Dear Mark: Hot Laptops, Wine Sulfites, Glutamine, Where’s Mackerel, and More

It’s Monday, and that means it’s time for another roundup edition of Dear Mark. This time, we’ll be covering laptops, fertility, and scrotal hyperthermia; sulfites in wine; glutamine as an anti-catabolic supplement; the scarcity of mackerel in the markets; and my hair engoldening protocol. If you prefer these roundup editions to the regular single question-and-answer editions, let me know. I’ll keep doing whatever you folks like best.

Okay, let’s get to the first of five questions:

Dear Mark,

I just finished reading the article on cell phones and fertility and I immediately started thinking about the computer that rests on my lap for hours a day and the waves that are transmitted to and from it. I was wondering if there are any studies linking wireless computing to infertility? Should I be taking the lap out of laptop?


There is some concern over laptop radiation affecting sperm motility and quality, but it’s generally accepted that the electromagnetic wave load from laptops using wifi is far lighter than that the load from mobile phones. The bigger problem may lie with scrotal hyperthermia, or overheating, from lap use of a laptop. Scrotal hyperthermia… it makes you shudder, eh?

Such eponymous use of a laptop does seem to increase scrotal temperature by about 2.8 degrees C, which some researchers think could affect male fertility. Since high scrotal temperatures have long been associated with lower fertility in humans, this seems like a reasonable assumption. Lap pads don’t really help, but keeping your legs apart (instead of locked together) mitigates some of the temperature increases. That said, the simplest solution is to never use your laptop as manufacturers intended – on your lap. Instead, just use a standing workstation, which – let’s face it – you should already be using for many other reasons beyond a hot scrotum (although that definitely suffices as justification!).


Noticed your list and saw you added one of my favorite wines Cabernet

Most include sulfites so do you have a suggestion for a good one without the added sulfites or chemicals in the grapes.



All wines contain sulfites, because sulfites are a natural byproduct of the fermentation process. Most vintners do add sulfites, because they act as a preservative and antioxidant. Without them, wines spoil more easily and more money goes into the preservation. Whites actually contain more sulfites than reds, and wines on average contain 80 mg/L sulfites, or about 10 mg per glass. A serving of dried fruit contains far more sulfites than a glass of Cab, for example.

If you really want to avoid added sulfites, drink organic wine. Makers of “organic wines” can’t add sulfites, but, again, there are naturally occurring sulfites so you can’t really escape them. Wines “made from organic grapes,” however, probably contain added sulfites, as they aren’t technically “organic wines.” Truly organic wines are also pretty rare.

Unless you are absolutely certain you have a sulfite allergy (which is rare), I wouldn’t base your choice of wine on the sulfite content. You’ll be missing out on a lot of delicious Cabs!

Hi Mark,

How do you feel about the 5 grams of Glutamine powder that I mix with some water right before I turn in for the night? There seems to be a lot of evidence to support that this strategy will prevent catabolism and help to preserve my lean mass during the 12-15 hour fast that is to follow.



Thanks for the kind words, Nick. In return, allow me to save you some money. Glutamine probably isn’t preventing catabolism in your  muscles. Are you a regular lifter? Squats, deads, full body movements, the whole nine? Do you eat a good amount of protein and healthy fats? Are you mineral replete? Do you get enough sleep? I’m guessing you have all that stuff dialed in, in which case glutamine isn’t going to do anything for your muscles.

Here’s a study on the effect of glutamine supplementation in young athletes performing weighted squats and heavy bench presses. Athletes received either glutamine (at 0.9 g/kg body weight, far higher than your 5 g) or a placebo. Both groups trained, and both groups improved muscle performance, body composition, and muscle degradation rates, but there was no significant difference between the two groups.

Glutamine has its benefits in certain populations. In the severely catabolic, post-surgical demographic (burn victims, blunt trauma victims, elective surgery patients), glutamine supplementation definitely helps rebuild tissue, improve immune response, and boost muscle protein synthesis, but I don’t think those benefits can be extended to the general, reasonable healthy population. Even if you’re breaking down your musculoskeletal system with heavy compound lifts, you simply aren’t in as grave a position as someone coming off a horrific car accident or dealing with third degree burns across a large portion of their body. Your damage is localized and relatively mild, and repairing it comes down to proper sleep, proper nutrition, including plenty of protein, and sufficient downtime.

Now, if you stop the glutamine and your performance suffers while maintaining all the other factors I mentioned, feel free to disregard this and resume the supplementation. Good luck!

Why is it so hard to find Mackerel at the supermarket?


I have a couple theories. First, mackerel is quite possibly the “fishiest” fish. A lot of other varieties can be dressed up with sauces, cooked until they’re bone dry and tasteless, or allowed to reside inconspicuously with the other ingredients in the dish, but not mackerel. It can’t be ignored. It doesn’t really dry out. It proudly proclaims to the world (and your tongue) that, “Yes, I’m a fish, I come from the frigid marine waters of the Atlantic, and I contain a lot of long-chain omega-3 fatty acids, but I refuse to apologize. If my taste offends you, so be it. I’ll never be suitable for fish sticks and tartar sauce, and I’m okay with that.” It boils down to the fact that “fishy” is a negative flavor for a lot of people in this country and mackerel is the embodiment of “fishy.”

Mackerel is also extremely volatile. It doesn’t stay fresh for very long, and you have to freeze it a certain way (like, immediately upon catching it) for it to be palatable. We coastal folk can get mackerel without issue, but inlanders might have trouble. It’s definitely worth pursuing, though. If you have an Asian supermarket or a dedicated fish monger nearby, those are the places to look. The standard grocery store probably won’t carry it.

Mark, could you explain the best way to get that beautiful golden long flowing hair. My girlfriend joked that I might be able to get your body (I’m getting close.), I’ll never have that hair.

This is one area of my life that necessitates an ultra-strict protocol. I was originally going to turn this into a book, but I figure my loyal readers deserve a sneak preview of my hair color maintenance protocol.

The answer is heavy eyebrow lifts, 3 sets of 5, twice weekly. Clip weights to eyebrows, then perform eyebrow lifts, a la Fred Savage from Wonder Years and his arched eyebrows when surprised. Proper form is crucial – maintain jaw rigidity, keep your mouth closed, torso lean forward with slight break at the hips to maintain neutral spinal column and prevent weight-face friction. Alternate standard compound double brow lifts with single brow lifts for variation of stimulus (Tony Horton calls this “muscle confusion”). These lifts are the premier stimulators of hair pigment growth factor. Be careful, though. More than twice weekly results in overtraining and a boost to stress hormones, which can bind to hair pigment growth factor receptor sites, thus inciting hair pigment growth factor resistance and premature graying.

Alternatively, you could just be born with good hair genetics. That’s how I did it.

Well, that’s it for this week. Thanks for writing in with your questions, and, as always, keep sending them. I love to help out however I can!

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.

If you'd like to add an avatar to all of your comments click here!

59 thoughts on “Dear Mark: Hot Laptops, Wine Sulfites, Glutamine, Where’s Mackerel, and More”

Leave a Reply

Your email address will not be published. Required fields are marked *

  1. So lemme get this straight, do the eyebrow lifts and I can turn my brown hair into blonde naturally?

    I’m off to Modell’s to buy the weights now!

  2. I just bought some smoked mackarel from Whole Foods the other. It is made by a brand out of maine called Duck Trap. It is quite tasty as well.

  3. I find sauana very helpful with hair. After 15 minutes or so, the texture of the hair changes. Noticeably smoother after, and just looks better. I’d like to say it prevents hair loss, but I doubt it.

    The trick, however, does not work so well with my GF.

    1. haha

      Your GF doesn’t get smoother and better looking after 15 minutes in the sauna?

  4. I like the multiple answered entries as long as you’re not leaving out any juicy important details (I don’t think you would do that). 🙂 Thanks Mark!

      1. I do as well. It allows for easy skimming and picking. The laptop question was relevant to me so I read it. The wine one was sort of so I read it. I skipped the rest.

        It allows me to read an article in less than a minute. All your other articles I love to read but they are very long and since its on one topic I always read it all since it all matters.

        These are my favorite posts after the success stories!

  5. Mark – I find that the eyebrow weights chafe some, and I’m also finding it hard to keep the weights from rubbing on my eyeballs. What are your suggestions for that? My hair has turned blonde, but the corneal scraping has me seeing red. Any advice?

  6. Thanks for answering the glutamine question. I was recently wondering about it because I had heard it was a valuable supplement. Sometimes the supplement swirl makes it hard to find the truth!

  7. For a good Biodynamic Cab, I love Benzinger. It’s a family owned Cali winery and a must visit when you are in wine country.

  8. We make our own wine, which is one way to avoid the added sulfites, and a fun hobby. There are a few good organic wines though, and most wines in Europe have a lower sulfite content. From my understanding, in Europe, it is not standard to add sulfites, though they are usually added to import into the US.

      1. I’m not Katie, but there are a number of different ways. You can buy kits (pour in juice, add the appropriate yeast, and wait), or you can actually get berries (grapes) and press them yourself. The process doesn’t change much from the juice to the grapes, just adds an additional amount of work. I would recommend starting easy and working towards the complex. Good luck!

    1. Katie… can you please tell us how? You did so well at telling me how to make beef jerky in my oven with ground beef… I want to make my own wine!!

      1. Could you link me to this ‘how to make beef jerky in the oven with ground beef’ I’d be interested….. Thanks.

  9. To my fellow Chicago readers, I have to give a shameless plug to my company! We sell fish and seafood (wholesale and retail) and we always have Mackeral in stock. We carry Boston and Spanish Mackeral, King Mackeral (Kingfish) in addition to about 80 other fresh fish varieties. Boston Mackeral is almost always frozen, Spanish Mackeral comes in frozen and fresh when available. Kingfish comes in fresh and frozen as well.

    Check us out for you fish and seafood needs.

    L. Isaacson and Stein Fish Company
    800 W Fulton Market
    Chicago, IL. 60607
    (312) 421-2444

    1. Been meaning to come here forever, seeing it on mda has given me the extra push I needed. I’ll be there on saturday!

  10. Always use a spotting partner if you are performing heavy eyebrow lifts.

  11. Mackerel’s a tough one, you either love it or hate it. Same goes for mullet.

    We’ve got a classic place here in my town called Ted Peters (featured on Diners, Drive-ins and Dives) that makes a killer smoked mackerel. Every now and then I’ll take one home and mix it in with some eggs for breakfast (beats sausage any day).

    1. Ted Peters rules! We just brought back a stash of smoked fish spread (and the German Potato Salad) to North Carolina. No smoked mackeral, though. They say they haven’t been able to obtain any for months, for some reason.

  12. Eyebrow weights…rofl.
    That has got to be one of the silliest things ever!

  13. When we were in St Thomas last winter we went fishing and caught some mackerel. We took them back to the townhouse we were renting and grilled them up. They were delicious. I don’t know that I agree on them being the ‘fishiest’ of taste, but what we did learn from our guide was that you need to cut out the dark strip that runs through the middle of the fillet before cooking. It’s actually an organ, not meat. And it tastes horrible. It wasn’t that difficult to remove, but I could see it being prohibitive to an effective commercial operation. On a side note, we haven’t seen it in any store or restaurant since we got back here to the midwest.

  14. Wow, didn’t realise how lucky we are in england to get abundant cheap mackerel. We get wild mackerel at out local supermarket at £3 for four fillets. It’s always been my go to for a quick home meal, and the fishiness you talk of is exactly why I love it so much. It has such a strong flavour of it’s own so requires very little meddling to make it delicious, for me it just takes a bit of lemon juice, lots of pepper, served with a rocket salad in dijon mustard dressing and it achieves perfection. And so healthy too!

    1. I’m with you on this one. In Ireland, but got some smoked, peppered mackerel reduced in tescos the other day, first time I ever had it. It is indeed one of the tastist things I’ve ever had.

  15. Couldn’t figure out why fish turned my stomach and made me gag just to smell it…then found out that I am “food sensitive” to fish. The body KNOWS…we just have to pay attention. Thank God for good fish oil supplements, which for some strange reason don’t seem to bother me.

  16. Good to know about glutamine. Lots of people in the gym use it and I have wondered as to the effectiveness of it in addition to a high protien diet.

  17. As a professional winemaker, I’d just like to chime in and say you nailed the sulfite question. There is so much misinformation out there, so bravo for getting it right.

    Regarding the mackerel question, my local supermarket carries a Cole’s wild mackerel from Portugal(in a tin), which I’ve enjoyed immensely and haven’t found to be overpowering at all.


  18. Re scrotal hyperthermia.

    Once, decades ago I got out of a hot whirlpool bath for a knee injury. The Doctor said “Hey, you’re sterile”. He went on to say that sperm, at elevated temperatures swims much harder, (like inside a woman), and that at very high levels for an extended period of time (like 104/105 they swim themselves to death. The scrotum regulates the testicular temperature by stretching to get them away from the body when hot, and shrinking when they get cold. (Cold ocean dip!)

    1. Can anyone attest to feeling any warmth at all with a laptop computer sitting on their laps for hours?
      Probably not….
      Even a 1-2 degree warmer than body temp object will produce a warming sensation sensed.
      I smell “urban-lengend” forming….

  19. My boyfriend has a sulfite allergy so we have to be careful with wines. We usually buy Frey, an organic wine company that states “No added sulfites”. He has a noticeably lesser reaction to the natural sulfites in their wines over sulfite added wines.

  20. For better hair, just stop using shampoo. Will shine, flow and be manageable within 2-3 weeks

  21. What about smoked mackerel?
    Delicious and quite easy to get here in europe.

    If you want thick shiny but dark hair, follow the general schemes outlined but attach the weights to the ears!
    (that’s the secret of all that bollywood movie dancers – ever see what huge earings they wear?)

  22. Really like this article and the daily apple! Check out my website about the simple things in life that can change your life and follow me on Twitter @thischngdurlife and please let me know what you think!

  23. Yeah I definitely worry about the laptop heating up things down there issue. My girlfriend’s old MacbookPro would get scorching hot and I always wondered how it could affect your man parts. Either way, always kept a pillow or something there as a barrier for protection…hopefully it worked 🙂

  24. I completely agree with Mark that using a standing workstation for a laptop is the most comfortable and productive set-up.

    Since I began using a standing workstation, my back pain and overall comfort at the desk has increased dramatically.

  25. For those of you interested in making your own wine, check out “cyser” and the SCA site (Society for Creative Anachronism). Cyser is a fruit based mead type wine (pears are fabulous) and were staples of the medieval era (what the SCA is all about!).

  26. For laptops… I personally just place my laptop on a pillow. Most of the time I am at my standup workstation though 🙂

  27. Living in Norway I’ve never thought of mackerel as something that was hard to track down. The most common way people eat mackerel here is as “Makrell i tomat” – a small container with a piece of mackerel sautéed in tomato purée. Yummy.

    1. I can say that it’s exactly the same here in Sweden. Mackerel in tomato sauce is actually quite common here, and basically every store has it.

  28. Mackeral may be hard to come by fresh but there’s a great canned smoked mackeral that makes for a great quick meal or snack–The brand is Bar Harbor Only two ingredients–naturally wood smoked mackeral and salt.

  29. I was slowly getting bald, but have the feeling that since going primal (in my 6th month) my hair is coming back, but it is still hard to judge. I wondered if anyone else had any experience with this.

  30. Sulfite sensitivity isn’t that rare — the FDA estimates it affects 1% of the general population, and I’ve seen studies giving ranges of 4 to 11% among asthmatics. (Yes, I have both asthma and sulfite sensitivity.)

    And it’s not “dried fruit” in general that sets most of us off, it’s the stuff treated with sulfites! Fortunately, places like Trader Joe’s often carry unadulterated stuff — and I recently bought my own dehydrator.

    Also, I switched from whites to reds as my asthma got worse in my twenties, and find I can usually drink a whole glass of commercial non-organic red wine without symptoms. (Different people’s sensitivities vary, of course.)