Sugar and wrinkles: what glycation really does

Glycation is not a marketing invention: it is textbook chemistry. The sugars in your blood attach themselves to your proteins without any enzyme telling them to, and that bond, when it stays, changes the properties of the tissue. It is the same family of reactions that browns bread in the oven, only at 37 degrees and over decades.

What is not textbook chemistry is the leap from there to "this serum reverses glycation" or "this capsule blocks AGEs". Here we separate the two: what has been measured in people, what has not, and what the regulator says. We will say it up front: part of what follows goes against what we sell, because the honey, the panela, the agave syrup and the organic cane sugar on our shelves are free sugars in exactly the same way white sugar is.

In short: the essentials

• Glycation is the reaction of sugars with the amino groups of proteins, without enzymes. In the first stage, glucose or fructose reacts with the amino group of lysine.
• It mainly affects long-lived proteins such as the collagen in the dermis, because they have time to accumulate the damage.
• Measured in people: for each extra mmol/l of blood glucose, perceived age rises by 0.40 years in people without diabetes (602 participants in the Leiden Longevity Study). It is observational.
• Two different things are called "glycation": the one inside you, which depends on your glucose, and the AGEs that form in the pan. They are not the same lever.
• On dietary AGEs, the 2024 systematic review by Germany's SKLM concludes that there is no convincing evidence of a causal association with adverse health effects.
• The European Union has not authorised a single health claim mentioning glycation: zero rows in the annex to Regulation 432/2012, checked in Spanish, French and English.
• What is authorised and does touch the skin: "Vitamin C contributes to normal collagen formation for the normal function of skin".

What glycation is, and why collagen pays for it

In glycation, a reducing sugar — glucose, fructose — binds to an amino group on a protein with no enzyme involved. The review by the Senate Commission on Food Safety of the German Research Foundation describes it precisely: in the first stage of the Maillard reaction, reducing sugars react with the amino group of lysine, the most exposed amino acid. From there come intermediate products and, at the end of the road, AGEs, advanced glycation end products.

Up to this point it is unavoidable. Everyone with glucose in their blood and proteins in their body glycates, just as everyone who breathes oxidises. The difference between tissues is not the reaction, it is time: a protein that is renewed in days accumulates almost nothing, and one that lasts years accumulates everything that happens to it. Dermal collagen belongs to the second group, which is why it is the unwilling protagonist of this story. When AGEs form cross-links between collagen fibres, the tissue loses elasticity and gains stiffness.

This can be measured without a biopsy, through skin autofluorescence. Reference values were established in 1,385 healthy Slovak people aged from a few days to 77 years, and the pattern is the expected one: AGEs accumulate with age in everybody. In other words, glycation is not a disease some people have and others do not. It is a clock we all carry, and the useful question is not how to stop it but how far the needle can be moved.

The honest answer is: a little, and slowly. Nobody ends up with sixty-year-old skin because of a slice of cake, and nobody gets their twenty-year-old skin back by giving up sugar. What has been measured is an association: in the Leiden Longevity Study, with 602 participants, perceived age estimated from facial photographs rose from 59.6 years in the lowest glucose group to 61.2 years in participants with diabetes. Among non-diabetic participants alone, from 59.6 to 60.6, and continuously, 0.40 years of extra perceived age per mmol/l of glucose. A year and a half of face across the whole range. Neither nothing, nor a transformation.

The two glycations everyone mixes up

The first is endogenous: the glucose in your blood reacting with your proteins. The lever here is the free sugars in your diet, body weight and physical activity, and this is the one with a direct link to skin, because the collagen involved is yours.

The second is dietary AGEs, the ones that form on the plate before they reach you. And here is the figure that throws almost everyone: the reference study on the AGE content of foods, the database by Uribarri and colleagues, found that dry heat multiplies AGE formation by 10 to 100 times compared with the raw food, and that foods high in fat and animal protein both contain the most and generate the most during cooking. Carbohydrate-rich foods — vegetables, fruit, whole grains and milk — contain relatively few AGEs even after cooking.

Put another way: anyone blaming fruit for glycation is reading the wrong column of the table. And on whether removing those AGEs from the diet achieves anything, the evidence is shorter than it looks. The systematic review of randomised trials by Clarke and colleagues gathered twelve interventions and 293 participants in total: the high-AGE diet raised TNF-alpha and circulating AGEs across all populations, 8-isoprostanes in healthy adults and VCAM-1 in people with diabetes, but the authors themselves conclude that high-quality trials are lacking. And not one of the twelve measured skin.

The most recent and most severe assessment is the one by the SKLM, the Senate Commission on Food Safety of the German Research Foundation, published in 2024: it retrieved 253 original publications, of which only 192 met its quality criteria, found the overall database "inconsistent or inconclusive", noted that effects in animals appear at doses far exceeding estimated human exposure, and concludes that there is at present no convincing evidence of a causal association between dietary intake of glycation compounds and adverse health effects. That does not mean the frying pan is irrelevant; it means we cannot promise you anything about your wrinkles for changing it.

Six things you can change, in order of evidence

1. Cut free sugars, and learn which ones they are

The WHO recommends reducing free sugars to less than 10% of total energy intake, and suggests, as a conditional recommendation, going below 5%. The definition is what matters: free sugars are the mono- and disaccharides added by the manufacturer, cook or consumer, plus the sugars naturally present in honey, syrups, fruit juices and fruit juice concentrates. Yes: the honey and the syrups and sugars we sell count as free sugars, and so do panela and coconut sugar.

Our own arithmetic, using the WHO figures: on a 2,000 kcal diet, 10% is 200 kcal, roughly 50 g of sugar a day, and 5% is about 25 g. For context, in Spain, where our shops are, the ANIBES study measured a median of 71.5 g of total sugars a day (17% of energy), of which 28.8 g were free sugars (7.3%) and 38.3 g intrinsic (9.6%). It is worth saying that ANIBES was funded by a grant from Coca-Cola Iberia through the Spanish Nutrition Foundation, the scientific body that coordinates the study, and that the main sources of free sugars were sugar-sweetened soft drinks (25.5%), table sugar (17.8%), bakery and pastry items (15.2%) and chocolates (11.4%).

2. Don't take fruit away from anyone over this

Whole fruit is not a free sugar under the WHO definition, and it is the leading source of intrinsic sugars in the Spanish diet, at 31.8% of the total. Juice does count as free, and contributes 11.1% of intrinsic sugars and 2.91% of free sugars: the difference between eating one orange and drinking three is not the molecule, it is the matrix and the speed.

And on the AGE side, carbohydrate-rich plant foods come out well even cooked. So seasonal fruit, vegetables and weekly baskets are nobody's problem in this story. For the detail of how fibre changes the curve, see our article on fibre.

3. Change the cooking method before the shopping list

This is the cheapest advice you will read today, because it costs nothing. In the same work by Uribarri, AGE formation was significantly reduced by cooking with moist heat, shorter cooking times, lower temperatures and acidic ingredients such as lemon juice or vinegar. An apple cider vinegar in the marinade does more for the chemistry of your dinner than any capsule.

Translated into real cooking: boiling, steaming and stewing before griddle, hot oven and deep frying. Not because the rest is poison, but because this is the only point in the chain where you choose the temperature. The spices and the olive oil in the marinade are also what keeps a boiled dish from tasting boiled.

4. Flatten the glucose peaks with food, not with a capsule

If the endogenous lever is glucose, what matters is the curve after a meal. And here there is an authorised EU health claim, even though it says nothing about skin: the one for oat or barley beta-glucans and the rise in blood glucose after a meal, with a demanding condition of 4 g of beta-glucans per 30 g of carbohydrate in the portion. We did that arithmetic in our article on oats.

The same goes via fibre and slowly digested starch: pulses are the cheapest food you have for this, with portions and grams in our article on pulses. Flakes and mueslis with no added sugar and loose nuts and dried fruit do the rest of breakfast.

5. Move: the only habit with a signal measured on skin

In the skin autofluorescence reference-values study, among healthy non-smoking adults, exercising for more than 30 minutes a day three or more times a week was associated with lower autofluorescence, that is, with fewer AGEs accumulated in the tissue. It is an association, not a trial, and that needs saying. But it is the only lifestyle variable in this article that appears directly linked to a measurement taken on skin.

We do not sell that. What we do have to go with it is coffee and teas without sugar, the easiest way to drop ten grams of free sugars a day without noticing, and drinks with no added sugars.

6. Vitamin C: the only one allowed to say "collagen" and "skin" in the same sentence

Regulation (EU) 432/2012 authorises this exact wording: "Vitamin C contributes to normal collagen formation for the normal function of skin". The condition is that the food be at least a source of vitamin C, that is 15% of the nutrient reference value, which for vitamin C is 80 mg: 12 mg per 100 g. And six more nutrients carry a claim on the maintenance of normal skin: biotin, niacin, riboflavin, vitamin A, iodine and zinc, whose authorised wording is "Zinc contributes to the maintenance of normal skin".

For oxidative damage, the authorised wording is "contributes to the protection of cells from oxidative stress" and exactly seven nutrients have it: copper, manganese, riboflavin, selenium, vitamin C, vitamin E and zinc. Those are the ones in the shop's antioxidant supplements, in formulas such as the Antiox with vitamins C, E and zinc or the Mega Antioxidant with selenium and zinc, and also in natural tocopherol and selenium on their own. What to take and what to apply is covered in our article on vitamin C and skin.

The table to stick on the kitchen wall

Ordered by what heat and moisture do to AGE formation on the plate, according to the database by Uribarri and colleagues. It is not a toxicity scale: it is a chemistry scale.

The shopping list

For the free-sugar side, what you read is the label: sugars and sweeteners, honey and pollen, chocolates, cookies, the bakery and drinks. Not to avoid them, but to know how many grams go in each day.

For the food side that needs no policing: fruit, vegetables, pulses, dried fruit and nuts, cereals, bars and muesli, plain yoghurt, refrigerated foods and organic baskets. And for the kitchen, oils and vinegars and spices.

For the supplement and cosmetic side, the one to look at with most suspicion: vitamins and minerals, hair, skin and nails, collagens and cartilage, superfoods, plants and extracts, immune system, digestive system and personal care. Whatever is on promotion is in offers, and the rest of the articles are on the health blog.

Do you need "anti-glycation" supplements or creams?

With the regulation in hand, the answer is short. We opened the annex to Regulation (EU) 432/2012, the one listing the health claims authorised in the European Union, and counted the rows mentioning glycation in its official Spanish, French and English versions. Zero, zero and zero. There is no authorised claim allowing anyone to say that a food or a supplement acts on glycation, in either direction.

Nor does the claim "antioxidant" on its own exist. The only permitted wording is "contributes to the protection of cells from oxidative stress", and only for the seven nutrients listed above, plus a specific claim for olive oil polyphenols and blood lipids, which we covered in our article on olive oil. Anything else written on a jar is, legally, something else. The shop's antioxidant category holds 89 references and not one carries an anti-glycation promise in its name, which is exactly what you would expect from a compliant catalogue.

In cosmetics the framework is different. Cosmetic products do not carry health claims but marketing claims governed by the common criteria of Regulation (EU) 655/2013, which requires every claim, explicit or implicit, to be supported by adequate and verifiable evidence, taking the state of the art into account, and requires any study used as evidence to be relevant to the product and based on well-designed, correctly conducted methodologies. In other words: "anti-glycation" on a jar is not forbidden, but the manufacturer has to hold the dossier that backs it. Asking for it is legitimate, and it is what we would do.

The cheap and well-supported list, for anyone looking for the headline: sun protection, not smoking, sleep, and free sugars within the WHO range. The other skin-ageing factors that really have been measured have more to do with the sun than with dinner. If what interests you is collagen as a supplement, what the evidence does and does not say is in our article on collagen, and if it is hair, in the one on hair loss.

Where to buy antioxidants and organic cosmetics in Barcelona and Sant Cugat

This is what a physical shop can do and a product page cannot: working out the free sugars with your packet in front of us. Because the label does not print "free sugars", it prints "sugars", and those are different things. Plain yoghurt declares grams of sugars that are lactose, and lactose is not a free sugar. Fruit purée declares the fruit's own. A soft drink declares the ones that were added. The same number on three packets means three different things, and subtracting what does not count takes a minute of conversation at the counter.

On top of that comes the nutrition claims regulation, (EC) 1924/2006, which sets the exact thresholds: "low sugars" requires no more than 5 g per 100 g for solids or 2.5 g per 100 ml for liquids; "sugars-free", no more than 0.5 g per 100 g or 100 ml; and "with no added sugars" is only allowed if no mono- or disaccharide and no food used for its sweetening properties has been added, and it also forces a statement on the label saying the product contains naturally occurring sugars. That detail, which almost nobody reads, accounts for half the confusion around this subject.

And buying loose allows the other thing: 100 g of a nut or a spice to try before taking home the kilo, instead of deciding blind from the packaging. We are at Provença 242, 08008 Barcelona, in the Eixample; at Còrsega 78, 08029 Barcelona, in the Eixample near Sants; and at Antoni Bell 2, 08174 Sant Cugat del Vallès, in Volpelleres. All three shops are in Spain. The phone number is +34 683 118 961 and the email is linverd@linverd.com.

• Bring the packet and we will work out the free sugars together, subtracting the ones that do not count.
• We compare two labels of the same product with the 1924/2006 thresholds in front of us.
• We check whether a supplement really contains the nutrients allowed to claim protection from oxidative stress.
• We weigh out 100 g loose so you can try before buying the large format.

Frequently asked questions

Does sugar cause wrinkles?

Not directly, and not demonstrably. What has been measured is an association: more blood glucose, slightly more perceived age, 0.40 years per mmol/l in people without diabetes. It is an observational study of 602 people, not a trial, and the effect across the whole range was a year and a half of face.

Does fruit glycate like table sugar?

Not in practice. Whole fruit is not considered a free sugar by the WHO and, in the food AGE database, carbohydrate-rich plant foods contain few AGEs even when cooked. Juice counts as a free sugar; the whole piece does not.

Is there an anti-glycation supplement that works?

No health claim authorised in the European Union mentions glycation: zero rows in the annex to Regulation 432/2012 in Spanish, French and English. What is authorised is limited to the protection of cells from oxidative stress, for seven specific nutrients.

Are anti-glycation creams any use?

Creams do not carry health claims but cosmetic claims, which Regulation (EU) 655/2013 requires to be supported by adequate and verifiable evidence. The word being allowed does not mean the effect is proven: what you should ask for is the dossier behind it.

How much free sugar can I have per day?

The WHO recommends less than 10% of energy and suggests going below 5%. With our arithmetic on 2,000 kcal, that is about 50 g and about 25 g a day. EFSA, the European Food Safety Authority, concluded in 2022 that no safe level can be set and that intake should be as low as possible within a nutritionally adequate diet.

Are honey or agave syrup better than sugar?

Not for this. The WHO definition of free sugars expressly includes the sugars naturally present in honey, syrups, fruit juices and fruit juice concentrates. We sell them and we say so: they change the flavour and the nuances, not the category.

Where can I buy antioxidants and organic cosmetics in Barcelona or Sant Cugat?

In our three shops: Provença 242 and Còrsega 78 in Barcelona, and Antoni Bell 2 in Sant Cugat del Vallès (Volpelleres). We stock antioxidant supplements and organic personal care, and we will work out the free sugars on your packet at the counter. Phone +34 683 118 961.

In short

Glycation is real, it is slow, and nothing sold in a jar stops it. The part you can act on is free sugars — the WHO puts the bar at 10% and suggests 5% —, the cooking method and movement. The part you cannot buy is the bigger one.

You have vitamins and minerals, hair, skin and nails and personal care in the online shop, and the three shops in Barcelona and Sant Cugat for the part that needs someone in front of you. To carry on from here, vitamin C for skin and collagen are the two articles that continue this one.

This article is for information only and does not replace the advice of a healthcare professional. If you have diabetes, prediabetes or are on treatment, any change of diet is worth discussing with your doctor or dietitian.