What are the benefits of a sugar-free diet for the skin?

The sugar-free diet is a nutritional approach aimed at reducing, or even eliminating, added and refined sugars, without completely excluding carbohydrates. These remain essential for the body’s proper functioning, as they provide the energy required by the brain, muscles, and cellular metabolism. The objective of this dietary pattern is to return to a more natural, unprocessed diet that is rich in nutrients and low in hidden sugars, which are often found in prepared meals, flavored yogurts, or fruit juices.

We generally distinguish three approaches to a sugar-free diet:

• The strict sugar-free diet, which excludes virtually all carbohydrates, including those from fruits, legumes, and grains. It is rarely adopted outside a medical context.

• The so-called “low-carb” diet, which reduces fast and refined sugars while preserving a moderate portion of complex carbohydrates from vegetables and whole grains.

• A diet without added sugars, the most common approach, which removes industrial sugars while preserving naturally occurring sugars in fruits or honey.

According to the World Health Organization (WHO) recommendations, free sugars should not exceed 10% of total energy intake in adults and children.

One of the major mechanisms of skin aging is the accumulation of advanced glycation end products (AGEs) over the course of life. Glycation is a non-enzymatic reaction in which sugar molecules, such as glucose or fructose, covalently bind to proteins, lipids, or nucleic acids. AGEs form both endogenously through the body’s natural processes and exogenously, notably via diet: excessive intake of refined sugars, simple carbohydrates, and high-temperature cooked foods (grilled, fried, roasted) promotes their buildup. Other external factors—such as tobacco, alcohol, a sedentary lifestyle, pollution, or UV exposure—can also stimulate AGE production in the skin.

The collagen and elastin, the primary proteins of the extracellular matrix, are particularly vulnerable to glycation. The latter leads to the formation of cross-links between collagen fibers, which increases their stiffness and sensitivity to stimuli mechanical, while impairing their ability to interact with cells and other extracellular matrix proteins. AGEs also promote oxidative stress and inflammation by increasing the production of free radicals and activating RAGE (Receptor for Advanced Glycation End Products) receptors on the cell surface, triggering inflammatory cascades that accelerate skin aging.

Glycation often increases after 35 years of age and accelerates with intrinsic aging. The most abundant AGEs in the skin are carboxymethyllysine and pentosidine, along with derivatives such as glyoxal, glucosepane, and the methylglyoxal-lysine dimer. Excess sugars and repeated glycemic spikes promote the formation of these proinflammatory molecules, which drive structural, morphological, and functional alterations in cutaneous tissues.

Several studies have examined the effects of sugar on the skin. A study conducted among 4,025 women aged 40 to 74 years evaluated the impact of diet on skin appearance and signs of skin aging. The results highlighted a direct link between carbohydrate intake and skin appearance. An increase in carbohydrates in the daily diet was associated with an increased likelihood of having wrinkled skin and skin atrophy. These associations were independent of factors such as age, body mass index, sun exposure, or physical activity. In contrast, higher intakes of vitamin C and linoleic acid were linked to improved skin appearance, with a reduction in wrinkles and skin dryness.

A sugar-free diet thus appears to contribute to slowing the onset of signs of skin aging.

A high intake of sugars and simple carbohydrates is also associated with inflammatory mechanisms in the skin. Increased sugar levels in the body promote the production of free radicals and AGEs, which stimulate inflammatory pathways. For this reason, it is sometimes suggested that a low-sugar diet could be beneficial for certain inflammatory dermatoses, such as eczema and psoriasis, reducing the systemic and cutaneous inflammatory burden.

However, clinical evidence establishing a link between sugar consumption and these inflammatory skin diseases remains limited.

A recent study conducted on 30 volunteers with atopic dermatitis assessed the effect of a very low–sugar diet versus a higher–sugar diet on eczema progression. Over three weeks, participants were supported by dietitians, and clinical monitoring was performed using the SCORAD (SCOring Atopic Dermatitis), a tool measuring lesion extent and severity as well as psychological impact. The results showed no significant difference between the two groups, leading researchers to conclude that sugar was not an exacerbating factor for eczema, at least within the scope of this short study.

On the other hand, the evidence is more abundant regarding acne. A study conducted between November 2018 and July 2019 analyzed 24,452 adults to examine a potential association between their dietary habits and their skin condition. Among them, 11,324 individuals (46%) reported suffering from acne. After adjusting for age, sex, physical activity level, smoking status, daily energy intake, and the presence of depressive symptoms, the results showed a significant association between acne and the consumption of high-fat and high-sugar products and sugar-sweetened beverages.

High sugar consumption may therefore increase the risk of acne.

These results were confirmed by dietary interventions specifically targeting the glycemic load of foods. A study involving 43 young men with acne compared the effects of a low–glycemic-load diet with a “standard” diet (42% higher glycemic intake than the low–glycemic-load group). Over a 12-week period, researchers assessed the number and severity of acne lesions during monthly visits. At the end of the study, the total lesion count had decreased more in the low–glycemic-load group (−23.5 ± 3.9) than in the control group (−12.0 ± 3.5). Similar findings were observed for inflammatory lesions (−17.0 ± 3.1 in the low–glycemic-load group versus −7.4 ± 2.5 in the control group).

These results suggest that a sugar-free diet could limit, or even reduce, acne.

A low-sugar diet poses no risk of nutrient deficiency in the skin. To date, no study has highlighted any harmful cutaneous effects associated with reducing or eliminating sugar. On the contrary, lowering simple sugars is often linked to improved skin quality by limiting inflammation and oxidative stress. Thus, removing added sugars does not induce any deficiency in the skin but rather contributes to maintaining balanced skin.

• ZUBERBIER T. & al. Sugar is not an aggravating factor in atopic dermatitis. Acta Dermato-Venereologica (2001).

• VARIGOS G. A. & al. A low-glycemic-load diet improves symptoms in acne vulgaris patients: A randomized controlled trial. The American Journal of Clinical Nutrition (2007).

• COSGROVE M. C. & al. Dietary nutrient intakes and skin-aging appearance among middle-aged American women. The American Journal of Clinical Nutrition (2007).

• World Health Organization (WHO). Guideline: Sugars intake for adults and children (2015).

• DESCHASAUX M. & al. Association Between adult acne and dietary behaviors. JAMA Dermatology (2020).

• HEKMATDOOST A. & al. Effects of a low free sugar diet on the management of nonalcoholic fatty liver disease: A randomized clinical trial. European Journal of Clinical Nutrition (2022).

• DOLATA N. & al. The impact of excessive sugar consumption on skin health: Analysis of biological mechanisms and dermatological effects. Journal of Education, Health and Sport (2024).

• MIKAIL M. A. & al. Diet and skin health: The good and the bad. Nutrition (2024).

• BILOSHYTSKA A. & al. Skin aging – The role of nutrition and sugar. Journal of Education, Health and Sport (2025).