Diet and Acne

Dairy

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.

HORMONES:

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.

STUDIES:

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).

IODINE:

At large doses, iodine can cause what are called acneiform 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.

SUMMARY:

Due to the lack of concrete evidence backing up any of the above hypotheses, 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 pathogenesis of acne is slim."¹

Glycemic Index / Glycemic Load

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.

HORMONES:

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

STUDIES:

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

SUMMARY:

I am excited to see researchers starting to tackle this issue, and look forward to more studies in this vein. However, 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.

Omega-3

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 about far more Omega-6 fats--from foods such as grains, vegetable oils, nuts, and poultry--than they do Omega-3 fats.¹

INFLAMMATION:

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.

HORMONES:

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.

STUDIES:

Scientists have yet to perform any consequential studies attempting to link Omega-3 intake and acne.

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.

Zinc

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.

THE EVIDENCE:

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

HOW ZINC WORKS:

Zinc helps reduce inflammation, and helps kill acne bacteria.⁵

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.²

Caloric intake

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 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

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 eaten or simply lowered calories.

Fatty / Oily foods

Overall, we lack evidence on either side of this issue. Several studies have been performed regarding diet and acne, but results regarding fat content are inconclusive.

EVIDENCE:

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.

SUMMARY:

Fat is needed for our overall health and well being. Whether saturated, unsaturated, and/or hydrogenated fats affect acne remains unknown.

Iodine

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:

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 have lower levels of acne.⁴ Other studies have shown no correlation between fish/seafood and acne.

SUMMARY:

Simply put, we do not have enough evidence to convict or acquit iodine in acne vulgaris formation at this point.

Chocolate

As with most other diet and acne mysteries, we still do not know whether chocolate has an effect on 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 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.

INSULIN:

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.

ANTIOXIDANTS:

On the other hand, chocolate contains antioxidants, which could theoretically help with acne symptoms.

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. In my opinion it is best to enjoy chocolate in moderation and as part of a healthy diet.

Antioxidants

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.

THE EVIDENCE:

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.

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.

The gut

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? How about probiotics? Would targeted intestinal antibiotics help? I'd like to see this research performed.