Cranberry juice: A natural boost for women's skin health

Cranberry-based beverage offers a new path to smoother, more resilient skin by boosting elasticity and protecting against UV damage, particularly in women over 40.

Can polyphenols slow skin aging?

Skin aging occurs through intrinsic and extrinsic mechanisms. Intrinsic aging results from the natural accumulation of reactive oxygen species (ROSs) over time, whereas extrinsic aging arises due to external factors like sun exposure, pollution, and smoking. Both processes can be attributed to oxidative stress, inflammation, and advanced glycation end products (AGEs).

Cranberry polyphenols improved skin elasticity on both the face and forearm, with the greatest effects seen in women over 40, suggesting a strong anti-aging potential for skin.

The skin microbiota, which comprises bacteria, fungi, and viruses, is crucial for immune function and skin homeostasis. Polyphenols, known for their antioxidant and anti-inflammatory properties, have been studied for their positive effects on skin aging.

However, further research is needed to fully understand the long-term effects of polyphenol-rich cranberry beverages on skin health, lipids, and the microbiome and to explore their mechanisms of action in different populations.

About the study 

The polyphenol-rich cranberry beverage used in the current study was prepared from concentrated cranberry juice and packed in eight-ounce bottles by Ocean Spray Cranberries. Each bottle contained 192.9 mg of procyanidins, 19.5 mg of anthocyanins, and 24.2 mg of flavonols.

The placebo drink was designed to mimic the cranberry beverage's appearance, taste, and color without the active compounds. The dosage was determined based on prior research on the effects of cocoa on skin parameters.

A power analysis was conducted to determine the sample size using results from previous studies on green tea polyphenols' impact on skin elasticity. This randomized, double-blinded, placebo-controlled trial was conducted at the University of Florida, adhering to ethical guidelines and approved by the institutional review board.

A total of 24 females between 25 and 65 years of age with Fitzpatrick skin types two and three were included in the study and divided into two age groups. The study participants consumed either the cranberry beverage or placebo for six weeks, followed by a three-week washout period before switching to the opposite treatment.

Various skin parameters were assessed, including elasticity, hydration, and ultraviolet (UV)-induced erythema. Blood samples were also collected for oxidative stress analysis. The researchers also examined skin lipid and microbiome changes through tape stripping and swabbing methods.

Study findings 

At the beginning of the study, twenty-four participants were enrolled and randomized. However, two participants dropped out due to scheduling conflicts after the first phase, leaving a total of 22 participants who completed both treatment phases.

Baseline characteristics were assessed, including age, weight, body mass index (BMI), Fitzpatrick skin type, and minimal erythema dose (MED). No significant differences in these parameters were observed between the groups.

Due to technical issues, skin lipid analysis was performed on 20 participants, whereas the microbiome analysis included 12 participants. Ten participants were included in the microbiome-lipid correlation analysis. The food frequency questionnaire was also utilized to confirm that study participants maintained their habitual diet throughout the study.

Cranberry beverage consumption for six weeks significantly protected the skin from UV-induced erythema compared to the placebo and baseline measurements, particularly in women 40 and older. Erythema improvements, measured as a change in skin redness after UV exposure, were significantly reduced following cranberry beverage consumption, whereas the placebo group did not exhibit this effect.

Six weeks of cranberry juice consumption improved net elasticity and smoothness on the face for all participants. The stratified analysis revealed that these effects were most pronounced in women 40 and older.

The cranberry beverage also improved gross elasticity and reduced wrinkles on the forearm, with the strongest effects similarly observed in older study participants. Following cranberry beverage consumption, trans-epidermal water loss (TEWL) was reduced, whereas biological elasticity increased.

The cranberry beverage also increased superoxide dismutase (SOD) activity as compared to placebo and improved glutathione peroxidase (GPx) activity while decreasing tumor necrosis factor-alpha (TNF-α) levels as compared to baseline. These effects varied by age group, with SOD and TNF-α changes more pronounced in younger women and GPx improvements stronger in women over the age of 40.

Lipidomic analysis revealed distinct differences between the cranberry and placebo groups, with several discriminant lipids identified. Although cranberry beverage consumption did not significantly affect microbial diversity on the skin, it modulated the abundance of specific microbial species and strains. These changes in microbiota composition were associated with certain skin parameters, thus indicating a potential link between cranberry polyphenols and skin microbiome health.

Conclusions 

The cranberry beverage protected against UV-induced erythema and enhanced skin elasticity, with these effects more pronounced in older women. Six weeks of consumption also modulated skin lipids, whereas hydration, pH, and other parameters were unaffected.

Cranberry beverage consumption altered the skin microbiome at the species and strain levels, with notable effects observed on the abundance of Rothia mucilaginosa and Staphylococcus epidermidis, which are associated with skin health. Overall, older women responded better to the dietary intervention than younger participants.

Journal reference:

• Christman, L., De Benedetto, A., Johnson, E., et al. (2024). Polyphenol-Rich Cranberry Beverage Positively Affected Skin Health, Skin Lipids, Skin Microbiome, Inflammation, and Oxidative Stress in Women in a Randomized Controlled Trial. Nutrients. doi:10.3390/nu16183126