Dear Mark: Peripheral Neuropathy, Primal Compromises for Love, and Carbs in Ketosis

Foot painFor this week’s edition of Dear Mark, I’m answering three questions. First up, what could be causing a reader’s peripheral neuropathy? Could it be gluten, B12 and/or B6 deficiency, diabetes, or inadequate vitamin D? The second question concerns homemade pasta, a beautiful woman, and a dilemma: do you indulge in the former to make the latter happy? My answer may surprise you, or it may not. I’m not sure. But I think you’ll find it helpful regardless. And finally, can carbs and ketosis co-exist? They certainly can, but there’s a little trick to make it work.

Let’s go:

I’m looking for alternative ideas for dealing with neuropathy pain in my legs and feet. Any suggestions?


Diabetes is the most common cause of neuropathy, so that’s worth exploring with your doctor. Be sure you’re practicing the basic best practices for blood sugar control: eating adequate protein, exercising (strength training and sprinting or HIIT, especially), managing stress (meditation, various anti-stress herbs and supplements if necessary), sleeping enough and well.

You’re probably already avoiding it, seeing as you’re reading Mark’s Daily Apple, but it’s worth reiterating the importance of gluten avoidance in all types of peripheral neuropathy. Of all extra-intestinal symptoms of gluten intolerance, peripheral neuropathy is probably the most common. I’ll sometimes discuss the occasional bite of bread or cake I have, or tell folks that regular soy sauce is probably okay for most and the residual gluten is mostly inert, but that’s intended for people without overt gluten intolerance or celiac disease. If you have problems with even minute amounts of gluten, or if you’re experiencing symptoms commonly associated with gluten intolerance like peripheral neuropathies, you should avoid all sources. So make sure you’re off gluten entirely.

Vitamin B6 status can also affect neuropathy, so make sure you’re getting enough. That’s why patients who take the tuberculosis drug isoniazid must also take vitamin B6 pills: the drug depletes B6 and causes peripheral neuropathy. This is an easy fix, if it’s indeed the cause. B6 supplements are cheap and plentiful and safe, and fish, poultry, pork, and red meat are the best dietary sources of the vitamin.

Vitamin B12 deficiency is a potential cause. Check out Chris Kresser’s podcast episode on neuropathy for an extensive treatment of the B12 issue. Chris also mentions a few other possibilities, like chronic Lyme disease or fungal infections.

And then there’s vitamin D deficiency, which is an independent risk factor for diabetic neuropathy. Grab some sunlight whenever possible, get your vitamin D levels checked out, and supplement with vitamin D3 if it looks like you need it.

What are the consequences of “backsliding” into the SAD on occasion? For instance you’ve met a beautiful woman who you have yet to convert to the Paleo ways. During this initial courtship she loves to have you over for homemade pasta every other Wednesday. You’ve just recently converted to Paleo yourself (say six months), and you certainly still enjoy pasta, but are at no risk of abandoning the Primal habits due to the biweekly indulgence. Are you at risk of compromising your newly undertaken gene expression? What if dinner is stepped up to every week?


I don’t usually wax too poetic on MDA, preferring to deal in the empirical and the objective, but I’m going to step out on a limb here and do things differently. Love, or even the prospect of love, trumps all. There is nothing finer or more important to human happiness — and ultimately health, for the two cannot be divorced — than shared human connections. You can’t discount the importance of finding someone you really, truly vibe with, whether on a romantic or platonic level. It trumps every material aspect of health, and any benefits you get from skipping the biweekly (or even weekly) pasta meal aren’t worth compromising that.

Don’t refuse the pasta. Enjoy it. I mean, homemade pasta is special, even if it’s gluten-spiked poison on a plate. It’s a painstaking, arduous process that you only undertake if you really care about the person for whom you’re making it. Weekly pasta? My answer stands. Consider it the 20 of your 80/20 and give it nary a further thought. Just try to serve yourself and scoop a little less of the noodles and a little more of the sauce, meat, and veggies. You’ll live. Trust me.

If you end up eating the pasta (and I think you probably should), there are a couple things you can do to curb the negative response to the pasta:

  • Mitigate the deleterious effects of a carb binge by engaging in vigorous postprandial physical activity. This could be a few sets of kettlebell swings, some air squats, or the hip thrust-centric movement of your choice. Exercising in this manner will lower the blood glucose response and utilize stored glycogen, thereby opening up space for all that dietary glucose.
  • Take a tablespoon or two of raw potato starch (or eat a green banana) an hour before eating the pasta. This provides resistant starch, which will blunt the blood glucose response. RS also helps support the gut bacteria that regulate gluten sensitivity, and it generally improves the health and reduces the permeability of your gut lining.

As always, I’ll insert the necessary disclaimer: if you’re celiac or gluten-sensitive, do not eat the pasta. Only relent if gluten poses no immediate health issues, whether serious (neuropathy, migraines, generally feeling like death) or “mild” (GI upset, diarrhea, etc). If the lady in question is worth your time, she’ll understand.

When you get more comfortable with her, you could always suggest making gluten-free pasta together. That could be a fun project.

I am experimenting with putting my body into nutritional ketosis, but also want to maintain my athletic performance. If I consume some CHO’s (not sure what the magic number of calories is) prior to my heavy or intense resistance training workout to fill my muscle glycogen stores (and hopefully perform better), will I get back to ketosis shortly after my workout assuming I don’t over consume the CHO’s?

Second to that, can you recommend anything to measure blood ketone levels?



If you eat the carbs before the training session, you’ll knock yourself out of ketosis because you haven’t yet created the “glycogen debt” necessary for carbs and ketosis to co-exist amicably. You’ll secrete insulin to deal with the glucose and that will reduce ketone concentrations and probably knock you out of ketosis.

What you want to do is consume the carbohydrates after the training session. You do this because the exercise will make your muscles extremely insulin sensitive and activate non-insulin dependent glucose uptake, thereby doubly reducing the amount of insulin you’ll require for disposal of the carbohydrates. It also clears out the existing glycogen, making space for the incoming glucose. Double plus good.

As long as you don’t get too wild in the interim, your muscles will be fully stocked whenever your next training session rolls around, and you’ll remain in ketosis as long as you want to.

Also, eat fewer carbs than you think you need. Remember that you’re only burning muscle glycogen in muscles you’re actually using. High rep barbell curls will tear through bicep glycogen given enough volume, but they won’t touch quadricep glycogen. A CrossFit WOD consisting of barbell thrusters, high-rep pullups, box jumps, and kettlebell cleans, on the other hand, is more likely to tap into glycogen from every muscle group. The average person stores about 400 grams of glycogen in muscles and 100 grams in the liver, and you’ll very rarely need to ever come close to replacing all of it. It’s better to err on the side of fewer carbs, just so you don’t overstep your debt and cancel ketosis. If that happens, though, don’t worry about it. You can drift back into it fairly easily.

That’s it for this week, everyone. Thanks for reading and if you have any more advice to contribute, please do so below in the comment section!

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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