Is Air Frying Healthier Than Deep Frying? Which Oil's Best for Each Method and How Do They Compare to Cooking?

Air- or deep-frying, what's healthier? For most people that's not even a real question... rightly so? 

"That's even a question?" I know, I know... With the health aura surrounding air frying it appears to be hilarious to even base a complete episode of SuppVersity | True or False on the question whether air frying is in fact so much healthier than deep frying, but listen up: a recent study from the University of Porto says that "most chemical parameters were similar on both frying processes, including [pro-carcinogenic] acrylamide content" (Santos 2017).

Can it really be that the air frying devices are another overhyped kitchen device you don't really need?

Lean more about frying & co at the SuppVersity

The Quest for the Optimal Frying Oil

MUFA Modulates Gut Bacteria → Weight Loss

Taste of Olive Oil Heals - Flavor's Enough!

GMO Soybean Oil Proven to Be Pro-Inflammatory

"Pimp My Olive Oil" - W/ Extra Antioxidants

Frying Does not Just Oxidize Oils, It Does Fat More!

If you bought one of these devices and use it regularly, you will be happy to hear that the answer to this question is a categorical "no". There's little, or I should say "no" doubt that air frying will produce healthier (not healthy) fried foods than deep frying and the example of everyone's favorite fried food, Pommes Frites or as my American friends say "fries", exemplifies why:

• 

  Figure 1: The 70% reduced fat content in air-fried potatoes is not just an advertisement claim (Santos 2017)

  Air frying will reduce the amount of fat and thus the caloric content of the fried foods: For classic fries Santos et al calculated a 70% reduction in fat and thus 45 kcal less per 100 g 
• Air frying will do less harm to antioxidants like vitamin C: Even though the fries in Santos study showed only "slightly better results" for the amount of ascorbic acid in the final product, it's the trend that counts - especially, in view of the fact that you may expect to see similar effects with other foods and/or antioxidants.

But air fried fries don't taste well, do they? Well, in the study at hand, the 10 assessors, including professors, investigators and students (8 females, 2 males with age range of 23 to 55) of the Faculty of Pharmacy of University of Porto, the air fried fries did quite well:

Figure 2: Boxplot of quantitative descriptive sensory analysis of potatoes in different frying process: deep-frying, Actifry and Airfryer; commercial soybean oil (SO), sunflower oil (SFO), canola oil (CO) and olive oil (OO) all from the supermarket (Santos 2017)

• the adhesiveness was only significantly different for potatoes that were fried in soybean oil, and slightly elevated in the air-frying vs. deep-fried products (p < 0.05),
• the crispiness of air-fried fries and deep-fried fries was likewise impaired with canola oil; in that, there was a trend for increased crispiness w/ deep frying.
• the color attributes and odor intensity presented higher scores in deep-frying than air-frying (p < 0.05); and again, canola oil was the odd one out with potatoes fried in CO (deep-frying and Airfryer) showing inferior odor attributes than other vegetable oils (p < 0.05), probably due to increased fatty acid oxidation, consistent with its increased PUFA content.
• a bad aftertaste was observed mostly with deep-fried products and may be attributed to the formation of unwanted fatty acid oxides, especially when high omega-6 oils like soybean or olive oil were used

With respect to the overall acceptability, the subjects who are used to consuming fries that are fried in sunflower oil (that's the way people do it in Spain) awarded the SFO-deep-fried fries the highest, the ones that were fried in canola oil the worst score.

Figure 3: Health and taste may often deviate, but the fact that olive oil was the best compromise for both (even though individual subjects didn't like the taste), taste and predictable health effects based on oxide-formation (Saontos 2017).

A completely different image emerges for air-frying, where using sunflower oil produced the lowest and using soybean oil the highest score. That's bad news? Well, not really, because olive oil came to the rescue and achieved, albeit with a high variability within the panel, ratings similar to the best potatoes for both frying processes.

Photos of the devices that were used in the study. No sign. differences were observed between the Tefal and Phillips devices, which makes it unlikely that you'd seen different results w/ your air frying device at home.

Methodology: Deep-frying was carried out in a domestic electric fryer (TRISTAR, FR-6929) with adjustable temperature up to 190 °C, 1.75 L capacity, and maximum load of 200 g per L. A portion of potatoes cubes (200 g) was fried in 1.5 L of vegetable oil, at 175 °C, during 6 min. The temperature was periodically controlled with a calibrated digital thermometer. Air-frying was tested in two different equipment’s: Actifry (Tefal, SERIE001) with a nominal power of 1400 W, and Airfryer (Philips, HD9220) with a nominal power of 1425 W. A portion of potatoes cubes (300 g) was involved in 3.6 g of vegetable oil, and fried during 20-25 min (Actifry) or 15-20 min (Airfryer; manual agitation at 10 and 15 min), adjusted to the equipment’s specifications.

Olive oil will also have no (sign.) effect on the amount of pro-carcinogenic acrylamide, of which I've previously pointed out that it was not affected by the device in which the scientists fried their potato sticks.

Figure 4: Levels of acrylamide according to frying method and oil used to fry/involve the fries before frying; commercial soybean oil (SO), sunflower oil (SFO), canola oil (CO) and olive oil (OO) all from the supermarket (Santos 2017).

What did affect the levels of acrylamide, at least in the Tefal Actifry device, was the type of oil that was used; with the highly popular sunflower oil (SFO) triggering a significant increase in the formation of acrylamide, it should be quite obvious that this shouldn't be your #1 choice for air-frying even if you don't own a Tefal device, in which the increased acrylamide formation may be explained by the direct contact with the chamber surface.

What's the latest on frying and your health, anyway? In one of the most recent reviews of the health effects of fried foods, Luke Forney highlights that "[n]ot all fried oil[/food] is equal" - or, as I would like to say: not all fried food is evil ;-) As a SuppVersity reader you will be aware of the so-called "French Paradox", i.e. the observation that the French eat all the good foods, the Americans deem unhealthy (high-fat cheese, absolutely non-whole grain baguette, etc.) and wash it down with liters of red wine and still have a significantly better heart health and smaller waists than their low-fat munching Amerian friends.

The "Spanish Paradox" shows no significant increase in heart disease risk (not shown in this figure) and, if anything, a non-significant reduction in all-cause mortality with increasing amounts of fried foods in the diet (Guallar-Castillón 2012).

For fried foods, however, it's the "Spanish Paradox" (Guallar-Castillón 2012; Gadiraju 2015), as frying is much more important in the Spanish than it is in the French cuisine. On the other hand, the Spaniards eat fried foods no more than three times per week and, probably, more importantly, (a) make the right oil choice(s) by choosing refined olive oil (not extra-virgin) over higher omega-6 or less stable oils and (b) avoid using oils repeatedly (that's a common practice in every fast-food restaurant). Thus they prevent the formation of both harmful phytosterol oxidation products (from using extra-virgin vs. regular olive oil | Ryan 2009) and polycyclic aromatic hydrocarbons (from (re-)using oils or using oils with a low heat stability, e.g. soybean oil, walnut oil, etc.).

Addendum: The topic of reusing oils is important enough for an addendum based on a study that has been published one day after I published this article.

Figure*: Changes in key-markers of oxidation (total polar material, TPM, and acid value) in french fries and breaded chicken, (Sung 2017).

In their experimental analysis of the oxidative properties of a commercial standard frying oil mix of soybean oil and palm olein (6:4 ratio with 650 ppm added tocopherols) as it is used in many fast food restaurants, Song et al. (2017) show that the key-markers of oxidation increase by more than two- and tenfold within less than 20 and less than 10 frying cycles (both happens even in the best fast food restaurants) in potatoes = french fries (Figure*, left) and breaded chicken (Figure*, right), respectively.

With that being said, Forney's review also reminds us that it's not necessarily the often overestimated amount of oxidized fat in fried foods that's making fried food lovers fat and sick. Rather than that, it is their high calorie-density and thus their significant contribution to "weight gain and obesity, which then increase diabetes, hypertension, and hyperlipidemia, which in turn are the most important factors leading to cardiovascular disease such as heart attack and stroke" (Forney 2016) - so, never forget: calories count, it's just more complex than CICO.

Next to acrylamide, the total antioxidant content and the degree of fatty acid degradation were two additional health-relevant characteristics of the test products the scientists evaluated. If we scrutinize this data, two important take-home messages emerge:

1. There's no question that you'd be better off not frying your potatoes, at all.
2. If you insist on frying, air-frying is the sign. healthier method when all's said and done.

Ok, I guess that most of you have been suspecting just that before they had read the SuppVersity article at hand. What I doubt, however, is that you also knew that... 

• air-fried potatoes contain significantly lower amounts of trans fats (TFAs); the level is in fact so low that there was no significant difference between the transfat content of boiled and air-fried potatoes
• if you insist on deep-frying your potatoes, using olive oil will sign. reduce the exuberant amount of transfats in comparison with other vegetable oils (p < 0.05), using (regular) canola oil, on the other hand, will yield sign. higher TFA levels (the scientists do yet remark that this may be an artifice due to methodological problems)

Moreover, common sense will not tell you that deep frying will leave your potatoes with significantly higher amounts of tocopherols (vitamins E) than air-frying, which, in turn, has the advantage of lowering the vitamin C content to a similar extent as cooking and thus sign. less than deep-frying.

Figure 5: Changes in total phenolic content and antioxidant activity in the DPPH assay (left), as well as increase in secondary lipid oxidation products during frying (right); all values expressed as rel. differences to cooked control,

Unlike deep-frying, which will reduce the total phenolic content of the content sign. (with olive oil reducing the loss to 3% and sunflower oil increasing it to 18%), air-frying will actually increase the number of phenolic compounds compared to boiling. In that, it is important to note that it would be stupid to use this observation to say that air-fried potatoes are healthier than cooked potatoes; after all, there's an apparent decrease in DPPH radical scavenging activity for both air-frying devices (p < 0.05 | see Figure 4, right).

And for those who are still not convinced, the scientists' analysis of the amount of unwanted and unhealthy secondary oxidation products, namely unsaturated aldehydes, that were estimated by the anisidine value (p-AV), likewise adds to the evidence that if you want to eat fries, you'd choose the ones from the air-fryer over deep-fried fries, which presented consistently a higher fat degradation state in comparison with all other processes (p < 0.05). Air-frying, on the other hand, left most if not all of the fats intact and showed no significant difference to the control (=boiling) condition. Similarly encouraging results were found for the total content of polar compounds (TPC), which increased only with deep- not with air-frying.

In my 2014 article about the "Quest or the Optimal Cooking Oil", canola oil fares much better than in the study at hand. Why is that? The reason is quite simple: it's not the same oil. Unlike the study at hand, the studies, I cite to verify the usefulness of canola oil for frying, all used high-oleic acid canola oil, which is high in MUFA and low PUFA - similar to olive oil | more.

Bottom line: You won't be surprised to hear that air-frying is indeed healthier than deep-frying potatoes. I am pretty sure, though, that you would not necessarily have expected the good old (non-virgin) olive oil to rank so high for both the sensory and the chemical qualities of fries.

I have to warn you, though, while I see no problem with using olive oil to involve your potato sticks before you turn them into Pommes Frites in an air-fryer, Frying in olive oil for more than 6 minutes, at temperatures >190°C or re-using the oil as it is done in 99.9% of the restaurants and commercial kitchen (who would throw away the oil after using it to fry a single serving of potatoes) will affect olive oil to a significantly greater degree than the low PUFA oils I suggested for frying in my 2014 article about "The Quest for the Best Cooking Oil" | Comment on Facebook!

References

• Fortney, Luke. "Fried Foods: Friend or Foe?." Integrative Medicine Alert 19.3 (2016): 25-28.
• Gadiraju, Taraka V., et al. "Fried food consumption and cardiovascular health: A review of current evidence." Nutrients 7.10 (2015): 8424-8430.
• Guallar-Castillón, Pilar, et al. "Consumption of fried foods and risk of coronary heart disease: Spanish cohort of the European Prospective Investigation into Cancer and Nutrition study." BMJ 344 (2012): e363.
• Ryan, Eileen, et al. "Phytosterol oxidation products: their formation, occurrence, and biological effects." Food Reviews International 25.2 (2009): 157-174.
• Santos, CSP, et al. "Deep or Air frying? A comparative study with different vegetable oils. Eur. J. Lipid Sci. Technol. (2017). Accepted Author Manuscript. doi:10.1002/ejlt.201600375
• Song, J., Kim, S., Kim, J., Kim, M.-J., Lee, S.-M., Jang, M.-I. and Lee, J. "Oxidative properties and moisture content in repeatedly used oils for French fries and breaded chickens during frying." Eur. J. Lipid Sci. Technol. (2017). Accepted Author Manuscript. doi:10.1002/ejlt.201600279

Olive Oil, a Health & Longevity Food | Plus: Frying With the Right Oils, Quickly + Discontinuously not Half as Hazardous for Your Heart, Pancreas & Waist as Previously Thought

If the frying time is short (2-5 min) and the heat not extreme, it's no problem to fry with virgin olive oil. If that's not the case there are better options.

You will probably remember my Facebook post about olive oil having recently become the first food that may officially call itself heart healthy in the European union. As María-Isabel Covas et al. point out in their latest paper, this leave a key question for the consumer unanswered: Which olive oil is the for you and your health? And how strong is the evidence it's actually going to make a sign. health difference (Buckland. 2015)?

In today's SuppVersity article I am going to answer these question and then turn to another, related issue: The alleged health-hazards of cooking and frying with vegetable oils as they were reviewed by Carmen Sayon-Orea (2015) and Carmen Dobarganes (2015):

Lean more about frying & co at the SuppVersity

The Quest for the Optimal Frying Oil

MUFA Modulates Gut Bacteria → Weight Loss

Taste of Olive Oil Heals - Flavor's Enough!

GMO Soybean Oil Proven to Be Pro-Inflammatory

"Pimp My Olive Oil" - W/ Extra Antioxidants

Frying Does not Just Oxidize Oils, It Does Fat More!

• Does it have to be virgin olive oil and how significant are the health benefits? The data from the EUROLIVE longterm study (Cicero. 2005) is unquestionably one of the more convincing arguments in favor extra virgin vs. regular olive oil (VOO). In said study 200 individuals from five European countries were randomly assigned to receive 25 ml/d of three similar olive oils, but with differences in their phenolic content (from 2.7 to 366 mg/kg of olive oil). The oil was administered in intervention periods of 3 weeks preceded by 2-week washout periods and the differential effects on important health markers were compared.
  
  What the authors found was that all olive oils increased HDL-cholesterol and the ratio between the reduced and oxidised forms of glutathione, but only the consumption of medium- and high-phenolic content olive oil (as you would buy it as "virgin olive oil" and "extra virgin olive oil" on the market) decreased lipid oxidative damage biomarkers such as plasma oxidised LDL, un-induced conjugated dienes and hydroxy fatty acids, without changes in F2-isoprostanes.
  

  

  Figure 1: Reduction in oxidized LDL in the PREDIMED study on Traditional Mediterranean Diet (TMD) with either virgin olive oil or nuts as one of the dietary sources of fat vs. recommended low fat diet (Fito. 2014).

  As Covas et al. (2015) point out, the scientists who conducted this larg-scale trial also found that the increases in HDL-cholesterol and the decrease in the lipid oxidative damage were linearly linked to the phenolic content of the olive oil the subjects consumed" (Covas. 2015)
  

  

  Table 1: Randomised, controlled studies on the effect of VOO on inflammatory markers (Covas. 2015)

  Even if we didn't have all the "Mediterranean diet studies" and the host of studies confirming the potent anti-inflammatory effects of virgin olive oil (see Table 1), the result of this well-controlled large-scale intervention alone would be quite convincing. In conjunction with the more recent PREDIMED study (Martínez-González. 2014; Fitó. 2014), however, the argument in favor of "virginity" (for olive oils ;-) becomes even stronger. An analysis of the PREDIMED study revealed that the beneficial effects of a Mediterranean style diet on LDL oxidation are most pronounced if extra virgin olive oil (with a high phenolic content of 316 mg/kg). With the EVOO version neither the "nutty" Mediterranean diet nor the still recommend low fat diet could compete (see Figure 1).
  

  

  Figure 2: The association between olive oil consumption (quartiles (Q) and per 10 g/d) and (a) overall mortality and cause-specific mortality ((b) CVD mortality, (c) cancer mortality and (d) other causes of mortality) in the European Prospective Investigation into Cancer and Nutrition Spanish cohort study (Buckland. 2015).

  The question you may still want to ask, though, is probably: "Are these markers actually relevant for my health?" Well, I guess we can hardly tell for sure what it is that mechanistically reduces the risk that you will die before your time, but the existing epidemiological data in Figure 2 leaves little doubt that the health benefits of consuming virgin olive oil can make the difference between life and death.
  
  So again, which oil do you use? The "extra virgin" among the olive oils, obviously. After all, EVOO has shown to promote additional benefits to those provided by regular olive oil and the few alternative vegetable oils. Effects of which Covas et al. point out that they are mediated by EVOO induced increases in the antioxidant content of LDL, nutrigenomic effects, and the modulation of atherosclerosis-related genes towards a protective mode.
• Does cooking and frying with vegetable oils kill? I have been addressing this issue shortly in my articles on the problems that arise with cooking with lard and tallow (read it) and my article about the "best" cooking oils (read it), but since we are already talking "oils" - in this case "olive oils" - it may be worth taking a look at two recent papers by Dobarganes et al. (2015) and Sayon-Orea et al. (2015).
  

  

  Table 2: Overview of the various substrates of vegetable oil and their effects in different experimental models as summarized by Dobarganes and Márquez-Ruiz (2015).

  In their latest review Dobarganes and Márquez-Ruiz list a whole host of processes and scientific evidence that (a) proves that there can be health hazardous compounds that form when you cook thermally unstable vegetable, that (b) these compounds are readily absorbed by mouse and man and that (c) even the relatively "small" amount that is found in industrially produced fried foods can be a threat to our health if we consume them in excell (see Table 2).
  
  

  

  Figure 3: Odds and hazar ratios and 95 % CI for the fully adjusted model in the studies included in Sayon-Orea's 2015 systematic review. * Fried food consumption as exposure. † Olive oil consumption as exposure. ‡ Sunflower oil consumption as exposure. § Palm oil consumption as exposure.

  This does not mean, though, that you will drop dead from the occasional serving of French fries - and that despite the existing evidence that some compounds that form during frying can impair the nutritional value of food or be potentially harmful. If you look closely at the time and heat it takes for the bad byproducts of cooking and frying to arise, it is evident that it's not you, but rather the food industry and restaurants with their high temperatures and cooking times that are to blame for the problems. They are the ones using the "discontinuous frying process" of which Dobarganes and Márquez-Ruiz say that only they allow frying oils to reach "degradation levels much higher than that established for human consumption" (Dobarganes. 2015).
  
  It is thus hardly surprising that Sayon-Orea et al.'s systematic review disproves the myth "that frying foods is generally associated with a higher risk of CVD" (Sayon-Orea. 2015 | my emphasis). Furthermore the authors analysis of the existing evidence indicates that cooking and frying with the previously praised virgin olive oil, in particular, is actually with a significantly reduced risk of CVD clinical events (see Figure 3).
  
  At this point it may be worth pointing out that this review has a small selection bias. If you look at the correlates in studies that are not as specifically interested in fried foods as the one reviewed by Sayon-Orea, but rather at food choices in CVD patients or diabetics there are positive correlations, correlations with "junk food", if you will. Therefore we can assume that any association between fried food consumption and cardiovascular disease (CVD) risk is probably mediated by the potentially obesogenic effect of certain types fried foods. Foods that are usually of overall low nutritive, but high caloric value - specifically if they are produced industrially or by fast food restaurants.
  
  If you are frying your foods at home, use oils with high amounts of unsaturated fast like virgin olive oil (or alternatives for longer frying durations and higher temperatures) and don't start frying snickers or ice-cream (as seen on TV ;-), frying your foods may actually be way less hazardous than many of you probably thought.

So what did you learn today? The health benefits of olive oil are not only, but largely dependent on its polyphenol content. From previous SuppVersity articles, you will know that those can be damaged by cooking and frying, but low cooking temperatures and short frying times minimize the risk of (a) missing out on all the polyphenol action in virgin olive oil and (b) allowing too many of the health hazardous metabolites of high PUFA oils - don't forget that olive oil still contains relatively high amounts of omega-6s - to rise.

The Quest for the Optimal Cooking Oil: Heat Stable, Low PUFA & Cholesterol Free - High MUFA Sunflower / Canola, Olive, Coconut & Avocado Oil Qualify for the TOP5 | more

Thus, unless you're a weak-willed victim of the food industry, your risk of dying from frying induced... ah, I mean from fried-food related heart disease is minimal. The same goes for your risk of obesity and diabetes... and let's be honest: Can you imagine a "Mediterranean Diet" (MeD) without tons (and I mean "tons") of fried foods? I can't. What I can imagine, though, is that the use of heat stable (virgin olive) oils, discontinuous frying to ensure overall short frying times, as well as frying healthy not junk food (mostly unbreaded meats and veggies) make the health-relevant difference between the effect of fried foods in the MeD and those from the Standard American Diet, which are usually fried discontinuously in less heat stable oils  | Comment! 

References:

• Buckland, Genevieve and Carlos A. Gonzalez. "The role of olive oil in disease prevention: a focus on the recent epidemiological evidence from cohort studies and dietary intervention trials." British Journal of Nutrition 113 (2015): pp S94-S101. 
• Cicero, Arrigo FG, et al. "Changes in LDL fatty acid composition as a response to olive oil treatment are inversely related to lipid oxidative damage: The EUROLIVE study." Journal of the American College of Nutrition 27.2 (2008): 314-320.
• Covas, María-Isabel, Rafael de la Torre and Montserrat Fitó "Virgin olive oil: a key food for cardiovascular risk protection." British Journal of Nutrition 113 (2015): pp S19-S28. 
• Dobarganes, Carmen and Gloria Márquez-Ruiz "Possible adverse effects of frying with vegetable oils." British Journal of Nutrition 113 (2015): pp S49-S57. 
• Fitó, Montserrat, et al. "Effect of the Mediterranean diet on heart failure biomarkers: a randomized sample from the PREDIMED trial." European journal of heart failure 16.5 (2014): 543-550.
• Martínez-González, Miguel Á., et al. "Extra-virgin olive oil consumption reduces risk of atrial fibrillation: the PREDIMED trial." Circulation (2014): CIRCULATIONAHA-113.
• Sayon-Orea, Carmen, Silvia Carlos and Miguel A. Martínez-Gonzalez "Does cooking with vegetable oils increase the risk of chronic diseases?: a systematic review." British Journal of Nutrition 113 (2015): pp S36-S48.

Rodent Study: GMO Soybean Oil is Pro-Inflammatory & Induces DNA Damage! Extra Virgin Olive Oil to the Rescue!

GMO Soybean oil? Better for cars only.

I am pretty sure there will be rebuttals to the results of this study... although, it's published in the OpenSource journal Nutrients and was conducted by scientists from Saudi Arabia and the UK who probably don't have the media-connections the scientists who conducted the GMO-corn study back in the day had.

Against that background it's unlikely that non-SuppVersity-readers will even hear about the paper El-Kholy et al. published in the June edition of Nutrients (El-Kohly. 2014) -- Well, that is - unless you spread the word, obviously ;-)

You better take creatine than ecdysteroids if you want to build muscle

Foods, not Macros Count!

Olive Oil Flavor is Healthy

Argan Oil as Test Booster

Oleic Acid ⇄ Microbiome

Tocotrienols? Red Palm Oil!

SAD Diet Analysis

Let's take a look at the methods and results, now. Needless to say that we are talking about preliminary rodent data, here - data from 40 adult male albino rats, to be precise. The rats were used in this study and divided into four groups.

• The control group of rodents was fed basal ration only. 
• The second group was given basal ration mixed with extra virgin olive oil (30%). 
• The third group was fed basal ration mixed with soybean oil from GM-soy (15%).
• The fourth group survived on a combination of EV olive oil, GM and the basal ration.

All rodents were kept on the respective diets for 65 consecutive days. On day 65, blood samples were collected from each rat for antioxidant enzyme analysis.

Figure 1: Lipid oxidation and glutathione levels (El-Kohly. 2014)

"In the group fed on basal ration mixed with GM soyabean (15%), there was a significant increase in serum level of lipid peroxidation, while glutathione transferase decreased significantly. [...] the amount of DNA and NCE were significantly decreased. [...] We can conclude that adding EV olive oil to the diet of rats appears effective in inhibiting oxidative damage and may act as a protective agent against chronic diseases such as liver fibrosis, hyperlipidemia and diabetes. In addition, EV olive oil may also have a protective function against carcinogenic processes." (El-Kohly. 2014)

That's an intriguing result and one of which I am asking myself if you'd see it with regular soybean oil, as well.

"True or False? Adding Fat to A Carby Meal Lowers Insulin Response. Muscle Hypertrophy Impairs Oxygen Diffusion. Reducing Carb Intake Improve Muscular Insulin Sensitivity" | more

Bottom line: Now, although we cannot tell for sure, whether it's the "GM", i.e. the genetic modification, or simply the fact that soy is devils excrement and not suitable for mammalian consumption *don't take this excursion to seriously*, we do know two ways to protect our DNA from the vegan assault:

1. Avoid soybean oil like a plague - easy for all of us who follow the SuppVersity-no-processed foods principle, but more or less impossible for everyone who buys products from the "food" industry
2. Add extra virgin olive oil to our diet  - the addition of EVO is simple and effective, but will only alter "the tested parameters towards normal levels" 

For me, personally, "towards normal" is not convincing enough. If you asked me, I'd thus suggest you chose option (1) - the switch to a "zero" processed foods diet is going to have a whole lot of other beneficial effects on your health, physique and performance, anyways.

Reference:

• El-Kholy, T.A.; Hilal, M.A.; Al-Abbadi, H.A.; Serafi, A.S.; Al-Ghamdi, A.K.; Sobhy, H.M.; Richardson, J.R.C. The Effect of Extra Virgin Olive Oil and Soybean on DNA, Cytogenicity and Some Antioxidant Enzymes in Rats. Nutrients 2014, 6, 2376-2386.

Foods, Not Macros: Isoenergetic Breakfast With Identical Macronutrient Content More Satieting With Eggs vs. Flakes. Plus: Omega-3 <> Microbiome <> Obesity Interactions

Eggs or Flakes? Not 30% vs. 25% protein! A brief reminder of the fact that the stuff you eat is still food.

I am not quite sure when or why this happened, but I know that more and more people are thinking in terms of "macros" instead of foods. What I do know, though, is that the recent publication of studies from the Pennington Biomedical Research Center at the Louisiana State University System (Bayham. 2014) and an ostensibly unrelated study that was conducted by researchers from the Alimentary Pharmabiotic Centre, Biosciences Institute in Cork and scientists working at the local university and the University of Pittsburgh School of Medicine (Patterson. 2014) confirms - once again (!) - how futile this ignorant approach to nutrition actually is.

Eggs vs. cereals - not the best example, but...

In that, I am well aware that the "battle" between an egg- and a cereal-based breakfast in the Patterson study is not exactly a good model of what's currently going on in the health and fitness community. With cereals being labeled as "the devil" (it's always nice to be "anti", isn't it?), no one would after all consider having ...

• One-and-a-half cup of Special K® RTE cereal, 200 ml Silk® original soymilk, one slice of Natural Grain “Wheat n’ Fiber”® bread, 13 g of butter, and 10 g of sugar-free strawberry jam (CG)

... for breakfast. In view of the fact that the same can be said for the calorie- and mocronutrient matched "high quality protein" breakfast, i.e.

• Two scrambled eggs, 120 mL skim milk, two slices of Holsum® thin white  bread, 5 g of butter, and 18 g of Smuckers® strawberry jam

... I still believe that the consequences of "breaking the fast" (learn why I am calling breakfast thus in "Breakfast or Breaking the Fast" | read more) with eggs vs. Special K are still relevant to the previously introduced context. And if you know that the acetylated form of ghrelin and PYY are "satiety hormones", it does not take a rocket scientists to interpret the data in Figure 1.

Figure 1: Level(s) of "satiety hormones" after the different breakfasts (Bayham. 2014)

What is difficult to tell, though, is whether the increased satiety after the egg breakfast would actually lead to a reduced intake at the subsequent meal.

• On an individual basis, i.e. on just one of the two eating occasions, the higher levels of acetylated ghrelin and PYY did not suppress the 20 healthy overweight or obese subjects energy intake during the subsequent lunch
• For day 1 and day 7, together, on the other hand, the 64kcal the egg eaters consumed less than the cereal eaters did reach statistical significance.

If we throw overboard all the things we (believe) we know about the fallacy of calorie counting, this would translate into a ~448kcal difference for one week and a whopping difference of 23,360kcal for a year, which should shed ~3.3kg of body fat a year.

7000kcal for 1kg of body fat? I know that this is a naive miscalculation, but it should suffice to demonstrate that the protein quality (remember the amount of protein in both breakfast conditions was identical) counts and two eggs (vs. Kellog's Special K) can make the difference between slow, but continuous weight gain on the one and weight stability (or more) on the other hand.

Whether or not similar concrete weight loss vs. gain effects can be achieved with different types of fat is nothing study #2 in today's science mash-up here at the SuppVersity could answer. What it can tell you though, is that protein and obviously carbohydrates, where even Mr. Average Joe thinks in terms of "low GI" = good and "high GI" = bad carbs, these days, is by no means the only food component, where unspecifically counting macros is not going to cut it (or get you cut, if that's what you want to achieve).

This is not just about fish oil

"Of course, the bad omega-6s" ... I know that this is what you're thinking right now, but let's be honest, isn't that a bit narrow-minded?  It sure is and still, the results Ellaine Petterson and her Irish and American colleagues present in their most recent paper demonstrate quite clearly that the ingestion of fish and flax seed oil has pretty unique effects that go beyond its ability to increase the tissue concentrations of DHA to levels way beyond what you'd see in low fat or high fat diets with palm, olive or safflower oil powered high fat diets.

Increased lipid oxidation in athletes w/ low dose fish oil (Filaire. 2010)

The health benefits of omega-3s: The often-cited evidence of the benefits of high omega-3 levels in the cells is by far not so conclusive as the laypress and supplement producers would have it. Danthi et al. have shown only recently that fish consumption, but not the omega-3 content of your cells is a reliable predictor of cognitive performance in the elderly. Associations between heart health, mortality, etc. and cellular omega-3 levels could thus be mediated by the whole food source of those omega-3s, i.e. fish consumption, and not by their mere presence in the cells, as well.

In addition it lead to an increase in the relative abundance of bifidobacteria, a gut tenant that has been linked to all sorts of beneficial health effects, but has recently been outshadowed by various strains of lactobacilli (0.95% vs. more than 2% in all other groups), which - and this is an important information - were the lowest in the rodents who were kept on diets with 45% of the energy from fish and flaxseed oils.

Whether or not, the negative effects of fish oil on the lactobacillacea count in the guts of the lab animals is also partly responsible for the more or less disappointing effects the fish and flax seed diet had on the body composition (Figure 2) of the wild-type C57BL/6J male mice (21 d old) in the study at hand is questionable.

Figure 2: Body composition analysis at the end of the study (Patterson. 2014)

It's not impossible, though. A brief glance at the insulin levels and leptin levels in Figure 3 reveals that neither of them looks anyway close to what someone who's religiously taking his fish oil caps on a daily basis would be expecting. In the end, it is thus not really that surprising that only the palm oil diet group ended up with an inferior lean-to-fat mass ratio of 1.17 (vs. 1.33 in the omega-3 group).

Figure 3: Changes (%) in relevant metabolic markers in response to the different diets (Patterson. 2014)

The results of the study at hand, i.e. the effects on body composition (Figure 2), as well as blood glucose and lipid metabolism (Figure 3) are thus clearly not in line with the ubiquitously placated message that "fish oil is good for you" - a message, the indoctrinated average supplement junkie will still discern from the abstract of the study:

"[...] Ingestion of the HF-flaxseed/fish oil diet for 16 weeks led to significantly increased tissue concentrations of EPA, docosapentaenoic acid and DHA compared with ingestion of all the other diets (P< 0·05); furthermore, the diet significantly increased the intestinal population of Bifidobacterium at the genus level compared with the LF-high-maize starch diet (P< 0·05). These data indicate that both the quantity and quality of fat have an impact on host physiology with further downstream alterations to the intestinal microbiota population, with a HF diet supplemented with flaxseed/fish oil positively shaping the host microbial ecosystem." (Petterson. 2014).

Neither the "loss" of lactobacilli, nor the - if anything - negative effects of the high omega-3 diet on the lean-to-fat-mass ratio and the amount of insulin that's floating around in the rodents' blood are mentioned in said abstract.

Fat = Diabetes - A FAT Mistake?

If you go take a look at the actual study data, we are thus left with the question, whether the purported benefits of having high amounts of omega-3 fatty acids in our cells (see red info box a couple of paragraphs above) are real enough (or really enough - whatever you prefer) to discard the fact that the study at hand would actually suggest that olive and not fish + flaxseed oil should be your go-to source of dietary fat on a high fat diet.

Moreover, if we abandon any paradigmatic believes, we would even have to concede that - within the current context, i.e. a rodent study and a diet with protein contents of only 19.2% (low fat) and 23% (high fat), the low fat mix of 1.25% of palm, 1.25% olive, 1.25% safflower oil, 0.625% fish and 0.625% flaxseed oil the rodents in the starch and sucrose groups received is superior to any of the high fat variants.

You may say that this is "rodent shit" (and it is, because this is what the scientists analyzed to access the SFCA metabolism of the mice) and a mere coincidence, but wouldn't you agree that this oil mix looks a little too much like the mixture you'd get on a low-to-moderate fat diet with olive oil as a staple for everything, where you add oils, palm and safflower oil from processed foods on your cheat days and fish oil / omega-3s from your once or twice a week serving of salmon... ?

Enough of the speculations, though: What I actually wanted was to remind you of the fact that you're still eating food not proteins, carbohydrates and fats and that there are physiological performance-, health- and longevity related, as well as psychological downsides, I can only hint at in the info-box to the right, to any form of "as long as it fits my macros" ignorance.

References: 

• Bayham, Brooke E., et al. "A Randomized Trial to Manipulate the Quality Instead of Quantity of Dietary Proteins to Influence the Markers of Satiety." Journal of Diabetes and its Complications (2014).
• Filaire, Edith, et al. "Effect of 6 Weeks of n-3 fatty-acid supplementation on oxidative stress in Judo athletes." International journal of sport nutrition 20.6 (2010): 496.
• Danthiir, Vanessa, et al. "Cognitive Performance in Older Adults Is Inversely Associated with Fish Consumption but Not Erythrocyte Membrane n–3 Fatty Acids." The Journal of nutrition (2014): jn-113.
• Patterson, E., et al. "Impact of dietary fatty acids on metabolic activity and host intestinal microbiota composition in C57BL/6J mice." The British journal of nutrition (2014): 1-13.

On Short Notice: Nucleotide Supplementation Increases Performance & Fortifies Immune Response. Plus: Oleic Acid Increases, SFA Lowers E2, Testosterone & DHT Binding

Are nucleotides a useful supplements for intensity maniacs and can olive oil reduce your free testosterone levels?

If you have been visiting the SuppVersity for a while now, you were probably surprised to see that the "Short News" (aka "On Short Notice") are back. The reason, I changed my mind and reintroduced this assembly of short news items is that I realized that there is an intemediate category of news and infos between the very short Facebook news that (a) disappear in the oblivion of the SuppVersity Facebook Wall, (b) don't allow me to post graphics that would illustrate the study results and (c) still take some time to write and the detailed analysis in the "original" SuppVersity articles.

So, if you disagree and can give me a good reason why I should not post news compilations like the one at hand more regularly, speak now or forever hold your peace ;-)

Nucliotide supplementation counters immune suppressive effects of exercise

(Ostojic. 2013) - I think I mentioned a similar study a couple of weeks ago in the SuppVersity Facebook News, but since this most recent investigation into the ergogenic effects of the small organic nitrogen-based combinations of a five-carbon sugar and a phosphate group that

• form the building blocks of nucleic acids, such as DNA and RNA, and 
• participate in cellular signaling and metabolism

deals with in young, healthy, fit men and their response to the provision of a supplement that looks similar to something you are probably goint to see on the market pretty soon, I thought it may be interesting enough to make it into this "news" article-format.

Figure 1: Illustration of the molecular structure of nuleotides (Sadava. 2000)

The supplement we are talking about is a combination of different nucleotides, i.e. cytidine 5′-monophosphate, uridine 5′-monophosphate, guanosine 5′-mono-phosphate and adenosine 5′-mono-phosphate from partially purified (90%) germinated barley seeds extracted during sporulation and the reason it's worth knowing what was in it, because it was able to ...

• Want a quick performance fix? Use sodium bicarbonate | learn more

  significantly increase time to exhaustion (+7%)
• ramp up serum levels of immunoglobulin A and
• elevate the NKC cytotoxic activity

in the blood of the 14 recreationally active participants (age 22; BMI 24kg/m²; body fat 11%) who participated in a standardized incremental exercise test on the treadmill ("Run till you drop") after taking 50mg/day of this product for 2 weeks.

Oleic Acid Increases E2, Testosterone & DHT Binding

Not from Greece, the land of olive oil and eve's cheese, but from Spain comes a study that links Oleic acid, the mono-unsaturated fat from Olive oil to increases in SHBG. The researchers from the Universitat Autònoma de Barcelona analyzed the lab reports and nutrition data of a total of 315 men and observed that

"SHBG serum levels were significantly higher in subjects using olive oil for cooking in comparison with subjects using sunflower oil. The SHBG levels correlated positively with MUFA (p < 0.001) and negatively with saturated fatty acids (p = 0.003)." (Sáez-López. 2013)

Based on multiple regression analysis of the data, the scientists calculated that the amount of MUFA in the subjects' diets accounted for 20.4% of SHBG variance. Despite the fact that this means that your MUFA intake determines "only" 20% your SHBG levels, the data in Figure 1 (left), clearly indicates that these 20% show pretty significant correlations with important health markers.

Figure 2: Correlation between SHBG levels and BMI, MUFA intake (in % total fat) and fasting blood glucose - left; correlation between phospholipid MUFA and SFA content and SHBG - right (Sáez-López. 2013)

In order to elucidate the underlying mechanisms, the scientists conduced an additional in-vitro study, in the course of which Sáez-López were able to confirm that oleoyl-CoA, a metabolite that's produced, when oleic acid is metabolized, downregulates PPAR-γ in the liver (HepG2 cells).

As a SuppVersity veteran, you'll know that any reduction in PPAR-gamma in the adipose tissue will result in a decreased propensity of fat storage (read up on it). In the liver, PPAR-gamma is  responsible for the production of SHBG, as well. In view of the fact that SHBG binds and deactivates* androgens and estrogens (*this is not essentially correct for all tissues!), your MUFA intake could thus be one of the set-screws that determine the level of unbound sex-steroids in your blood.

With 60-80% olive oil is one of the best sources of oleic acid and this is not a reason to stop consuming it - irrespective of T-binding (read more)

Bottom Line: Based on the currently available evidence it appears as if nucleotide supplements could have a future as immune and performance booster for intense training athletes.

Despite the fact that it is unlikely that there will be any side effects, (a) the increased immune activity, which could be a problem for people with auto-immune disease and (b) the non-existence of scientific evidence to support their long-time efficacy (and safety), I would wait and see how things develop before investing significant amounts of money in supplemental RNA / DNA precursor.

Something very similar is true for results of the Sáez-López study that investigated the "SHBG raising" effects of oleic acid. In view of the negative association between SHBG levels BMI and fasting blood glucose, which have, by the way, been observed in previous studies: Phillips & Gerald, for example, observed a significant negative correlation between SHBG and the waist / hip ratio in 55 obese men aged 21 to 70 (Philips. 1993). And while SHBG binds testosterone the small change will not render all your testosterone useless, so that you don't have to be afraid of sudden olive oil induced anti-virility effects ;-)

References:

• Ostojic, Sergej M., Kemal Idrizovic, and Marko D. Stojanovic. "Sublingual Nucleotides Prolong Run Time to Exhaustion in Young Physically Active Men." Nutrients 5.11 (2013): 4776-4785.
• Phillips, Gerald B. "Relationship between serum sex hormones and the glucose-insulin-lipid defect in men with obesity." Metabolism 42.1 (1993): 116-120.
• Sadava, D. et al. Life: The Science of Biology, 9th ed. 2009
• Sáez‐López, Cristina, et al. "Oleic acid increases hepatic sex hormone binding globulin production in men." Molecular nutrition & food research (2013).

The Healthy Taste of Olive Oil. Would the Flavor Be Enough to Induce At Least Some of Its Health & Satiety Effects? Plus: Cholesterol Control - Pomace vs. Refined Olive Oil

What about an EVOO perfume, then?

I know, it sounds crazy, but in view of what you've learned in previous articles here at the SuppVersity about sweet taste receptors (learn more) and their far-reaching influence on our metabolism, it does not appear to far-fetched to assume that there is a receptor that "tastes" the flavor-active compounds of olive oil that's responsible for some of its beneficial health effects - right?

I guess, Sabine Frank and almost a dozen of other scientists from Germany and Austria must have had a similar idea, when they came up with the research question of their most recent study.

Olive oil flavored yoghurt?! Really?

I suppose, olive oil flavored, or, more specifically, low-fat yogurt mixed with a fat-free aroma extract from olive oil may not sound appealing to the average Western customer, but it would certainly deserve the label "functional food":

Figure 1: Only the olive oil enhanced yogurt will also enhance the activity of the frontal operculum (Frank. 2013)

As you can see in Figure 1, it's a functional food that has a statistically highly significant effect on the cerebral blood flow in the frontal operculum 30 and 120 min after a meal: This and the increased activity in the anterior insula of which the scientists found that it correlated positively with the postprandial change in bloos glucose change in the 11 healthy male subjects of the study, clearly suggest: The taste of olive oil alone has significant effects on the blood flow in parts of the brain that are involved in the control of energy intake and metabolic rate.

"What is the "frontal opercular" and why would I care about its blood supply?"

If the subheading to this paragraphs describes what you are thinking right now, it's about time to take a look at the little information we have about the frontal operculum:

• 

  Suggested read: "Pimp My Olive Oil! When Virgin is not Phenol-Rich Enough: The Pharmacokinetics of Phenol-Enriched Virgin Olive Oil." | read more

  We know from previous studies that the frontal operculum (FP) is sensitive to food intake.
• The study at hand shows that the FP does not care about caloric values (the yogurts were isocaloric).
• In task-related studies, the frontal operculum as part of the primary taste cortex, has shown pronounced activation to visual food cues and anticipation of food intake.
• The activation of the frontal operculum appears to control the "this smells good" or "this looks good, I must have it" response that makes weight loss so difficult.
• There is a telling relation between the sensitivity of the frontal operculum and the BMI of a person (Batterink. 2010; Yokum. 2011)
• Earlier fMRI studies showed that oral delivery of a drop of fat leads to an immediate increase in insular and frontal opercular activity, which suggests that there are "fat taste receptors" somewhere in the oral cavity or digestive tract that are wired to the the frontal perculum (Small. 2012).

Now, in context of the results of the study at hand, it is obviously the last of these points, which is particularly interesting. The discovery Frank et al. made would after all suggest that we can get satisfactory "fat effect" without the fat - simply by having the right "aroma."

Figure 2: Modulating effect of the minor components of pomace olive oil (POMACE) on lipid composition in 10 healthy young men (Cabello-Moruno. 2013) - severs as illustration for the importance of the "non-fat" components for our health.

Frank et al. also point out that the fact that they measured the CBF not immediately but 30 min and 120 min after the consumption of the yogurt would make it quite unlikely that they had mistaken an acute aroma response for what they believe is the "association with fat" - in other words, the researchers believe that the ingestion of the olive oil flavor components "modifies later responses to achieve an appropriate sensory control." Effects just as we know them from glucose and artificial sweeteners which "prepare" the body to release insulin.

Per capita consumption of vegetable oils and fats in selected European countries in 2009 (Eurostat. 2011)

Bottom line: I guess it is too early to say, whether and what kind of applications the said olive oil extract could have in the future. What the study does however show is that focusing on macros and even micronutrients, only, is insufficient.

In fact, the "ideal" diet, with the perfect macros and 100% adherence could in the end turn out to produce inferior results to a "sub-optimal", but tasty diet with olive oil and other aromas triggering all-sorts of still to be elucidated beneficial downstream effects on our physiology and psychology.

Reference: 

• Batterink L, Yokum S, Stice E. Body mass correlates inversely with inhibitory control in response to food among adolescent girls: an fMRI study. Neuroimage 2010;52:1696–703.
• Cabello-Moruno R, Martinez-Force E, Montero E, Perona JS. Minor components of olive oil facilitate the triglyceride clearance from postprandial lipoproteins in a polarity-dependent manner in healthy men. Nutrition Research. Oct. 2013 [accepted manuscript]
• Small DM, Green BG. A proposed model of a flavor modality. In: Murray MM, Wallace MT, eds. The neural bases of multisensory processes. Boca Raton, FL: 2012
• Yokum S, Ng J, Stice E. Attentional bias to food images associated with elevated weight and future weight gain: an FMRI study. Obesity (Silver Spring) 2011;19:1775–83.