Diet & Acne
Science still does not know whether diet and acne are related, but evidence is starting to trickle in. Based on what we are seeing in clinical research, it seems prudent to eat a relatively low-glycemic diet rich in colorful fruits and vegetables and omega-3 fats and to perhaps supplement with 30mg of zinc gluconate per day. However, due to our modern diets and Western style of living, achieving sustainable relief of acne from changes in diet alone remains an elusive goal.
No matter what anti-acne diet you embark upon, while you may see a short-term reduction in acne while your body loses weight, symptoms are likely to return as your weight levels off. If your goal is to achieve completely clear skin, your time is likely much better spent effectively treating your skin than chasing any theoretical, yet unproven, diet.
Dairy & Acne
Due to the lack of concrete evidence on the subject of dairy and acne, and major design limitations in the studies researchers have performed thus far, scientists in the Journal of Clinics in Dermatology wrote after a review of the existing evidence, “Our conclusion, on the basis of existing evidence, is that the association between dietary dairy intake and the development of acne is slim”¹. It makes common sense based on the hormones present in milk that dairy products could affect acne, but study results remain inconclusive, and evidence of an association between dairy and acne is sparse²−³.
Milk contains insulin-like growth factor (IGF-1)⁴. IGF-1 is a hormone which helps the body build necessary tissues. Increased levels of IGF-1 result in increased skin oil production. Since over-production of skin oil is a contributor to acne, some scientists hypothesize that milk, and its IGF-1 component, could potentially lead to increased skin oil production and resulting breakouts. IGF-1 also stimulates the body to produce cells. Acne is thought to sometimes begin with an over-production of skin cells inside the pore which causes the pore to become clogged. Thus, some scientists also hypothesize that milk may lead to over-production of skin cells within pores which cause the pores to become clogged and produce the beginning stages of acne lesions.
Milk also contains male hormone (androgen) precursors⁴−⁵. These precursors require enzymes to convert them into actual male hormones in the body, and these enzymes are readily available in the pores of the skin.6 Similar to IGF-1, male hormones have been implicated in increased skin oil production and increased skin cell production.
Several studies in which researchers surveyed large populations of people have pointed toward a possible connection between dairy products and acne⁶−⁹. When it comes to milk itself, low fat and whole milk were not found to be correlated, but skim milk did show a correlation, a finding which scientists hypothesize may be due to the processing of skim milk and the resulting, somewhat different, hormonal content of skim milk. Two recent studies show a correlation with milk and ice cream, but yogurt and cheese were not correlated¹º−¹². These studies, however, suffer from major design limitations (see below).
At large doses, iodine can cause what are called acneiform (pronounced “acneform”, the i is silent) eruptions¹³−¹⁵. While unproven, some scientists postulate that the iodine content of milk, due largely to the sterilization of the teats of cows with an iodine solution prior to milking, may also contribute to acne vulgaris.
1) Davidovici B, Wolf R. “The role of diet in acne: facts and controversies.” Clinics in Dermatology. 2010 Jan-Feb; 28(1): 16-6.
2) Costa A, Moises T, Lage D. “Acne and diet: truth or myth?” Annals of Brazilian Dermatology. 2010 Jan; 85(3): 346-53.
3) Bowe W, Joshi S, Shalita A. “Diet and acne.” Journal of the American Academy of Dermatology. 2010 Jul; 63(1): 121-41.
4) Koldovsky O. “Hormones in milk.” Vitam Horm. 1995; 50: 77-149.
5) Danby F. “Acne and milk, the diet myth, and beyond.” Journal of the American Academy of Dermatology. 2005; 52: 360-2.
6) Chen W, Thiboutot D, Zouboulis C. “Cutaneous androgen metabolism: basic research and clinical perspectives.” Journal of the American Academy of Dermatology. 2002; 119:992-1007.
7) Adebamowo C, et. al. “High school dietary dairy intake and teenage acne.” Journal of the American Academy of Dermatology. 2005; 52: 207-14.
8) Adebamowo C, et. al. “Milk consumption and acne in teenaged boys.” Journal of the American Academy of Dermatology. 2008; 58: 787-93.
9) Hitch J. “Acneiform eruptions induced by drugs and chemicals.” Journal of the American Academy of Dermatology. 1967; 200: 879-80.
10) Ismail NH, Manaf ZA, Azizan NZ. “High glycemic load diet, milk and ice cream consumption are related to acne vulgarism in Malaysian young adults: a case control study.” BMC Dermatology. 2012; 12: 13.
11) Salomone C, et al. “Comparative study of dietary habits between acne patients and a healthy cohort.” Indian Journal of Dermatology, Venereology and Leprology. 2012; 78(1): 99-101.
12) Pennington J. “Iodine concentrations in US milk: variation due to time, season, and region.” Journal of Dairy Science. 1990; 73: 3421-7.
13) Robinson H. “The acne problem.” Southern Medical Journal. 1949; 42: 1050-60.
14) Anderson P. “Foods as the cause of acne.” American Family Physician. 1971; 3:102-3.
15) Adebamowo C, et. al. “Milk consumption and acne in adolescent girls.” Dermatology Online Journal. 2006.
At this time, we do not know if low-glycemic diets reduce acne symptoms based on the glycemic load of the foods eaten, or simply based on the accompanying weight loss of such diets. What does the glycemic index refer to? The glycemic index compares different foods, giving them a numerical ranking, based on how much they spike blood glucose levels. What does glycemic load mean? The glycemic load takes the glycemic index one step further by taking into account how much of a certain food is eaten and then calculating the effect that portion size of food will have on blood glucose¹.
Eating lots of high glycemic foods (i.e. sugar, white bread, white potatoes, white rice) which are prevalent in modern diets cause people to live with chronically elevated insulin levels. These chronically elevated insulin levels may lead to problems with:
Increased blood insulin levels lead to increases in insulin-like growth factor (IGF-1), a hormone in our bodies which promotes increased cell growth. Scientists hypothesize that this could lead to an overgrowth of cells inside pores and/or an increase in skin oil production, which could cause pores to become clogged, leading to acne²−⁷. Scientists also hypothesize that high IGF-1 levels could lead to increased skin oil sebum production which may lead to breakouts.
Chronically elevated insulin levels lower the amount of insulin-like growth factor binding-protein 3 (IGFBP-3) in the blood. IGFBP-3 regulates IGF-1 and keeps it in check by preventing IGF-1 from binding to its cellular receptor. Lower amounts of IGFBP-3 mean even higher IGF-1 levels. As we have discussed, scientists postulate that increased IGF-1 may lead to overgrowth of cells inside pores²−⁴. A second way that low levels of IGFBP-3 may potentially affect acne is through lowering the effectiveness of the natural retinoids in the skin. These retinoids prevent cell overgrowth. When IGFBP-3 is low, these retinoids can’t do the work they are made to do⁷−¹⁴.
Insulin acts as a “master” hormone. Increased insulin levels raise androgen (male hormone) levels. Increased androgen levels are well known for their effect on stimulating sebum production, which can lead to more severe acne symptoms¹²−¹³.
mTORC1 and Fox01 proteins:
Could our Western, high glycemic diet be suppressing and/or over-activating cell proteins which in turn unbalance hormones and increase skin oil production, leading to acne? Scientists are discussing it ⁶−¹⁸.
Australian researchers have produced two small studies attempting to measure glycemic load and acne. In the studies, subjects who ate low-glycemic diets had less acne at the end of 12 weeks compared with the control group. However, the studies have major design limitations, the most serious being that the researchers could not separate out the effects of weight loss. The low-glycemic groups lost weight in all 3 studies. It is well known that lowered calories can decrease skin oil. To their credit, the authors note, “…the role of diet in sebum composition is yet to be fully clarified and further studies are required to isolate the underlying mechanistic factors¹−¹⁹. A recent study of 80 young people (13-25 years old) in Chili again seems to show people with acne ingesting more sugary juices, sodas, milk, bread, and rice than people without whose diets were based more on fruits and vegetables²º. Another recent study in Malaysia again corroborates a possible connection between high glycemic load diets and the incidence and severity of acne²¹.
1) Smith R, Brane A, Varigos G, Mann N. “The effect of a low-glycemic load diet on acne vulgaris and the fatty acid composition of skin surface triglycerides.” Journal of Dermatological Science. 2008 Apr; 50(1): 41-52.
2) Nam S, et. al. “Effect of obesity in total and free insulin-like growth factor (IGF)-1, and their relationship to IGF-binding protein (BP)-1, IGFBP-2, IGFB’I-3, insulin, and growth hormone.” International Journal of Obesity. 1997; 21: 355-359.
3) Brismar K, Ferngvist-Forbes E, Wahren J, Hall K. “Effect of insulin on the hepatic production of insulin-like growth factor – binding protein-1 (IGFBP-1), IGFBP-3, and IGF-1 in insulin-dependent diabetes.” The Journal of Clinical Endocrinology & Metabolism. 1994; 79: 872-878.
4) Evens T, Kaye S. “Retinoids: present role and future potential.” British Journal of Cancer. 1999; 80:1-8.
5) Kumari R, Thappa DM. “Role of insulin resistance and diet in acne.” Indian Journal of Dermatology, Venereology, and Leprology. 2013; 79(3): 291-9.
6) Melnic BC, Zouboulis CC. “Potential role of Fox01 and mTORC1 in the pathogenesis of Western diet-induced acne.” Experimental Dermatology. 2013; 22(5): 311-5.
7) Del Prete M, et al. “Insulin resistance and acne: a new risk factor for men?” Endocrine. 2012; 42(3): 555-60.
8) Attia N, et. al. “The metabolic syndrome and insulin-like growth factor I regulation in adolescent obesity. The Journal of Clinical Endocrinology & Metabolism. 1998; 83: 1467-1471.
9) Yang Q, et. al. “Biallelic inactivation of retinoic acid receptor B2 gene by epigenetic change in breast cancer.” The American Journal of Pathology. 2001; 158: 299-303.
10) Liu B, et. al. “Direct functional interaction between insulin-like growth factor-binding protein-3 and retinoid X receptor-alpha regulate transcriptional signaling and apoptosis.” The Journal of Biological Chemistry. 2000; 275: 33607-33613.
11) Wendling O, Chambon P, Mark M. “Retinoid X receptors are essential for early mouse development and placentogenesis.” Proceedings of the National Academy of Sciences of the United States of America. 1999; 96: 547-551.
12) Chiba H, Clifford J, Metzger D, Chambon P. “Distinct retinoid X receptor-retinoic acid receptor heterodimers are differentially involved in the control of expression of retinoid target genes in F9 embryonal carcinoma cells.” Molecular and Cellular Biology. 1997; 17: 3013-3020.
13) Grimberg A, Cohen P. “Role of insulin-like growth factors and their binding proteins in growth control and carcinogenesis.” Journal of Cellular Physiology. 2000, 183: 1-9.
14) Thacher S, Vasudevan J, Chandraratha R. “Therapeutic applications for ligands of retinoid receptors.” Current Pharmaceutical Design. 2000; 6: 25-58.
15) Eichenfield L, Layden J. “Acne: current concepts of pathogenesis and approach to rational treatment.” Pediatrician. 1991; 18: 218-223.
16) Thiboutot D. “Acne: an overview of clinical research findings.” The Dermatology Clinic. 1997; 15: 97-109.
17) Danby FW. “Turning acne on/off via mTORC1.” Experimental Dermatology. 2013; 22(7): 505-6.
18) Melnic BC, John SM, Plewig G. “Acne: risk indicator for increased body mass index and insulin resistance.” Acta Dermato-Venereologica. 2013; 93(6): 644-9.
19) Smith R, et. al. “The effect of a high protein, low-glycemic-load diet versus a conventional, high glycemic-load diet on biochemical parameters associated with acne vulgaris: A randomized, investigator-marked, controlled trial.” Journal of the American Academy of Dermatology. 2007; 57: 247-56.
20) Salomone C, et al. “Comparative study of dietary habits between acne patients and a healthy cohort.” Indian Journal of Dermatology, Venereology and Leprology. 2012; 78(1): 99-101.
21) Ismail NH, Manaf ZA, Azizan NZ. “High glycemic load diet, milk and ice cream consumption are related to acne vulgarism in Malaysian young adults: a case control study.” BMC Dermatology. 2012; 12: 13.
If in fact lower calories help with acne symptoms, this may be why almost any “acne diet” appears to work. When we remove foods from our diet and do not replace them with others, we are eating less calories, and thus losing weight. It is important that scientists flesh this out. Until then, we cannot say whether any acne diet is working based on the content of what is eating or simply the overall calories. An article in the Journal of the Academy of Nutrition and Dietetics puts it well: “These gaps in the literature should not intimidate but rather challenge dermatologists and registered dietitians to work collaboratively to design and conduct quality research¹.
Can increased calories cause acne?
The argument for: Increased calories result in higher male hormone (androgen) levels. Higher androgen levels can lead to skin cell growth and increased skin oil (sebum) output. Skin cell overgrowth may clog pores, leading to acne formation, and increased skin oil may lead to worsening of acne symptoms.
Doctors have noted that in hard hit parts of the world, starvation level calories result in dramatic reduction in skin oil production and a complete halting of acne symptoms²−³. This is obviously not a sustainable acne treatment. However, even when exposed to a moderate calorie deficit the body becomes insulin sensitive. Insulin is a master hormone, and insulin sensitivity lowers levels of insulin.
This results in a hormonal cascade which theoretically would help pores from becoming clogged and help the skin produce less oil. After a period of lowered calories, however, when calories resume to a maintenance level, this could also theoretically lead to an acne symptom recurrence.
Increase body mass (BMI) was found to be correlated with acne in one study of young males⁴. In another study, no significant correlation was found in young men, but a significant correlation was found amongst young women⁵.
Obesity is correlated with other skin diseases such as psoriasis⁵.
The argument against: From three studies, obesity and body mass index do not appear correlated with acne⁶−⁸.
It is far too early to draw conclusions between chocolate and acne. While there may or may not be a correlation between chocolate and acne, singling out any food as an acne villain is likely to be a wild goose chase. The combined stress involved in nervously avoiding chocolate and other perceived “bad” foods may itself lead to stress-induced acne.
History Of The Debate
For decades in the early 20th Century, doctors and medical texts warned acne prone people to avoid chocolate. This advice was put to the test with two studies in 1969 and 1971¹². Both studies showed no correlation with chocolate intake and acne. However, these studies were small, uncontrolled, short duration, subjective, included very short follow up, and employed inadequate statistical analysis. They also did not account for the sugar or dairy content of chocolate being ingested. Despite the severe design limitations inherent in these chocolate-specific studies, not only did the dermatology community dismiss the possible chocolate/acne correlation, but also sent out the message that diet and acne is not related. This massive overstating of flawed evidence is an historic and staggering error of the entire dermatology community. However, as time has moved on, modern scientists are putting diet, and along with it, chocolate, back under consideration.
A 2003 study showed insulin levels raised after meals which included chocolate, especially chocolate mixed with milk (chocolate milk) in lean young adults³ While it is certainly too soon to draw conclusions, this could theoretically be the result of the active compounds in chocolate spiking insulin levels and/or the combination of the amino acids in chocolate mixed with carbohydrates and causing an insulin spike⁴−⁷. If in fact elevated insulin levels lead to acne symptoms through increased skin cell production which cause clogged pores and/or increased skin oil (sebum) production which provides a breeding ground for acne bacteria, chocolate could theoretically be part of this insulin cascade and resulting acne symptoms.
Protein signaling or something else entirely
Scientists have uncovered a small amount of evidence pointing toward chocolate perhaps increasing IL-10 protein production⁴. Might this or something else entirely such as the unique effects of the monounsaturated and saturated fats in cocoa butter contribute to acne?⁵
Beneficial effects of chocolate
On the other hand, chocolate contains antioxidants, which could theoretically help with acne symptoms. Dark chocolate may actually reduce blood pressure as well. Might reduced blood pressure in some way promote oxygen and nutrient distribution to the dermis, thus preventing acne in some marginal way?⁵
1) Fulton J, Plewig G, Kligman A. “Effect of chocolate on acne vulgaris”. The Journal of the American Medical Association. 1969; 1969; 210: 2071-4.
2) Anderson P. “Foods as the cause of acne.” American Family Physician. 1971; 3: 102-3.
3) Brand-Miller J, Holt SHA, de Jong V, Petocz P. “Cocoa powder increases postprandial insulinemia in lean young adults.” Journal of Nutrition. 2003; 133: 3149-52.
4) Netea SA, et al. “Chocolate consumption modulates cytokine production in healthy individuals.” Cytokine. 2013; 62(1): 40-3.
5) Latif R. “Chocolate/cocoa and human health: a review.” The Netherlands Journal of Medicine. 2013; 71(2): 63-8.
Fat is needed for our overall health and well being. However, whether saturated, unsaturated, and/or hydrogenated fats affect acne remains unknown.
Current evidence shows that the fat we eat is in fact used to make skin oil (sebum). In addition, at least one study has shown that fatty diets lead higher fat content in sebum¹. The evidence stops there. Whether fattier sebum leads toward increased or decreased acne symptoms is up for debate. Scientists are looking into the nature of sebum, particularly its saturated or unsaturated content, to see if they can find clues to acne development.
1) Pappas A, Anthonavage M, Gordon J. “Metabolic fate and selective utilization major fatty acids in human sebaceous gland.” Journal of Investigative Dermatology. 2002; 118: 164-71.
Most people living in modernized societies eat far more Omega-6 fats from foods such as grains, vegetable oils, nuts, and poultry than they do Omega-3 fats from foods such as fish and fish oils, grass fed meat, seeds such as flax seeds and chia seeds, and hemp¹. This is in stark contrast to hunter/gatherer societies and to what our ancestors evolved to eat. Eating a more balanced ratio of Omega-3: Omega-6 fats can help modulate inflammation in the human body². Since acne is an inflammatory disease, it makes sense that anything that can reduce inflammation would also help reduce acne.
Omega-3 fats, especially the omega-3 fatty acids from EPA and DHA commonly found in cold-water fish, work by reducing the production of inflammatory cytokines³−⁵ and inflammatory leukotriene B4 molecules.6 EPA and DHA also inhibits mTORC1, a protein which can signal skin oil glands to produce more oil⁶−⁹.
Omega-3s are known to improve mood and reduce stress and anxiety¹º. Since stress and acne are linked¹¹, this is another way omega-3 fats could theoretically help reduce acne symptoms.
EPA in particular is anti-bacterial¹² and along with other fatty acids can inhibit the growth of Propionibacterium acnes (P. acnes) as well as Staphylococcus aureus bacteria, both of which have been associated with acne¹³.
Omega-3s also help keep IGF-1 (insulin-like growth factor) levels in check⁵, which theoretically could help keep the skin from overproducing skin cells, and skin oil thus preventing breakouts.
Korean researchers in one study demonstrated that taking 2000mg EPA + DHA alongside 400mg of gamma-linoleic acid, a type of omega-6 fatty acid, significantly reduced inflammation and acne⁶−¹⁴. More studies attempting to link Omega-3 intake and acne are needed.
1) Logan A. “Omega-3 fatty acids and acne.” Archives of Dermatology. 2003; 139: 941-3.
2) Simopoulos A. “Omega-3 fatty acids in inflammation and autoimmune diseases.” Journal of the American College of Nutrition. 2002; 21: 495-505.
3) Cordain L. “Implications for the role of the diet in acne.” Seminars in Cutaneous Medicine and Surgery. 2005; 24: 84-91.
4) Vowels BR, Yang S & Leyden JJ. “Induction of pro-inflammatory cytokines by a soluble factor of Propionibacterium acnes: implications for chronic inflammatory acne.” Infection and Immunity. 1995; 63(8): 3158‑3165.
5) Cordain L. “Implications for the role of diet in acne.” Seminars in Cutaneous Medicine and Surgery. 2005; 24(2): 84‑91.
6) Cordain L. “Implications for the role of diet in acne.” Seminars in Cutaneous Medicine and Surgery. 2005; 24(2): 84‑91.
7) Melnik B. “Dietary intervention in acne.” Dermato-endocrinology. 2012; 4(1): 20‑32.
8) Melnik BC. “Linking diet to acne metabolomics, inflammation, and comedogenesis: an update.” Clinical, Cosmetic and Investigational Dermatology. 2015; 8: 371‑388.
9) Grossi E, et al. “The constellation of dietary factors in adolescent acne: a semantic connectivity map approach.” European Academy of Dermatology and Venereology. 2014 short report.
10) Freeman MP, et al. “Omega-3 fatty acids: evidence basis for treatment and future research in psychiatry.” Journal of Clinical Psychiatry. 2006; 67(12): 1954‑1967.
11) James MJ, Gibson RA & Cleland LG. “Dietary polyunsaturated fatty acids and inflammatory mediator production.” American Journal of Clinical Nutrition. 2000; 71: 343S-348S.
12) Desbois AP. “Antimicrobial properties of eicosapentaenoic acid (C20 : 5n-3).” Marine Microbiology: Bioactive Compounds and Biotechnological Applications, First Edition. Edited by Se-Kwon Kim. 2013; 351‑367.
13) Desbois AP and Lawlor KC. “Antibacterial activity of long-chain polyunsaturated fatty acids against Propionibacterium acnes and Staphylococcus aureus.” Marine Drugs. 2013; 11: 4544‑4557.
14) Jung JY, et al. “Effect of dietary supplementation with omega-3 fatty acid and gamma-linolenic acid on acne vulgaris: a randomized, double blind, controlled trial.” Acta Dermato-Venereologica. 2014; 94: 521‑525.
As far as supplementation goes, zinc stands alone with the most evidence pointing toward a beneficial effect on acne, however moderate that effect may be. Over-the-counter zinc supplements normally come in 30-50mg tablets. The National Institutes of Health put tolerable levels of zinc for adults at 40mg a day¹. Zinc gluconate may be a better choice than zinc sulfate due to its superior bio-availability. Since meat and poultry provide the majority of zinc in Western diets, vegetarians may want to take special care to ensure they are ingesting adequate amounts of zinc. A systematic review of medical literature in the Journal of Drugs in Dermatology concludes, “The preponderance of evidence suggests zinc has anti-bacterial and anti-inflammatory effects and that it may decrease sebum production². 6% of our body’s supply of zinc is in our skin³ and after years of study and quite a bit of evidence, it appears that zinc supplementation may help with acne symptoms.
Multiple studies have been performed on people with acne who are administered oral zinc supplementation⁴−⁷. Overall results show a reduction in acne lesion count above that of placebo, albeit only moderately. The dosage of zinc in these studies is normally quite high⁸ and more studies are needed to see if the reduction in acne symptoms could be sustained at lower levels of zinc. However, since other studies show lower blood zinc levels in people with acne⁹−¹º, keeping zinc levels up to par is a compelling option.
How Zinc Works
Zinc helps maintain skin integrity, reduces inflammation, promotes wound healing, helps kill and suppress acne bacteria, and may reduce skin oil production¹¹−¹⁵.
Getting zinc naturally
Oysters contain 10X more zinc than any other food. Eating 2 ounces (about 4 oysters) is a fun way to get 50mg of zinc.
1) “Zinc.” — Health Professional Fact Sheet. N.p., 05 June 2015. Web. 04 Feb. 2014. Link
2) Brandt S. “The clinical effects of zinc as a topical or oral agent on the clinical response and pathophysiologic mechanisms of acne: a systematic review of the literature.” Journal of Drugs in Dermatology. 2013; 12(5): 542-5.
3) King J, Shames D, Woodhouse L. “Zinc in humans.” Journal of Nutrition. 2000; 130: 1360-65.
4) Dreno B, et al. “Low doses of zinc gluconate for inflammatory acne.” Acta Dermato-Venereologica. 1989; 69: 541‑543.
5) Dreno B, et al. “Zinc salts effects on granulocyte zinc concentration and chemotaxis in acne patients.” Acta Dermato-Venereologica. 1992; 72: 250‑252.
6) Dreno B, et al. “Multicenter randomized comparative double-blind controlled clinical trial of the safety and efficacy of zinc gluconate versus minocycline hydrochloride in the treatment of inflammatory Acne vulgaris.” Dermatology. 2001; 203: 135‑140.
7) Meynadier J. “Efficacy and safety study of two zinc gluconate regimens in the treatment of inflammatory acne.” European Journal of Dermatology. 2000; 10(4): 269‑273.
8) Bowe W, Joshi S, Shalita A. “Diet and acne.” Journal of the American Academy of Dermatology. 2010 Jul; 63(1): 121-41.
9) Amer M, et. al. “Serum zinc in acne vulgaris.” International Journal of Dermatology. 1982; 21: 481-4.
10) Michaelsson G, Vahlquist A, Juhlin L. “Serum zinc and retinoil-binding protein in acne.” British Journal of Dermatology. 1977; 96: 283-6.
11) Bae Y, et. al. “Innovative uses for zinc in dermatology.” Clinics in Dermatology. 2010; 23(3): 587-597.
12) Jasson F, et al. “Different strains of Propionibacterium acnes modulate differently the cutaneous innate immunity.” Experimental Dermatology. 2013; 22(9): 587-92.
13) Poiraud C, et al. “Zinc gluconate is an agonist of peroxisome proliferator-activated receptor-α in the epidermis.” Experimental Dermatology. 2012; 21: 347‑351.
14) Dreno B, et al. “Effect of zinc gluconate on Propionibacterium acnes resistance to erythromycin in patients with inflammatory acne: in vitro and in vivo study.” European Journal of Dermatology. 2005; 15(3): 152‑155.
15) Isard O, et al. “Propionibacterium acnes activates the IGF-1/IGF-1R system in the epidermis and induces keratinocyte proliferation.” Journal of Investigative Dermatology. 2011; 131: 59‑66.
We do not have enough evidence to convict or acquit iodine in acne vulgaris formation at this point. High levels of iodine have been shown to illicit what are called acneiform eruptions. These eruptions are different from run-of-the-mill acne and are evidenced by a quick onset, wide distribution on the body, and pustule-only outbreaks. Whether smaller levels of iodine affect acne is unknown. According to an overview of the latest evidence regarding diet and acne published in the Journal of the American Academy of Dermatology, “Iodine has been implicated as a cause of acne vulgaris, however, no literature to date supports iodine as a culprit in comedonal acne¹.
The evidence is sparse. It appears that consuming very high levels of iodine containing kelp and iodine containing drugs can cause acneiform eruptions²−³. However, in one study from 1961, people who ate a lot of seafood and fish, a food group which contains high levels of iodine, were shown to actually have lower levels of acne⁴. Other studies have shown no correlation between fish/seafood and acne.
1) Danby F. “Acne and iodine: reply”. American Academy of Dermatology. 2007; 56: 164-5.
2) Harrell B, Rudolph A. “Kelp diet: a cause of acneiform eruption [letter].” Archives of Dermatology. 1976; 112: 560.
3) Jackson R. “Nonbacterial plus-forming diseases of the skin.” Canadian Medical Association. 1974; 111(801): 4-6.
4) Hitch J, Greenburg B. “Adolescent acne and dietary iodine.” Archives of Dermatology. 1961; 84: 898-911.
Eating a diet rich in colorful fruits and vegetables will help your overall health and may or may not help reduce the inflammation inherent in the acne process. Acne is partly an inflammatory disease. The inflammatory process is what causes acne affected pores to become characteristically inflamed and red. Antioxidants in the body help resolve this inflammatory response.
People with acne tend to have less antioxidants, such as vitamin A, vitamin E, and selenium, in their skin¹−³. It makes common sense that bringing antioxidant levels up to par would help calm the inflammatory response. However, we do not have enough evidence at this point to definitively say whether or not antioxidants in food or supplements help with acne. Topical antioxidants on the other hand, have shown promise in reducing acne lesion count. Examples of topical antioxidants include green tea, resveratrol, and licochalcone.
1) El-Akawi Z, Abbel-Latif N, Abdul-Razzak K. “Does the plasma levels of vitamins A and E affect acne condition?” Clinical and Experimental Dermatology. 2006; 31: 430-4.
2) Michaelsson G. “Decreased concentration of selenium in whole blood and plasma in acne vulgaris.” European Academy of Dermatology and Venereology. 1990; 70-92.
3) Ozuguz P, et al. “Evaluation of serum vitamins A and E and zinc levels according to the severity of acne vulgaris.” Cutaneous and Ocular Toxicology. 2013; July 5. [Ahead of print].
The Gut & Probiotics
Probiotics are the good bacteria that help with digestive health. New research shows that they may also help with the skin. The American Academy of Dermatology notes that people prone to acne may find improvement with daily probiotic use. Get probiotics from yogurt labeled “live, active cultures.”
Acne rosacea AKA (Rosacea), a disease which presents somewhat similar symptoms to acne vulgaris (run-of-the-mill acne), tends to show a strong correlation with intestinal issues, including bacteria overgrowth¹.
Acne vulgaris is not the same disease as acne rosacea, and intestinal discomfort is not as common amongst acne vulgaris sufferers. However, this would be an interesting area of study. Would a high fiber diet help with acne? What about probiotics?