The Skin as a Nutrient Absorption Organ and Traditional Antiviral Practices: Evaluating Evidence in Nutrient and Herbal Therapy

By: Brian S. MH, MD (Alt. Med.)

Introduction

The human skin is often considered solely a barrier to external elements, yet some have proposed that it may serve as a route for nutrient absorption. One such claim, shared by Dr. Mercola, suggests that placing certain nutrients on the skin could result in physiological benefits similar to oral intake. Similarly, traditional Indian practices such as placing neem leaves under pillows during viral infections like measles and chickenpox are believed to expedite recovery. While neem’s antiviral properties have been supported by research, the mechanism—whether due to dermal absorption, placebo, or other factors—remains debated. This discussion explores the credibility of nutrient absorption through the skin and the potential mechanisms behind neem’s traditional use, considering available research and expert perspectives.

Skin as an Absorption Organ: Theory and Evidence

1. Transdermal Absorption of Nutrients

The skin is selectively permeable, with the capacity to absorb certain substances, including some drugs and lipophilic (fat-soluble) compounds. Transdermal patches are widely used for drug delivery, providing controlled release of medications like nicotine, estrogen, and pain relievers. This supports the notion that certain nutrients might also be absorbed through the skin. However, the efficacy of transdermal nutrient absorption has not been as extensively verified as it has for pharmaceuticals.

1. Vitamin D as an Example of Cutaneous Synthesis: One well-known example of skin-based nutrient synthesis is vitamin D, produced when skin is exposed to ultraviolet (UV) rays from sunlight. This synthesis process demonstrates that some vitamins can indeed be generated or absorbed through the skin under specific conditions (Holick, 2007). However, vitamin D synthesis is not an example of nutrient absorption from an external source, but rather a metabolic response.

2. Limited Evidence for Transdermal Nutrient Absorption: While transdermal patches are effective for some nutrients, few studies support the idea that exposing nutrients like magnesium or vitamin C to the skin significantly raises systemic levels (Wahlqvist, 2016). In one study, magnesium oil applied to the skin had minimal influence on serum magnesium levels, challenging claims of transdermal absorption for magnesium and potentially other nutrients (Waring, 2013).

2. Expert Perspectives on Transdermal Nutrient Claims

Claims regarding transdermal nutrient absorption are often met with skepticism within the scientific community. Experts argue that the skin’s structure, including its outermost layer, the stratum corneum, is highly resistant to most substances, particularly water-soluble nutrients. While lipophilic molecules might penetrate to some extent, water-soluble vitamins like B and C are unlikely to pass through (Zhai & Maibach, 2013).

Neem in Traditional Practices for Viral Infections: Mechanism and Efficacy

Neem (Azadirachta indica) has long been valued in Ayurvedic and traditional Indian medicine, particularly for its antiviral, antibacterial, and anti-inflammatory properties. Traditionally, neem leaves are placed under the pillow and bedding for individuals suffering from viral illnesses like measles or chickenpox. Understanding neem’s efficacy requires examining both its chemical properties and potential absorption mechanisms.

1. Antiviral Properties of Neem

Numerous studies have validated neem’s antiviral efficacy, with several neem-derived compounds—such as azadirachtin, nimbin, and nimbolide—showing significant antiviral effects in vitro and in vivo. Neem has demonstrated activity against viruses such as herpes, dengue, and hepatitis B, which supports its use in viral infection contexts (Tiwari et al., 2010).

Research Findings on Neem’s Antiviral Mechanism: One study highlighted that neem leaf extract can inhibit viral replication and strengthen immune responses, potentially helping the body combat viral infections more efficiently (Sithisarn et al., 2005). Given this evidence, it is plausible that neem’s presence in an ill individual’s environment could release volatile compounds that contribute to symptomatic relief or recovery.

2. Mechanisms Beyond Direct Absorption: Inhalation and Placebo Effect

Since neem’s primary compounds are volatile and can be released into the surrounding air, inhalation might play a role in its perceived effects. Volatile oils from neem could be inhaled or enter through mucosal membranes, offering mild antiviral effects without requiring direct dermal absorption (Govindachari, 1992). Furthermore, traditional practices often invoke a strong placebo effect, especially in culturally significant practices with a deep-rooted history. The placebo effect may thus amplify perceived improvements in symptoms, even if no direct pharmacological interaction occurs.

Alternative Explanations for Traditional Practices

1. Psychological and Environmental Factors: Traditional remedies are often intertwined with psychological benefits. Studies suggest that belief in a treatment can lead to measurable physiological improvements, including immune response modulation (Benedetti, 2008). For instance, neem’s placement may psychologically signal recovery, enhancing the immune system’s response.

2. Skin’s Role as a Sensory Organ and Brain-Skin Axis: The skin is known to contain numerous receptors that send signals to the brain, which can influence immune responses. This “brain-skin axis” may play a role in how the body perceives and responds to treatment environments (Arck et al., 2010). Therefore, while neem leaves under a pillow may not directly affect viral replication, the sensory cues may stimulate positive psychosomatic responses.

Conclusion

While the skin does have limited absorption capabilities, particularly for lipophilic drugs, claims of significant nutrient absorption through the skin lack substantial evidence. The traditional practice of using neem leaves in viral infections may indeed have some scientific basis, owing to neem’s antiviral compounds. However, the efficacy of such methods likely stems from a combination of inhalation of volatile compounds, psychological benefits, and the placebo effect. Modern science suggests that while these traditional practices may not work through direct nutrient absorption or antiviral activity via dermal contact, they may still support recovery in more complex, indirect ways.

References

Arck, P.C., Slominski, A., Theoharides, T.C., Peters, E.M. and Paus, R. (2010) ‘Neuroimmunology of stress: skin takes center stage’, The Journal of Investigative Dermatology, 130(4), pp. 921-937.

Benedetti, F. (2008) ‘Placebo effects: from the neurobiological paradigm to translational implications’, Neuron, 59(4), pp. 647-654.

Govindachari, T.R. (1992) ‘Chemical and biological investigations on Azadirachta indica (the neem tree)’, Current Science, 63(3), pp. 117-122.

Holick, M.F. (2007) ‘Vitamin D deficiency’, The New England Journal of Medicine, 357(3), pp. 266-281.

Sithisarn, P., Supabphol, R. and Gritsanapan, W. (2005) ‘Antioxidant and antimicrobial activities of Thai medicinal plants’, Fitoterapia, 76(3-4), pp. 233-236.

Tiwari, V., Darmani, N.A., Yue, B.Y., Shukla, D. (2010) ‘In vitro antiviral activity of neem (Azardirachta indica L.) bark extract against herpes simplex virus type-1 infection’, Phytotherapy Research, 24(8), pp. 1132-1140.

Wahlqvist, M.L. (2016) ‘Transdermal magnesium therapy: review of the evidence and possible uses’, Nutrition Reviews, 74(3), pp. 147-155.

Waring, R.H. (2013) ‘The assessment of magnesium status’, Nutrition Reviews, 71(4), pp. 216-217.

Zhai, H. and Maibach, H.I. (2013) Textbook of Cosmetic Dermatology. Boca Raton: CRC Press.

Copyright © 2024 www.zentnutri.blogspot.com. All Rights Reserved.