Tuesday, December 22, 2020

Breakfast of the Healthy: Coffee... or a Purple-Orange Carrot Smoothie? Chlorogenic Acid in Coffee and Beyond

Don't worry you can stick to coffee
Good news has become scarce in 2020, it feels. So, let's appreciate the ones we have: A coffee shortage is not in sight. Reason enough for me to write another "latest coffee research"-article. One that turned out to be a chlorogenic acid (#CGA) article because ... 

well, it's still 2020, so scientists drink coffee to speed up their warp-speed operations and don't spend time investigating the effects of the stimulant the world is craving (Think you're drinking a lot of coffee? Are you a Fin?).

You can learn more about coffee and caffeine at the SuppVersity

For Caffeine, Timing Matters! 45 Min or More?

Caffeine Helps When Taken Intra-Workout, too

Coffee can Help You Get into Ketosis

Post-Workout Coffee Helps With DOMS

Coffee Brewing 101 (Optimal Health)

Caffeine dosing 4 Testosterone:Cortisol Increase
Needless to say that previous research shows (Sinisi 2017) that - coffee, and the previously mentioned polyphenol CGA, can take on respiratory viruses and would thus make a good addition to the warp-speed agenda - cannot be worse than all the b*s* about vitamin D ;-)

  • Chlorogenic acid (5-CQA) content of plant dietary sources (Lu 2020)
    Review of chlorogenic
    acid discusses 5-CQA's including neuroprotective, cardiovascular protective, gastrointestinal protective, renoprotective, hepatoprotective, glucose and lipid metabolism regulatory, and anticarcinogenic effects (Lu 2020 | cf. Figure 2).

    The review is very detailed and honestly rather something for science vs. coffee nerds. This, however, turns out to be its strength. After all, you'd probably not have the extensive information about the chlorogenic acid content of non-coffee sources of CGA in a less comprehensive review.

    You can find this data in the tabular overview on the right. The values are far lower than those in green, raw coffee beans, but the not so humble purple-orange carrot powder rivals a lightly roasted coffee, be it Arabica (~12 mg/g of beans | 7 minutes of roasting)  or Robusta (~14mg/g of beans | 5 minutes of roasting).

    I am sure that all of you know the SuppVersity Coffee Brewing 101, right?

    Now, most of us don't eat our coffee powder by the pound. In fact, the #1 way to consume coffee is not Starbucks (yet?), but the good old filtered coffee (learn more about filtered coffee in this older special and how it relates or, rather, doesn't relate to high cholesterol) Hence, it is important to know how much of the CGA can actually be extracted by common preparation methods and the data in Figure 1 originally collected by Budryn et al. (2009) who probed the effect of different extraction methods on the recovery of chlorogenic acids, caffeine and Maillard reaction products in coffee beans:
    Figure 1: 5CGA and total CGA content (total includes all sorts of caffeoylquinic acids, as well as caffeic acid and ferulic acid) of coffee brewed or cooked in and pressurized into 100ml of water (Budryn 2009); if we assume you absorb 100% of the CGA, this means that a cup (237ml) of coffee should yield between 0.72 grams and 0.011 grams (720mg and 11mg) per cup, for water-boiled green (no roast) and dark roast, respectively - not shabby, considering supplements contain 0.1-0.3 g only, no?  
    The values have been calculated based on 100 ml samples that were prepared with 5g of the respective type of coffee. How much of the CGA that is contained in the coffee (which was then dried to analyse it) would finally end up in your blood is still debated, or as the authors of the review argue wrt #bioavailability."
    Figure 2: Physiological actions of 5-CQA (Lu 2020).
    [...] However, the absorption and bioavailability of 5-CQA are still controversial due to the large interindividual variations in its utilization, metabolism, and excretion in both basic and clinical studies." (Lu 2020)

    Ah, and just in case you already forgot why on earth you'd drink coffee not just for its taste and #theBuzz but also as your #1 chlorogenic acid source (let's be honest: how many purple-orange carrots have you had today?), I decided to include a nice visual illustration of 5CQA's physiological actions (Figure 2), which I found in the very same review in the aptly named journal Comprehensive Reviews.
  • Coffee works instantly, that's why people love it ... and guess what the same goes for the heart-health benefits of CGA! And even a single cup of mildly roasted coffee (total CGA content, i.e. 5CQA + all other forms per 160mg/100ml for arabica and 255mg/100ml) delivers effective doses of CGA. Let's assume you like it bitter and choose the lightly roasted robusta coffee and pour a regular cup of brewed coffee, that would be 237ml of coffee with ~604mg total CGAs. The type of beans and, even more so, degree of roasting is key. After all, from a dark-roasted arabica coffee, you'll get only 90mg (note: most cheaper commercially sold coffees are blends), according to the data presented in the previously discussed review (Lu 2020).

    It's not impossible that the 90mg would have a beneficial effect on your cardiovascular system, too, but the lowest dose tested in an international study by Naylor et al. (2020) was 156mg CGA from a green coffee bean extract. The subjects were healthy, normal-weight, and in the age range from 45–65 y (women were post-menopause) and the study seems to confirm what some people won't believe: Yes, you can have too much coffee - even decaffeinated one.
    Figure 3: Flow-mediated dilation in healthy 45–65 y-olds 0-24h after the ingestion of low (302mg) or high (906mg) increases significantly over placebo wit the lower dose, not with the high one (Naylor 2020).
    In fact, the lowest dosage of decaffeinated green coffee extract (302 mg DGCE, 156.4mg total CGA), was the only one (302, 604, and 906mg were tested) to significantly increase flow-mediated dilation (%FMD) compared to a placebo. Both, the medium and high dose failed to produce consistent (significant benefits) in the 5 female and 16 male subjects in the first 8.5 h, 12 h, and 24 h after product intake.
More doesn't help more - That's not unusual for polyphenols. As Naylor et al. point out previous studies on CGA and other polyphenols also observed a nonlinear relation between coffee compounds and FMD, with "several meta-analyses of randomized controlled trials which [finding] that the relation between the doses of different types of polyphenols and FMD follow[s] an inverted U-shape and that high doses of polyphenols [, including those from blueberries, for example (Rodriguez-Mateos 2013), can] have smaller effects on endothelial function than lower doses" (Naylor 2020).. Finally, a previous study testing the effect of purified CGA (5-CQA) at different doses (450 and 900 mg) did not show any significant effect on peak FMD response relative to control although a post hoc analysis found a significant effect on the continuous FMD assessment compared with control at 1 and 5 h, respectively (14).
  • If you look at the magnitude of the effect, though, you will realize that the increase, as statistically significant as it may be, amounted to no more than a 1% - So the question is:

    How relevant is a small 1% increase in FMD?

    How do you even answer this important question? Well, if we look to the left and the right we see studies "similar acute effects on FMD" for purified compounds or extracts from other polyphenol-containing foods such as cocoa, tea, grape, apple, and blueberry. In other words: It's by no means a prerogative of coffee or its polyphenols. In fact, for cacao flavanols (~200mg | Heiss 2005) FMD increases from 4.5% to 6.9% have been reported, similar improvements were seen with trans-resveratrol (300 mg | Marques 2018), and a single dose of blueberry anthocyanins (160 mg | Rodriguez-Mateos 2019) acutely improved FMD by 1.3% and 1.1%. So, coffee's CGA is nothing extra-ordinary, here, but what about the more general question: Does 1% even matter?

    Yes, it matters: "Every 1% increase in FMD has been associated, in several systematic reviews and meta-analyses, with a 10%–13% lower risk of cardiovascular events" (Naylor 2020).

    So, your morning joe, and your afternoon cup will contribute to heart health... also because they contain CGA (and related polyphenols). There are two questions that new research will have to answer: (a) Whether the caffeine in regular coffee may (partly) reverse the effects (Buskemi et al. 2010 would suggest just that, but epidemiological data indicate a net positive effect in form of a J-shaped relation between coffee consumption and the risk of developing CVD, stroke, heart disease, or acute coronary syndromes). And (b) which of the CGA-related polyphenols and their metabolites is eventually the driving force behind the benefits Naylor et al. observed is not yet clear, though, and should - just like the effects of darker roasts with less CGAs as well as the effect of co-administration of caffeine - be investigated in future studies.
Needless to say that someone already cashes in on the purported health benefits of purple (-orange) carrots. I'd still advise against consuming liquid calories - avoid juices and start thinking about smoothies as a meal, not a superfood.
Cheers ☕! I have to warn you about your morning Joe's caffeine content, though.
While it seems to contribute to your metabolic (especially liver) health, it seems that it counters and even overcompensates the acute FMD%-improving effect of CGA and other coffee polyphenols, but ... it's certainly better to bridge periods of acute fatigue with a good cup of coffee than with alternatives such as energy drinks or pre-workouts. Ah, and let's not forget: After having read both items in today's coffee research update, you know that there's a non-energizing alternative: purple-orange carrot smoothies as a snack 😋 | Comment on Facebook!

  • Budryn, Grażyna, et al. "Effect of different extraction methods on the recovery of chlorogenic acids, caffeine and Maillard reaction products in coffee beans." European Food Research and Technology 228.6 (2009): 913-922.
  • Buscemi, S., et al. "Coffee and endothelial function: a battle between caffeine and antioxidants?." European journal of clinical nutrition 64.10 (2010): 1242-1243.
  • Heiss, Christian, et al. "Acute consumption of flavanol-rich cocoa and the reversal of endothelial dysfunction in smokers." Journal of the American College of Cardiology 46.7 (2005): 1276-1283.
  • Marques, B. C. A. A., et al. "Beneficial effects of acute trans-resveratrol supplementation in treated hypertensive patients with endothelial dysfunction." Clinical and Experimental Hypertension 40.3 (2018): 218-223.
  • Naylor, et al. "Acute dose-response effect of coffee-derived chlorogenic acids on the human vasculature in healthy volunteers: a randomized controlled trial." Am J Clin Nutr. 2020 Dec 16;nqaa312. doi: 10.1093/ajcn/nqaa312. Online ahead of print.
  • Rodriguez-Mateos, Ana, et al. "Intake and time dependence of blueberry flavonoid–induced improvements in vascular function: a randomized, controlled, double-blind, crossover intervention study with mechanistic insights into biological activity." The American journal of clinical nutrition 98.5 (2013): 1179-1191.
  • Rodriguez-Mateos, Ana, et al. "Circulating anthocyanin metabolites mediate vascular benefits of blueberries: insights from randomized controlled trials, metabolomics, and nutrigenomics." The Journals of Gerontology: Series A 74.7 (2019): 967-976.
  • Sinisi, Valentina. "Coffee: A Rich Source of Antimicrobial and Antiviral Compounds." Clinical Immunology, Endocrine & Metabolic Drugs 4.1 (2017): 19-32.

Wednesday, October 21, 2020

Fish Oil for Athletes? Fish for Everyone? Not for Ergogenic Benefits | Summary of Latest Metas + Umbrella Review

An illustrated synthesis of the most recent evidence.
There are two fishy articles in the latest issue of Advances in Nutrition, two articles worth taking a closer look at, as I've found. Paper 1 and probably the more SuppVersity-ish paper comes from the University of Bath and is, as the authors themselves highlight, the first systematic review of fish oil supplements (#FS) in athletes that has ever been conducted in the 25-years+ history of fish oil supplements 😮 (the "fish-eating" umbrella review is addressed in the infobox).
You can learn more about omega-3 & co. at the SuppVersity

Don't drink rancid fish oil

How to Avoid N3 Oxidation

N3/N6 Ratio Doesn't Matter!?

MUFA & Fish Oil Don't Match

Fish Oil Doesn't Help Lose Weight

Rancid Fish Bad 4 Health
Impossible? Everybody knows that fish oil is rather a vitamin than a supplement, right? So why wouldn't athletes benefit? Ahh... Wrong question: The right question would read "In which domains of health and performance will athletes benefit?" and the answer is both exciting and disappointing:

No performance benefits (no benefits in any of the reviewed studies), but overall beneficial trends in  central nervous system (#CNS), cardiovascular system (#CVS), proinflammatory cytokines, and certain aspects of skeletal muscle physiology.

The N=32 RCTs that made the cut were all rather small-scale studies, averaging only 27 participants (ranging from 15-81 athletes per study). That's 32 out of 137 papers the researchers identified and eliminated the 115 papers that "failed to report fully the methodology and statistical approach were excluded, [and] studies where the participants were not classified as athletes (i.e., recreationally or physically active, or resistance-trained were excluded)" (Lewis 2020).
Bias? "Sponsorship and research funding by the fish oil industry was clearly reported in 7 RCTs," the authors report. When this came in combination with a lack of blinding on part of the authors, this is an issue to consider. With the share of single-blind studies being only 20%, it's yet not surprising that excluding those won't generally change the results.
What the scientists generously overlooked were studies in which the fish oil came as part of an (antioxidant) supplement stack, and that few studies actually tested the n–3 fatty acid status. Moreover, they included studies in a diverse group of athletes (sport, sex of participants), didn't pre-specify the fish oil dose, or the duration of the study, and whether supplements were EPA or DHA only.

"We are not aware of any RCTs that have demonstrated a negative effect of FS on performance"

Figure 1: There was no evidence of performance benefits in 2016 (Peoples 2016) and there are non, today (Lewis 2020). But does this make supplementation 'useless'? Not really.
This is good news! But performance benefits were not confirmed, either. As previously hinted at, that doesn't mean the products are totally useless, they're just not acutely ergogenic - and that's something we have known for several years (Peoples 2016). 

Figure 1 illustrates the proven benefits and underlines the lack of ergogenic effects in athletes in form of either maximal aerobic power or sports-specific exercise performance ... with the list of sports in Lewis 2020 including cycling, judo, soccer, basketball, swimming, paddling, marathoning, track and field, rugby, wrestling, football, etc.
Will fish work just as well? As the authors of the meta-analysis point out, the majority of studies used dosages of DHA and EPA that are "achievable through the consumption of oily fish" (Lewis 2020). Good sources are Mackerels (5,134 mg/100g), Salmon (2,260 mg/100g) or Herring (2,366 mg/100g | total n-3 content).  Plus: All of those contain plenty of protein, and other essential nutrients while having negligible on your levels of unwanted heavy metals (learn more about the 'healthiest' fish).

Risk reduction per additional 100g of fish/day (Jayedi 2020). 
According to the latest umbrella meta-analysis "[e]very 20 g/d increment could decrease 2%–7% risk of various health outcomes" (Li 2020); a result that is in line with the significant evidence from another 2020 meta-analysis that demonstrated that every 100-g/d increment in fish consumption was associated with a 8% lower risk of all-cause mortality, 25% reduced cardiovascular mortality, 22% risk reduction of coronary heart disease, and more in the figure to the left based on data from Jayedi 2020
The benefits the latest meta-analysis confirmed were a general reduction in inflammation was the most frequently studied variable in athletes, with doses of EPA ranging from 300 to 2400 mg/d, and of DHA from 400 to 1500 mg/d. In that,  different markers of inflammation reacted differently with particularly significant effects (4/5 studies) for TNF-α for which we have no evidence that it could make an important (positive) contribution to training-induced adaptation. But wait, there's more:
  • insufficient evidence for reduced incidence of upper respiratory tract illness (URTI),
  • muscle recovery in 4/7 RCTs, as measured in form of muscle soreness, countermovement jump, creatine kinase activity 
  • positive effects of EPA and DHA at various doses were observed on cardiovascular and oxygen kinetics in all studies of cyclists [cycling efficiency, maximal oxygen uptake (VO2max)]
Great? Well, even though Lewis et al. al didn't find evidence of ergolytic (performance impairing) effects, I would like to note that the increased (unwanted) oxidation of fatty acid you may have heard about is real:
"Three RCTs with various doses of EPA and DHA showed that FS increased biomarkers of lipid peroxidation (i.e., malondialdehyde, F2-isoprostanes) at rest, and 4 RCTs reported this postexercise" (Lewis 2020).
With albeit few studies detecting cognitive benefits and positive effects of DHA on biomarkers of neuronal injury it still seems to be a (literally) smart move to eat the generally recommended two servings of fish per week - that will also help you to avoid the rancid supplements
Bio-advantage of krill may not be relevant in the long run | Plus: What we learned about krill oil in 2018 | Archive
Two servings of fatty fish a week? Yes, you can... eat that much fish conveniently and cheaply, even. After all, it can be canned (no pun intended) fish, too: as Tenore et al. (2014) highlight, canned bluefin tuna s not just a "cardioprotective functional food" but also "potentially safer than commercial fish oil". With more than 1g of DHA and EPA, each 50g serving of canned tuna also contains slightly more long-chain n3s than your average fish oil cap. Plus: The main nutrient loss/deterioration occurs way before canning during chilling, freezing, cooking which you'll do w/ "fresh" fish as well (Aubourg 2001) | Comment!
  • Aubourg, Santiago P. "Loss of quality during the manufacture of canned fish products." Food Science and Technology International 7.3 (2001): 199-215.
  • Jayedi, Ahmad, and Sakineh Shab-Bidar. "Fish Consumption and the Risk of Chronic Disease: An Umbrella Review of Meta-Analyses of Prospective Cohort Studies." Advances in Nutrition (2020).
  • Lewis, Nathan A., et al. "Are there benefits from the use of fish oil supplements in athletes? A systematic review." Advances in Nutrition (2020).
  • Li, Ni, et al. "Fish consumption and multiple health outcomes: Umbrella review." Trends in Food Science & Technology (2020).
  • Peoples, Gregory E., and Peter L. McLennan. "Fish oil for physical performance in athletes." Fish and Fish Oil in Health and Disease Prevention. Academic Press, 2016. 119-136.
  • Tenore, Gian Carlo, et al. "Canned bluefin tuna, an in vitro cardioprotective functional food potentially safer than commercial fish oil based pharmaceutical formulations." Food and chemical toxicology 71 (2014): 231-235.

Wednesday, October 14, 2020

Coffee Research 10/2020: Coffee's Origin Affects Glucose Effects | Coffee, Tea & Cancer - Similar but Different + More

Why are the captions in the thumbs back? Facebook won't allow replacing the preview picture of links easily.
Don't worry, not all news in 2020 is bad news... unfortunately, though, there's some 'bad coffee news' out there, too. In the following overview, I am going to cover a bunch of interesting studies - good and bad news, just as you'd see them in the ever-more non-scientific apocalypse that we live in.

Enough said, here's what I've found being published from late September to early October 2020:
You can learn more about coffee and caffeine at the SuppVersity

For Caffeine, Timing Matters! 45 Min or More?

Caffeine Helps When Taken Intra-Workout, too

Coffee can Help You Get into Ketosis

Post-Workout Coffee Helps With DOMS

Coffee Brewing 101 (Optimal Health)

Caffeine dosing 4 Testosterone:Cortisol Increase
  • Kenyan coffee - a special bru for glucose management? (Okada 2020) Japanese researchers report in their latest paper that coffee of different origins will affect one's glucose levels differently.

    Turns out that origins matter - for coffee.
    Okada et al. studied the effects of the intake of 3 different types of coffee (Tanzanian, Ethiopian, and Kenyan) on postprandial interstitial glucose levels. What's interesting is that they measured the interstitial glucose levels every 15 minutes using the FreeStyle Libre glucose monitoring system (Abbott Diabetes Care Ltd, Witney, United Kingdom) in each individual after drinking coffee compared with when not consuming coffee. 

    The results were unexpected - at least for me:

    Figure 1: The significant difference in both, glycemia (left) and uric acid (right) could be a result of a significantly higher chlorogenic:caffeine ratio in Kenyan coffee, which contains 0.69 (vs. 0.23) g per 100g of the former and only 1.12 (vs. 1.33) g per 100g of everyone's favorite drug, caffeine.
    "Unlike Tanzanian and Ethiopian coffees, Kenyan coffee suppressed the increase of postprandial interstitial glucose levels. Kenyan coffee beans contain less anhydrous caffeine and more chlorogenic acid than Tanzanian and Ethiopian coffee beans. These findings may explain the different effects of these coffee types on postprandial interstitial glucose levels." (Okada 2020)
    If you look at the glycemic and uric acid data in Figure 1 you will see that improved glucose management was not the only benefit of the high chlorogenic acid coffee from Kenya. The production of potentially gout-triggering and heart-damaging #uricAcid, which was increased significantly when the subjects consumed Tanzanian coffee and dropped back to lower than pre-intervention levels after 2 months on the Kenyan variety.

    The mechanism has also been found to partly depend on α-glucosidase activity, i.e. a "carb blocker" effect that won't work with glucose or other simple sugars. Apropos things to consider: Another thing you should remember when looking at Figure 1, though, is that the interstitial glucose levels that were measured in the study at hand have been found to give you an adequate assessment of your blood glucose levels, but one that is delayed by >15 minutes (Kulcu 2003). This, and the overall more important limitation that the study used exactly one subject (different occasions, but still).
Caffeine seems to be the bad guy in coffee for people with elevated uric acid (Towiwat 2020): Study comparing decaffeinated to caffeinated coffee shows significant decline in uric acid, in the #decaf phase.
  • Your instant coffee deserves an upgrade and scientists have just come up with one (Zanin 2020): Microparticles of roasted coffee oil do the flavor-enhancing trick.

    In "Food Chemistry", Brazilian scientists report, on the successful addition of spray-dried microparticles containing roasted coffee oil, to soluble coffee (SC) and instant cappuccino (IC), to increase and tailor aroma release.

    Microparticles with higher loads of roasted coffee oil were effective in increasing aroma intensity in SC while, for IC, all loads of microparticles improved aroma intensity. Volatility drove the VOC release in SC, and volatility and polarity for IC. Most compounds reached maximum headspace concentration in < 16 s upon start of reconstitution.

    "These results open new perspectives for the development of instant coffee products and demonstrate their unique aroma release characteristics," the authors conclude.
  • Table 1: Comparison of anticancer effects in humans
    between tea and coffee (Hayakawa 2020).
    Coffee, tea, and #cancer - Similar but different (Hayakawa 2020): Reviewers confirm that #EGCG and #chlorogenic acid both work their anti-cancer magic by their anti-oxidant effects, however...

    "EGCG and CGA have also different target molecules which might explain the site-specific differences of anti-cancer effects found in human studies" (Hayakawa 2020).

    Exact underlying mechanisms still unknown. This means we cannot tell what exactly is to blame for the observed cancer-specifity with breast, colon, lung and blood cancers being prevented by green tea consumption and those such as liver, endometrial, and skin cancers by coffee consumption (see Table 1). 
Coffee will be back... in the @SuppVersity news: With the exception of my good friend Carl Lanore from SuperHumanRadio, everyone seems to love coffee, so you can safely expect a November issue of the "Coffee Research Update" in about a month | Comment!
  • Hayakawa, Sumio, et al. "Anti-Cancer Effects of Green Tea Epigallocatchin-3-Gallate and Coffee Chlorogenic Acid." Molecules 25.19 (2020): 4553.
  • Kulcu, Eray, et al. "Physiological differences between interstitial glucose and blood glucose measured in human subjects." Diabetes care 26.8 (2003): 2405-2409.
  • Okada, Junichi, et al. "Differences in the effects of Kenyan, Tanzanian, and Ethiopian coffee intake on interstitial glucose levels measured by FreeStyle Libre: A pilot case study." Current Therapeutic Research (2020): 100606.
  • Towiwat P, Tangsumranjit A, Ingkaninan K, Jampachaisri K, Chaichamnong N, Buttham B, Buttham B, Louthrenoo W. Effect of caffeinated and decaffeinated coffee on serum uric acid and uric acid clearance, a randomised within-subject experimental study. Clin Exp Rheumatol. 2020 Oct 1. Epub ahead of print. 
  • Zanin RC, Smrke S, Kurozawa LE, Yamashita F, Yeretzian C. Modulation of aroma release of instant coffees through microparticles of roasted coffee oil. Food Chem. 2020 Sep 25;341(Pt 1):128193. doi: 10.1016/j.foodchem.2020.128193. Epub ahead of print.