Category Archives: fiber

Almonds: nutrition’s coolest drupe, Op. 89

(it’s a “drupe,” not a nut.  [Thank you Wikipedia.])

Should almonds be upgraded from “snack” to food?  Should almond flour be used in place of some or all white flour?  Yes and yes, IMHO.

In 2007, Josse and colleagues did a quick-and-dirty study on almonds and glucose tolerance.  They fed a group of volunteers 50 grams of carbs from white bread and either 0, 30, 60, or 90 grams of almonds and then measured blood glucose over the following two hours.  “Quick” because they probably had almonds and bread in the refrigerator, and glucometers in their desk drawers; “dirty” because there were a lot of uncontrolled variables; for example: fiber, protein, and fat content of the test meals differed wildly:In a proper study, they might have tried to feed everyone the same amount of fiber, protein, and fat, because each of these is known to affect blood glucose.  In any case, the result was pretty cool:

Whole almonds dose-dependently blunted the blood glucose response to the test meal.  Conclusion: almonds = anti-hyperglycemic.  But almonds are complex lil’ things; they’re made of protein, fat, fiber, and a lot of nutrients; so what’s responsible for all the anti-hyperglycemic effect?  this post is not simply an academic pursuit; indeed, almond flour and almond oil are commercially available, affordable, widely used, and are comprised of different fractions of the almond.  So Mori and colleagues decided to study.

Acute and second-meal effects of almond form in impaired glucose tolerant adults: a randomized crossover trial.  (Mori et al., 2011)

In this excessively high quality study, the effect of 4 different types of almond preparations on glucose tolerance was assessed.

What was tested (in a FIVE-WAY crossover study):
WA = whole almonds
AB = almond butter
AF = defatted almond flour (remember this stuff? lacks all the bifidogenicity of regular almond flour )
AO = almond oil
V = vehicle: negative control.

Basically, the participants were fed a breakfast of OJ and Cream of Wheat with the equivalent of 33 almonds (42.5 grams) for a total of 75 grams of carbs, and blood glucose was measured over the next 2 hours.

Notable nutritional differences between the almond preparations:  they all contain a similar fat content except for the defatted almond flour; whole almonds and almond butter have 2-3 times more fiber than almond flour and almond oil; almond oil has half the protein as all the others.

In brief, no almond preparation affected insulin or free fatty acids.

Whole almonds, almond butter, and almond oil, on the other hand, all blunted the glycemic response.  Defatted almond flour, which only really differs in its lack of almond fat, did not.  Thus, according to last post, almond fat is a potent bifidogen (i.e., good for gut bacteria); and now we see it’s also responsible for the anti-hyperglycemic effect of almonds.  These two effects are probably unrelated, however, as any effect on gut bacteria will take significantly longer than a few hours as the almond fat hasn’t even reached the large intestine by then… (the anti-hyperglycemic effect is evident within 2 hours; the bifidogenic effect noted by Mandalari was 8-24 hours).

OK, almond fat slows the absorption of glucose, so what? this is not exciting… it’s common among most fats- “dietary fat reduces the glycemic index of food.”  But this has a greater implication: one could alternatively conclude that almond flour’s lack of fiber was at fault, as dietary fiber is also known to slow glucose absorption.  However, almond oil, which has even less fiber than defatted almond flour, was also anti-hyperglycemic.  So it’s not the fiber (… perhaps because almond fiber is predominantly insoluble).

With regard to all-things-almonds: almond fat, not almond fiber, is anti-hyperglycemic and bifidogenic (what can’t it do?).

Almond fat: +2

Solution: whole almonds (with meals?), almond oil (with whatever), and regular [non-defatted] almond flour (for baking?).  WRT the latter, get all the benefits, a boost for the gut microbiota, and significantly fewer carbs than with white flour (while actually attenuating the glycemic impact of said white flour).

An argument for almond flour: most baked goods are made with white flour.  These foods are predominantly empty calories, the bane of human health and well-being.  Substituting almond flour for white flour is one way to decrease the emptiness of those calories, and thus of life itself (it’s gluten-free too).

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The day almonds became interesting.

Non-sequiter nutrition: Atwater’s almonds, et al., Op. 87

Almonds have been considered a super-food for as long as I can remember.  And in accord with my level of interest in super-foods, I’ve never cared.  Today, however, almonds became interesting. One small serving of almonds (1 ounce or 28 grams) provide ~171 kilocalories (alternatively, 100 calorie packs have, well, 100 kilocalories).  This measurement of a food’s energy content takes into account the amount of heat produced when it is electrocuted in a bomb calorimeter as well as its digestibility.  The importance of taking both of those things into consideration?  Marshmallows and tree bark produce a lot of heat when they burn.  Unlike marshmallows, however, a tree bark smoothie wouldn’t give us any energy because we can’t digest wood.  This is further complicated because digestibility of a food consumed by itself can differ when it’s eaten with a meal.

Usually, and unlike carbs and protein, the digestibility of fat is impeccably high and unvarying.  Almond oil, however, might be an exception in more ways than one.

Discrepancy between the Atwater factor predicted and empirically measured energy values of almonds in human diets (Novotny et al., 2012)

This was a ridiculously complicated study designed to determine the calories in almonds.  It was a three-way crossover with 18-day feedings of 0, 42, or 84 grams of almonds per day (0, 1.5, or 3 ounces per day).  The researchers gave the volunteers ALL of their food for the entire study, and in exchange, the volunteers gave the researchers the byproducts (urine, feces) for the second half of each feeding period.  This is already an expensive and extremely  labor-intensive study, but I think they were trying to do more than just quantify the calories in almonds; I think they were trying to stick-it-to-the-man.

N.B. the almonds were eaten with normal meals.  The diet was normal.  There are no tricks up my or the researcher’s sleeves.  And I’m honestly fascinated by Table 2.

1.5 servings of almonds (42 grams) had a phenomenal effect on food digestibility.  And 3 servings doubled the amount of non-absorbed calories.  In the beginning of the post I noted that a serving of almonds had 171 kilocalories.  But a serving of almonds increases the non-absorbed kilocalories by about 50.  So does this mean we should re-assign a serving of almonds to 121 kcal?

Yes, the authors decided; and I agree.  And I think this sticks-it-to-the-man.  Perhaps this is the source of almond weight loss lore (?)… imagine the fastidious dieter who weighs out 3 servings of almonds for their daily snack, accounts for the 513 kilocalories in their food diary (but is really only getting 357 kilocalories), and they lose weight…  and those 100 calorie packs only have 68 calories.  Ha!

OK, but just out of curiosity which calories aren’t absorbed?  Are almond calories poorly absorbed, or do almonds block the absorption of other nutrients?

From Table 3, it’s probably fat.  Combined with earlier findings from Ellis, it’s probably almond fat that was trapped inside delicious and crunchy cell walls (Ellis et al., 2004).

In brief, Ellis measured almond fat after three treatments:

1)      Mechanically crushing the almonds

2)      Chewing the almonds (and measuring spit-out almond fat)

3)      Eating the almonds (… and measuring accessible fecal almond fat)

The first two methods didn’t release a lot of almond fat, but the third did, by a little.  As opposed to crushing or chewing, after actual digestion, gut microbes degrade the crunchy cell walls to release the almond fat contained therein.  Unfortunately, however, fat absorption is very inefficient in the large intestine (where this is all happening), which is why the almond fat is either fermented or excreted.

So at this point we’ve got more fat, but also more carbs and fiber from the almond cellular structures making their way into the large intestine (on a high almond diet)… what do the resident microbes have to say about all of this?

A lot, according to a series of studies by Mandalari and his robotic gut simulator  (Mandalari et al., 2008).

Unless you are seriously constipated, the bacterial changes after 24 hours of fermentation are irrelevant.  Looking at 8 hours, which is probably more physiologically relevant, gives us this:FOS, fructooligosaccharides; FG, finely ground almonds; DG, defatted finely ground almonds.

Table 2 (above) is, in a word, perplexing.  Whether or not Mandalari set out to stick-it-to-the-man, he sure did (unless that is just a thing with almonds [?]).  Similar to FOS, almonds had a relatively potent bifidogenic effect.  This is not surprising because of almond’s high fiber content.  What was surprising, however, was that this is completely absent in defatted almonds.  The fiber is the same in almonds and defatted almonds, therefore there is something uniquely magical about almond fat and the long series of unfortunate unlikely events that must occur in order for the bifidogenic effects of almonds to manifest.

The unlikely events: the almond fat must first be protected during chewing and digestion, otherwise it would be absorbed in the small intestine, before it made it all the way to the more “microbial” large intestine.  This is accomplished by almond’s robust cell walls.  Almond fat needs to be released in the large intestine; this requires microbes and is therefore less likely to occur in the small intestine (where microbes are less abundant; if there were more microbes in the small intestine, the almond fat would be released and absorbed before it made it into the large intestine).  The almond fat needs to be not absorbed in the large intestine so it can exert its bifidogenic effect; this happens because the large intestine is inherently poor at fat absorption.  Everything must be exactly in place (kind-of-like in M. Night Shyamalan’s “Signs”): almond’s cellular structure, the intestine’s region-specific digestive enzymes, microbial geography, differential fat absorption capacity, etc., etc.  It’s like an astrological event that occurs once every million years.


Back to the Novotny (Atwater) study for a moment.  48 grams (1.5 servings) of almonds only provide about 5 grams of fiber, but it increased stool weight by almost half.  Fiber is known to increase “regularity,” but the effect of almonds is pharmacologically disproportionate to it’s fiber content.

According to a review by Ahmad (2010), almond oil improves bowel transit time and reduces the symptoms of irritable bowel syndrome.  Not whole almonds.  Not almond fiber.  Almond oil.  And injecting it might even cure IBS (don’t try this at home; Sasaki et al., 2004).

Is it time for a paradigm switch?  Will almond oil open the door for other fats to be researched for bona fide prebiotic properties, akin to inulin and GOS?

Indeed, almonds became interesting today.

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Candy in disguise II, Op. 87

Rundown on a few new protein bars, pro’s & con’s, etc.

Perfectly Simple by ZonePerfect
The catch: 3 new bars with 10 or fewer ingredients.  All are gluten-free and have 10 grams of protein.

as the number of ingredients increases, so does the sugar

Peanut Crunch: “invert evaporated cane juice”
Toasted Coconut: “invert dried cane syrup”
Cranberry Almond: “date paste”

It takes more sugar in the form of “date paste” (Cranberry Almond, 19 g sugar) to compensate for the lack of “invert evaporated cane juice” (Peanut Crunch, 14 g sugar) or “invert dried cane syrup” (Toasted Coconut, 16 g sugar).  Invert sugar is basically table sugar (sucrose) that has been broken down into glucose & fructose.  1) It’s sweeter, which is why you need less of it; and 2) it’s essentially identical to high fructose corn syrup = used in everything from candy and crackers to cigarettes and soda.  Not good.

Active X Energy Bar
Kosher, organic, but not gluten-free.

Pro’s: less sugar and more fiber than ZonePerfect’s Perfectly Simple. 

These bars rely on the sweetener brown rice syrup which is primarily glucose (significantly less fructose than invert sugar), but it’s complimented with agave (significantly more fructose than invert sugar)… end result?  Organic high fructose corn syrup (a polished turd).

Good2Go bars

High protein, moderate sugar, and preservative-free.

These bars are sweetened with honey, brown rice syrup, invert sugar, and a little coconut sugar.  These bars have more protein and less sugar than both Perfectly Simple and ActiveX.

Last but not least, my personal favorite in the “coolness” department: Chapul.

Pro #1: they owned it!  “sugar” actually appears in the list of ingredients.

Pro #2: while it’s only 6 grams of protein, you’ll never guess where it comes from… crickets!  Yes crickets.  Baked, then ground into a fine powder.

Con: the most sugar and least protein of all.

To put this all into perspective: relative to the nutritional profile of Quest protein bars, these noobs pale in comparison.

Conclusion: candy in disguise.  just sayin’.

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Dark chocolate meets probiotics; the bifidobacteriomance continues

or the next big thing in functional foods, Op. 84

Altered gut bacteria can cause a whole host of problems, anywhere from depression and fatigue to ADHD and heartburn.  Thus, while running my daily search for “bifidobacteria,” I happened across these little goodies: 

The Attune Foods Dark Chocolate Probiotic Bar.  Combining probiotics (e.g., bifidobacteria, acidophilus, etc.) with chocolate?!  And with 68% cocoa, I’d expect this bar to deliver at least some of the benefits of dark chocolate (e.g., improved insulin sensitivity). They’re gluten-free and even contain inulin! (my second favorite bifidogenic prebiotic.)

And it packs a big, or rather huge, probiotic punch (6.1 billion B. lactis HN019, L. acidophilus NCFM, & L. casei LC-11).  Attune loses a little cred by trying to disguise their sugar as “evaporated cane juice,” like it’s something inherently healthier than plain old sugar… just like all-natural agave syrup, honey, and organic coconut blossom sugar.  just own it for crying out loud.  On the other hand, at only 6 grams, the sugar in Attune’s bar is harmless especially in the context of the high cocoa content, inclusion of inulin, and whopping dose of probiotics.

But, chocolate & probiotics?  Alas, the curiousity bug had bitten.

Apparently, a lot of companies think dark chocolate is a good vehicle for probiotic delivery.

GI Health’s Probiotic Chocolate is gluten-free and contains a half billion L. helveticus R0052 and B. longum R0175 per serving.  A half-billion is low by conventional standards*, but such standards might be irrelevant if the delivery vehicle (i.e., chocolate) is superior.

*Most probiotic products are rated (by me) by the number of live bacteria per serving, or “colony forming units (cfu).”  This is usually in the billions because most die in transit, thus the importance of the delivery method.  Yogurt and apparently now chocolate seem to be good delivery vehicles, however, yogurt and most probiotic pills require refrigeration; these chocolate products do not.  And neither do Nature’s Way Probifia Pearls, although they are the only pill that doesn’t (I suspect alien technology).

gimme Probiotics Dark Chocolate Candies, Youngevity Triple Treat; the list goes on and on.  Apparently, I was late to the game… (expect to see these in your local grocer soon.)

Enough shameless promotion, what about the data?

Possemiers (2010) set out to test how well probiotics survived in a robot gut simulator when mixed in chocolate.  1 billion L. helveticus CNCM I-1722 and B. longum CNCM I-3470 were mixed with either chocolate or milk.  An astounding 85% of the probiotics survived when administered in chocolate compared to only 25% with milk.  FYI the study was funded by Barry Callebaut, a fancy Belgian chocolate maker who is currently developing their own line of probiotic chocolates … it’s not a conflict of interest, it’s what companies should be doing IMO (while an independent third party would be optimal, any data are better than none).  I have no idea how well their robot gut simulator emulates actual human digestion, but these results suggest that chocolate is [at least] potentially a good candidate to deliver probiotics.

An additional benefit of loading probiotics into chocolate is that cocoa itself can function as a prebiotic.  Tzounis (2011) gave real-life live humans cocoa every day for 4 weeks and showed that bifidobacteria increased dramatically.  These findings were confirmed by Fogliano (2011), who showed (via another robotic gut simulator) that water-insoluble cocoa fractions (e.g., cocoa fiber) alone markedly stimulated the growth of bifidobacteria.

So: 1) chocolate is a good vehicle to deliver exogenous bifidobacteria; and 2) cocoa promotes the growth of endogenous bifidobacteria.  win-win.

Why is this relevant?  because probiotics by themselves don’t survive the trip!  They die off somewhere between the factory and your large intestine.  In a study by Prilassnig (2007), 7 people were fed one of 6 different commercially available probiotics for a week.  2 of the products contained bifidobacteria, Omniflora and Infloran.  None of the bifido in Omniflora survived in any of the volunteers, and the bifido in Infloran was detectable in only 1 out of 4.  Feeling lucky?

Thus, chocolate may be not only viable, but an optimal way to administer probiotics.  The bifidobacteria can feed on the cocoa while in transit (from the factory to your cupboard to your bowels), and the cocoa can directly stimulate them along with your native gut flora.

And chocolate with GOS?!  according to Davis (2010), chocolates enriched with 10 grams of GOS increased endogenous bifidobacteria a whopping 3-fold.

Formula for the healthiest chocolate on Earth? >70% cocoa, a billion bifidobacteria, and a few grams of GOS… don’t get your hopes up, however, this won’t likely be made any time soon.  Despite all of the data showing the remarkable health-promoting properties of GOS, it’s still not widely commercially available.  In the meantime, Attune’s use of inulin will have to suffice.


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Decepticon Promicor (soluble corn fiber), Op. 81

I heard a comedian say he wished exercise was like high school; once you get your diploma, that’s it.  You never need to do high school again.  Unfortunately, the same isn’t true with artificial nutrition.  the mad food scientists are at it again.

Enter: Soluble corn fiber (SCF), mass produced by Megatron Promitor

Over a decade ago, Atkins released low carb bars.  Well, they weren’t actually low carb per se, they were low sugar.  This was accomplished by replacing sugar with glycerol (a sugar alcohol) and polydextrose (a pseudo-fiber).  While their bars are made from cheap ingredients and low quality protein, sugar alcohols and pseudo-fibers are certainly better than sugar.

Later, sugar alcohols took off in popularity, appearing in Met-Rx Protein Plus, Detour Lean Muscle, Dymatize Elite Gourmet, etc., etc.  Glycerol was prominent in Labrada and Pure Protein bars.  Supreme Protein bars use glycerol and maltitol, and a LOT of ‘em.  Quest took a stand against glycerol and uses the lower calorie and more stomach-friendly erythritol (if it ends in “-ol,” its probably an alcohol).

More recently, the field took a considerable philosophical leap forward and starting using real fiber, good fiber.  Inulin appeared in some Atkins bars, VPX Zero Impact, and the original Quest bars.  Quest has since switched to another good fiber, isomalto-oligosaccharides.  Unfortunately no one is using GOS, yet, but they will … mark my words (that’s a prediction, or stock tip… not a threat).

But now the field has taken a turn and we have another artificial ingredient, a pseudo-fiber, with which to deal.  “Soluble corn fiber (SCF)” first appeared in Splenda Fiber packets and then in Promax LS bars.

If you’re like me, you’re asking yourself: what is this stuff?  Is it real fiber?  Is it like the super fibers inulin and GOS?  Hello Pubmed

Divide and conquer

Stewart (2010) compared SCF to 3 other fibers and maltodextrin, 12 g/d x 2 weeks =

Pullulan, a rather potent fiber, is not well-tolerated.  Resistant starch (an insoluble fiber), soluble fiber dextrin, and SCF were all OK.  The gut microbiota seemed to have no preference, as short chain fatty acid production was similar in all groups (perhaps 12 grams is subthreshold?).  Similarly, health biomarkers, hunger levels, and body weight were unaffected.

Boler (2010) compared a commercially available SCF preparation to polydextrose, 21 grams per day for 21 days in 21 healthy men (cute.)

NFC, no fiber control; PDX, polydextrose; SCF, soluble corn fiber

In this study, however, SCF didn’t do so well.  It caused gas and reflux.  Perhaps this wasn’t observed in Stewart’s study because of the lower dose (12 vs. 21 grams).  Furthermore, polydextrose reduced while SCF increased short chain fatty acid production, both of which resulting in a higher acetate:butyrate ratio.  So unlike 12 grams of any of Stewart’s fibers (including SCF), the gut microbiota seems to respond to 21 grams of SCF.  And they pooped more (both fiber groups).

Data are expressed as log cfu/g feces.

Interestingly, SCF was remarkably bifidogenic.  Much more so than PDX, MOS (see Yen et al., 2011), and inulin (see Menne et al., 2000), but WAY less than GOS (see Silk et al. 2009).

the holy grail

This same group reported a more detailed analysis of the gut microbiota which unfortunately did NOT exactly confirm their earlier finding (Hooda et al., 2012):

Data presentation is different in the two publications, and if both are true, then SCF selectively increases a few specific strains of bifidobacteria but reduces many others (enough to increase the total amount but decrease the variety).  The functional implications of this are unclear (to me).

In the meantime, SCF appears to be at most an OK pseudo-fiber substitute.  Megatron Promitor is not likely to test it against the super fibers (e.g., inulin, GOS, etc.) any time soon, so we won’t know if it’s an advance or simply a side-step.  Such is life.

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