Fructose Epimer D-Psicose Could Be First Sweetener to Actively Promote Weight Loss: Reduced Weight Gain and Direct Inhibitory Effect on Adipocyte Maturation in Rodent + Reduced Postprandial Glucose & Insulin in Human Trial

Image 1: No, just a few grams of d-psicose won't turn these into a "health food", but it could help ameliorate the "damage"

Good news for everyone with a sweet tooth! Right after stevia has finally made it to the European market, the next 1/2 natural sweetener is at the ready. It's called d-psicose and it is a cousin of fructose that is yet only 70% as sweet as sucrose (fructose is +20% sweeter than sugar) but has only 0.3% of its energy content. In other words on a per calorie base it is 233x sweeter than sugar. That alone would however hardly justify an individual blogpost. What is yet exciting about this molecule is that a recently published rodent study does suggest that it can inhibit adipocyte maturation and thusly exerts direct anti-obesity effects.

The first sweetener that will actively help in weight loss?

In the course of a 12-week trial, a group of Sprague-dawley rats was initially fed up with the standard laboratory "high fat diet" that is essentially an identical twin of the standard American diet with 15.1% of the energy from protein, 38.8% from fats and 47.1% from carbohydrates. After four weeks the rodents were assigned to different groups, which were either switched over to a standard diet (14.7% protein, 9.4% fat, 76.9% carbohydrates) or were maintained on the energy-dense high fat diet. Each of the study arms had another 5 sub-groups the animals in which received, either

• normal (ND) or high fat (HF) diet without supplement (control),
• ND or HF + 5% sucrose (SU-5),
• ND or HF + 5% erythritol (ES-5),
• ND or HF + 2.5% d-psicose (DP-2.5), or
• ND or HF + 5% d-psicose (DP-5)

for another 52 days. The food intake and body weight of the animals was measured three times a week. At the end of the study, serum levels of total cholesterol (TC), triglycerides (TG), LDL-C and HDL-C were measured and biopsies were conducted to evaluate adipose tissue and liver weight.

Figure 1: Change in body weight, total food intake and feed efficiency (right axis) in the 2nd half of the study (data adapted from Chung. 2012)

As you can see in figure 1 there was a dose-dependent decrease in body weight gain, which left the rats in the HFD - ND-DP5 group, i.e. those animals who had been fattened up for 4 weeks and were then switched to a "normal" diet supplemented with 5% of d-psicose (with a food intake of ~20g per day, whit would be 1g per day, or in human terms ~ 0.3g/kg) at a final body weight level that was identical to the animals who had never been fat in the first place - and that despite a slightly higher food intake.

Could d-psicose be an ideal adjunct to your weight loss regimen?

In this context, it is important to note that the previously fattened rodents were already 23% "overweight". In other words, while the rodents on the normal diet kept gaining weight at a rate of 2.4-2.7g per day, the weight gain of the "fat" rodents in the ND-DP5 group was so profoundly ameliorated that they ended up at the same "normal" weight at the end of the study as the intially non-obese rodents on the standard diet. And even without the dietary switch, the addition of 5% d-psicose led to a profound (-50%) reduction in diet induced weight gain in the high fat group.

Figure 2: Total white adipose tissue (right axis, in g), epididymal, perirenal and retroperitoneal visceral fat (in g) in the different groups at the end of the post-fattening 52-day feeding period (data adapted from Chung. 2012)

And while the addition of the C-3 fructose epimer lead to a reduction in body fat in all animals, only the animals who had been switched to the high carb (=normal) diet, achieved body fat levels identical (2.5% d-psicose) and even below (5% d-psicose) those of the rats in the control group (cf. figure 2).

Lose weight, lose fat, but what about your liver?

Yet despite the fact the combined "weight loss effect" of the "normal" (=low fat) diet with supplemental d-psicose is thusly fundamentally different and unquestionably way more desirable than the "Half as Heavy, Twice as Fat" effect of the Atkins diet (cf. news from last Friday), the structural kinship of d-psicose and fructose raises the question if the former did induce similarly detrimental health effect on the liver as its notoriously sweet cousin.

Figure 3: Light image of liver tissue sections from ND, ND-SUS and ND-DP-5 groups (adapted from Chung. 2012)

The light image of liver tissue sections from the ND, the ND-SUS and the ND-DP-5 group does yet show that the dreaded NAFLD fatty deposition did not occur in the DP-5 group. The statistically significant increase in liver weight, on the other hand, is something the researchers attribute to increases in hepatic glycogen stores:

Our results [...] showed that ND-DP group tended to induce liver enlargement suggesting increased glycogen deposition in liver as extra-energy storage of d-psicose. However, HF-DP group did not show any difference compared to HF group. It is possible that HF diets containing relatively low carbohydrates [...] induced lower liver glycogen level masking the effects of d-psicose.

Moreover, previous long-term studies (12-18 months) by Yagi & Matsuo did not reveal any adverse side-effects in relation to the d-psicose induced increase in liver weight (Yagi. 2009).

Figure 4: Lipid profiles (triglycerides, LDL-C and HDL-C) at the end of the study period (data adapted from Chung. 2012)

The totally normal lipid profile (cf. figure 3), with lower triglyceride and cholesterol levels than the control group and identical total cholesterol to HDL-C (control: 1.73; DP5: 1.89) and LDL-C to HDL-C (control: 0.39; DP5: 0.39) ratios also supports the notion that, despite its "frutosian heritage", d-psicose is not promoter of diabesity and metabolic disease.

Bottom line: Promising, but more than one human study would be nice

Image 2: Sponge cakes made without addition, with fructose or with d-psicose (img courtesy of the Kagawa Industry Support Foundation)

If we add to that the results of a previous human trial, in which d-psicose administration reduced the postprandial glucose and insulin response following the ingestion of 75g of maltodextrin with 5g of d-psicose (Lida. 2008), and take into consideration that the incubation of pro-adipocytes with d-psicose led to a dose-dependent inhibition of adipocyte differentiation in the study at hand, the fructose epimer d-piscose could in fact turn out to be way more than just another artificial sweetener. And as you can see in image 2, the first practical applications, or should I say highly marketable "nutritional idiocies" are already on their way: Yummy sponge cakes ;-)

Science Round-Up Seconds: Rare Sugar Syrup, HFCS 2.0? Body Recomposition W/ 7 Marathons in 7 Days!? Reduced REM Sleep With Intense Workouts in the Evening.

99% of the guys & gals on this photo are not going to see anywhere similar improvements in body composition from marathon running as the highly trained 7x7 runners in the Karstoft study.

It's Friday and that means its time for the wrap-up of yesterday's installment of the Science Round-Up on SHR. Well, let's see then what this weeks Round-Up of the Round-Up has to offer. Somehow I felt like picking up something we did actually cover in the live-show yesterday (download the podcast here). I guess I want to give everyone the chance to look at the data himself in order to decide whether "rare sugar syrup" (RSS) is going to be the savior of the Western world and the unfortunate rest who's currently "westernized" by the big Ms, the big As and the rest of the corporate alphabet soup with a vested interest in the prosperity of mankind, or - to be precise - that the part of mankind who owns their shares ;-)

Rare Sugar Syrup has 90% of the sweetness of regular sugar + "cleaner taste" than HFCS

(IIda. 2013) -- Assuming that you've by now all listened to the podcast, I will stick to some additional explanations, citations and graphs in this follow up.

While D-psicose is not the only fructose epimer in rare sugar syrup, it is probable the one with the most potent beneficial effects on blood glucose management (learn more). One potential caveats of RSS is that its d-psycose content is only 5% with te rest being other hexoses including D-allose, D-sorbose, and D-mannose,

As the scientists point out, the main intention of their study was to assess whether their rare sugar syrups would suppress

"body weight gain and abdominal fat accumulation in rats fed on diets composed of different carbohydrate sources: starch, starch + HFCS (50:50), and starch + RSS (50:50) were examined. (Iida. 2013)"

Accordingly, they maintained their rodents on otherwise identical diets containing (on a per weight not per kcal basis!) 57% carbs, 18% protein, 4% fat, cellulose, added methionine and a couple of vitamin and trace elements with either plain corn starch, corn starch and HFCS or cornstarch and rare sugar syrup (see figure 1, left).

Now, as mentioned in the show, there is no debating that this feeding regimen worked and with "90% of the sweetness of sucrose, and a more rich and clean taste than HFCS" replacing HFCS with RSS could even improve the taste of respective products, but let's be honest: How likely is it that we are going to see products without HFCS and 50% of rare sugar syrup actually making up the lion's share of the processed junk in the super market anytime soon?

Figure 1: Carbohyrate content of the diets and weight of different visceral fat pads after the 8-week dietary intervention in otherwise healthy rodents on a cornstarch only, cornstarch + HFCS or cornstarch + RSS diet (Iida. 2013)

Isn't it more likely that you will see labels like "now with rare sugars" on the front of the packaging and the hardly legible figure "contains 3% carbohydrates from rare sugars" hidden on its back? I would think so and the fact that neither this study nor the general existence of this HFCS substitution did as of now hit the media certainly doesn't refute contradict this hypothesis.

7 marathons (!) in 7 days - A marathon a day keeps the fat stores at bay?

(Karstoft. 2013) -- I probably don't have to preface this part of the seconds with a "don't do this at home" (or anywhere else ;-), but I think it's nevertheless newsworthy that accordingly trained people can actually run 7 marathons  in 7 days without the dreaded negative effects the average bro is expecting when he is just walking for 40min on a treadmill.

Figure 2: Body composition before and after the race (left) and changes in markers of muscle damage as well as hormonal changes and differences in markers of blood glucose management (right) in 8 experienced recreational runners participating in a multiple-marathon running event in which 7 marathons were completed on consecutive days (Karstoft. 2013)

Doesn't look so bad, ha? The reason I still stick to the initially voiced recommendation not to copy this protocol if you intend to lose body fat is pretty simple. The main reason "nothing" happened here is that the subjects were conditioned to run marathons.

That's the same "repeated bout effect, we have seen only a couple of days ago in the "No Pain No Gain" post (click here to go back) and the ~2kg of "muscle mass" are (despite being measured with DEXA) probably rather a result of glycogen hyper-compensation from tons of energy gels and pasta (the subjects did not follow a prescribed diet, but simply ate, drank and supplemented what had helped them on previous marathons), than structural increases in muscle tissue.

No high intensity training before a good night's sleep

Unless you have read the SuppVersity Circadian Rhythm Series, you have no right to complain about being overweight or undermuscled (read it ;-)

(Wong. 2013) -- After listening to the show, you know what you got to do once you got out of the bed, namely to switch on your bright light therapy lamp, but what do you have to do before you go to bed? I did actually discuss most of the things you should do (curtains, ear-plugs, turn the temperature down, etc.) in the Circadian Rhythm Series, but with the recent publication of a study by Wong et al. there is another thing you should - or in this case should not do and that's working out at a high intensity.

According to the results the researchers present in their soon-to-be-published paper in the Journal of Sports Science, a cycling exercise at intensities of  65% and 75% VO2Max lead to significant increases in light sleep and reductions in the recuperative REM sleep from 22.5% to 19& and 18.7% of the total sleep time.

Light exercise, in this study done at 45% and 55% of the VO2max, on the other hand did not have these side effects it did however not improve sleep, which is by the way an urban myth of which Driver and Taylor wrote in a Y2k paper in the Sleep Medicine Review that it "has yet to be established empirically" (Driver & Tailor. 2000).

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That's it for today, unless you want to head over to the SuppVersity Facebook Wall and check out some of the news that are already available over there, e.g.

• 

  Newsweek title from the year 2000 - "Fat for Life?"; did his mother love her soy protein more than her son's health? (learn more)

  "High" dose supplementation with vitamin C and/or E increases cataract risk - 1,000mg of vitamin C increase the risk +36% and 100mg of vitamin E by 57% (read more)
• Aerobic fitness could have greater impact on academic achievement than obesity -- Although obesity is a concern for children, this study shows that aerobic fitness can have a greater effect on academic performance than weigh (read more) 
• Aqua Mel, Portuguese "folk medicine" works for the alleviation of simple symptoms of upper respiratory tract -- Effect probably mitigated by the phenols in the honey this product is made of (read more).
• Serum albumin carries cholesterol out of the cells -- Hitherto scientists thought that this was a prerogative of HDL (read more)

If you don't like these or the other ones I did not mention just wait for further news to be posted. Alternatively switch of the computer and your mobile devices and head off into a well deserved weekend!

Don't worry, there is going to be a whole heap of short news tomorrow, you won't get bored... ah, you don't get bored on the weekend, anyway - do you?

References:

• Driver H.S., Taylor SR. Exercise and sleep. Sleep Medicine Reviews. 2000; 4(4):387–402
• Iida T, Yamada T, Hayashi N, Okuma K, Izumori K, Ishii R, Matsuo T. Reduction of abdominal fat accumulation in rats by 8-week ingestion of a newly developed sweetener made from high fructose corn syrup. Food Chem. 2013 Jun 1;138(2-3):781-5.
• Karstoft K, James Solomon TP, Laye MJ, Pedersen BK. Daily Marathon Running for a Week - the Biochemical and Body Compositional Effects of Participation. J Strength Cond Res. 2013 Feb 25.
• Wong SN, Halaki M, Chow CM. The effects of moderate to vigorous aerobic exercise on the sleep need of sedentary young adults. J Sports Sci. 2013 Feb;31(4):381-6.