Scientific Evidence on noema

Intermittent fasting: what actually works

Mon, 04 May 2026 00:00:00 +0000

Abstract. “Intermittent fasting” has entered public discourse as a single category, but very different practices live under the same label — from daily 16:8 to the five-days-a-month fasting-mimicking diet. On the daily protocols the literature is by now clear: at equal calories, they don’t drive more weight loss than a classic diet, and the “extra” metabolic benefits are small or extrapolated from mice. The case that holds up clinically is the FMD: five days a month of heavily reduced intake, with replicated human data on insulin sensitivity, inflammatory markers, and cardiometabolic profile. The molecular rationale runs through mTOR — the amino-acid and insulin sensor that periodic fasting modulates over a long enough stretch, while sixteen hours of daily fasting modulates only briefly. A disproportionate enthusiasm remains: 16:8 autophagy, white-fat browning, “demonstrated” longevity are still mostly rodent stories. Here I try to separate the solid case (FMD, early time-restricted eating for specific profiles) from the noise.

When an idea actually works in medicine and nutrition, it usually doesn’t need evangelists. When it does, it’s worth looking carefully.

Intermittent fasting reached the general public around 2012-2013 with Michael Mosley’s The Fast Diet and the 5:2 protocol, and from there it never stopped: 16:8, 18:6, 20:4, OMAD, alternate-day fasting, fasting-mimicking diet, prolonged fasts of three, five, seven days. Every variant has its book, its influencer, its biological rationale told as if it were the answer.

Yet if you go back to the basic question — which intermittent fasting does something unique that a good normal diet doesn’t? — the answer that emerges from the better literature of the last ten years is one and specific: the protocol with the most convincing clinical data isn’t 16:8, but the fasting-mimicking diet developed by Valter Longo’s lab at USC. Five days a month, not sixteen hours a day. It’s a different thing, and it has to be told as such.

An honest routine: few actives, right doses, consistency

Thu, 30 Apr 2026 00:00:00 +0000

Abstract. A rational skincare routine is much shorter than the cosmetics industry’s narrative suggests. Three products can do 80% of the job; five cover almost every real need. Here I lay out a practical synthesis: the minimal routine for those without specific concerns, the complete routine for anyone targeting photo-ageing or dyschromia, the order of application, the most common mistakes, and when it makes sense to move from the bathroom mirror to the aesthetic-medicine chair. Third and final part of a series, in continuity with Skincare: actives, concentrations and medical grade — the second part, devoted to the actives applied at home and to the real difference between over-the-counter and medical grade products.

By this point in the series we have dismantled a lot. Most of the heavily marketed aesthetic-medicine treatments don’t have the evidence the marketing suggests. Most of the trendy skincare ingredients don’t do what they promise. Most of the routines described by magazines and social channels are oversized, underdosed, or both.

One practical question remains. So what do I put on, in what order, how often?

The honest answer is short. Three or four products, used consistently for months, do the job most people are after when they walk into a beauty store with a shopping list of thirteen items. Adding products rarely improves the result — more often it makes it worse, irritating skin that would have responded better to less.

This third part is the practical synthesis of the first two. Nothing new, but everything pulled together.

Skincare: actives, concentrations, and medical grade

Mon, 27 Apr 2026 00:00:00 +0000

Abstract. Almost all mass-market skincare is under-dosed, unstable, or poorly formulated. Almost all medical grade skincare costs more — but not always for the right reasons. Here I draw the line on what “active” really means in a cosmetic (concentration, pH, vehicle, penetration, stability), which pillars of the dermatological literature actually hold up (retinoids, vitamin C as L-ascorbic acid, niacinamide, azelaic acid, AHA/BHA), and which are the more recent fashions selling mostly stand-in ingredients: cosmetic peptides, bakuchiol as “natural retinol”, snail mucin, plant stem cells. And why — beyond a certain marketing premium — medical grade products often have technical reasons to cost more. Second part of a three-part series, after Aesthetic medicine: what works, what is marketing.

In the cosmetics aisle of a pharmacy or in the pages of a skincare e-commerce site, ingredients turn up everywhere. Vitamin C, retinol, peptides, hyaluronic acid, niacinamide, ceramides, plant oils, botanical extracts. The promise is always the same — younger, firmer, brighter, more protected skin — and the vocabulary is almost identical between an eight-euro serum and a hundred-and-twenty-euro cream.

There is a problem, and it is hard to fit on a label. A cosmetic works — when it does work — because it contains a sufficient amount of a molecule with proven efficacy, formulated so that it stays stable, and delivered so that it crosses the stratum corneum enough to do something. Almost the entire mass-market skincare industry trades on the perception of efficacy — pleasant texture, fragrance, bottle design, marketing claims — more than on actual efficacy. It is not a scam: it is a sector with an enormous grey area between “contains an active ingredient” and “does what it promises”.

Aesthetic medicine: what works, what is marketing

Sat, 25 Apr 2026 00:00:00 +0000

Abstract. Aesthetic medicine is one of the medical fields where the gap between scientific evidence and advertising narrative is widest. Some treatments have thirty years of solid literature behind them; others were born yesterday and live on sponsored trials and photographic promises. Here I draw the line, one by one, between what has real clinical foundations (botulinum toxin, hyaluronic acid fillers, some lasers, peels), what has an interesting biological rationale but evidence still being built (Profhilo, polynucleotides such as Plinest, new-generation biostimulators like Ellansé and Juvelook), and what travels almost entirely on marketing (HIFU as a “lift”, injectable vitamin cocktails, mesotherapy, carboxytherapy). First of a three-part series, written for those who want to understand before they choose; the second part is Skincare: actives, concentrations and medical grade.

When you walk into an aesthetic-medicine clinic, you are usually handed a menu. Toxin, fillers, biostimulators, skinboosters, polynucleotides, injectable vitamins, next-generation lasers, scalpel-free lifts, peels, microneedling, PRP. Prices change, names change every year, the promises do not: “natural rejuvenation”, “skin quality”, “collagen stimulation”, “lifting effect”. But behind this menu — almost always presented in identical language — lies an enormous gap in scientific evidence. Some treatments have thirty years of independent literature, randomised trials, well-documented safety profiles. Others have a handful of studies, often manufacturer-sponsored, and a mechanistic rationale that sounds convincing — but is not yet clinical evidence. Others still are pure narrative, propped up by before-and-after photos and the perceived authority of whoever is offering them.

There are two mirror-image mistakes when discussing aesthetic medicine. The first is wholesale rejection — “it’s all vanity, it’s all marketing, it’s all dangerous”. This is wrong because many treatments really do work, have medical as well as aesthetic indications, and improve the quality of life of those who choose them with awareness. The second is blind enthusiasm — “if it’s new it’s better, if it costs more it’s better, if everyone is doing it, it must mean something”. This is wrong because aesthetic medicine is one of the fields where marketing innovation systematically precedes clinical innovation, and where many technologies we now consider obsolete are still on sale.