I was once asked why nutrition is the preferred method of treating acne.
"Well … is it?" I thought to myself.
As a registered nutritionist, the therapeutic treatment of acne with food was not part of my training. I was therefore skeptical of the evidence behind a media hype.
But I was also aware that acne has a great impact on people's self-esteem . So if diet could help, I wanted to know.
What Causes Acne?
For most of us, late teens acne resolves into the early twenties, but can last longer and develop for the first time in people in the late twenties and thirties.
The exact cause is unknown, but dermatologists believe that factors such as hormones, weight, genetics, inflammation, and emotional stress play a role.
The British Association for Dermatologists describes the oil-producing glands of people with acne as particularly sensitive to normal blood levels of key hormones. This causes glands to produce excess oil.
Skin cells that line the pores cannot detach properly either, which blocks follicles. This combined oily and blocked pore environment causes the acne bacteria (which live on everyone's skin) to multiply.
Diet Acne – Back in History
In the late 1800s and early 1900s, scientists speculated that there was a connection between diet and acne. Processed fatty foods, chocolate, bananas, nuts, alcohol, sugar and cheese were all to blame.
In the 1960s, two frequently cited studies seemed to prove that there was no such connection . So much so that textbooks were revised and dermatologists believed that any mumbling about diet and acne was unscientific.
But we now know that these studies contained major design flaws, which led to a wrong conclusion, which meant that no research was done for another 40 years!
Only recently has an association with acne and food reappeared.
A link between diet and acne appeared in 2002 when scientists reported that acne was almost non-existent in western populations.
From their observations, they concluded that the large differences in the incidence of acne between non-western populations and modern societies are not only due to genes.
There must be something environmentally conscious in the game – maybe a diet they thought. These non-Western individuals ate diets that were predominantly high in plant-based, unprocessed foods with low glycemic loads. A list of them can be seen below.
If diet plays a role in promoting acne, it is believed that this is due to the ability of some foods to stimulate complex ways to promote acne.
The strongest association to date is considered by scientists to be between milk and glycemic load (GL).
Diet and Acne – What You Can Do
The glycemic index (GI) is a number that is given to a food to reflect its effect on a person's blood sugar. High GI foods include sugar breakfast cereals, white flour, cookies, and candy.
The GL is based on the portion sizes that we eat and is therefore a practical extension of GI science to our daily life.
The theory states that foods with a high GL are quickly digested and absorbed, which leads to an increase in blood sugar. This sends a message to the pancreas, which along with other hormones causes an acute surge in insulin.
GL and acne research
Overall, this appears to be a controversial area with conflicting evidence between studies.
In a recent study 248 men and women living in New York were asked to complete a validated food frequency questionnaire and to indicate their severity in acne. The results showed that participants with moderate to severe acne had a significantly higher GL diet and additional sugar consumption.
Randomized controlled trials (the gold standard study design) were also performed.
Several of these studies have shown improvements in the following areas: acne, hormone levels and sebum production after a low GL diet ( here here and here ), while another did not . In short, more research is needed!
Diet and Dairy Products
There is another theory that milk can make acne worse by increasing insulin levels and a hormone called IGF-1 in the blood. Because milk contains carbohydrates, this leads to an increase in blood sugar and insulin, similar to a diet with a high GL.
Interestingly, milk has a GL 3-6 times higher than expected . Adding only a small amount of milk to a low GI meal increases the insulin response to values characteristic of a high GI meal. This applies to skimmed milk and whole milk, but not to cheese.
Milk can also contribute to acne due to its hormone content, which contains IGF-1. This, when drunk in large amounts, has been shown to increase IGF-1 levels in the blood.
Milk and acne research
Two large studies provide the most convincing evidence for a link between milk and acne ( here and here ).
In both cases, they asked participants to write down what they ate and followed them for three years. In both studies, high milk intake increased the risk of acne by about 20%.
Another attempt found that acne was positively associated with frequent milk consumption, but not with whole milk or cheese.
The problem is that the literature on the study of milk and acne is observational. There are no randomized controlled trials that investigate a link between milk and acne.
This means that we cannot definitively prove that milk causes acne, but we can suggest milk drinking increases your risk.
Since milk contains over 60 different molecules, it is extremely difficult to find out which of these components could have an acne-promoting effect. Especially when there is such a wide range of dairy products.
Scientists are still trying to find out whether it is the hormones, their GL effects, or the protein in milk that drives associations.
Make an appointment
Discuss medical treatments such as topical creams that can be used in addition to dietary changes with your family doctor. The British Association of Dermatologists discuss treatment options here .
Choose make-up and facial products with the designation non-comedogenic (free of pore-blocking ingredients) . Pais Day cream to balance geraniums and thistles would tick this box .
Keep a food / symptom diary and look for patterns between food and outbreaks.
Consider a milk or milk exclusion period for a few months. Make sure you get enough calcium using this British Dietetic Association star guide . Note that organic milk alternatives are not fortified with calcium. You may need to consider calcium supplements if you don't get enough.
Go low GL
Consider a low GL diet. This recipe book with low GL by Registered Dietitian Nigel Denby is excellent. He explains that a GL rating of <10 = low, 11-19 = medium and 20+ = high. To have a day with low GL, aim for a total GL of 80 or less. A total of 120 or more would be a day with high GL.
An example of a day with low GL:
Breakfast : Two poached eggs, a slice of pumpernickel bread, avocado and fresh tomatoes.
Snack : Small handful of almonds
Lunch : Lentils with fresh spinach, grated fennel and goat cheese.
Snack : Two oat cakes with a tablespoon of hummus.
Dinner : Chicken and quinoa salad with butternut squash, chilli and broccoli
Summary: The Relationship Between Diet and Acne
There is no strong evidence that diet causes acne but there is evidence to suggest that it does can make them worse. In addition to medical treatment, there are some nutritional strategies that are worth trying.
A typical western diet based on refined carbohydrates with high GL and dairy products can be responsible.
Eat a healthy and varied diet, rich in whole foods such as fruits, vegetables, legumes and nuts to determine whether the acne symptoms improve. The exclusion of milk could also be considered as long as daily calcium levels can be reached.
The exclusion of milk could also be considered as long as daily calcium levels can be reached.
Looking to the future, we need to research to understand what is going on before evidence-based recommendations can be developed.
Registered nutritionists, nutritionists and dermatologists should be open-minded. They should be aware of their potential to have a very positive impact on a person's life by improving their skin with food.
Hopefully we will see more cooperation between the two professions in the coming years.
Rosie Saunt (Registered Nutritionist) @ rosie-saunt