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Sabtu, 30 Agustus 2014

Scientists Probe the Interaction Between Saturated and Unsaturated High Fat Diets and Their Corresponding Carbohydrate Sources Cornstarch vs Fructose

This add is a perfect example of how saturated fat, in this case lard has always been blamed for the "lard" on ones hips.
Any hypothesis that tries to blame for our "fat misery" on a single nutrient is short-sighted. After years of fat-bashing, carbophobia and fructose hating in the course of which the situation progressively, we are now seeing the first studies which investigate what the Polish researchers, Adam Jurgoński, Jerzy Juśkiewicz and Zenon Zduńczyk from the Institute of Animal Reproduction and Food Research at the Polish Academy of  Sciences call the "biological interactions among these dietary factors" in their latest paper in the peer-reviewed open-source journal Nutrients (Jurgoński. 2014).

With the publication of the data of a their latest rodent study, the scientists have already taken the first step to a new, an "interactionist" perspective on the obesogenic effects of saturated vs.unsaturated and simple vs.complex carbohydrates and their interaction with another previously overlooked factor that has gotten quite some attention in the past months: The gut and its inhabitants.

Goodbye! Nutritional scapegoatism 

It goes without saying that this model study is nothing but a first step on a long road we still have to travel, but the differential effects the four diets (see Table 1)...
  • Table 1: Composition of the diets.
    the soybean powered high cornstarch diet (OS),
  • the lard-laden high cornstarch diet (LS), 
  • the soybean-powered high fructose diet (OF), and
  • the lard-laden high fructose diet (LF)
...had on the health, caecal short-chain fatty acid concentrations, cholesterol and triglyceride levels are revealing, to say the least.
World premiere! I know it sounds hilarious, but this is actually the first study I have seen that focused on nutrient interactions, instead of individual (macro-)nutrients in diets that are not even suitable to isolate the effects of the nutrient of interest - most prominent example the "high fat diet"  which is high in fat (45% of the energy is the standard; there are yet also "high fat" diets with only 32% of the total energy from fat; Gajda. 2008) but leaves enough room for carbohydrates to complement, some would say "trigger" the obesogenic effects by providing a pro-insulinogenic stimulus that will blunt the oxidation of the dietary fat and help drive it into the cells.
If you take a closer look at the actual study outcomes, you will see that the answer(s) the study provides are about as complex as its design.

In contrast to the dietary fat which had no independent effect on any of the measured markers of gut function, the carbohydrate source, i.e. cornstarch vs. fructose lead to significant differences in total small intestinal mass, mean pH of the ileal digesta and the mucosal activity of sucrase, all of which were increase on the high fructose diet.
Figure 1: Serum lipid levels of the rodents after 4 weeks on obesogenic diets containing different forms of dietary fat and carbohydrate (Jurgoński. 2014)
Interactive effects were observed for the mass of the cecum itself (the tissue) and the digesta with opposing effects of fructose on when it was administered in conjunction with lard (reductions) vs. soybean oil (increases in cecum mass). Slightly different effects were observed for the short-chain fatty acid composition (SCFA):
"Both the dietary fats and carbohydrates contributed to changes in the total SCFA concentration in the caecal digesta of rats (p < 0.05 and < 0 0.001, respectively). The highest total SCFA concentration was in group LS, while group OS had a significantly lower concentration (p ≤0.05). Similarly, the acetate concentration in the caecal digesta was influenced both by dietary fats and carbohydrates (p < 0.05 and p < 0.001, respectively) with a similar span of differences among particular groups (p ≤0.05). The type of dietary carbohydrate had significant influence on the propionate and isobutyrate concentrations in the caecal digesta (p < 0.001 and p < 0.05, respectively); however, both dietary factors had an interactive effect on their concentrations (p < 0.05). The highest propionate concentration was observed in the LS and OS group, whereas significantly lower concentration was found in the OF group. The lowest isobutyrate concentration was in group OF and it was significantly higher in group OS (p ≤0.05)." (Jurgoński. 2014)
The serum lipid profiles were influenced by both, the types of fats and carbohydrates as shown in Figure 1. Whats particularly striking, here, is the nasty effects of a combined lard + fructose feeding on the triglyceride levels.

A similar fat-dependence as for the fructose induced triglyceride boost can be observed for the levels of total and HDL cholesterol, which were increased only by the combination of fructose + saturated fat. In the rodents that received soybean oil with their coke, ... ah, I mean with their fructose, the researchers observed the exact opposite trend and a 5x lower yet similarly increased artherosclerosis risk (as evidenced by the 5x higher atherogenic index).
Suppversity Suggested Read: "EGGS - A Four-Letter Food Improves Both Cholesterol Particle & Phospholipid Profile + HDL-Driven Lipid Reverse-Transport" | read more
The results are still difficult to place. The complementary increases in total and HDL cholesterol in the lard + fructose group for example could be interpreted as unproblematic in view of the contemporary social media trend to depict high cholesterol as absolutely irrelevant. In view of the concomitant 2.3x increase in the ratio of triglycerides to HDL-cholesterol, of which we do know for sure that it predicts extensive coronary disease (Luz. 2008), it is still warranted to conclude that the combination of fructose and saturated fats is even worse than the combination of a high fructose intake with unsaturated fats, which had almost no effect on the triglycerides to HDL ratio and left the rodents in the corresponding group with a trig:HDL ratio what was >2.5x lower than that of the lard + fructose rodents.

Yes, I know - thats only rodent data, there is no information on body weight, or the gut microbiome and even the impact on glucose metabolism wasnt measured (you can predict from the triglyceride levels, though, that the animals lard + fructose diet had the lowest insulin sensitivity), the reason I still spent a whole article on this paper is that this is the kind of study, wed need if we actually want to understand "why we are fat" from the inexplicably popular (macro-)nutrient perspective... I mean, lets be honest: On the level of food items, the complexity is not a problem and we all know the food items that propel the obesity epidemic, dont we?
References:
  • Gajda, Angela M. "High fat diets for diet-induced obesity models." A Report for Open Source Diets (2008).

Melato Cola™ or What Fructose for Improved Glucose Metabolism and Melatonin to Counter Fructose Overload

There was a time, when Coke still contained "coke"... so why not add some melatonin for health benefits? I am obviously just kidding here, but a combination of fructose + melatonin may actually make sense.
The title of todays SuppVersity article is confusing, I know. Firstly, it contains the almost heretical notion that fructose could actually improve instead of impair your glucose metabolism and secondly it does not appear to make sense that you would have to use melatonin to counter the pro-diabetic effects of fructose, if the latter is in fact so good for you.

Before you are getting totally confused, let me clarify how the improvements in glucose metabolism and the melatonin-powered diabesity protection go together: Both have been observed in a recent study from the Pontificia Universidad Católica Argentina in Buenos Aires, Argentina (Cardinali. 2013), in the course of which the improved glucose metabolism was nothing but a side-finding of a study Cardinali et al. conducted to  examine the effect of melatonin when it is administered to rodents simultaneously with fructose in the drinking water.

This is the Coke + sufficient sleep study ;-)

Obviously this is not as the subheading would suggest the "coke + sufficient sleep study", but in light of the fact melatonin is after all the "sleep" hormone and in view of the results of a recent study by Senador et al. who observed that fructose had a negative effect on glucose management only, when it was available during the light phase (which is the inactive phase for a rodent; cf. Senador. 2012), it comes close; and that despite the fact that fructose timing was yet not an issue in the study at hand. Instead of modifying the timing, Cardinali et al. used different amounts of fructose with half of the rodents in the experimental arm of the study having a 5% and the other half having a 10% fructose solution as their main water supply.

Figure 1: Glycemia (mg/dL) 0-140min after 2g/kg body weight  glucose tolerance test (Cardinali. 2013)
If we trust the nutritiondata.com information about the average fructose content of a "carbonated beverage, cola, with higher caffeine" ...
  • the rodents in the 10% fructose group were consuming the total carbohydrate equivalent of coke, but with a 100% instead of ~50% fructose content, while
  • the rodents in the 5% fructose group were consuming less total carbohydrates, but roughly the same amount of fructose someone would ingest if he drank nothing but coke.
A direct comparison of either of the groups to the "coke only"-drinking human being is thus not warranted.

It is nevertheless intriguing that the 5% fructose group showed a significantly higher glucose tolerance - not just compared to the 10% fructose group, but also compared to the control group that was fed with water, only (see figure 1).
"Meta-Analysis: Lower Glucose, Insulin and HbA1c Levels From Catalytic Dose of 36g Fructose" | read more
"But isnt fructose the reason you develop diabetes?" Before we get on to the effects of melatonin, I want to emphasize that this is by no means an outlier, in fact, I have written about the catalytic effects of 36g of fructose in a previous post "6x Bananas a Day!? Meta-Analysis: Lower Glucose, Insulin and HbA1c Levels From Catalytic Dose of 36g Fructose" (learn more).

Previous studies have also shown that a 2:1 mixture of glucose + fructose is at least up to the regular glucose only drinks in terms of post-workout glycogen repletion (learn more) - partly because the fructose will keep the liver occupied, while the muscles suck up the glucose.
As previously mentioned the main research interest of the Argentinian scientists was not the effect of fructose on the glucose sensitivity of their rodents, but rather if the administration of 25 μg/mL of melatonin in the tapwater the rodents received would lead to significant changes in the study outcomes.
Figure 2: Effects of melatonin in drinking water with or without 5% [left] and 10% [right] fructose on body weight, systolic blood pressure and glucose response to glucose tolerance test (Cardinali. 2013)
As you can see in figure 1 it did: Melatonin did ameliorate the weight gain, and the increase in blood pressure that was observed even with only 5% fructose in the drinking water. It did not improve the glycemic response of the rats in the 5% fructose group even more, though, but it bulnted the negative effects of the 10% fructose solution had on the glycemic response in the glucose tolerance (figure 2, right).
SuppVersity Suggested Read: "Circadian Rhythmicity - Sunlight, Bluelight, Backlight & Co Mess Learn How THey W/ Your Internal Clock. Plus: Tips & Tricks to Prevent Negative Side-Effects" | read more
Is a melatonin solution the solution? If we also consider the negative effects of 10% fructose feeding on LDL (the rodents on 10% + Mel had even lower LDL than the control), the normalization of triglycerides and the potential therapeutic reduction in uric acid (-30% even vs. control), of which Cardinali et al. point out that it could have therapeutic effects in people with gout and other uric acid related metabolic disorders, it would appear smart that do dissolve the human equivalent dose of 21-35mg melatonin in your drinking water in the morning and keep guzzling it all day long.

Well, as I said, it "would appear to be" smart, but is it really smart? I wouldnt be too sure about that. Despite the fact that that you probably wont die, the chronically increased systemic melatonin levels could have long-term negative consequences on your circadian rhythm that could undo all potential benefits.

Restricting your fructose intake to fructose from fruit, only, getting enough sleep and using melatonin timely, i.e. 20min before bed would thus appear to be a more prudent approach to improve / maintain optimal blood glucose levels and insulin sensitivity. And if you are more into hard facts than "erring on the side of caution", you may consider the acute decrease in glucose tolerance, Cagnacci et al. observed in postmenopausal women, when they participated in a blood glucose test after the administration of 1 mg melatonin more convincing (Cagnacci. 2001).
References:
  • Cagnacci A, Arangino S, Renzi A, Paoletti AM, Melis GB, Cagnacci P, Volpe A. Influence of melatonin administration on glucose tolerance and insulin sensitivity of postmenopausal women. Clin Endocrinol (Oxf). 2001 Mar;54(3):339-46. 
  • Cardinali DP, Bernasconi PA, Reynoso R, Toso CF, Scacchi P. Melatonin may curtail the metabolic syndrome: studies on initial and fully established fructose-induced metabolic syndrome in rats. Int J Mol Sci. 2013 Jan 25;14(2):2502-14.
  • Senador D, Shewale S, Irigoyen MC, Elased KM, Morris M. Effects of restricted fructose access on body weight and blood pressure circadian rhythms. Exp Diabetes Res. 2012;2012:459087.