Dear Mark: Apple Cider Vinegar, DNA Damage, Lactaid, and Miracle Noodles

I’m really liking these Monday morning rapid fire question-and-answer sessions – are you? At some point, I’ll get back to the musings, but as long as you keep sending in great questions, I’ll probably keep answering them. We’ve got four this week: vinegar and its effect on insulin levels, sugar and DNA damage, the nutritional merits of lactose-free milk, and whether Miracle Noodles are Primal. So let’s get started.

Dear Mark

I have read that apparently cider vinegar influences/ reduces insulin level after a high carb meal. I was wondering what Grock’s view on this point is?

Thank you for looking into this & your time.


Apple cider vinegar does display some interesting benefits for diabetics. In one study, ten type 2 diabetics, eleven insulin resistant non-diabetics, and eight insulin sensitive non-diabetics were given 20 grams of apple cider vinegar (or a placebo) two minutes prior to a bagel, butter, and orange juice meal. The vinegar drink reduced postprandial glucose and insulin spikes in the insulin resistant, and both diabetics and insulin resistant non-diabetics enjoyed greater total body insulin sensitivity in response to the high carb meal after drinking cider vinegar. In another study, a pre-bedtime snack of two tablespoons of apple cider vinegar and a bite of cheese led to slight improvements in waking blood glucose levels in type 2 diabetics.

For all its folkloric renown, I doubt the “apple cider” is all that important compared to the “vinegar,” at least when it comes to diabetes and glucose tolerance. Plenty of other studies show that it’s the acetic acid (that’s the organic acid that gives all vinegars their sour taste) that helps. Here’s one, using plain ol’ vinegar, in which eating bread with vinegar lowered glucose/insulin responses and improved satiety compared to eating bread alone. Hmm, maybe there’s something to dipping bread in balsamic after all… And finally, a comprehensive review of the purported health benefits of vinegar found that while evidence for most of the stuff people claim it does is nonexistent or equivocal, multiple studies have shown that vinegar combined with carbohydrate exerts a beneficial effect on glucose tolerance, insulin sensitivity, and even satiety.

A tablespoon or two of apple cider vinegar before a carb-heavy meal sounds fine by me, especially if you’re insulin resistant. Maybe an olive oil and vinegar-dressed green salad before dinner? You might also try making vinegar-based dishes. I make a mean balsamic and butter reduction that goes well with just about anything.

I remember reading in the Primal Blueprint about an Australian study that concluded that sugar can cause DNA damage 2 weeks after consumption. Does this also apply to fruit? Would eating a banana or a papaya have the same affect on DNA as eating a chocolate bar?


If I recall correctly, the lingering effects occur as a result of hyperglycemia. So, if whatever you’re eating leads to a massive elevation of blood glucose levels, whether it be a chocolate bar or a couple bananas, you may be doing serious damage. That’s a big “if,” though. A bowl of blueberries rarely has the same effect on blood glucose as a Snickers. If you’re really worried about it, get a blood glucose monitor, eat a papaya, and test your blood sugar levels at one and two hours post meal. At one hour, you should ideally be below 140 mg/dL, and at two hours, you should be below 120 mg/dL. Three hours should see you return to baseline levels.

I highly doubt reasonable amounts of fruit, especially lower sugar ones like berries, will cause most people to incur much damage, but the only way to know for sure is to test.


I purchased the Primal Blueprint in Hardcover, and I love the book. I have a question though about milk. It seemed like the major complaint about milk had to do with lactose intolerance (which I do experience with regular milk)…I am highly active 27yo male, I lift weights as well as run. For me the inexpensive delicious protein source of whole milk seems indispensable. Since I discovered the Lactose Free version I can drink as much as I want without getting an upset stomach. I guess I am just wondering what are your opinions on Lactose Free Whole Milk from the standpoint of a healthy diet. Does the process of making it Lactose Free do anything negative or detrimental to the Milk?

Thank you for your time!


Lactose free milk simply has added lactase, the digestive enzyme that’s responsible for breaking down lactose and that your body no longer produces. This doesn’t affect the nutritional merit of the milk, but if the nutritional merit of the milk is low or questionable to begin with, you’re not left with much.

Still, whole milk (conventional, raw, or otherwise) is undoubtedly a powerful tool for the young, active athlete. If you’re trying to put on size and recover from heavy lifting, milk will help. I don’t like the stuff myself, and at this point in my life I don’t need to be GOMADing it up, but it can be used effectively for a specific purpose. If I were you and dead set on drinking milk, I’d keep my eyes out for raw milk, or even just a high quality pasteurized, non-homogenized milk from grass-fed cows. Trader Joe’s has a cream-top, non-homogenized milk that comes from better cows than you’ll get from Lactaid – pastured but supplemented with a bit of organic grain and hay. These tend to run on the pricier side of things than Lactaid, but you can add your own lactase, or take lactase tablets. I wouldn’t go through all this trouble, but then again, I’m not big on milk. If I had to take a tablet to enjoy butter, though? Yeah, I’d do it.

To answer your question – lactose free whole homogenized milk is just as as safe (or not) as homogenized whole milk.

What are your thoughts on these Asian noodles with no calories or carbs (brand name Miracle Noodles but also sold in Asian markets)? I know that Grok wouldn’t eat them, but if you’re craving pasta, are these a reasonable alternative?


You’re thinking of shirataki, a traditional Japanese noodle made from the extremely fibrous konjac root. The powdered konjac root is mixed with water and pickling lime to form a gelatinous mass, which can then be cut into noodles and added to soups or stir frys. The noodle itself is fairly tasteless, from what I understand (I haven’t tried them myself), making it an innocuous addition to dishes as far as flavor goes. Whether the miracle noodle is suitable nutritionally depends on your situation.

Konjac root is almost entirely glucomannan, a kind of soluble fiber, or prebiotic. Is that a good thing, necessarily? Well, glucomannan seems to encourage the growth of butyrate-producing gut bacteria in human subjects on a low fiber diet, and more butyrate production is generally positive: as Stephan explains in an older post, butyrate appears to improve insulin sensitivity and blood lipids, decrease intestinal permeability, and provide protection against the development of certain gut disorders. Heck, our bowels even use the stuff as fuel. All in all, butyrate – which is also in butter – is a nice little short chain fatty acid with some nice health effects. On the other hand, soluble fiber can lead to absolutely epic bouts of in-house gas production. If you live alone, this may not be a problem. Just don’t order shirataki noodles and meatballs in red sauce on a first date, yeah?

You know, I’ve never actually had the urge to try them myself, but I don’t see anything wrong with konjac noodles. They might (okay, probably will) give you gas as the glucomannan is broken down in your gut, but they might also provide some butyrate production. Give ’em a shot and see what you think. If the gas is bearable or nonexistent, I see nothing wrong with eating shirataki noodles when pasta cravings strike, or even on a regular to semi-regular basis; just don’t let them displace more nutritious (macro- and micro-nutrient wise) foods.

Keep the questions coming, folks! I love answering them. Feel free to ask any followups in the comment section, and thanks for reading!

TAGS:  dear mark

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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