Blog
News, research and guides
348 articles from our editorial and science team.
GuidesOmega-3 and ADHD Symptoms in Children — What Does the Meta-Analysis Show?
Omega-3 fatty acids, specifically EPA, have for years been one of the most-studied supplements considered for ADHD in children — usually by families looking for something alongside stimulant medication, or hesitating before starting it. The most important meta-analysis on the topic, covering 10 studies and 699 children, did find a real, statistically significant effect. The catch is that the authors themselves call it “modest” and clearly smaller than the effect of medication — a distinction that matters before anyone treats fish oil as a replacement for established treatment.
PZdr Piotr Zieliński11 min
August 25, 2026
GuidesSleep Apnea and Weight Loss — Is Losing Weight Enough to Cure It?
Obesity is one of the strongest risk factors for obstructive sleep apnea, and weight loss — even the drastic kind achieved through bariatric surgery — can markedly improve its severity. But a meta-analysis of bariatric surgery studies reveals something rarely stated outright: despite the huge improvement, the average patient's sleep apnea usually doesn't disappear completely. It remains, just in a milder form — which has concrete, practical implications for the decision to continue treatment.
JWJulia Wiśniewska11 min
August 25, 2026
GuidesAshwagandha and Cortisol: Does This Adaptogen Really Lower Stress?
"Ashwagandha lowers cortisol" is one of the most repeated claims in the world of adaptogens — and, rarely for this kind of claim, one actually backed by solid numbers from meta-analyses. But the newest, largest meta-analysis to date, from 2025, shows something that changes how this effect should be understood: a drop in blood cortisol and a subjective feeling of reduced stress turn out to be two separate, not always linked, stories.
PZdr Piotr Zieliński12 min
August 24, 2026
GuidesCoffee and Longevity: What Do Large Cohort Studies Show?
Coffee has a reputation as either "something that raises your heart rate and dehydrates you" or one of the few everyday pleasures that actually extends life — depending on who you ask. Large, multi-year cohort studies covering hundreds of thousands of participants give a much clearer answer to this question than the popular, contradictory opinions suggest.
AKdr Anna Kowalczyk12 min
August 24, 2026
GuidesCreatine and Cognitive Function: Who Really Benefits for Memory and Focus?
For decades, creatine was associated purely with the gym — today it's increasingly marketed as a nootropic for anyone wanting sharper memory and focus. The newest meta-analyses, however, paint a far more selective picture than popular headlines suggest: the benefit for the brain is real, but clearly concentrated in specific groups, not universal for every healthy, young user.
PZdr Piotr Zieliński13 min
August 24, 2026
GuidesEggs and Blood Cholesterol: Does an Egg-Rich Diet Harm Your Heart?
For decades, eggs served as the poster child for a food to "avoid" if you cared about your heart — because of the high cholesterol content in the yolk. The newest, massive analysis combining three prospective US cohorts (215,618 people, followed for up to 32 years) and an updated meta-analysis spanning 1.72 million participants worldwide paints a far calmer picture: eating up to one egg a day shows no significant association with elevated cardiovascular risk. In Asian cohorts, researchers even observed a mild protective effect. This is one of those cases where the scale and quality of newer data shifts conclusions from decades past — not because the old studies were poorly done, but because newer analyses have the statistical power to catch nuances smaller samples couldn't see. In this article, we look at exactly what the numbers show, where certainty ends, and where nuance begins.
AKdr Anna Kowalczyk11 min
August 24, 2026
GuidesNon-Alcoholic Beer and Marathon Recovery: Does It Really Help Runners?
It sounds like a gym joke, yet it's one of the more intriguing findings in sports recovery science: a double-blind randomized controlled trial on 277 marathon runners found that drinking non-alcoholic beer for several weeks before and after a race cut the risk of upper respiratory tract infection more than threefold compared to placebo. This isn't locker-room folklore or brewery marketing — it's concrete data from the Munich Marathon, with measurements of interleukin-6, leukocyte counts, and actual illness tracking for two weeks after the race. In this article, we look at exactly what the study showed, what mechanism might explain it, and where scientific certainty ends and overinterpretation of a single, if solidly designed, experiment begins.
MNMichał Nowak11 min
August 24, 2026
GuidesCoffee and Iron Absorption: How Much Do You Really Lose Drinking Coffee With Meals?
If you drink coffee or tea alongside a meal, you're probably losing more iron from your food than you think — and this isn't an approximation from a pop-science article, it's a concrete figure from classic controlled human studies using radiolabeled iron. Coffee served with a standard meal reduced non-heme iron absorption by 35%, and tea by as much as 62% — nearly two-thirds of the iron the body could have absorbed simply passed through unused. Newer research adds a second dimension: this is a dose-dependent polyphenol effect, so strong black tea blocks far more than herbal tea, and adding milk doesn't actually rescue the situation, contrary to popular belief. For people with low ferritin levels or in a risk group for iron deficiency, this is a detail that can genuinely carry clinical weight.
JWJulia Wiśniewska12 min
August 24, 2026
GuidesMigraine and Magnesium: Does Supplementation Really Prevent Attacks?
Magnesium for migraine gets recommended almost reflexively, somewhere between grandma's advice and "just in case" supplementation — but this time there's more behind the recommendation than tradition. A fresh 2025 dose-response meta-analysis, covering 22 randomized trials, shows that magnesium supplementation reduced migraine attack frequency by an average of 2.51 episodes per month versus placebo, while also reducing pain severity and the number of migraine days per month. That result is comparable to, and in some respects better than, other well-known preventive interventions like CoQ10 or vitamin D. In this article, we look closely at what these numbers show, how they stack up against other supplements tested in the same study, and why this is a different topic from our article on magnesium and sleep quality — despite sharing the same mineral, the mechanism and clinical context are entirely separate.
PZdr Piotr Zieliński12 min
August 24, 2026
GuidesDaytime Napping: How Many Minutes to Avoid Sleep Inertia?
Intuition suggests a longer nap is a better nap — more recovery time should yield more benefit. A controlled sleep-lab study comparing 5, 10, 20, and 30-minute naps after restricted nocturnal sleep shows something surprisingly the opposite: a 10-minute nap produced nearly immediate, wide-ranging improvement in alertness and cognitive function, lasting up to nearly 2.5 hours, while a 30-minute nap triggered measurable sleep inertia — right after waking, participants performed worse, not better, before any benefit even appeared. This is one of those rare cases in sleep science where "less" genuinely means "better," not a trade-off. In this article, we look closely at what the Brooks and Lack crossover study showed, and how to translate that data into a practical napping strategy.
JWJulia Wiśniewska11 min
August 24, 2026
GuidesLemon Water on an Empty Stomach: Does It Really Speed Up Metabolism?
"Drink a glass of lemon water right after waking up to kickstart your metabolism" is one of the most repeated pieces of advice online, almost always without a source. The truth is more interesting than the myth itself: there's a solid study showing that plain drinking water genuinely, measurably raises metabolic rate — by as much as 24% within an hour of drinking it. The catch is that no human study has ever tested adding lemon to that water for its effect on metabolic rate or weight loss. This isn't a story about a "debunked myth" — it's about a myth nobody has formally tested, and that distinction matters. In this article we separate the two elements: what water actually does, and why we honestly can't say the same about lemon.
AKdr Anna Kowalczyk11 min
August 24, 2026
GuidesWalking After Meals: How Much Does It Really Lower the Post-Meal Blood Sugar Spike?
"Be active" is advice so general it barely tells you when exactly to move. A randomized clinical trial in people with type 2 diabetes found something far more specific: a short walk right after a meal lowers the post-meal glucose spike more effectively than a generic recommendation to "meet your daily activity target" without specifying timing. What's more, the effect wasn't the same across all meals — after dinner specifically, walking cut the glucose spike by roughly 22%, considerably more than after other meals of the day. This suggests that for blood sugar control, what matters isn't just how much you move over 24 hours, but precisely when you do it. In this article we break down these findings step by step and explain exactly which population they've been shown in.
MNMichał Nowak12 min
August 24, 2026
GuidesChewing Gum and Appetite: Does Chewing Gum Actually Help With Weight Loss?
"Chew gum instead of snacking" is advice almost everyone who's ever tried to control their appetite between meals has heard — but rarely does anyone check whether there's actually data behind it. It turns out there is, and from two independent experimental studies: chewing gum genuinely, measurably reduces later snack and calorie intake at the next meal. The catch is that the size of this effect is much more modest than the popular narrative of gum as a "weight-loss tool" would suggest — we're talking about a difference of a few dozen kilocalories, not hundreds. In this article we show exactly what was measured, how large the effect is in numbers, and why it's worth treating as an interesting but small piece of the puzzle rather than a standalone strategy.
AKdr Anna Kowalczyk10 min
August 24, 2026
GuidesPopcorn as a Snack: Fiber, Volume, and Satiety Versus Chips
Picture two snacks: a cup of potato chips worth 150 kcal and six cups of popcorn worth just 100 kcal — a huge difference in volume, but surely "a calorie is a calorie," right? Not necessarily. A controlled experimental study found that the much larger, less calorie-dense portion of popcorn produced a stronger feeling of fullness than the smaller portion of chips — and more strikingly, people who ate chips went on to eat more at their next meal than people who ate popcorn, even though the chips had delivered more calories in the snack itself. This study is one of the cleanest pieces of evidence that food volume, not just calorie count, has a real effect on how much we eat afterward. In this article we show exactly how the experiment was designed and what it means in practice.
AKdr Anna Kowalczyk11 min
August 24, 2026
GuidesArtificial Sweeteners and Insulin: Do They Raise Blood Sugar Despite Zero Calories?
"Zero calories, so zero effect on the body" is the assumption behind the popularity of artificial sweeteners among people watching their blood sugar — but two solid scientific studies paint a far more complicated, even contradictory, picture. A large network meta-analysis covering 36 studies found no effect of artificially sweetened beverages on glucose or insulin compared with water — but those studies mostly tested a single, one-off dose. Meanwhile, a 10-week clinical trial testing daily, chronic consumption of sucralose alone found a real, measurable rise in insulin levels and a drop in insulin sensitivity in healthy young adults. This contradiction is itself the most interesting takeaway of this article — because it suggests a single sip of a sweetened drink is probably nothing, but a daily, weeks-long habit might be something else entirely.
PZdr Piotr Zieliński13 min
August 24, 2026
GuidesMediterranean Diet and Longevity: How Much Does It Really Lower Death Risk?
"The Mediterranean diet extends life" is one of those statements repeated so often that almost no one asks for the actual numbers. By how much, exactly? For whom? And is this an effect visible after a few weeks, or only after decades of consistent adherence? In this article we break the topic down, drawing on the largest available meta-analysis (over 4 million participants) and a separate study focused specifically on older adults — two sources that together give a far fuller picture than the popular, oversimplified headlines.
AKdr Anna Kowalczyk14 min
August 23, 2026
GuidesCreatine and Hair Loss: Does the Supplement Really Raise DHT?
"Creatine causes baldness" is one of the most repeated warnings in gym culture — and it rests on exactly one study from 2009, which never measured hair loss at all. That study did show a real spike in DHT, the hormone responsible for pattern hair loss, up 56% after a week of creatine loading. The catch: nobody since has ever tested whether that DHT spike actually translates into real hair loss — and those are very different questions.
MNMichał Nowak11 min
August 23, 2026
GuidesCold Water After Strength Training: Does It Help or Block Muscle Growth?
An ice bath after a strength session is associated with recovery and professionalism — yet a 12-week study shows the opposite: people using cold water after every workout gained significantly less strength and muscle mass than people using standard active recovery. The culprit is suppression of the very molecular signals muscle relies on to grow after exercise.
MNMichał Nowak12 min
August 23, 2026
GuidesThe Post-Workout Anabolic Window: Myth or Real Time Limit?
"You have 30 minutes after training to eat protein, or you lose the gains" is one of the most deeply rooted beliefs in gym culture. A meta-analysis covering over 1,000 participants shows it's an oversimplification based on misreading short-term cellular signaling data. What matters is total daily protein intake, not a rigid minute-count after your last rep.
MNMichał Nowak11 min
August 23, 2026
GuidesHigh-Protein Diets and Kidneys: Do They Harm Healthy People?
"Too much protein wrecks your kidneys" is a warning almost everyone hears the moment they start eating more meat or protein powder. A systematic review shows higher protein intake raises glomerular filtration rate (GFR) — but that means the kidney is working harder within normal range, not that it's being damaged. There's an honest catch, though: almost no study ran longer than six months, so the truly long-term question remains open.
MNMichał Nowak12 min
August 23, 2026
GuidesAlcohol After Training: How Much Do You Really Lose From Your Muscle Gains?
One beer or a couple of drinks after a hard workout doesn't zero out the whole session's effects — but it isn't neutral either. A study published in PLOS ONE shows that alcohol consumed after strength training clearly lowers the rate of muscle protein synthesis, and pairing alcohol with protein doesn't fully protect against that drop. The good news: even after alcohol, protein synthesis remains elevated above resting levels.
MNMichał Nowak11 min
August 23, 2026
Guides8 Glasses of Water a Day: Where Does the Rule Come From, and Do You Need to Follow It?
The "8×8" rule — eight 8-ounce glasses of water a day — is one of the most repeated health tips in the world, and also one of the least documented. A systematic review of the scientific literature couldn't find a single study actually justifying that specific number for healthy adults in a temperate climate — and coffee and tea, contrary to popular belief, do count toward your daily fluid intake.
AKdr Anna Kowalczyk10 min
August 23, 2026
GuidesDaily Multivitamins: Do They Actually Help You Live Longer?
A daily multivitamin is one of the most purchased supplements in the world, driven by the belief that it's a simple "insurance policy" for a longer life. A massive cohort study covering nearly 400,000 US adults, followed for 27 years, shows the opposite of what you'd expect — people who regularly took a daily multivitamin had slightly higher, not lower, all-cause mortality than those who didn't.
AKdr Anna Kowalczyk12 min
August 23, 2026
GuidesCalories in Nuts: Why Is the Label Off by a Third?
The calorie count on a bag of almonds looks like a precise, scientific fact — yet a controlled feeding trial shows the body actually absorbs far less energy from them than the label suggests: 32% less. The reason is surprisingly physical, not chemical — a large chunk of the fat in almonds stays trapped inside intact plant cell walls and passes through the digestive tract undigested.
AKdr Anna Kowalczyk10 min
August 23, 2026