Dear Mark: Glutathione, Workout Nutrition, Cartilage Regeneration, Pam, and the Best of the Worst

It’s another round of rapid-fire Q&A with reader questions this week. Ever wonder about olive oil in a spray can, or which meat to choose when dining out? Do you have joint issues, or questions about workout nutrition? These readers do.

Read on to learn my answers to these and other questions. And if you have your own pressing nutrition and fitness quandaries shoot me a line and I’ll try to answer them in a future “Dear Mark” post.

What do you know about Glutathione and what is your opinion of it?


I have a high opinion of glutathione (though I’m not sure what it thinks of me), which the body synthesizes from the amino acids L-cysteine, glycine, and L-glutamic acid. It’s a potent endogenous antioxidant – your body’s favorite, perhaps, if it were forced to choose – that neutralizes free radicals and reactive oxygen compounds, regulates the nitric oxide cycle (important for control of blood pressure and inflammation), helps the liver process toxins, and plays a role in DNA synthesis. Simply put, it’s the master antioxidant in the human body, and we need it to stave off assaults on our health.

I don’t, however, have a very good opinion of glutathione supplementation. The problem is that orally supplementing with glutathione does little to affect levels in our body. Maybe it’s neutralized by the digestive process, but the point is that we already make our own glutathione, and eating the stuff straight is essentially useless, unless you really, really like the taste. If you want to boost your glutathione with supplements, take glutathione precursors, like N-acetyl-cysteine (NAC), whey, or alpha-lipoic acid (which helps recycle glutathione), all of which have been shown to increase cellular levels of glutathione. Get a regular, moderate dose of a wide variety of polyphenol-rich foods and spices, like chocolate, coffee, berries, red wine, tea, cinnamon, and turmeric; polyphenols often up-regulate the body’s natural antioxidants, among which glutathione features prominently. Also, make sure you’re replete in selenium (found in fish, brazil nuts, and organ meats), a crucial regulatory agent for the antioxidant activity of glutathione, because many people are not. There’s some talk that glutathione given as an anal suppository or via IV works, but how tenable is that for the average guy or gal that simply wants to fortify their generally solid health?

Hi Mark,

Quick question related to fueling my intense anaerobic workouts. I understand that I should keep workouts below an hour on the Primal Blueprint diet, or my body will crave carbs/sugar to replace the glycogen. Correct? My main question: when should I eat the most carbs. I am reading that post-work out is ideal but I am feeling enervated during workouts (heavy lifting/crossfit/sprinting). I remember one day recently I had a big hero sandwich (all the bread included) for lunch and I felt like superman for my evening crossfit workout.

Sincere thanks for your insight.



If you perform better having eaten before a workout, eat before your workouts! Don’t listen to dogma and Pubmed abstracts that contradict your experience. You’ll find that different types of workouts require different fueling strategies. While the longer Crossfit WOD, for example, might require some appreciable preworkout nutrition, you might feel and perform fantastically lifting heavy or hiking on an empty stomach.

If you train hard on consecutive days (a strategy that is NOT part of the PB Fitness plan, by the way) you will want to be sure to top off glycogen stores after each hard workout to prep for the next. That does mean upping your carbs from fruit or starchy tubers a bit over the next few hours (and, yes, that means taking advantage of the 45 minute “window of opportunity” just post workout).

If I were you I’d play around with all the various feeding strategy/workout permutations. Then, go with what works. Different things might work for different days, and that’s fine. Crossfit WODs in particular are heavily glycolytic, regardless of how long you spend doing them, simply because of the crazy intensity. In fact, that’s the point of many of them – to cram as much work into as little time as possible. If you’re regularly engaging in Crossfit WODs while adhering to the main-site 3 on, 1 off schedule, go into your workouts sufficiently fueled up (although I would recommend against the hero sub).

Hello Mark,

I think what your doing is awesome and really appreciate your daily articles. To start off I’m 16 years old and a couple of years ago I got Lyme’s disease. One day I went to the doctor when my knee blew up and he told me that I must have got bit by a tick a couple of months ago, which would explain why my knee was extremely swollen. I had taken many pills and injections which failed but finally a couple of months of infusions cleared it. A month later I collided with another kid playing baseball tearing my meniscus. So I had surgery a month later just to repair a simple meniscus. Well the 45 minute surgery ended up being 3 hrs in which the doctor drilled several holes into my kneecap to try and draw blood to the surface of the knee in hope to repair any cartilage I had left. The doctor said it had a 20 percent chance of working, of course it didn’t. So after a year at Columbia Hospital my parents decided to take me to a specialist at Hospital Special Surgery in NYC. After a long hi-def MRI my doctor told me that all of my knee cartilage was gone and my meniscus was torn again. He performed an osteotomy to realign my leg because it was collapsing inwards. A year goes by with multiple large screws in my leg and my doctor tells me that my knee is finally aligned and my bones look great. Well that’s awesome but now he has to take the hardware out and put cartilage in my knee. So after 6 months of waiting for donor cartilage I had my third surgery on January 12, 2011. The surgery was 6 hrs, he took half of the screws out and tore my acl to get to the cartilage. So long story short, I now sit at home with a home tutor everyday patiently waiting to walk again and for my pain to be over with. I go to the doctor in a couple of months for an MRI to see if the cartilage was not rejected and it was properly healed. To be honest I have doubt that it will work but I’m hoping that there is something I can do besides eat Primal and drink bone broth that can help. My question for you Mark is there any Primal trick that Grok would have done to help heal cartilage? Thanks!


The regeneration of cartilage is not settled science. Most orthopedic surgeons will probably tell you that once it’s gone, it’s gone, and that the regrowth of severely damaged cartilage will never reach its original capacity. They may be right, but I’ve seen people with dire prognoses for the state of their cartilage regain what appears to be full mobility and activity levels.

Eating Primal and drinking (homemade) bone broth is a great start, maybe with some chicken feet for added connective tissue. It also can’t hurt to focus on maximizing the nutritional content of the food you eat, so be sure to eat your liver and other organs, bone marrow, leafy greens, and get plenty of vitamin D via sunlight or through supplementation. Avoid inflammation by ditching excess omega-6 fats and taking time to relax and de-stress. Get plenty of quality sleep, since that’s when the healing occurs. And be sure to avoid all grains and legumes, as the dietary lectins may trigger autoimmune attacks on your connective tissue (researchers are beginning to think that wear-and-tear osteoarthritis may also have an autoimmune component, similar to rheumatoid arthritis). You must also use your knee as much as possible, taking care to follow your physical therapist’s instructions and guidelines. Don’t be afraid to test your knee if you feel ready because, ultimately, the resumption of weight bearing activities (which could be anything from body weight squats to weighted squats to simply walking) will send the necessary signals to your joints to begin regrowing the cartilage – if it’s going to happen. The old adage “use it or lose it” applies here.

Basically, I’m not asking you to do anything different than what I’d tell someone looking to get healthy and stay fit. Just do it as if your ability to enjoy life to the fullest extent possible depends on it, because it might. Good luck!

Hey Mark

Your post on olive oil based mayo made me think about if using olive oil-based Pam is actually good for us. I use this whenever making anything in a pan, to spray on a chicken or turkey I am baking, or on my George Foreman grill so meat does not stick.

Is it ok to use or are there better substitutes to get the same or better results?

Thanks for your time and advice 🙂


The fact that I was unable to find the exact ingredients of Pam online makes me think that ingesting it is not the best idea. Also, Pam? Really? Just use some real fat!

I can name dozens of superior alternatives: butter, lard, tallow, coconut oil, olive oil, palm oil, bacon grease, red palm oil, macadamia oil, duck fat, palm shortening, intramuscular hind quarter clover-fed mutton fat… If it’s the convenience attracting you, keep some olive oil in a pressurized spray bottle.


I was wondering if you could do a post on how to choose the best worst option:

i.e. my girlfriend and I are always debating when we go out to a crappy old normal dinner is it “better” to get the beef or the chicken or the shrimp curry. Chickens have high omega 6’s and are fed crap, but they have no antibiotics.  Beefs (if they are lean) do have antibiotics but most of the bad stuff is in the fat, and what about farmed fish/shell fish?

I would be interested in knowing when faced with “less than ideal” options how you would rate their relative merits.



p.s. (I usually go beef and she goes chicken)

If this is an irregular occurrence, I’d suggest simply getting whatever you want. But for the sake of the question, I think you’re right, Jeff, and here’s why:

Remember though, the most important thing to consider is how the food is cooked. The aforementioned answers assume that everything else about the meal is equal except the protein source. If you’re choosing between grilled chicken breast or country fried steak, you’re obviously going to go for the chicken.

Thanks for reading, and be sure to keep sending in questions! I’ll do my best to answer. And as always, feel free to chime in on the comment section and expound on the answers.

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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