Diet and Acne: Zinc

The relationship between acne and nutrition is not well determined. Although many theories abound regarding the role of things like chocolate, milk, fat, sugar, and numerous other food and food compounds on acne development none of these have actually been confirmed in controlled trials.

Perhaps this issue was best summarized by Apostolos Pappas in a recent review (1) of the scientific literature on diet and acne:

“We did not realize how daunting it would be to write an article dedicated to making sense of the relationship of acne to foods. It turns out that there are no meta-analyses, randomized controlled clinical studies, or well-designed scientific trials that follow evidence-based guidelines for providing solid proof…We reviewed the updated arguments, facts, and relevant data on this ancient debate, but we warn the truth-seekers among you that the jury is still out.”

However, one possible dietary factor is zinc. Several studies have investigated the ability of zinc to improve acne. A number of these studies reported some degree of benefit (2-7), although some reported no effect (8,9).

This treatment most likely works correct a zinc deficiency, so be aware that in the absence of a deficiency a high zinc intake, especially from supplements, may cause toxic effects such as nausea, tiredness, and copper deficiency as well as disregulated appetite and glucose control. The safest course of obtaining enough zinc in the absence of a medically diagnosed deficiency may be by increasing foods rich in it, such as red meat, shellfish and, to a lesser extent, white meats. Plant sources include many types of seeds, beans and lentils. However, these sources typically provide less absorbable zinc than from meat, so they may be less preferable in this regard.

1. Pappas A. The relationship of diet and acne: A review. Dermatoendocrinol. 2009 Sep;1(5):262-7.

2. Göransson K, Lidén S, Odsell L. Oral zinc in acne vulgaris: a clinical and methodological study. Acta Derm Venereol. 1978;58(5):443-8.

3. Hillström L, Pettersson L, Hellbe L, Kjellin A, Leczinsky CG, Nordwall C. Comparison of oral treatment with zinc sulphate and placebo in acne vulgaris. Br J Dermatol. 1977 Dec;97(6):681-4.

4. Verma KC, Saini AS, Dhamija SK. Oral zinc sulphate therapy in acne vulgaris: a double-blind trial. Acta Derm Venereol. 1980;60(4):337-40.

5. Michaëlsson G, Juhlin L, Vahlquist A. Effects of oral zinc and vitamin A in acne. Arch Dermatol. 1977 Jan;113(1):31-6.

6. Michaëlsson G, Juhlin L, Ljunghall K. A double-blind study of the effect of zinc and oxytetracycline in acne vulgaris. Br J Dermatol. 1977 Nov;97(5):561-6.

7. Weimar VM, Puhl SC, Smith WH, ten Broeke JE. Zinc sulfate in acne vulgaris. Arch Dermatol. 1978 Dec;114(12):1776-8.

8. Orris L, Shalita AR, Sibulkin D, London SJ, Gans EH. Oral Zinc Therapy of Acne: Absorption and Clinical Effect. Arch Dermatol. 1978;114(7):1018-1020.

9. Weismann K, Wadskov S, Sondergaard J. Oral zinc sulphate therapy for acne vulgaris. Acta Derm Venereol. 1977;57(4):357-60.


Glutathione: What It Is and How You Can Eat to Maximize It, Part 1: Coffee

With the popularity of “detox” diets today being what is I’m hoping some people actually want to learn how to increase their body’s natural defenses against toxins using scientifically sound dietary methods, rather than just following one of the many silly “detox juice cleanse” clogging up the internet like a clump of hair stuck in a drain.

With that said let me talk a little about glutathione. Glutathione is a neat little chemical made of 3 amino acids; cysteine, glutamic acid, and glycine. In addition to its role as a strong antioxidant, glutathione plays a very important role in the detoxification process by attaching to various electrophilic toxins, wherein it typically reduces their chemical reactivity and increases their polarity, causing the chemical to be excreted from the body at a greater rate.

The list of toxins to which this process occurs is massive and includes mercury, acrolein, methylglyoxal, and the toxic metabolites of benzo(a)pyrene, 7,12-benzo(a)anthracene, aflatoxin B1, acetominophen, and benzene.

The way glutathione neutralizes these chemicals involves enzymes called Glutathione S-Transferases. These enzymes transfer gluathione onto the dangerous chemicals in question. This review series will look at some dietary factors which support making and using glutathione. It will begin with coffee.

Although coffee is full of hundreds of chemicals, two in particular seem to play the biggest role in coffee’s effect of glutathione. These chemicals are cafestol and kahweol, a pair of lipid soluble diterpenes which are largely removed by paper filters but retained when coffee is made using alternative methods, such as a french press. These chemicals are one of those most heavily studied upregulators of Glutathione S-Transferase and probably explain why french press and italian style coffee increase such enzymes (as well as some other detoxifying enzymes, such as glucoronasyltransferase). In addition, coffee itself seems to increase glutathione itself in various tissues.

These facts may explain why coffee and those two diterpenes, when given to animals, seem to protect against numerous toxins known to be detoxified by glutathione. This may also explain why coffee consumption has been associated with a lower risk of certain cancers, including the liver, one of the primary sites of detoxification.

Although one should be cautious when extrapolating to real life situations, I think their is decent evidence to suggest that coffee, particularly coffee made using a french press or similar devices, has a place in a “detox” diet, should such a thing even be needed in first place (I’ll hold onto my opinions here).



Sreerama L, Hedge MW, Sladek NE. Identification of a class 3 aldehyde dehydrogenase in human saliva and increased levels of this enzyme, glutathione S-transferases, and DT-diaphorase in the saliva of subjects who continually ingest large quantities of coffee or broccoli. Clin Cancer Res. 1995 Oct;1(10):1153-63. PubMed PMID: 9815907.

Esposito F, Morisco F, Verde V, Ritieni A, Alezio A, Caporaso N, Fogliano V. Moderate coffee consumption increases plasma glutathione but not homocysteine in healthy subjects. Aliment Pharmacol Ther. 2003 Feb 15;17(4):595-601. PubMed PMID: 12622769.

Grubben MJ, Van Den Braak CC, Broekhuizen R, De Jong R, Van Rijt L, De Ruijter E, Peters WH, Katan MB, Nagengast FM. The effect of unfiltered coffee on potential biomarkers for colonic cancer risk in healthy volunteers: a randomized trial. Aliment Pharmacol Ther. 2000 Sep;14(9):1181-90. PubMed PMID: 10971235.

Cavin C, Holzhaeuser D, Scharf G, Constable A, Huber WW, Schilter B. Cafestol and kahweol, two coffee specific diterpenes with anticarcinogenic activity. Food Chem Toxicol. 2002 Aug;40(8):1155-63. Review. PubMed PMID: 12067578.

Cavin C, Holzhäuser D, Constable A, Huggett AC, Schilter B. The coffee-specific diterpenes cafestol and kahweol protect against aflatoxin B1-induced genotoxicity through a dual mechanism. Carcinogenesis. 1998 Aug;19(8):1369-75. PubMed PMID: 9744531.

Miller EG, McWhorter K, Rivera-Hidalgo F, Wright JM, Hirsbrunner P, Sunahara GI. Kahweol and cafestol: inhibitors of hamster buccal pouch carcinogenesis. Nutr Cancer. 1991;15(1):41-6. PubMed PMID: 2017397.


Gershbein LL. Action of dietary trypsin, pressed coffee oil, silymarin and iron salt on 1,2-dimethylhydrazine tumorigenesis by gavage. Anticancer Res 1994; 14: 1113 6.

Mori H, Kawabata K, Matsunaga K, Ushida J, Fujii K, Hara A, Tanaka T, Murai H. Chemopreventive effects of coffee bean and rice constituents on colorectal carcinogenesis. Biofactors. 2000;12(1-4):101-5. Review.

Johnson, S., Koh, W., Wang, R., Gobindarajan, S., Yu, M., & Yuan, J. (2011). Coffee consumption and reduced risk of hepatocellular carcinoma: findings from the Singapore Chinese Health Study. Cancer Causes & Control, 22(3), 503-10.

Tornai, I. (2010). Role of environmental factors in the etiology of hepatocellular carcinoma. Orv Hetil, 151(28), 1132-6