Acne is one of the top three most common skin disorders in the US, with approximately 85% of people between 12 and 24 years suffering from the condition at some stage.
If you struggle with acne, you may be wondering whether changing what you eat could help to eliminate and prevent it.
We hear a lot of mixed messages about which foods can cause acne and which foods can prevent it. Before you start cutting out food groups, it’s important to understand if and how diet may affect your acne and what you should or shouldn’t eat to prevent it.
It is known that genetics and hormones both play a significant role in the development of acne. But less is known about the role — if any — of environmental factors such as diet.
When evaluating studies examining the relationship between diet and acne, it is important to differentiate between an association and a causal relationship.
Just because an association exists between a certain type of food and acne, it doesn’t necessarily mean that that food either causes or prevents acne. Sometimes, further research is necessary to prove whether there is actually a causal link.
There is circumstantial evidence to suggest that diet may be a factor in causing and managing acne. Certain populations, such as the Canadian Inuit, South African Zulu, and Japanese Okinawans, have not experienced acne until they adopted a more Westernized diet.
Western diets tend to be high in processed foods and refined sugars. This finding indicates that there could be benefits for your skin in following a diet low in processed foods and refined sugars.
The glycaemic index (GI) or glycaemic load (GL) measures how quickly your blood sugar rises after eating certain foods. The higher your blood sugar spike, the higher your subsequent insulin spike. Insulin is required to move glucose from your bloodstream into cells, which are used as energy.
Foods with a high GI or GL include highly processed and refined foods, such as white bread, fries, potato crisps, pastries, doughnuts, and sugary drinks. The glycaemic index chart¹ can be used as a quick reference to determine a food’s GI.
There have been a few studies² that show that following a low-GL diet may prevent acne. Two randomized controlled trials comparing a low-GL diet with a high-GL diet that involved consuming large amounts of refined carbohydrates showed that subjects on the low-GL diet had less acne than those on the carbohydrate-rich high-GL diet.
Another study looked at patients with mild to moderate acne who had been randomly grouped into following a low-GL or high-GL diet for ten weeks. The participants on the low-GL diet showed significant reductions in inflammatory and non-inflammatory acne, decreased sebaceous gland size, and reduced severity of their acne.
It is not fully understood how GI or GL affect acne, but it is likely due to a combination of factors, including the following:
High-GI diets lead to spikes in blood sugar levels, which can cause increased levels of inflammation within the body. Inflammation contributes to the development of acne.
Spikes in blood sugar levels can also cause hormonal changes that lead to increased sebum production (the oil your body naturally produces to lubricate the skin). Excess sebum is recognized as a cause of acne.
A low-GI diet may decrease sebum levels by decreasing the size of the sebaceous glands.
While some studies have shown a link between GI and diet, others have not found any association. More research must be done to establish a stronger link between diet and acne.
Some studies have shown a link between the consumption of cow’s milk and the development of acne. The relationship between dairy and acne was first flagged in a retrospective study that questioned women about their diet. It found a positive association between total milk intake, skimmed milk intake, and acne.
However, the study was limited because it relied on the participants self-reporting their own diet over a period of at least a decade before the study. It is also important to note that this study found an association and not a causative link between cow’s milk and acne.
A prospective study of 6,094 girls found a positive association between acne prevalence and total milk consumption. A similar study of 4,273 boys of the same age found only a weak association between acne and skimmed milk and no association between acne and full-fat milk.
Two small studies³ looked at the diets of a group of participants who had acne compared to a control group and found that the group with acne consumed significantly more milk. Again, this was an association, and no causal link was found.
Before clearer medical recommendations can be made about whether or not omitting milk from your diet will improve your acne, more research needs to be done to establish a causal link.
Some studies have shown an association between diets low in fish consumption and increased acne severity. Based on this, a small randomized controlled trial was conducted on 45 participants with mild to moderate acne that compared the effects of taking an omega-3 fatty acid supplement and a placebo over ten weeks.
The study found that the group taking the omega-3 supplement experienced a significant reduction in both inflammatory and non-inflammatory acne. While it was a small study, it indicates that a diet high in fish or omega-3 fatty acids could potentially prevent acne.
While there is a lot of anecdotal information about how diet affects acne, the medical evidence is currently limited. Many of the studies assessing the effect of certain foods on acne have been unreliable or involved small sample sizes.
However, evidence indicates an association between a low-GI diet and reduced acne. An association has also been shown between cow’s milk intake and the severity of acne, but more research is needed to prove a causative link.
Increased fish intake or fatty acid supplementation may have a role in acne prevention, but larger studies are also required to confirm or negate this.
If you are wondering whether your diet may be affecting your acne or if changing it could improve your condition, you could look at whether any particular foods seem to trigger or worsen your acne. If you identify a possible culprit, try omitting it from your diet for a while to see if you notice an improvement in your acne.
Glycemic index chart: GI ratings for hundreds of foods | University Health News Daily
Can the right diet get rid of acne? | American Academy of Dermatology Association