A Century of Beauty Research

November 3 is Culture Day in Japan. Culture is the work of accumulating knowledge across generations. Skincare, too, is a culture. The ingredients and routines we now take for granted did not appear out of nowhere. They stand atop nearly a century of trial and error, occasional grand misunderstandings, and the steady accumulation of scientific verification. For this special feature, we trace roughly one hundred years of beauty research and the journey by which cosmetics shifted from something chosen by sensation to something chosen by evidence. And we will honestly discuss where KAIAN stands at the leading edge of that lineage.

Knowing history is the best vaccine against being swept along by trends. How many times have we been enthralled by the word "new," and how many times have we let it go? Once you recognize the pattern of that repetition, you can calmly grade the next buzzword that appears.

1. 1920s–1950s: When the standard of beauty reversed

Until the early twentieth century, fair skin was a marker of the upper class in both West and East, because a tan signaled outdoor labor. Then in the 1920s that value flipped dramatically. Against a backdrop of resort culture and shifting fashion, bronzed skin became a symbol of leisure and affluence. There was almost no awareness then that ultraviolet radiation contributes to skin aging and cancer, and people bathed in sunlight unprotected.

The turning point came from the 1940s onward. The earliest sunscreen agents were commercialized, and eventually the concept of photoaging took hold: the recognition that UV denatures dermal collagen and elastin and is a leading cause of wrinkles, sagging, and spots. Today we have a well-organized toolkit of physical scatterers such as zinc oxide and titanium dioxide, and photostable modern filters like bemotrizinol. Yet the starting point was the belief that "a tan is healthy"—the exact opposite of what we now know.

2. 1960s–1980s: The science of vitamins and retinoids begins

In this era cosmetics moved from "empirically applying plants and oils" to asking what specific molecules do to skin. Vitamin C—ascorbic acid—was biochemically shown to act as a cofactor in collagen synthesis, and the intersection of antioxidants and beauty came into view. But ascorbic acid oxidizes readily and is hard to formulate. To address this weakness, derivatives such as ascorbyl glucoside, 3-O-ethyl ascorbic acid, and the oil-soluble ascorbyl tetraisopalmitate (VC-IP) were developed one after another in later years.

The greatest discovery of this era was the vitamin A derivatives—the retinoids. As retinoic acid, the oxidized form of retinol, was used clinically to treat acne, improvements in wrinkles and pigmentation were observed almost by chance. Reports that retinoids act through nuclear receptors to influence epidermal differentiation and collagen production became the first solid evidence that a topical ingredient could act on skin at the level of gene expression. Evidence-based beauty science truly began to run from here.

What the history of retinoids teaches is a principle: the more potent the ingredient, the more it tends to carry the cost of irritation. That is precisely why later branches emerged toward the milder retinaldehyde and the plant-derived, reportedly gentle bakuchiol.

3. 1990s–2000s: The age of exfoliation and peptides

The 1990s popularized the idea of gently shedding old corneocytes to balance skin turnover. AHAs such as glycolic and lactic acid, and the lipid-soluble salicylic acid (BHA) that reaches into the pore, came into wide use. As the naive notion that "stronger is better" revealed its downsides, options broadened toward gentler, larger-molecule next-generation exfoliants such as mandelic acid, lactobionic acid, and gluconolactone.

The protagonists of the 2000s were peptides. Molecules that mimic signaling in skin repair—reported to prompt fibroblasts toward collagen production—appeared, such as palmitoyl tripeptide-1 (Matrixyl®) and the wound-healing-derived copper tripeptide-1 (a copper complex of tripeptide-1 (GHK)). Peptides reported to soften excessive muscle contraction, such as acetyl hexapeptide-8 and acetyl octapeptide-3 (SNAP-8®), diversified the idea of "instructing the skin." At the same time, the importance of barrier-supporting ceramides was reappraised, and moisturizing deepened from mere hydration to "repairing skin structure."

4. 2010s–present: Regenerative medicine and the longevity current

Entering the 2010s, insights from regenerative medicine flowed into beauty. human stem cell conditioned media containing secreted cytokines and growth factors, exosomes that carry intercellular signals, and growth factors such as FGF and EGF drew attention. These are rich in promise, yet they are always shadowed by questions of absorption and delivery: does an applied molecule truly reach its target cell? It became an era in which speaking frankly about the strength and weakness of evidence matters more than ever.

The current frontier is longevity science. Molecules tied to cellular energy metabolism such as NMN and nicotinamide riboside; resveratrol, studied in relation to sirtuins; spermidine, discussed in relation to autophagy; urolithin A, involved in mitochondrial function; and fisetin, studied for approaches to senescent cells—all are increasingly carried into the cosmetic context. Yet much of this knowledge leads with oral and basic-research findings, while human-trial evidence for topical cosmetic use is still accumulating. Honestly measuring the distance between hope and reality is the responsibility of those of us living now.

5. KAIAN's perspective, and the practice ahead

One line runs through the whole century: the direction from sensation to evidence. From an age that believed a tan was healthy, we have built a culture of asking about mechanisms of action and measuring effects and limits in human trials. KAIAN aspires to stand at the leading edge of this current. Rather than claiming to "cure" aging, we seek to preserve, as long as possible, the functions the skin inherently has. This is the thinking behind our Skin Longevity philosophy.

What history has proven is that not every trendy ingredient endures. What remains is only what can be explained mechanistically and has withstood human verification. KAIAN does not leap at buzzwords; we choose our words only after weighing the accumulation of evidence.

The practice readers can apply daily is simple. First, make UV protection the lifelong foundation. What a century of research most strongly supports is still daytime defense. Second, when you meet a new ingredient, ask yourself three things: Can its mechanism be explained? Is there human verification? Is the balance against risk reasonable? Third, introduce potent ingredients little by little, watching how your skin responds—the lesson the history of retinoids taught us.

Note that some of the longevity ingredients mentioned here are, even globally, still in the dawn of development as topical cosmetics. In KAIAN's own brand EVOLURE as well, areas where evidence is not yet sufficient remain unoffered for now; we will judge honestly as verification progresses. What is worth reflecting on this Culture Day is both how far we have come and how humbly we can proceed from here.

A century ago, people sunbathed with conviction. A century from now, we too will likely have let go of some of today's common sense as error. That is exactly why we choose verification over assertion, lineage over fashion. With that posture, KAIAN will continue to build a science that stays close to the skin's functional lifespan.