Dear Mark: D-Ribose, Bean Sprouts, Backyard Rabbits, and More

I haven’t gone to the rapid fire question-and-answer format in awhile, and you guys seem to dig it, so let’s do one today. We’ve got questions regarding a popular bodybuilding supplement, whether bean sprouts are Primal or not, the fatty acid composition of backyard rabbit meat, the old protein-leaches-calcium-from-bones myth, and my opinion on the new government food plate. As always, if you’ve got any questions about (almost) anything, send them my way and I’ll do my best to answer them. Not every topic deserves a full post – and, let’s face it, I don’t always have it in me to produce a full-length post. This way, we cover a lot of ground and I get to give myself a break. So, yeah: keep ’em coming.

And yes, I was also pleased with the opportunity to post a cute bunny photo.

Hey Mark,

It’s been a while since I’ve written. I’ve been training harder lately and have been experiencing some muscle fatigue. I heard about using D Ribose as a way to help accelerate the repair process. I was curious if you thought using this in the one hour window post workout might be a good idea or just another way to sell a supplement? Thanks!


The literature is quite conclusive regarding D-Ribose: it doesn’t work as advertised by bodybuilding supplement makers. While it has shown some efficacy in the treatment of chronic fatigue and in congestive heart disease patients, possibly by increasing ATP production, studies consistently demonstrate that D-Ribose does not improve workout recovery or performance in healthy trained athletes. From one, “Results indicate that oral ribose supplementation (10 g/d for 5 d) does not affect anaerobic exercise capacity or metabolic markers in trained subjects as evaluated in this study.” Another study found that ribose supplementation had no effect on cycle sprint performance in trained men. Still another showed that ribose taken before and during intense exercise, again, had no effect on metabolic markers or anaerobic capacity in cyclists. I would definitely save your money or spend it on something like creatine, which has undergone extensive testing, is inexpensive, and actually works.

Are bean sprouts not part of legume family? Are they approved for primal living?


Bean sprouts are fine. There’s nothing to them, really, for good or for bad. I’ll admit that they make a nice crispy addition to a salad or Thai-style stir fry. They’re like green beans to me – technically a legume, but a benign texture enhancing legume that thinks it’s turning into a plant. Most bean sprouts you’ll come across (in the US, at least) are mung bean sprouts. Low in nutrition (6 g carbs and 3 g protein in 100 grams of sprouts), high in water, highly unlikely to inflame passions. Since you’re asking, though, I bet you like them and I bet they help you eat other, better foods. If that’s the case, eat away! Just don’t think they’re adding many micronutrients directly to your diet. At least they aren’t subtracting any (phytic acid is extremely low in mung bean sprouts – PDF).

I searched the Internet and MDA first but couldn’t find anything, so thought I’d check with you. Maybe this would be useful for others as well.

We are considering raising rabbits for meat. They will get some pasture, veggies and supplemental feed. Before we did this, though, I wanted to find out how they compare to grass-fed beef and lamb, in terms of O6/O3 balance? Those are our two primary meats at this time.



According to the USDA database, a pound’s worth of rabbit meat from composite cuts has 25 grams of fat, with 7.5 g saturated, 6.8 g monounsaturated, and 4.9 g polyunsaturated. Of the polyunsaturates, there’s about a gram of omega-3s and 3.9 g omega-6, giving it an omega-6:omega-3 ratio of (roughly) 4:1. That’s not too shabby. The total omega-6 content is higher than something like lamb or beef, but it’s far lower than chicken, and the ratio destroys chicken’s (which is closer to 18:1, though a backyard pastured chicken should have an improved ratio).

You might find this paper (PDF) helpful. In it, the authors determined that increasing the omega-3 content of rabbit feed improved the omega-6:omega-3 ratio of the resultant meat. The lower the ratio of the feed, the more the ratio of the meat improved. While I suppose you could try to dose your rabbits with fish oil capsules (it may impart an odd flavor, but it’s safe and could even reduce atherosclerosis!), flax seed is a good rabbit-friendly, species-appropriate, omega-3-rich dietary addition. I bet, with some smart tinkering, you could improve the ratio beyond 4:1. Let us know how the project works out!

My question for you arises from a claim I’ve heard from vegetarian friends and seen elsewhere on vegetarian/”nutritarian” sites: specifically, that milk and animal protein causes osteoporosis by leaching calcium from the bones. As far as animal protein is concerned, the alleged culprits are cystine and methionine, which are “sulfur-containing”.

What’s your take on all this? Do milk products and animal proteins really “leach” calcium from our bones? Somehow it doesn’t seem to add up to me.

Grok on!

Joel M.

This one just won’t die, will it? The “animal protein leaching calcium from bone” is a canard that the anti-meat crowd latches onto for dear life, even as it sinks, pulling them beneath the waves. Well, here’s what the latest review of human dietary protein and skeletal health literature concluded: “Recent epidemiological, isotopic and meta-analysis studies suggest that dietary protein works synergistically with calcium to improve calcium retention and bone metabolism. The recommendation to intentionally restrict dietary protein to improve bone health is unwarranted, and potentially even dangerous to those individuals who consume inadequate protein.” Moreover, the idea that dietary animal protein acidifies the blood leading to calcium leaching is deemed “untenable.” What’s hilarious is that plant protein appears to have the opposite effect on bone mass in another study. Animal protein was slightly protective (but it wasn’t statistically significant), while plant protein intake predicted bone density loss. Ironic, eh?

Hi Mark,

I’m certain you’ve seen this but some friends and I would love to see your thoughts on our new, ‘official’ CW!

The news room/press release:

Take care!


The slick graphic belies the same old story: “enjoy your food, but eat less,” the inability to say “protein” without “lean” preceding it, the insistence of “low and non-fat dairy,” heaping compulsory piles of grains (what is with our dear leaders’ obsessive grain fetish?). Instead of observing the growing number of obese men, women, kids, tots, and infants (!) and reevaluating the meat of their recommendations, the authorities just repackaged it. I wish I had more to say, but nothing’s really changed.

I eagerly await the collective melt-off of the nation’s pounds and the diffusion of its calories into the atmosphere as folks “eat less, move more” in response to this groundbreaking new information.

Thanks for reading, and be sure to send me your questions!

TAGS:  dear mark, DIY

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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