Introduction
Acne vulgaris is a common skin condition, affecting people of all ages but is mainly prevalent among teenagers. This condition appears in various forms and severity levels, leading to multiple classification systems based on dermatologists' perspectives. Acne types include comedonal, papular, pustular, and nodular or "cystic" acne.1
The highest prevalence of acne is found in 19-year-olds (46.8%), with a gradual decline in older age groups (20 to 30 years of age), becoming rare in individuals over 50.2
Nodular acne, a severe form of inflammatory acne, is marked by firm, painful lumps under the skin with red bumps on the skin surface.
Acne significantly impacts self-image, leading to feelings of embarrassment, self-consciousness, and lowered self-esteem, which in turn decreases self-confidence. This emotional toll is particularly severe for those with facial acne, prompting many to seek treatment. This is known to be statistically significant, underscoring the profound psychological effects of this skin condition.3
This article will explore how diet and nutrition impact nodular acne, presenting scientific evidence and practical advice for those struggling with this persistent skin condition. By examining the connection between our diet and skin health, we aim to provide insights that can lead to more effective acne management strategies and improved quality of life for individuals affected by nodular acne.
Nodular acne develops when your skin's pores become blocked by dead skin cells, hair, and sebum, trapping Cutibacterium acnes bacteria and causing infection, inflammation, and pain. Untreated blocked pores can form comedones (whiteheads and blackheads), leading to inflammatory lesions like papules, pustules, cysts, and nodules. Nodules result from ruptured pustules spreading inflammation, creating larger, painful cysts. Key factors that lead to blocked pores include:
- Excessive sweating: Sweat can clog pores, especially with hyperhidrosis or sweat-trapping clothing
- Genetics: A family history of nodular acne increases the risk
- Hormones: Changes during puberty, pregnancy, menstruation, and menopause can boost oil production. Higher androgen levels in teenagers and young adults assigned male at birth also contribute
- Medications: Drugs like corticosteroids can worsen acne
- Skincare products: Certain lotions, creams, and makeup can clog pores
- Stress: An increase in stress levels increases cortisol, the "stress hormone," which boosts sebum production
Nodular acne can appear as one or several inflamed lumps and pseudocysts. These nodules are firm, tender, and sometimes filled with fluid. They are commonly seen on the face, neck, and trunk.
Diet and its role in acne development
Dermatologists can no longer ignore the link between diet and acne. There is a strong correlation between high-glycemic diets and worsening of acne. While there may be a connection between dairy consumption and acne, the evidence is not very strong. The impact of omega-3 fatty acids, antioxidants, zinc, vitamin A, and dietary fibre on acne is poorly understood.4
Omega-3 fatty acids and acne
The balance of omega-6 to omega-3 fatty acids in our diet can affect inflammation. The typical Western diet has a higher ratio of omega-6 to omega-3 fatty acids than those rich in fish and wild plants. Low-glycemic diets and higher omega-3 intake may explain the lack of acne in specific indigenous populations. Omega-3 fatty acids can reduce inflammatory cytokine production and inhibit the inflammatory molecule leukotriene B4, potentially reducing acne inflammation. They also decrease the hormone IGF-1, which is linked to worsening acne.
Few human studies have investigated the effects of omega-3 on acne. One study from 1961 found that teenagers who ate a lot of fish and seafood had fewer acne lesions. Another small case series with five patients using an omega-3 supplement showed possible improvements in inflammatory acne and overall well-being. More research is needed to understand the role of omega-3 fatty acids in acne treatment.6
Antioxidants and acne
Role of reactive oxygen species (ROS) in acne
- Reactive oxygen species (ROS) contribute to acne inflammation
- Antioxidants like glucose-6-phosphate dehydrogenase and catalase normally remove ROS
- Acne patients have lower levels of these antioxidants, suggesting oxidative stress involvement
Antioxidant levels in acne patients
- Acne patients have lower levels of antioxidants (vitamins A and E) and selenium
- Supplements showed some improvement, but more reliable studies are needed
More studies are needed to confirm the effectiveness of these antioxidants in acne treatment.
Zinc and acne
Role of zinc
- Essential for skin health; 6% of the body's zinc is in the skin
- Zinc gluconate is preferred over zinc sulphate due to better absorption and fewer gastrointestinal issues
Clinical trials
- Randomised double-blind trials demonstrated oral zinc’s effectiveness for severe and inflammatory acne, less so for mild or moderate acne
- Zinc acts against Propionibacterium acnes and reduces inflammation
Side effects
- High doses (200-600 mg daily) can cause nausea, vomiting, and diarrhoea
- Taking zinc with meals can help reduce gastrointestinal side effects
- Chronic zinc therapy may require 1-2 mg of copper supplementation to prevent deficiency
Comparison with antibiotics
- Oral zinc is as practical or less effective than tetracyclines
- A modern trial comparing zinc with antibiotics could provide new insights, especially considering antibiotic resistance
Further studies are needed to explore lower zinc doses' efficacy and side effects. Current evidence suggests limitations due to gastrointestinal side effects and lower efficacy than antibiotics.
Vitamin A and acne
Types of vitamin A
- Preformed vitamin A: Easily absorbed from sources like multivitamins, fish liver oil, and fortified foods (milk, butter, margarine, breakfast cereals)
- Provitamin A carotenoids: Found in plants, less easily absorbed, and not toxic
Absorption and storage
- Preformed vitamin A is absorbed and stored well in the liver
- Provitamin A sources are safe and do not cause toxicity
Concerns with vitamin A supplements
- Dermatologists are cautious about recommending oral vitamin A for acne due to the risk of too much vitamin A (hypervitaminosis A)
- Too much vitamin A can harm the liver, cause birth defects, weaken bones, lead to hair loss, dry skin, and increased pressure in the brain
Studies on high-dose vitamin A
- A study in 1981 by Kligman et al. showed that high doses of vitamin A (300,000 U daily for women, 400,000-500,000 U daily for men) can help treat acne
- Only minor side effects were reported, like dry skin and lips
- Long-term use of high doses can still pose safety risks, especially to the liver
Dietary fibre and acne
There haven't been specific studies on how dietary fibre affects acne treatment. Some reports suggest that acne might improve when people regularly eat high-fibre breakfast cereal. Another study found that acne improved in those on a low glycemic load diet, which includes more fibre. This suggests that eating more fibre could help with acne, but more research is needed to be sure and understand how fibre might help treat acne.
Iodine and acne
Iodine is often thought to cause acne vulgaris, but current research doesn't support iodine as a direct cause of comedonal acne. Acne linked to iodine usually appears suddenly with pustules. Foods like kelp, which is high in iodine, and medications containing iodine can trigger this type of acne.
Early studies in 1961 suggested a link between acne and iodine. Still, later findings indicated that adolescents who ate a lot of seafood and fish (high in iodine) had lower rates of acne. Recent theories propose that the association between milk and acne might be due to varying levels of iodine in milk, influenced by factors like animal feed and sanitising solutions.5,6
Nutritional deficiencies and acne
Vitamin deficiencies
Vitamin A
It supports skin cell regeneration and is found in foods like butter, fish, and liver. Its derivatives, called retinoids, are used in acne treatments because they penetrate the skin easily, modulate gene expression for cell growth, and protect against ageing by fighting free radicals and UV radiation.
Vitamin C
It helps in acne treatment by reducing inflammation through inhibiting inflammatory cytokines. It's more effective when applied topically and is abundant in foods like blackcurrants, peppers, and citrus fruits. It also aids in wound healing and reduces hyperpigmentation.
Vitamin D
It inhibits acne lesions by reducing sebum production, preventing pore blockage, and inhibiting the growth of acne-causing bacteria. Sun exposure and foods like fatty fish, liver, and eggs are good sources. Supplements have been shown to lower inflammation markers like IL-6 and TNF-alpha in acne patients.
Vitamin E
Found in eggs, green vegetables, and oils, vitamin E supports skin hydration and has strong antioxidant and anti-inflammatory effects. It also helps manage acne by preventing skin dryness and inflammation.
B Vitamins
Include B1, B2, B3, B5, B6, and B7, which collectively inhibit sebum production and reduce Cutibacterium acnes colonisation. Foods like yeast, nuts, fish, and liver are rich sources. However, high doses of vitamin B12 may exacerbate acne in some individuals, especially women, as observed in cases of acne-like eruptions after supplementation.
Mineral deficiencies
Zinc
It supports acne therapy by inhibiting Cutibacterium acnes, reducing inflammation, and is an antioxidant. The serum zinc levels were low in AV(Acne vulgaris) patients compared to healthy individuals. Food sources include oysters, pumpkin seeds, sunflower seeds, and whole grains.
Selenium
It controls the production of sebum and contains anti-inflammatory effects. This is why it is combined with vitamin E and zinc when their antioxidant effects are considered. Combinations of selenium with other nutritional supplements such as silymarin and N-acetylcysteine have been found in a few reports to reduce markers of oxidative stress and inflammatory lesions in AV patients. Sources include Brazil nuts, fish, and red meat.7
Beneficial nutritional practices for acne management
Although dietary changes can provide support in the treatment of acne, they should be based on evidence to avoid potential nutritional complications. A low GI diet is recommended in acne patients. Diet has a direct bearing on the control of sugar fluctuations in the blood. High GI foods will elevate blood sugar levels, while low GI foods have little effect. The factors affecting the GI of foods include fibre, fat, protein, type of sugar, starch, cooking, size of food, acidity etc.
Chocolate is linked to acne and should be avoided, but there's no strong evidence to avoid oily or fatty foods. Milk, especially skim milk, and whey protein might worsen acne, particularly in women and those without a history of acne, but more research is needed.
Obesity is linked to inflammatory acne. Children with a lower BMI (under 18.5 kg/m²) have less acne, while those with a higher BMI (95th percentile or above) have more, likely due to obesity-related hormone changes.8
To manage acne, avoid too much sugar, desserts, and sodas. Instead, eat more leafy greens, fruits, and vegetables rich in vitamin C and beta-carotene, which can help reduce inflammation. Some studies suggest that dairy products might be linked to acne, so be cautious with them.9 Probiotics also show promise in reducing acne, but more research is needed to confirm this.7,10
While diet can influence breakouts, achieving clear skin involves more than changing your diet. It's also important to use acne-friendly skincare products and medications to help prevent new breakouts.
Practical recommendations
For many years, the connection between diet and acne was uncertain. It wasn’t considered a significant cause initially, but recent studies show that certain foods can worsen acne. Future studies should avoid common limitations like small sample sizes and poor documentation to better understand how diet affects acne. Knowing which foods impact acne will help doctors provide better advice. An elimination diet could help reduce acne and improve quality of life.11
Summary
Nodular acne is a severe form of inflammatory acne characterised by painful lumps and cysts. It predominantly affects the face, neck, and trunk. It often begins in adolescence and can persist into adulthood, significantly impacting self-esteem and quality of life due to its visible nature.
Diet plays a crucial role in managing nodular acne. Incorporating evidence-based dietary changes alongside appropriate skincare and medical treatments can help manage nodular acne effectively, improving both physical symptoms and emotional well-being.
References
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- Zhang J, Shen Y, Wang T, Zhou C, Wang X, Ding X, et al. Prevalence of Acne Vulgaris in Chinese Adolescents and Adults: A Community-based Study of 17,345 Subjects in Six Cities. Acta Derm Venerol [Internet]. 2012 [cited 2024 Sep 17]; 92(1):40–4. Available from: https://medicaljournalssweden.se/actadv/article/view/8775.
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