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 final education. I was therefore skeptical of the evidence behind a media hype.
But I was also aware that acne has a huge impact on people's self-esteem . So if diet could help, I wanted to know.
What Causes Acne?
For most of us, acne subsides in our late teens until the early twenties, but it 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 and block follicles. This combination of oily and blocked pore environment causes the acne bacteria (which live on every skin) to multiply.
Diet Acne – Back in History
In the late 1800s and early 1900s, scientists speculated about a connection between diet and acne. This was due to fat-processed foods, chocolate, bananas, nuts, alcohol, sugar and cheese.
In the 1960s, however, 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.
However, we now know that these studies contained major design flaws that led to a false conclusion that meant no research was done for another 40 years!
Only recently has a connection 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.
Based on their observations, they came to the conclusion that the enormous differences in the frequency of acne between non-western population groups and modern societies are not exclusively due to genes.
It must have something to do with the environment – maybe a diet they thought of. These non-western individuals ate diets that were mostly high in plant-based, unprocessed foods with low glycemic loads. You can find a list of them below.
If diet plays a role in acne promotion, it is likely due to the ability of some foods to stimulate complex acne-promoting pathways.
The strongest association has so far been viewed by scientists as 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 breakfast cereals, white flour, cookies, and candy.
GL is based on the portion sizes we eat and is a practical extension of GI science to our daily life.
The theory states that foods with high GL are quickly digested and absorbed and cause 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 New York men and women were asked to complete a validated food frequency questionnaire and to indicate the severity of their 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 others not . In short, more research is needed!
Nutrition and Milk
There is another theory that milk can make acne worse by increasing the levels of insulin and a hormone called IGF-1 in the blood. Because milk contains carbohydrates, there is an increase in blood sugar and insulin, similar to a diet with a high GL.
Interestingly, milk expected a GL 3-6 times higher than . The addition of 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 has been shown to increase IGF-1 levels in the blood when consumed in large quantities.
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 their eating habits and followed them for three years. In both studies, high milk intake increased the risk of acne by around 20%.
Another attempt found that acne was positively associated with frequent milk consumption, but not with whole milk or cheese.
The problem is that literature dealing with milk and acne is observational. There are no randomized controlled trials that examine a link between acne and dairy products.
That means we cannot definitively prove that milk causes acne, but we can suggest drinking milk may increase 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 with your family doctor that can be used together with a possible change in diet. The British Association of Dermatologists discusses treatment options here
Consider the selection of makeup and facial products that are not comedogenic as (free of pore-blocking ingredients) Marked are. . Pais Day cream to balance geranium and thistle would tick this box .
Keep a food / symptom diary and look for patterns between food and outbreaks.
Consider an exclusion period for milk products or milk products 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.
Think about a diet with a low GL. This recipe book with low GL content by registered dietitian Nigel Denby is excellent. He explains that a GL rating of <10 = low, 11-19 = medium and 20+ = high. For a day with low GL, aim for a GL of 80 or less. 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 oatmeal 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 strong evidence that diet causes acne, but there is emerging evidence that it can make it 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 may be responsible.
Eat a varied and rich diet of complete plant foods such as fruits, vegetables, legumes and nuts to determine whether the acne symptoms improve. Excluding milk could also be considered as long as daily calcium levels can be maintained.
The exclusion of milk could also be considered as long as the daily calcium level can be maintained.
If we look to the future, we need to examine what happens before evidence-based recommendations can be developed.
Registered dietitians, dieticians and dermatologists should be open-minded. You 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 collaboration between the two professions in the coming years.
Rosie Saunt (Registered Dietitian) @ rosie-saunt