study.) This change may explain why they saw such a clear result compared to earlier studies.

So what’s next? According to the press release, “the researchers are hoping to find out whether combining the two methods could bring an even greater improvement in athletic performance.” In the meantime, perhaps L-arginine will prove to be a more user-friendly option than beet juice. Here’s what Amby Burfoot reported about one world-record-holder’s abortive try:

Two days before the ING New York City Marathon, I asked Paula Radcliffe if she actually drank beet juice. This moved her to stage one: silly giggles. And an embarrassing response. “I tried it once,” she said, “but most of it came out the other end.

THANK YOU FOR VISITING SWEATSCIENCE.COM!

My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

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The more we study antioxidants, the more it looks like — despite the hype — popping big doses of vitamin C and so on doesn’t do much to help your muscles recover from strenuous exercise. In fact, some researchers now suggest popping antioxidants might actually hurt your recovery.

On the other hand, no one doubts that eating lots of fruit and vegetables is just about the best thing you can do, nutritionally speaking. So how about taking a supplement that is, essentially, concentrated fruit and vegetable, like Juice Plus+, which is “whole food based nutrition, including juice powder concentrates from 17 different fruits, vegetables and grains“? That’s what researchers from the University of North Carolina Greensboro decided to test, in a study now appearing online in Medicine & Science in Sports & Exercise (funded, needless to say, by the makers of Juice Plus+).

The 41 volunteers in the study took Juice Plus+ (or a placebo) for four weeks  prior to an intense, muscle-damaging workout. They continued taking it for another four days after, while various measures of antioxidant status, muscle soreness, strength, and range of motion were recorded at intervals. The conclusion:

This study reports that 4 weeks of pretreatment with [Juice Plus+] can attenuate blood oxidative stress markers induced by [eccentric exercise] but had no significant impact on the functional changes related to pain and muscle damage.

So what does this tell us? Yes, fruit and vegetable concentrates supply antioxidants (along with, presumably, other interesting ingredients). These substances may have some health benefits — though whether the benefits are greater or less than taking pure vitamins, we don’t know. But, as far as exercise and recovery goes, antioxidants don’t seem to have anything to do with it.

So for now, my feeling is: why take a powder that might have some benefits when you can take the actual fruits and vegetables that definitely have benefits, and taste better anyway? That being said, I’ll give some credit to Juice Plus+. I’m sure they didn’t get the results they were hoping for, but at least they’re making the effort to fund independent studies — which is a lot more than can be said for most of the products on health-food store shelves!

THANK YOU FOR VISITING SWEATSCIENCE.COM!

My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

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Jane Brody has a piece in today’s New York Times on vitamin D needs — nothing particularly new, but summing up the trend of the last few years to believe that insufficient vitamin D in modern sun-phobic societies is behind a whole range of chronic diseases, and noting that current recommended intakes are far below the levels some experts believe are necessary:

The current recommended intake of vitamin D, established by the Institute of Medicine, is 200 I.U. a day from birth to age 50 (including pregnant women); 400 for adults aged 50 to 70; and 600 for those older than 70. While a revision upward of these amounts is in the works, most experts expect it will err on the low side. Dr. Holick, among others, recommends a daily supplement of 1,000 to 2,000 units for all sun-deprived individuals, pregnant and lactating women, and adults older than 50.

With that in mind, it’s worth pointing out the press release from Osteoporosis Canada that I noticed last week, announcing a revision of their recommended vitamin D intake:

The new guidelines recommend daily supplements of 400 to 1000 IU for adults under age 50 without osteoporosis or conditions affecting vitamin D absorption. For adults over 50, supplements of between 800 and 2000 IU are recommended. For people who need added supplementation to reach optimal vitamin D levels, doses up to the current “tolerable upper intake level” (2000 IU) are safely taken without medical supervision.

I’m still a little gun-shy about the very broad claims made by vitamin D advocates, but the evidence is strong enough that D is the only supplement I’ve taken (albeit sporadically) over the past few years. The bottle I have right now is 400 IU per pill — maybe I need to ramp that up, or at least take it every day during the winter.

THANK YOU FOR VISITING SWEATSCIENCE.COM!

My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

***

Reuters is reporting on a newly published article in Neuropsychopharmacology (a pretty cool journal name, I must say) about habitual caffeine use:

Bristol University researchers found that drinkers develop a tolerance to both the anxiety-producing and the stimulating effects of caffeine, meaning that it only brings them back to baseline levels of alertness, not above them.

“Although frequent consumers feel alerted by caffeine, especially by their morning tea, coffee, or other caffeine-containing drink, evidence suggests that this is actually merely the reversal of the fatiguing effects of acute caffeine withdrawal,” wrote the scientists, led by Peter Rogers of Bristol’s department of experimental psychology. [The study is described in more detail here.]

This caught my attention (a) because I don’t drink coffee and I enjoy making fun of my wife’s addiction, and (b) because I’ve seen conflicting information about whether habitual coffee drinkers get less of a boost from each cup. I spoke to Terry Graham from the University of Guelph, one of the world’s top experts on the effects of caffeine, for this article back in 2008. He said that, as far as sports performance goes, habituation isn’t a problem:

Surprisingly, the same performance boost from caffeine is seen in regular coffee drinkers and in complete abstainers. We do habituate to some of caffeine’s effects, such as elevated pulse and blood pressure, but apparently not to its performance-enhancing effects.

That finding was backed up by another study last year on the effect of caffeine on pain perception during intense 30-minute cycling sessions, by Robert Motl of the University of Illinois:

“What’s interesting,” Motl said, “is that when we found that caffeine tolerance doesn’t matter, we were perplexed at first. Then we looked at reviews of the literature relative to caffeine and tolerance effects across a variety of other stimuli. Sometimes you see them, sometimes you don’t. That is, sometimes regular caffeine use is associated with a smaller response, whereas, other times, it’s not.”

No one’s been able to figure out the reason for the inconsistency, Motl said.

“Clearly, if you regularly consume caffeine, you have to have more to have that bigger, mental-energy effect. But the tolerance effect is not ubiquitous across all stimuli. Even brain metabolism doesn’t show this tolerance-type effect. That is, with individuals who are habitual users versus non-habitual users, if you give them caffeine and do brain imaging, the activation is identical. It’s really interesting why some processes show tolerance and others don’t.”

Regarding the outcome of the current research, he said, “it may just be that pain during exercise doesn’t show tolerance effects to caffeine.”

So it seems that for enhancing sport performance, it doesn’t really matter whether you use caffeine regularly. But that boost you get every morning — well, that’s not really a boost, it’s just a return to normal.