Aging skin: the role of diet: facts and controversies

Impact of nutrition on skin wound healing and aesthetic outcomes: A comprehensive narrative review

Background

While current wound treatment strategies often focus on antimicrobials and topical agents, the role of nutrition in wound healing and aesthetic outcomes is crucial but frequently overlooked. This review assesses the impact of specific nutrients and preoperative nutritional status on surgical outcomes.

Methods

A comprehensive search was conducted in PubMed, Scopus, Web of Science, and the Cochrane Library, from the inception of the study to October 2023. The study focused on the influence of macronutrients and micronutrients on aesthetic outcomes, the optimization of preoperative nutritional status, and the association between nutritional status and postoperative complications. Inclusion criteria were English language peer-reviewed articles, systematic reviews, meta-analyses, and clinical trials related to the impact of nutrition on skin wound healing and aesthetic outcomes. Exclusion criteria included non-English publications, non-peer-reviewed articles, opinion pieces, and animal studies.

Results

Omega-3 fatty acids and specific amino acids were linked to enhanced wound-healing and immune function. Vitamins A, B, and C and zinc positively influenced healing stages, while vitamin E showed variable results. Polyphenolic compounds showed anti-inflammatory effects beneficial for recovery. Malnutrition was associated with increased postoperative complications and infections, whereas preoperative nutritional support correlated with reduced hospital stays and complications.

Conclusion

Personalized nutritional plans are essential in surgical care, particularly for enhanced recovery after surgery protocols. Despite the demonstrated benefits of certain nutrients, gaps in research, particularly regarding elements such as iron, necessitate further studies. Nutritional assessments and interventions are vital for optimal preoperative care, underscoring the need for more comprehensive guidelines and research in nutritional management for surgical patients.

The association between activity levels and skin moisturising function in adults

Factors associated with skin moisture retention include age and lifestyle, such as diet and sleep efficiency. However, the impact of exercise habits on skin moisturising function is unclear. We surveyed 86 participants from a Japanese university about their activity levels using the International Physical Activity Questionnaire. We also examined their skin moisturising function, measuring stratum corneum (SC) hydration levels and transepidermal water loss (TEWL). Comparisons of participants’ activity levels, SC hydration, and TEWL, accounting for their gender and age differences, revealed activity levels significantly related to differences in SC hydration levels. Results of multiple comparisons showed increased activity relates to significantly higher SC hydration − the higher the activity levels, the higher the hydration. No difference was found in TEWL. The results suggest exercise habits can prevent dry skin. The findings may be useful for the prevention and treatment of dry skin and promoting the benefits of exercise.

Diet and Skin Aging-From the Perspective of Food Nutrition

We regularly face primary challenges in deciding what to eat to maintain young and healthy skin, defining a healthy diet and the role of diet in aging. The topic that currently attracts maximum attention is ways to maintain healthy skin and delay skin aging. Skin is the primary barrier that protects the body from external aggressions. Skin aging is a complex biological process, categorized as chronological aging and photo-aging, and is affected by internal factors and external factors. With the rapid breakthrough of medicine in prolonging human life and the rapid deterioration of environmental conditions, it has become urgent to find safe and effective methods to treat skin aging. For diet, as the main way for the body to obtain energy and nutrients, people have gradually realized its importance to the skin. Therefore, in this review, we discuss the skin structure, aging manifestations, and possible mechanisms, summarize the research progress, challenges, possible directions of diet management, and effects of foodborne antioxidants on skin aging from the perspective of food and nutrition.

Collagen Hydrolysates for Skin Protection: Oral Administration and Topical Formulation

Antioxidants are molecules that delay or inhibit the oxidation of other molecules. Its use significantly increased in recent years in the diet of people. Natural antioxidants are replacing the use of synthetic antioxidant ingredients due to their safety, nutritional, and therapeutic values. Hydrolyzed collagen (HC) is a popular ingredient considered to be an antioxidant. This low molecular weight protein has been widely utilized due to its excellent biocompatibility, easy biodegradability, and weak antigenicity. It is a safe cosmetic biomaterial with good moisturizing properties on the skin. The antioxidant properties of HC are conditioned to the size of the molecule: the lower the molecular weight of peptides, the greater the ability to donate an electron or hydrogen to stabilize radicals. The antioxidant capacity of HC is mostly due to the presence of hydrophobic amino acids in the peptide. The exact mechanism of peptides acting as antioxidants is not clearly known but some aromatic amino acids and histidine are reported to play an important role in the antioxidant activity. Oral ingestion of HC increases the levels of collagen-derived peptides in the blood torrent and improves the skin properties such as elasticity, skin moisture, and transepidermal water loss. Additionally, daily intakes of HC protect the skin against UV melasma, enhances the fibroblast production and extracellular matrix of the skin. HC has been identified as a safe cosmetic ingredient for topical formulations with good moisturizing properties at the stratum corneum layer of the skin. It reduces the effects of skin aging (dryness, laxity, and wrinkles). The use of HC as a principal ingredient in safe formulations for skin protection was reviewed and compared when it is used by topical and/or oral administration.

A variety of processes that affect the perception of skin aging

The purpose of this paper is to discuss the most important factors affecting perceived age. Aging is an unavoidable and irreversible process, but perceived age is a modifiable psychosocial factor. Our exterior has become one of the determinants of our social position, the key to success in our professional and personal lives. Today, we see people through their appearance, we judge after the first impression. With the help of aesthetic medicine, we can change the perceived age, but we cannot stop aging. This article discusses factors affecting the perceived age, such as hair color, skin color, general appearance and environmental factors. Many cannot be avoided, but we can make changes in life to look younger and more well-groomed. Indeed, we can change our habits for the benefit of the whole body, not only for the skin.

Dietary Protein Deficit and Deregulated Autophagy: A New Clinico-diagnostic Perspective in Pathogenesis of Early Aging, Skin, and Hair Disorders

Background:

Diet has an important role to play in the well-being of human body.

Aims:

The study intends to establish the “hypothesis of conscious, selective, and self-destruction i.e., deregulated autophagy of skin and hair in low dietary protein scenario” by determining the facial profile, clinical presentation, and histopathological correlation of deficient protein intake and missing of meals in a tertiary care aesthetic skin institute.

Methods:

A total of 98 patients of skin- and hair-related complaints were enrolled in the study and a histopathological correlation was established by skin and scalp biopsies in high and low protein groups.

Results:

A significant number of subjects (68.4%) were taking less than half of the recommended daily allowance of proteins and faced problems like hair fall, acne, pigmentation, vitiligo, hirsutism, melasma, and premature aging. Subjects missing breakfast were found to have hypothyroidism, diffuse hairfall, autoimmune disorders like vitiligo, lichen planus, and alopecia areata. Histopathological images from submental area showed loose and fragmented collagen in high carbohydrate group in comparison to high protein group where thick, uniformly stained collagen bundles were found in dermis. Histopathology of scalp tissue showed chronic perifollicular inflammatory infiltrate and fibrosis in high carbohydrate group which was absent in histopathology specimen of high protein group. Patients taking early and nutrient-rich breakfast had higher mean protein intakes and less severe skin and hair problems suggesting a role of circadian rhythm as well.

Conclusion:

Dietary protein adequacy and early breakfast have significant role in preventing self-destruction or deregulated autophagy in trichology and cosmetic dermatology and may prevent various autoimmune, inflammatory, and metabolic diseases.

The role of nutrition in inflammatory pilosebaceous disorders: Implication of the skin-gut axis

Nutrition plays a critical role in the manifestation and management of inflammatory pilosebaceous disorders. There is rich potential for insight into the impact of dietary effects on the pathophysiology of inflammatory pilosebaceous disorders including acne vulgaris, hidradenitis suppurativa, rosacea, and the closely related seborrhoeic dermatitis. Acne vulgaris and hidradenitis suppurativa are thought to have similar diet-modulating pathogenic pathways. Western diet influences Acne vulgaris and hidradenitis suppurativa by increasing insulin and modulating FOX01/mTOR, resulting in over-expression of cytokeratins, hyperproliferation of keratinocytes, and hypercornification of the follicular wall. Key receptors in rosacea are alternatively activated by UV radiation, hot beverages, spicy foods, vanilla, cinnamon, caffeine, alcohol, cold temperatures, and niacin- and formalin-containing foods, to increase oedema and flushing, resulting in erythema, telangiectasia, and warmth, characteristic features of the condition. Seborrhoeic dermatitis, while not a follicular disorder, is closely related, and can be modulated by dietary influences, such as biotin and probiotics. This overview summarizes the role that nutrition plays on these disorders, and identifies dietary modifications as potential adjunctive therapies.

The Roles of Vitamin C in Skin Health

The primary function of the skin is to act as a barrier against insults from the environment, and its unique structure reflects this. The skin is composed of two layers: the epidermal outer layer is highly cellular and provides the barrier function, and the inner dermal layer ensures strength and elasticity and gives nutritional support to the epidermis. Normal skin contains high concentrations of vitamin C, which supports important and well-known functions, stimulating collagen synthesis and assisting in antioxidant protection against UV-induced photodamage. This knowledge is often used as a rationale for the addition of vitamin C to topical applications, but the efficacy of such treatment, as opposed to optimising dietary vitamin C intake, is poorly understood. This review discusses the potential roles for vitamin C in skin health and summarises the in vitro and in vivo research to date. We compare the efficacy of nutritional intake of vitamin C versus topical application, identify the areas where lack of evidence limits our understanding of the potential benefits of vitamin C on skin health, and suggest which skin properties are most likely to benefit from improved nutritional vitamin C intake.

An anthocyanin-rich strawberry extract protects against oxidative stress damage and improves mitochondrial functionality in human dermal fibroblasts exposed to an oxidizing agent

This study investigates the protective effect of the Sveva strawberry polyphenol-rich extract on human dermal fibroblasts against AAPH-induced oxidative stress. The HPLC-DAD/ESI-MS analysis was used for evaluating the phenolic composition of the fruits. Sveva strawberry presented a high anthocyanin content (639.79 mg per kg fresh fruit), representing ∼86.08% of the total phenolic content, with Pg-3-glc as the most abundant representative (611.18 mg per kg fresh fruit). Only one ellagitannin (agrimoniin) was identified, while two quercetins, three kaempherol derivates, and three ellagic acid derivatives were detected and quantified. Strawberry pre-treatment (0.5 mg ml(-1)) markedly increased human dermal fibroblast viability, with a significant reduction of apoptotic and dead cells, and suppressed AAPH-induced ROS generation, after only 30 minutes of incubation with the oxidizing agent, and lipid peroxidation, against a range of AAPH concentrations tested. Notably, the strawberry extract also improved the mitochondrial functionality: the basal respiratory performance after treatment was ∼1.59-fold higher compared to control cells, while pre-treatment with strawberry extract before oxidative damage increased ∼2.70-fold compared to stressed cells. Our results confirm that the strawberry possesses antioxidant properties, and may be useful for the prevention of free radical-induced skin damage.

Polyphenol-rich strawberry extract protects human dermal fibroblasts against hydrogen peroxide oxidative damage and improves mitochondrial functionality

Strawberry bioactive compounds are widely known to be powerful antioxidants. In this study, the antioxidant and anti-aging activities of a polyphenol-rich strawberry extract were evaluated using human dermal fibroblasts exposed to H₂O₂. Firstly, the phenol and flavonoid contents of strawberry extract were studied, as well as the antioxidant capacity. HPLC-DAD analysis was performed to determine the vitamin C and β-carotene concentration, while HPLC-DAD/ESI-MS analysis was used for anthocyanin identification. Strawberry extract presented a high antioxidant capacity, and a relevant concentration of vitamins and phenolics. Pelargonidin- and cyanidin-glycosides were the most representative anthocyanin components of the fruits. Fibroblasts incubated with strawberry extract and stressed with H₂O₂ showed an increase in cell viability, a smaller intracellular amount of ROS, and a reduction of membrane lipid peroxidation and DNA damage. Strawberry extract was also able to improve mitochondrial functionality, increasing the basal respiration of mitochondria and to promote a regenerative capacity of cells after exposure to pro-oxidant stimuli. These findings confirm that strawberries possess antioxidant properties and provide new insights into the beneficial role of strawberry bioactive compounds on protecting skin from oxidative stress and aging.