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 30-50mg 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.
Summary: 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 sparse.
IGF-1: 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.
Androgens: Milk also contains male hormone (androgen) precursors.4-5 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 acne.7-9 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. 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) eruptions.10-11 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.
|Year and type||# of subjects||Limitations|
|1949 case series11||1925||Short duration, no data|
|1971 case series12||27||Small sample, unblended, no statistical analysis, no lesion count, no control, no randomization|
|2005 retrospective cohort7||47,355||Retrospective-relied on distant recall of diet, loosely defined definition of “acne”|
|2006 prospective cohort13||6094||Unvalidated self-reporting of “acne”|
|2008 prospective cohort8||4273||Unvalidated self-reporting of “acne”|
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. Pennington J. "Iodine concentrations in US milk: variation due to time, season, and region." Journal of Dairy Science. 1990; 73: 3421-7.
11. Robinson H. "The acne problem." Southern Medical Journal. 1949; 42: 1050-60.
12. Anderson P. "Foods as the cause of acne." American Family Physician. 1971; 3:102-3.
13. Adebamowo C, et. al. "Milk consumption and acne in adolescent girls." Dermatology Online Journal. 2006; 12(4): 1.
Summary: 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 glucose.
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:
IGF-1: 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, which could cause pores to become clogged, leading to acne.2-4 Scientists also hypotesize that high IGF-1 levels could lead to increased skin oil sebum production which may lead to breakouts.
IGFBP-3: 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. So, lower amounts of IGFBP-3 means even higher IGF-1 levels. As we have discussed, scientists postulate that increased IGF-1 may lead to overgrowth of cells inside pores.2-4 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 do.5-11
Androgens: 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 symptoms.12-13
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.1,14 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 factors."1
|Year and type||# of subjects||Limitations|
|2008 parallel, intervention trial1||31||Small cohort, drop-out rate (54 started study, 31 completed), short duration (12 weeks) with no follow up|
|2007 parallel, intervention study14||43||Small cohort, short duration (12 weeks) with no follow up|
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. 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.
3. 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.
4. 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.
5. Evens T, Kaye S. "Retinoids: present role and future potential." British Journal of Cancer. 1999; 80:1-8.
6. 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.
7. 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.
8. 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.
9. 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.
10. 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.
11. Thacher S, Vasudevan J, Chandraratha R. "Therapeutic applications for ligands of retinoid receptors." Current Pharmaceutical Design. 2000; 6: 25-58.
12. Eichenfield L, Layden J. "Acne: current concepts of pathogenesis and approach to rational treatment." Pediatrician. 1991; 18: 218-223.
13. Thiboutot D. "Acne: an overview of clinical research findings." The Dermatology Clinic. 1997; 15: 97-109.
14. 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.
Summary: Due to the lack of concrete evidence, we are left with only conjecture at this point. Having said that, Omega-3 fats have many benefits in our bodies, and eating an adequate amount of them is a healthy option regardless of whether it will help with acne.
Omega-3 fatty acids exist in fish and fish oils, grass fed meat, seeds such as flax seeds and chia seeds, hemp, and various other foods. 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.1
Eating a more balanced ratio of Omega-3:Omega-6 helps modulate inflammation in the human body.2 Omega-3 fats have been shown to reduce inflammatory cytokine production3 and inflammatory leukotriene B4 molecules.4 Since acne is partially an inflammatory disease, it makes common sense that anything one can do to limit inflammation is welcomed.
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.
Scientists have yet to perform any consequential studies attempting to link Omega-3 intake and acne.
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. Zouboulis C, et. al. "A new concept for acne therapy: a pilot study with zileuton, an oral 5-lipoxygenase inhibitor." Archives of Dermatology. 2003; 139; 668-70.
5. Bhathena S, et. al. "Effects of Omega-3 fatty acids and vitamin E on hormones involved in carbohydrate and lipid metabolism in men." The American Journal of Clinical Nutrition. 1991; 54: 684-8.
Summary: 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. Safe levels of zinc supplementation are up to 50mg a day. Zinc gluconate appears to be a better choice than zinc sulfate due to its superior bioavailability.
6% of our body's supply of zinc is in our skin.1 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 supplementation. 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 high2, 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 acne, keeping zinc levels up to par is a compelling option.3-4
Zinc helps reduce inflammation, and helps kill acne bacteria.5
1. King J, Shames D, Woodhouse L. "Zinc in humans." Journal of Nutrition. 2000; 130: 1360-65.
2. Bowe W, Joshi S, Shalita A. "Diet and acne." Journal of the American Academy of Dermatology. 2010 Jul; 63(1): 121-41.
3. Amer M, et. al. "Serum zinc in acne vulgaris." International Journal of Dermatology. 1982; 21: 481-4.
4. Michaelsson G, Vahlquist A, Juhlin L. "Serum zinc and retinoil-binding protein in acne." British Journal of Dermatology. 1977; 96: 283-6.
5. Bae Y, et. al. "Innovative uses for zinc in dermatology." Clinics in Dermatology. 2010; 23(3): 587-597.
Summary: 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.
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 symptoms.1 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.
The argument against: From two studies, obesity, body mass index does not appear correlated with acne.2-3
1. Downing D, Strauss J, Pochi P, "Changer in Skin Surface lipid composition induced by severe caloric restriction in man." The American Journal of clinical Nutrition. 1972; 25: 365-7.
2. Pochi P, Downing D, Strauss J. "Sebaceous gland response in man to prolonged total caloric deprivation." Journal of Investigative Dermatology. 1970; 55: 303-9.
3. Bourne S, Jacobs A. "Observations on acne, seborrhea, and obesity." British Medical Journal. 1956; 1: 1268-70.
4. Wolf R, Matz H, Orion E. "Acne and diet." Clinics in dermatology. 2004; 22: 387-33.
Summary: 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 sebum.1 The evidence stops there. Whether more fatty 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.
Summary: 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 acne."1
The evidence is sparse. It appears that consuming very high levels of iodine containing kelp and iodine containing drugs can cause acneiform eruptions.2-3 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 acne.4 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.
Summary: 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.
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 1971.1-2 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 are 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 adults.3 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 spike.4-7 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.
On the other hand, chocolate contains antioxidants, which could theoretically help with acne symptoms.
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.
Summary: 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 skin.1-2 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.
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 overgrowth.
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?
As a critical sociology major in college, I learned that it is important for an author to present his or her bias. Because we are human and it is impossible to be completely unbiased, the presentation of bias allows the reader to take the author's bias into account when absorbing content.
My bias: Throughout my adolescence and early adulthood, I read in various places that chocolate and sugar were bad for acne. I carefully avoided chocolate and sweets for years, which did not end up helping with my acne, but did harm social interactions. I finally gave up on eliminating so-called “bad” foods from my diet, and my acne did not change considerably. Years later, after I had already discovered The Regimen and cleared up, I decided to attempt to clear my skin from the inside out by eating in a hunter/gatherer way, thus eliminating any potential “modern” dietary causes of acne. About 25 Acne.org members joined me in stopping The Regimen and instead eating a caveman style diet, which consisted of only food which was available before modern civilization emerged about 10,000 years ago. This meant vegetables, fruit, tubers (potatoes, yams, sweet potatoes), nuts, seeds, and meat. I completely eliminated sugar, added salt, all grains, legumes (beans), and dairy. The diet seemed to work at first. My skin did not break out much for the first month or so. However, during this first month I was also losing weight from eating in such a clean way. About six weeks into the diet, as soon as my weight leveled off, the acne returned. Unfortunately, due to the rigors of eating in such a strict fashion, none of the 25 Acne.org members kept to the diet as strictly as I did, so I am left with only my anecdotal experience. My conclusion, drawn from personal experience, was that no matter how cleanly I ate, it was not enough to stay clear. I slowly returned to a Western style of eating, but still try to remain aware of my glycemic load. My common sense tells me that eating lots of sugar and high carbohydrate items can’t be a good thing for my overall health or the health of my skin."Dan Kern