Acne and diet

Chocolate? I love it. My four children do too. But does it give them spots? I am constantly drumming home the importance of healthy eating. Such as a good breakfast with lots of fruit, porridge, eggs and extra vitamin D. No milk though. If only because I have seen too many studies where a link has been made between dairy products and acne. Junk food, by the way, doesn’t cause more spots, even though I would love to use this as a threat at home. Sugars have, on the contrary, been found guilty in all sorts of studies. More recently I have read everything I could get my hands on about the role (gut) bacteria plays in relation to spots. How wonderful would that be if you could help your skin with a probiotic? And did you know that positive stories about zinc is doing the rounds? This resides in oysters, nuts, grains, prawns… A supplement, however, would be faster acting. So I would like to know more about this. Food with spots: it’s got my attention. Are you going to read with me? Kind regards, Jetske.

The effect of diet
on acne: what do
we already know?

The views about the relationship between diet and acne has changed over the last decade. Is there or isn’t there a link between what you eat (or drink) and the appearance or aggravation of spots? A great deal of research has been carried out into this. The authors of this review summarise. From sugars and dairy to zinc, iodine and fibre: what is known about the effect thereof on acne. And what does chocolate actually do….?

Changing views around the sixties and seventies

In the United States before 1960, dietary advice formed an integral part in the treatment of acne. It was advised that no chocolate, fat, sweet and carbohydrate drinks should be consumed.
In 1969 and 1971 two studies published their results which actually showed that there was no correlation between nutrition and acne, resulting in a change in advised treatment. A good deal about both studies can, however, be criticised.
The effect of chocolate was observed in the first study. Half of the people in the experiment ate a bar of food containing chocolate every day while the other half ate a bar of food containing no chocolate. The reason that no difference was found between the groups may be due to the fact that the bar containing no chocolate had just as much sugar and fat as the bar with chocolate. The test duration was also short: too short for blackheads to appear.
In the second study the consumption of chocolate, milk, roasted peanuts and cola was observed. There was also no link found with acne. But because only a small group of people was followed, these results are also less reliable.

It looks as though there is a link between milk and spots

The effects of dairy products are often observed when research is carried out into how diet influences acne. It does indeed seems as though there is a link between acne complaints and the consumption of milk.
In 2005, researchers (led by Adebamowos) asked 47,355 women what they ate and drank during their school years. The participants were also asked if they were ever diagnosed with severe acne by a doctor. What was revealed from the interviews was that the amount of milk consumed correlated with the severity of the skin complaints.
It was striking that only skimmed milk was associated with acne, not semi skimmed or full fat milk. A reason for this may be that skimmed milk contains less oestrogen, a hormone that reduces acne.
This study also has a number of shortcomings. It is difficult for the participant in the study to remember exactly how much milk they drank during their youth. Alongside this, patients who had acne years ago were told to avoid fizzy drinks. It was thought that this would aggravate the acne. If these women did indeed stop drinking fizzy drinks, they were probably more likely to drink milk. These women would then have consumed more milk as a result of acne.

This same group of researchers conducted a similar study with 6094 girls between the ages of 9 and 15 years. Again this study actually found a link between all sorts of milk and acne. The same study with 4237 boys resulted in a link being found between the consumption of skimmed milk and spots.
This concluded, therefore, that a link is proven between milk and acne within three different groups. This link is still statistically weak though. Follow up research with more substantial proof would be necessary to endorse the results.

How do carbohydrates affect acne?

The role of sugars on acne has also been measured in detail. Is there a connection between carbohydrates and spots? There certainly seems to be. The most convincing evidence for this is ultimately conveyed through a study by Smith and his colleagues. They showed that skin complaints in a group of males between the ages of 15 and 25 years improved after following a diet with a low glycaemic load*. However: the diet also meant that the intake of fat and dietary fibre was also reduced. Through this the participants lost weight. This can, of course, have had an effect on the improvement in symptoms. The diet also caused a dip in the androgen index (male sex hormone). The results, therefore, do not necessarily apply to (young) women.
The same researchers showed that a diet with a low glycaemic load also had a positive effect on the formation of sebum and thereby on acne. This study was also only conducted on young men.
Another important indication for the effect of diet on acne can be seen in women who are suffering from polycystic ovary syndrome. These patients are treated with glucose reducing medicines. A side effect of these medicines is a positive effect on skin with acne.

*The glycaemic load informs you about the extent by which the blood sugar increases after eating certain foods. The sooner this takes place the higher the load.

Insufficient research into the effect of omega 3 fatty acids on acne

The intake of omega 3 fatty acids in comparison to the intake of omega 6 fatty acids could have a role with acne. A relatively high intake of omega 3 fatty acids suppresses the occurrence of inflammatory responses and therefore could have a positive effect on spots. More research into this theory needs to be done though.

Treatment with antioxidants potential effective

Free oxygen radicals also play a part in the aggravation and presence of acne. Antioxidants or medicines which eliminate these free radicals can therefore be used as a treatment.
A study showed that patients with acne have less vitamin A and E (antioxidants) in the blood than subjects without spots. Also certain flavonoids (deriving from plants) and resveratrol have demonstrated an antibacterial effect and can be used to counteract the bacteria P. acnes which plays a fundamental role in the presence of spots.
The use of antioxidants looks promising. Studies, however, still need to demonstrate that treatment leads to a significant result.

The advantages and drawbacks of zinc for acne symptoms

Zinc is an important element in the development and functioning of the skin. Several studies have demonstrated that the oral administration of zinc has a positive effect on acne, more than on a mild form of the disorder. The doses used in the study were however relatively high, resulting in the following side effects in the participants: nausea, vomiting and diarrhoea.

Vitamin A is effective on spots, but also has side effects

Treatment for acne with (oral) vitamin A is effective. Intake of excessive amounts of vitamin A can however lead to severe side effects such as osteoporosis or birth defects if an excessive amount of vitamin A is taken during pregnancy.

Is dietary fibre beneficial for acne /strong>

Onduidelijk is wat het effect is van de inname van voedingsvezels. Deze relatie is onvoldoende onderzocht.

What is known about iodine and acne?

The use of iodine can lead to an outbreak of spots, but is not linked to the presence of blackheads.

Conclusion: there is actually a link between acne and diet

The authors of this review conclude that a relationship between diet and acne has been proved. Although the link to products with a high glycaemic load is stronger than those with dairy, when using a treatment, it is also worth paying attention to the intake of dairy products.

There isn’t one simple cause of acne. There is even less of a simple solution. You just need to have a good deal of patience in the treatment of this skin complaint. You can also read more about the correct skincare for acne on Dr. Jetske Ultee’s weblog.

Title: Diet and acne

Year:  2010

Authors: W.P. Bowe, S.S. Joshi, A.R. Shalita


More ‘fast’ sugars
in diets of
people with acne

What role does diet play in acne? An enormous amount of research into this has been conducted. Particularly into the effect of sugar on (the formation of) spots. In this study the diets of people with and without acne symptoms have been observed. Is there a difference?

Spots, a big problem in the West

Acne is one of the most common skin disorders, often having a great social and emotional impact. In America alone, where this study was undertaken, 50 million patients were counted. Despite this high incidence there is still much misunderstanding and uncertainty about the disorder and the correct course of treatment. What, for instance, is the effect of lifestyle, or more specifically, the relationship between diet and acne? Interestingly, an epidemiological study suggested that acne was much less common in developing countries. What role does our western diet play in the formation of spots?

For this reason, the possible relationship between acne and (fast) carbohydrates in our diet has been looked into many times. Not all of those studies are well set up. This study with a group of New Yorkers looked at the difference between the glycaemic load in the diets of people with and people without acne.

What exactly is glycaemic load

What is glycaemic index (GI) and what does glycaemic load (GL) exactly stand for? The GI of a foodstuff tells you about the rate at which the blood sugar rises, and the rate of carbohydrate conversion. The GL gives a more complete picture. This value also tells you about the GI of a product, while taking into account the portion size. A snack size portion of white pasta, for instance, doesn’t have the same effect as two full plates.

Acne and the role of hormones

Acne is caused by a combination of factors including an increase in sebum production, blocked pores and an inflammatory response in the sebaceous glands and hair follicles. Male sex hormones (androgens) and various other hormone substances such as insulin and insulin like growth factor (IGF-1) stimulate sebum production. The so-called IGF binding protein (IGFBP-3) and the sex hormone binding globulin (SHBG) contribute to acne through growth stimulation of keratinocytes and sebaceous glands.

The diets of young men with and without spots: are they different?

A total of 64 people with an average age of 22 years were studied in New York. Half of the group had moderate to severe acne symptoms, the other group of 32 people had no problem with spots. The participants had to record their diets for five days according to specific measuring procedures. They were asked to keep to their normal eating habits as much as possible. Not only the skin was assessed. Blood samples were also taken on two separate occasions during the study in order to be able to assess various biological factors that play a role in acne. Included in this were the glucose values, the amount of insulin, insulin like growth factor (IGF), IGFB-3 and the concentration of SHBG. There were also general measurements taken of the build of the body (height, weight, BMI and waist size). Also studied was the way in which the participants looked at food and acne; which (incorrect) assumptions play a role? Lastly, the quality of life within both groups was recorded.

More fast sugars in the group with severe acne

Although in the setting up of this study no specific observation was made into the exact food products which cause spots, the results certainly suggest a relationship between the so-called glycaemic load and acne.

The participants with moderate to severe acne were found to have a greater intake of carbohydrates. Higher concentrations of insulin and IGF-1 were also found in this group. Additionally, more insulin resistance was found in the people with spots. They also had lower concentrations of SHGB.

Knowledge and assumptions about whether or not diet plays a role in acne, was found to be no different in both groups. In total, approximately 61 percent thought that diet can influence the presence and/or aggravation of acne symptoms. Alongside this, chips (31%), pizza (23%) and chocolate (19%) were the most frequently named as being culprits.

Dermatologists and dieticians pay more attention to food and acne

The researchers call for more follow up studies in order to identify which mechanisms play a role in the development of acne through food. Research into the effect of special medical nutrients on the biological factors which play a role in the development of acne would also be worthwhile, as well as the quality of life.
Last but not least the researches call for much more attention to this subject by dermatologists and dieticians. It has a huge impact on patients. There are not only many questions, but also many (obstinate) assumptions and misunderstandings about not only the presence of acne but also the treatment of it. Are you or are you not allowed to drink milk, for example. It would be beneficial if those opinions can be identified further.

Title: Differences in Dietary Glycemic Load and Hormones in New York City Adults with No and Moderate/Severe Acne

Year: 2017

Authors: J. Burris, W. Rietkerk, J.M. Shikany, K. Woolf


Does milk give
you (more) spots?

Many studies have been conducted into the relationship between dairy products and acne. The outcomes of these were not always clear. These meta-analyses demonstrated that the consumption of milk products can be linked to the development of acne symptoms. It is not entirely clear if milk actually causes spots or just aggravates them.

Iranian nutritionists, from the University for Medical Science in Tehran, gathered 1750 studies into dairy consumption and acne symptoms from the scientific databases of Pubmed/Medline, Scopus, Web of Science and Embase. Eventually fourteen studies met all the criteria for selection. The analysis of the studies showed that the consumption of all types of milk can be related to acne. Alongside this semi skimmed, but above all skimmed milk products showed a stronger relationship with the development of spots.

More symptoms from skimmed milk

How can skimmed milk types cause more problems in skin? One possible explanation for this is that the concentration of milk proteins, as it were, increases when fat is removed from milk.
Research has, for example, shown that milk with 80% casein and 20% whey protein causes an increase of 15% IGF-1 and 20% insulin respectively. Those effects increased even more when the amount of fat in milk was reduced.
Another explanation is that full fat milk contains more oestrogen and that this suppresses the formation of spots. Semi-skimmed and skimmed milk, on the other hand, contains a higher concentration of whey protein that actually stimulates acne.

More milk more spots?

The analysis also took into account the possible effect the amount of dairy product had on the most severe complaints. Do symptoms rise correspondingly with an increase in consumption? And if so, how? For dairy products in general, full fat milk and skimmed milk, with every extra portion, caused a linear increase of the risk of acne with 83, 13 and 26 percent respectively. No linear dosage-response relationship was seen in the consumption of semiskimmed milk and general milk products.
The analysis did lack useful data on the effect of bacteria and temperature on dairy products. It seems as though cooking and specific heating techniques have a protecting effect from acne.

How do yoghurt and quark affect spots?

No connection between eating yoghurt or quark/cheese and acne has yet been found. This might be due to the fermentation process these products go through. This would reduce any hormonal effects. As well as this products such as yoghurt contains so-called good bacteria (probiotics) which are possibly advantageous for the skin.

More research needed

The scientists plead for more advanced studies in order to confirm the effects described from dairy on the development of acne; in particular randomised research with control groups.

Title: Dairy intake and acne development: A meta-analysis of observational studies.

Year: 2018

Authors: Aghasi M, Golzarand M, Shab-Bidar S, Aminianfar A, Omidian M, Taheri F.


Other bacteria
in the gut of
patients with acne

Much research has been conducted in recent years into the role the gut has in skin problems. Is there an actual link between gut bacteria and the presence of acne? There appears to be a relationship, according to new research by skin specialists in China. People with moderate to severe acne were found to have a different collection of microbiotica in the gut.

What part does microbiome play in the gut

The exact cause of acne is still not completely clear. It has been established that a combination of various factors contribute to the presence of spots on the skin. So, among other things, there is talk of an abnormal thickening of the outermost skin cells because of an increased sebum production and an inflammatory response due to the presence of bacteria.

But to what extent these factors actually influence the outbreak of spots is not completely clear.
In recent years more and more studies have been shown to suggest that the gut microbiome plays a part in the development and course of acne. In these studies there was an approximate observation that, for example, bacteria flora in patients with acne sometimes differs from that in people with healthy skin. And that conversely there is often talk of all sorts of bowl problems in people with this skin problem.

Analysing DNA stool samples

In the meantime more efficient and precise techniques have become available in order to be able to zoom in on the multi-million gut residents, and the possible differences in these in people. The Chinese research group uses the so-called ‘high throughput sequencing technology’. Or from computer technology with an immense processing capacity, which through certain DNA sequences, enables bacteria in stool samples to be analysed.

This study involved 31 young people with mild to severe acne symptoms being compared to a control group of the same number. It involved 23 women and 8 men, with an age range of 17 to 35 years, with an average age of 22.16 years, all residing in Beijing. The participants were recruited through the dermatological clinic of the Peking University Hospital.

Reduction in ‘good bacteria types’ with acne

The researchers saw a clear difference in the types of micro-organisms present in the stool samples of both groups. They found less fungal-like bugs (actinobacteria) and, in fact, more proteobacteria (this family includes the often pathogenic species). They also noted a lower presence of certain ‘good bacteria types’ such as the  Bifidobacterium, Butyricicoccus, Coprobacillus, Lactobacillus and Allobaculum.

More research required to include other population groups

The way in which the different collection of bacteria causes skin problems is still unclear.
The researchers reason/argue that a lower production of particular substances due to bacteria (such as butyrate) causes the intestinal wall to function less well and that is why certain defence mechanisms are activated, which can ultimately also aggravate acne symptoms. More research, however, is necessary to support this.

Meer onderzoek nodig, ook bij andere bevolkingsgroepen

The researchers also emphasize that only Chinese patients have been observed. The group studied here was furthermore a modest number. The level of bacterial species was unable to be examined by the method used as well (so which bifidobacteria or lactobacilli were reduced). In order, therefore, to broaden the research results larger scale studies need to be set up – also to include different population groups. A reason being that the gut compilation of Chinese people, for example, is different from American and Egyptian people. That has, among other things, more to do with diet and other environmental factors.

The Chinese study nonetheless confirms that diet, gut and skin are not isolated from each other. And that a link exists between acne and a change in the gut’s microbiome. Those insights offer new perspectives for (the research into) the treatment of acne, for example with diet or probiotics.

Original title: Gut microbiota alterations in moderate to severe acne vulgaris patients

Authors: Hui‐Min Yan, Hui‐Juan Zhao, Du‐Yi Guo, Pei‐Qiu Zhu,Chun‐Lei Zhang,Wei Jiang

Magazinet: The Journal of Dermatology

Year: aug 2018


Does dark
chocolate also
aggravate acne?

Certain foods can aggravate acne. Dairy and products with a so-called high glycaemic load* can especially cause an increase in spots. Chocolate and sweets for example. But what about dark chocolate?

Does dark chocolate (also) lead to acne symptoms?

For a long time the extent to which spots were caused by chocolate was unclear. As most chocolate contains milk it was unclear until now which ingredient in chocolate causes acne. Milk, sugar…? Therefore the scientists in this study researched the effect of the intake of dark chocolate (99% cocoa). A group of 25 men with acne were asked to consume a piece of chocolate (25 grams of 99% cocoa) at approximately 8pm every day for 4 weeks.

More spots from dark chocolate

The dark chocolate seemed to exacerbate the acne in the participants. After 2 weeks and after 4 weeks the number of blackheads (non-inflamed lesion) and papules (inflamed lesion) increased significantly.
Other factors which may have played a part in the exacerbation of the acne such as sleep, bed time and stress were also recorded during the trial period. These factors did not appear to play a part in the exacerbation of the acne.

Cocoa does also has an anti-inflammatory effect

The reason for dark chocolate causing acne to worsen is unclear. The cocoa in the chocolate contains on the one hand a large number of flavonoids, substances with among other things an anti-inflammatory effect. So that should be beneficial for spots. On the other hand dark chocolate also contains cocoa butter, that includes among other things oleic acid. The idea is that these oily acids influence the descaling of skin cells and thereby contribute to the presence of pimples and blackheads.

Conclusion: a piece of dark chocolate every day can aggravate acne symptoms

This study showed that eating a piece of dark chocolate (25 grams) every day can aggravate symptoms in acne sensitive skin types.

Food with a high glycaemic load is food which leads to a rapid increase in glucose in the blood. Examples are fried potatoes, white bread and popcorn. The amount of this also plays a part. (Source: Voedingscentrum)

Title: Dark chocolate exacerbates acne

Year: 2015

Authors: S. Vongraviopap, P. Asawanonda


How do
omega 3 fatty acids
affect acne?

The consumption of omega 3 fatty acids and gamma linolenic acid (omega 6 fatty acids) can help reduce spots. That is the conclusion of a study whereby adults took a supplement for a period of 10 weeks. Acne improved in both groups, but not in the control group (a group of adults who didn’t take a supplement).

Omega 3 and omega 6 fatty acids are equally beneficial

A group of 45 adults with mild to moderate acne took part in the study. Dermatologists counted the number of inflamed and non-inflamed places on the faces of the participants before and after the testing period. The number of spots decreased in both groups, but not in the control group.

Participants were able to indicate if they found an improvement in their acne. This also showed that only participants who took gamma-linolenic acid or omega 3 capsules saw a reduction in their acne. All results were comparable for both groups.

Analysis of the acne inflammation at cell level showed that both omega fatty acids (IL-8) are an important factor in inhibiting the inflammatory process.

Gamma linolenic acid is an omega 6 fatty acid, derived from borage seed oil. One group took 1000mg of this oil which contained 200mg of gamma linolenic acid. The omega 3 group took a capsule containing 500mg of eicosapentaenoic acid and 500mg of docosahexaenoic acid. Both groups took 2 capsules per day.

Diet plays a part in acne

Although acne is one of the most common skin disorders, the exact cause is unclear. Diet seems to play a part in the presence or aggravation of symptoms. Food with, for example, a low glycaemic load can have a positive effect. Research shows that milk products can actually aggravate acne symptoms.

Title: Effect of dietary supplementation with omega-3 fatty acid and gamma-linolenic acid on acne vulgaris: a randomised, double-blind, controlled trial.

Year: 2014

Authors: J.Y. Jung, H.H. Kwon, J.S. Hong, J.Y. Yoon, M.S. Park, M.Y. Jang, D.H. Suh.


Is red wine
for acne?

Resveratrol is an interesting substance that is present in the skin of black grapes to which many health benefits have been attributed. This study revealed that acne patients could benefit from this ingredient. A glass of red for spots…?

Benzoyl peroxide is a commonly used and effective medication in the treatment of acne. Its application though is often accompanied by side effects such as skin irritation. Therefore a lot of research is carried out into milder alternatives. This study looked at the effect of resveratrol. This substance is present in the skin of black grapes- and therefore also in red wine. How does the ingredient help skin with spots? Is it more effective and milder than benzoyl peroxide?

Effect on the growth of acne bacteria

The researchers found a noticeable difference between both of the treatments. The substance resveratrol appeared to inhibit the growth of the P. acnes bacteria for a longer period of time. Benzoyl peroxide on the other hand only seemed to have a fairly short term effect on the number of bacteria. The combination of the two components turned out to work the best and inhibit more of the bacteria from re-growing for the greatest length of time.

Less damage to cells

The researchers also observed the harmfulness of both substances in the laboratory. The grape component also emerged better in this: benzoyl peroxide caused 20 to 30 percent more damage to body cells than resveratrol.

The results of this study are hopeful. The researchers propose that a treatment of benzoyl peroxide together with resveratrol could be effective for acne and could lead to less side effects than a treatment with benzoyl peroxide alone. It is unclear whether the same results could be gained outside the laboratory. Research is necessary for this which entails acne patients using resveratrol on the skin.

Title: Resveratrol demonstrates antimicrobial effects against propionibacterium acnes in vitro

Year: 2014

Authors: E.J.M. Taylor, Y. Yu, J. Champer, J. Kim


What happens with
spots if you change
your diet?

An eating pattern with a low glycaemic index*can improve acne. A diet with less ‘fast’ carbohydrates helps to reduce inflammation and black heads and, in addition, a decline in the the severity of the symptoms.

What does a change in diet do?

A total of 32 acne patients took part in the study. Half of the participants changed their diet for 10 weeks and the other half did not. The diet was adjusted by swapping foodstuffs with a high glycaemic load (e.g. fried potatoes, white bread and fizzy drinks) for such things as whole wheat products, fish, fruit and vegetables. The change in diet meant that this group consumed less carbohydrates and fat. The diet was supplemented with protein rich products so that the results were not affected by a decline in the amount of calories being consumed.

Improvement only seen after ten weeks

A difference in the severity of acne between the groups was only seen after ten weeks (last recording). The amount of swelling had already declined after five weeks though. After ten weeks the amount of lesions in the group with a low glycaemic load had declined by 70.9 percent, while no difference was found in the group of acne patients who had not changed their diet.

May not just be carbohydrates effect

It seems clear that there is a relationship between food and acne. Even so, it cannot be said with certainty that this is completely attributed to carbohydrates. Even though there was a noticeable difference in glycaemic load between the groups diets no other characteristics of the foodstuffs in the study was recorded. The amount of saturated fatty acids or fibre could have also influenced the results. The intake of milk products was not recorded either (often mentioned as the cause of acne).

*The glycaemic index (GI) is a measure to record how quickly carbohydrates are digested in the gut and absorbed into the blood as glucose. Source: Voedingscentrum

Title: Clinical and histological effect of a low glycaemic load diet in treatment of acne vulgaris in Korean patients: a randomized, controlled trial.

Year: 2012

Authors: H.H. Kwon, J.Y. Yoon, J.S. Hong, J.Y. Jung, M.S. Park, D.H. Suh


Do apples, strawberries
or green tea
help with acne?


The Fact Checker


Powerful antioxidants are found in apples and strawberries as well as green tea. Two different studies looked at the effect of these substances on acne symptoms. The focus is on the substances phloretin and EGCG. Both extracts appeared to be effective on spots.

Phloretin: an unusual antioxidant in apples and strawberries

In laboratory tests phloretin was shown to inhibit the growth of the bacteria P. acnes. The substance also has an anti-inflammatory effect.
The extract was then tested by 33 subjects. They applied a cream with 0.05% phloretin on one half of the face and a cream without it on the other half for a period of four weeks. The half of the face which was treated with the cream containing phloretin saw a significant reduction in the number of blackheads and papules. But also in the amount of sebum and porphyrins (product of P. acnes).

Both experiments show that phloretin can improve acne. The scientists conclude that phloretin has potential as a new medication for acne.

Green tea extract: also effective on spots

The other study looked at an effective antioxidant found in green tea: EGCG
(epigallocatechin gallate). It was established in the laboratory that green tea extract can deal with three of the four most common causes of acne, specifically: the overgrowth of the P. acnes, the sebum production and the thickening of the skin.

This study also then observed the effect on test subjects. A total of 37 test subjects applied a cream with 1% or 5% EGCG on half of their face twice a day for a period of eight weeks. A placebo was applied on the other half . Both the cream with the low and high concentration of EGCG reduced the amount of acne lesions in comparison with the placebo cream.

The scientists conclude that the application of EGCG can be an effective and rapid treatment for acne.