I was once asked why nutrition is the preferable method for treating acne.
“Well…is it?” I thought to myself.
As a Registered Dietitian, treating acne therapeutically with food wasn’t part of my degree training and I’d consequently been sceptical about the evidence behind any media hype.
But I was also well aware acne has a major impact on people’s self-esteem, so if diet could help I wanted to know.
What causes acne?
For the majority of us, acne resolves in late teens to early twenties, but it can persist for longer and also develop for the first time in people during their late twenties and thirties.
The exact cause is unknown, but Dermatologists believe factors such as hormones, weight, genetics, inflammation and emotional stress play a role.
The British Association for Dermatologists describe the oil producing glands of people with acne as being particularly sensitive to normal blood levels of key hormones, causing glands to produce excess oil.
Skin cells lining the pores may also not shed properly, causing follicles to block. This combined oily and blocked pore environment causes the acne bacteria (which live on everyone’s skin), to multiply.
Diet-acne – going back in history
In the late 1800s and early 1900s, scientists speculated there was a link between diet and acne. Processed fatty foods, chocolate, bananas, nuts, alcohol, sugar and cheese where all to blame.
But then in the 1960s two highly cited studies seemed to prove there was no such link. So much so, that textbooks were revised and dermatologists took the view that any murmurings about diet and acne were unscientific.
But we now know these studies contained major design flaws and leading to an erroneous conclusion which meant there was no research for a further 40 years!
It’s only recently that an association with acne and food has reemerged.
A diet-acne link seemed to resurface in 2002 when scientists reported that acne was almost non-existent in outside Western populations.
From their observations, they concluded that the vast differences in the incidence of acne between non-Western populations and modern societies could not be solely down to genes.
Something environmental must be at play….perhaps diet they thought. These Non-Western individuals ate diets predominantly rich in plant-based, unprocessed low glycemic load foods. A list of which can be seen below.
Table credit: Cordain et al, 2002
If diet does play a role in promoting acne, it’s thought to be due to the ability of some foods to stimulate complex acne-promoting pathways.
The strongest association to date is thought by scientists to be between dairy and glycemic load (GL).
Check back tomorrow for part two of Rosie’s investigation into the diet-acne link.