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.

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