Potatoes: Part Deux
Last week, I made the case that potatoes aren’t nearly as bad as some people make them out to be. They’re carby, sure, but lean, active people who can tolerate carbs are way better off eating potatoes than grains, and even for low-carbers, a potato makes for a good, gluten-free cheat meal. Their place in your diet depends on the metabolic context. In my so-called “final word,” I said there isn’t one, at least not ordained from above. You have to figure out for yourself whether or not they fit into your diet. You might even say you have to go with your gut on this one (in more ways than one, as you’ll see).
So: potatoes. Just what are we to make of them? They are lumpy, white things that appear mostly harmless. They are, some would say, non-toxic sources of essentially pure starch. But actually, there’s more to the potato than glucose. First, the standout numbers for a standard white potato, baked, just the flesh (skin removed), 200 grams worth (which is a decent sized Russet):
Carbs: 43 g
Fiber: 3 g
Protein: 4 g
Fat: 0.2 g
Vitamin C: 20 mg
Magnesium: 50 mg
Potassium: 782 mg
Copper: 0.43 mg
That’s actually pretty decent. It’s certainly more interesting than rice. It contains very little phytate, so the minerals will be plenty absorbable. The carbs are almost all starch, meaning they’re perfect for replenishing glycogen stores after a workout. It’s a solid tuber, and a better, more nutritious starch source than are grains.
I also promised to discuss the secondary concerns people have with potato consumption. More specifically, I’m going to get into the potentially toxic glycoalkaloid content, the intestinal permeability issue, and the anecdotal reports of joint pain and inflammation.
Potatoes, being the reproductive organs of potato plants, have “passive” defenses against predators. They are stem tubers. They can’t run or bare teeth, so they chill underground to stay safe and employ toxic chemical defenders. For a group of smart, tool-wielding apes like ourselves, that first line of defense is easy enough: dig ‘em up. The second is a bit more difficult to circumvent: the toxic glycoalkaloids are in the potato itself. If we plan on eating the potato, we plan on eating the glycoalkaloids, too.
The glycoalkaloids most prevalent in potatoes are alpha-solanine and alpha-chocanine, which the plants use to repel pests. Most of the glycoalkaloids are luckily concentrated in the skin of the potato, forcing less refined pests to eat through the toxic stuff to get to the good stuff. We have the luxury of employing peelers (pinky in the air, no doubt) to avoid most of the glycoalkaloids (which are not reduced through cooking; you have to physically remove them). This is probably why traditional potato-eating cultures peel the potatoes they eat, unless you count the urbanized Quechua migrant eating cheesy tater skins at the Chili’s in Lima. And, as commenter Anand points out in Don’s excellent post, our ancestors would have definitely removed the charred skins after roasting tubers directly in the hot coals. These days, the most common potatoes, like Russets, also tend to have the lowest amount of glycoalkaloids (see Stephan’s chart); this is no accident, instead being the product of generations of careful agricultural selection by farmers. Throughout history, then, humans have tended to avoid the bulk of potato glycoalkaloids, either unwittingly, by peeling potato skins, or by selecting the low-glycoalkaloid varieties that didn’t provoke stomachaches, digestive issues, or inflammation and sold well at the market.
But glycoalkaloids remain. Are they harmful? Certainly, but the devil lies in the details. High dose glycoalkaloids are clearly harmful, but most peeled normal potatoes do not contain high doses of glycoalkaloids (again, I refer to Stephan’s chart). Most studies showing harm used supra-physiological doses of pure glycoalkaloids; one of the only studies to show harm using physiological doses that you’d normally get from eating potatoes used intestinally permeable rats with a genetic proclivity toward inflammatory bowel disease. This is a useful study, though, because it tells us that potatoes might be a danger for humans with leaky guts or existing inflammatory bowel disease. I’m sure you know someone in that position. It may even be you, or a loved one. How common is leaky gut? It’s difficult to know for certain, but I think looking at how many people still eat wheat, grains, sugar, and vegetable oil as a significant portion of their diet can give us a pretty good idea.
The Paleo Diet newsletter on nightshades pointed out a couple studies showing increased inflammation markers upon potato feeding, but one altered multiple dietary factors simultaneously (not just potatoes) and the other used potato chips. Was it the rancid seed oil the chips were fried in, or the potatoes? Was it the wheat bread or the potatoes? These tell us very little about the effects of whole, untarnished potatoes on inflammation.
I can also see potato glycoalkaloids being problematic in the context of the inflammatory standard American diet (rich in gluten, omega 6, and sugar). This is similar to the persuasive argument that casein is only problematic once gluten has perforated the gut lining and allowed entry. Do potatoes pose an issue for people with intact guts? As it stands now, there is very little published evidence that potato gycoalkaloids cause problems in metabolically health individuals without compromised guts, but there are anecdotal accounts.
Like my own. I avoid grains, vegetable oils, and excessive sugar, and I’m pretty darn healthy, but I have found that eating potatoes on a regular basis, especially potatoes with the skin, seems to lead to joint pain in my feet and ankles (of all places). So I don’t eat them on a regular basis. This doesn’t happen when I eat other starchy foods, like yams or squash. Only with white potatoes. That said, I still eat the odd spud – though I prefer Yukon golds, red potatoes, fingerlings, or any of the strange farmers’ market varieties. I’ve heard from people who get crippling joint pain from a single potato meal, though, so I’m not sure what to say about potatoes for everyone.
If you feel up to it, head out to the store and try some potatoes. The basic Russets are good, but dozens of varieties exist. Grocery stores should carry Yukon golds, red potatoes, fingerlings, and maybe a couple boutique varieties, but the real interesting ones are found at farmers’ markets. At the local Santa Monica market, there’s a whole stand devoted to potatoes of all kinds. They’ve probably got a dozen varieties, and it’s always changing. Purple potatoes, half yellow/half purple potatoes called Laker potatoes (hey, it is LA), tiny little red ones the size of gumballs, multicolored gnarled ones that look like an old crone’s rheumatic claw – these guys are committed to their tuberous artistry. Even for someone who doesn’t eat a ton of potatoes (I, honestly, don’t train hard enough anymore to require a lot of glycogen repletion), I find myself generally picking a handful or two up when I’m there. I’m rarely disappointed.
Always store your potatoes in a cool, dark area. Avoid light exposure, which can turn them green and increase the glycoalkaloid density. Cut off any sprouts or stems; better yet, just toss ‘em altogether if they sprout. You don’t want to take the risk, and they’re cheap enough to sacrifice. For heavy lifters and highly active exercisers who want to incorporate potatoes, it makes sense to bake a bunch at once and store them in the fridge for easy post-workout consumption. They’ll stay good in the fridge for about a week and a half. For PBers interested in trying a carb refeed, potatoes are a great choice.
Other bloggers have put up some incredible series on potatoes. By and large, they agree that humans have a long and storied history with potatoes and other tubers, and I find it difficult to argue. Reading their thoughts has made me reevaluate my own views on potatoes. I highly suggest reading both series.
Don’s Primal Potatoes series, in which he makes a strong argument for the tuber’s prevalence in our ancestral diets (especially when game was lean), even making the case that tubers gave us an advantage in the hunt: Primal Potatoes
Stephan’s Potatoes and Human Health series, in which he goes into more detail on the glycoalkaloid concerns (short version: very little evidence that normal levels of potato glycoalkaloids poise a problem for healthy humans) and discusses several traditional cultures that fared well on high-potato diets: Parts 1, 2, 3.
A Few Additional Thoughts on Potatoes
It is impossible to argue with your own personal anecdotal evidence. Anecdotes won’t stand up to peer review, but I find it difficult (and unwise) to discount a barrage of them.
If you’re overweight, avoid potatoes for the carb count and because you’re probably still fairly inflamed, and potatoes might aggravate your condition.
If you’re sensitive to nightshades (tomatoes, peppers, eggplant are the common ones) and have experienced negative effects from consuming them in the past, be wary of potatoes. Potatoes are also nightshades.
If you have a known autoimmune disease, a leaky gut, or are especially sensitive to dairy, grains, eggs, or nuts, avoid potatoes until it clears up.
If you insist on “cheating” with wheat, avoid potatoes to minimize any collateral damage to your gut.
If you need an affordable source of whole food calories, consider potatoes.
If you’re having trouble recovering from workouts on a very low-carb diet, try adding some post workout potatoes for the glycogen. Your muscles, having been drained of glycogen, will be insulin sensitive and most of your dietary glucose will go to good use.
If you’re stalling on weight loss as you near your goal, try carb refeeds with potatoes to restore leptin and jumpstart the leaning out process.
If potatoes give you fits, don’t eat them. You’re not missing much beyond a cheap source of calories that converts to glucose almost instantly. If lots of people you trust on other matters are reporting problems with potatoes, be mindful, be wary, and always pay close attention to how they affect you.
Thanks for reading and let me know what you think in the comment board. Grok on!
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Posted By: Mark Sisson
Great summary, very nuanced! Thanks.
Can you talk more about, “leaky gut”? I am confused about the opposing research. Thanks
I see in the news where the head of the Washington State Potato Council will be eating 20 potatoes a day for two months. I guess we’ll find out about any bad effects with such an extreme potato diet! Maybe we can have a spud or two every so often without guilt.
I don’t know Mark. The primal diet is so good on its own I don’t see why cheat with a potato?!. If, I want to cheat I do it with steak and oyster rockefeller topper. Hey wait that’s primal. All kidding aside potatos like grains I think raise glucose levels fast and can lead to falling off the wagon into starch madness. But, if potatos are your thing…. I for one never really liked the pasty, bland things anyway. I have found much better things to sop up my butter and cream with.
Great post, Mark.
We eat potatoes occasionally, always organic and always peeled. They help stretch our Primal budget. It would be nice if we could afford to eat our fill of steak or grass fed ground beef every night, but we can’t, so occasionally we add white and/or sweet potatoes, usually cooked in butter, to round out our meals, and ease the budget. Haven’t noticed any ill effects, but we’ll pay more attention, just in case.
So if you eat red/purple/fancy potatoes, should those all be peeled as well? It seems easy enough to avoid the skins on the bigger potatoes like russet and yukon gold, but the smaller potatoes are usually served with the skins still on.
I still won’t eat them very often, but I’m just curious as to what to do with the smaller spuds.
“the smaller potatoes are usually served with the skins still on.”
They are in US, and that was a big surprise for me when I first saw it. Potato eating cultures always peel potatoes before cooking. It is a very boring process, especially if you have to serve a lot of potatoes. I think Americans decided not do that. Why waste time? Time is money.
wow you’re always so quick in with first cmmneot . you’re right, hasselbacks are great. how were they done in the class? there seems to be so many different twists on these, but they’re all good!
I was just thinking the same thing…
Whatever works for you I guess. I cut out rice and replaced them with sweet potatoes and never looked back :I
What about saponins?
Good info Mark, thanks!
The chart lists Snowden potatoes has having a very high glycoalkaloid level – I couldn’t find much on them, but one sentence on Wikipedia says that they’re often used for potato chips. That might explain why potato chips create digestive issues.
How about a dissertation like this on sweet potatoes?
I added potatoes back in small amounts after having been on PB for 9 months, and I find I’m tolerating them much better now than pre-PB. Still not at my goal weight, so I don’t do it every day (or even every week) but it makes a nice change, and I’m tolerating them MUCH better than the rice I also recently tried again. I eat Yukon Golds from the farmers market and I don’t peel them. So far, so good.
you’re on a roll again, Mark! It’s great to be back to the well thought out and information-laden articles. For a while there all of the recipe posts and grok-picnic posts were getting old.
thanks.
Potatoes are delicious with tons of butter and sour cream! But they are not a part of my diet at the moment. They have been a lifesaver when out though. Case in point, we went to a big pizza franchise that caters to kids. Pizza, Pasta, and crazy other junk. If it were not for the salad bar and baked potato I would have not survived. So I am thankful it is a gluten free alternative when necessary.
We’ve run into exact situation with our kiddo.
I haven’t had any in a long time, but i think one good-sized one would be okay in a stew with plenty of bison, elk, vegetables, and arrowroot.
I dearly miss the Middle Earth metaphor from the initial treatise on taters.
It is interesting to see many recommendations these days to remove the peel of potatoes, many fruits etc. This after years of people telling me that the peels had all of the nutrients, so I should make sure to eat them.
I suppose it is a trade off in many instances of losing some nutrients in order to avoid the toxins.
Would you say that in general the Primal lifestyle avoids peels on most or all foods, or is this a gross over generalization??
Mark-
What this, and Stephan’s article lack, are thoughts & analysis on sweet potatoes, specifically. Personally, I have done my own analysis comparing the white russet potato versus the sweet potato and yam, and the SP is the superior choice for “health” when comparing Glycemic Load, Vitamins, and Inflammation (I’d post a link to my blog post, but the comments section won’t allow url’s). I know sweet potatoes are technically potatoes and could be lumped into this article, but I think they are different enough to deserve their own paragraph.
Aside from that, I have found that sweet potatoes (and yams on occasion for variety) make for an excellent CHO/fuel source during periods of heavy exercise. Hell, I even use them for pre-race meals, and have had fantastic results with them! In summary, I agree with your (changing) viewpoint.
Thanks for posting!
ps- This article was much better than the previous one. When you said “stay with me here…”, I already had a “glazed over” look
Excellent summary Mark! That one is a keeper for future referal!
Geez, first rice, now potatoes…what’s next? corn is okay too? Kidding. It’s good to know I don’t have to change my recipe for curry chicken (with potatoes, over rice of course)…totally primal
. I have to watch it though because I’m fat but my skinny family members can enjoy!!
Nice Mark.
My perspective is that potatoes are an excellent food to cycle into the diet for nutrition and diversity’s sake. I first eliminated them (~6 months), then added them back in to my diet after I reached a healthy equilibrium. I now find them a nice addition every week or two, or incorporated into a post-workout meal.
Another thing to put bacon, butter and cream on that won’t inflame my gut?! Yay!! My kiddos won’t mind a change from yucca (casava) and sweet potatoes… Woohoo.
Thanks for the update Mark. I’m down almost 30 lbs 157-128 lbs since this summer and as I approach my ideal (well, my vanity weight) of 125 lbs and really upping the anti with my workouts I’m glad to know I can add this to the mix at least for my ‘feast’ day which is followed by my ‘famine’ day!
What’s next Mark… pasta from non-grains??
I Too would like to know if sweet potatoes fall into the “peel the skin” category.
Michael Pollan Has some interesting potato tidbits in “The Botany Of Desire”. The one that really gets me is that Monsanto’s “NewLeaf” is not considered a food by the FDA, but a pesticide. They are being discontinued because McDonald’s has just stopped buying most of the crop.
Bummer, I have always eaten the skins of potatoes and sweet potatoes as they have the most overall nutritious aspect of it.
I really wonder what the prop/con of doing this is. I’ve never felt bad after eating a potato skin so I am curious as to what the actual effects may be.
Hi Mark,
Please give us your advice on sweet- potatoes/yams skin. I always ate the skins thinking they were healthy. Any help at all would be most welcome.
Thanks
Marc
Hi Mark and all primals!
In Sweden potatoes are being consumed in large amounts, and always has been. It’s one of the most common foods in diet, historically. Tell your grandpa that you’re on a paleo, non potato diet, and they’ll likely wack you with their walking stick for being such a fool.
Therefor I kinda like to see you ease up your position on this matter, even though I won’t go on a potatofrenzy just because of this.
I do have one question though. What’s the difference between an ordinary potato and a sweet potato or a yam? It seems that it’s been allright to indulge on sweet potatoes every once in a while, but not on regular potatoes. How come?
How would potatoes be historical when they came to Europe after the americas were “discovered”? The earliest they would appear was 1500′s and that’s dubious because people were wary of them.
By historical I meant that they’ve been a big staple for us during a couple of hundred years. We’ve had it in the country since around 1600 though.
Historically perhaps wasn’t the best word to use. How about traditionally?
And any answer to my question would be welcome.
Potatoes are a huge staple food in many North European countries. In Sweden and Norway potatoes are eaten in huge quantities, but always peeled (after boiling). The potato saved many families from starvation in Scandinavia for hundreds of years. (The first potatoes in Norway were grown in 1757)
The fact that they have been eaten in quantity does not mean we should eat them. One of the main reasons to eat paleo is to avoid the diseases of civilization. All of North European countries have plenty of diseases of civilization.
The reason it became popular in those countries is it grows well in a cool climate and has a high yield per the planted area.
Speaking of potatoes… Dinner tonight is Round Steak, Broccoli and Sweet Potato smothered in butter or coconut oil!
Great post Mark. When I started on paleo/primal I was leery of any carb heavy foods but have learned to embrace, not fear the potato as an integral paleo food.
One suggestion: It looks like there is a lot of questions regarding the potato’s relation to the sweet potato, which are very different – not even the same biological family. Mark, I am sure a post discussing the differences between the two would be helpful for the readership.
Hey Mark! I was wondering what you thought of Cassava, since it is literally toxic unless heated (it produces arsenic as a defense mechanism). Are they still primal?
Hey Mark,
I want to thank you for changing my life for the better. I’ve been trying to convert my parents to The Primal Blueprint eating plan, but you know how that goes. I have a question that I’ve been pondering for quite some time now, and no, it’s not about potatoes. I was wondering if you’ve ever talked to Tony Horton about your eating strategy, because I know he’s into the whole “vegan thng”. I don’t mean to stir the pot, but he recommended your book on Facebook when it first came out, which is the reason why I was introduced to your knowledge in the first place. I just want to know if you’ve talked about it with him.
@Dillon, Tony is one of my best friends. Over the past 24 years that we’ve known each other we’ve debated this diet thing a lot and have agreed to disagree in minor nuances of all this. We both agree that veggies and some fruits, certain nuts, etc should be the basis of the diet and that avoiding simple sugars is critical. OTOH, I eat everything that moves (animals). He does get a fair amount of quality protein from non-vegan sources (eggs, fish on occasion, protein powders, etc) and some from vegan-friendly (primal-unfriendly) things like legumes and whole grains. He also trains like a fiend almost every day – I do as little as possible to still stay fit.
Well…certainly interesting…especially the part about IBD…have stayed away from potatoes, rice and grains for quite awhile, and decided to slice a few tiny cooked ones into my scrambled eggs, along with diced cooked onions and bacon…the variety helps once in awhile with an anti-fungal diet…excuse me….lifestyle. Yum! Now…excuse me, I must take my sexy brussels sprouts out of the steamer.
Anyone else bring up the potato only guy from washington? To “prove” the health benefits of potatoes he is eating only potatoes for 2 months. Apparently he’s a month into it and totally sick of them. for more info here’s a news link on it: http://www.startribune.com/nation/105793278.html?elr=KArks:DCiUMEaPc:UiacyKUzyaP37D_ncyD_2yckUr