Ever wonder why some teens and adults can do everything ‘right’ – eat great, wash their faces, etc. – and still have acne?
While others can eat pizza three times a day, shower once a week — and end up with perfectly clear skin!
Yep, you guessed it. Genes are important when it comes to acne.
A 2013 study puts the cost of acne treatment in the US alone at over $3 billion /year. [ref] About 80-95% of teens deal with acne, and over 40% of adults in their 20s are still struggling with it. [ref]
Moderate to severe acne affects 20% of teens. Researchers estimate that acne is about 80% heritable, so there is a strong genetic link to the susceptibility to acne. [ref]
There is no single gene that causes acne. Rather, there are multiple genetic variants (small changes in a gene) that increase the risk of acne — when combined with the right environmental factors.
There have been quite a few studies digging into the genetic variants that may increase the susceptibility to acne. These genetic studies tell us a lot about the root causes of acne, and they also point towards several solutions.
There are four factors that you need for acne:
All four of those come together in acne.
The bacteria P. acnes is a common resident on most people’s skin. P. acnes is referred to as Cutibacterium acnes in some newer studies. The use of antibiotics to eliminate P. acnes has given rise to strains that are now resistant to common antibiotics. [ref]
For male teenagers, increased androgen hormones lead to excess sebum.
I’ve always ‘known’ that teens get acne due to their poor diet, but it turns out that diet may not be as big a factor as I thought. (A lot of things that I’ve always ‘known’ turn out not to be backed by a lot of science!)
The studies on dietary factors that cause acne are not all that convincing when it comes to solid results. Many studies are inconclusive or contradictory.[ref]
Here are a couple of dietary links with acne that seem to be backed by several studies:
According to a meta-analysis, dairy intake increases the risk of acne by about 25-40%, depending on the frequency of dairy consumption.[ref] So why would dairy matter? One theory is that it upregulates mTOR and IGF-1 due to its amino acid composition. [ref]
But… not all studies on dairy and acne agree. This may be due to population differences and whether as adolescents/adults they are likely to still produce lactase (the enzyme that breaks down lactose in milk). A Danish study (with 93% of participants producing lactase as adults) found that dairy consumption decreased acne only in people who still produced lactase. [ref]
In general, people of Asian descent are much less likely to produce lactase as an adult. So the meta-analysis results on dairy may be more accurate in populations that tend to not produce lactase. The majority (over 90% usually) of people of Northern European heritage still produce lactase. Other population groups vary between those two extremes.
What about sugar? Everyone knows that sugar is the devil…
Instead of being able to directly point a finger at sugar, it seems that insulin resistance may be a problem with acne. In a study comparing teens with acne and without, their fasting blood glucose levels were actually very similar. Interestingly, though, insulin levels were higher in the group of teens with acne compared to those without.[ref] Thus a diet with a high glycemic load (whether sugar or other highly processed foods) may play a role in acne. An individual’s response to sugar and starch may be important — e.g. two people can eat the same diet and have a different glycemic response.
Not getting enough vitamin A in your diet could also increase the risk of acne. A new study shows that vitamin A is important in the skin’s defense against pathogens, such as P. acnes. [ref] Vitamin A derivatives, known as retinols, are often used topically for acne. [ref]
In addition to the role that genetics plays, the epigenome also comes into the picture for acne. Epigenetics is the study of how genes get expressed – which ones are turned on to be transcribed and translated vs. which ones are silenced.
A recent study used biopsies of acne skin to see which genes were upregulated, or turned on, more than normal. Most of the upregulated genes were in the inflammatory pathways.[ref]
Below are the genetic variants associated with an increased risk of acne that are covered in 23andMe or AncestryDNA. There are other genetic variants and repeated segments of genes that are also linked to acne that aren’t covered by the common sequencing companies.
How can you use this information? Knowing which genetic variants you carry that are associated with acne may help you figure out the solutions that would work best for you
TYK2 gene: codes for tyrosine kinase 2, a signaling molecule involved in the inflammatory response.
Check your genetic data for rs33980500 (23andMe v4, v5; AncestryDNA)
TNF-alpha gene: Tumor necrosis factor, alpha is part of the immune response against pathogens.
Check your genetic data for rs1800629 (23andMe v4, v5; AncestryDNA):
Check your genetic data for rs1799724 (23andMe v4, v5)
CTLA4 gene: cytotoxic T lymphocyte associated antigen-4
Check your genetic data for rs3087243 (23andMe v4, v5; AncestryDNA):
IL1A gene: inflammatory cytokine
Check your genetic data for rs1800587 (23andMe v4, v5; AncestryDNA):
Check your genetic data for rs17561 (23andMe v4; AncestryDNA):
Check your genetic data for rs846910 (23andMe v5 only)
IL6 Gene: interleukin 6 is another inflammatory cytokine. Higher levels of IL-6 are linked with an increased risk of acne.
Check your genetic data for rs1800796 (23andMe v4, v5; AncestryDNA):
RETN gene: produces resistin, which is important in sebum production and inflammation
Check your genetic data for rs3745367 (23andMe v4, v5; AncestryDNA):
Vitamin A deficiency is linked with skin disorders, including acne. Strong, prescription-based retinol is available for treating acne, but the side effects can be severe.
People can convert beta-carotene, from plants, into the form of vitamin A used by the body (retinol). That conversion, though, varies according to genetic variants in the enzyme for beta-carotene conversion (BCMO1). An informal study (not published in an academic journal) found that people who don’t convert beta-carotene to vitamin A very well were more likely to have acne. [ref]
People with a T allele on both rs12934922 and rs7501331 have a 69% decreased conversion of beta-carotene to retinol. For people with only a single T in the rs7501331 SNP, the conversion is decreased by 32%. [ref]
Check your genetic data for rs7501331 (23andMe v.4 and v.5, AncestryDNA):
Check your genetic data for rs12934922 (23andMe v.4 and v.5):
Hormonal changes at puberty trigger increased sebum production.
CYP17A1 gene: This enzyme is involved in steroid hormone metabolism
Check your genetic data for rs743572 (23andMe v4; AncestryDNA):
HSD11B1 gene: this codes for 11β HSD1, which is involved in the production of cortisol
Check your genetic data for rs846910 (23andMe v5 )
LCT gene: codes for whether you produce lactase (the enzyme that breaks down lactose) as an adult
Check your genetic data for rs4988235 (23andMe v4, v5; AncestryDNA):
There are a couple of genetic variants identified by a genome-wide association study that involves the way the hair follicle grows. These aren’t covered on 23andMe.
Check your genetic data for rs121908120 (AncestryDNA only):
Here are some solution options that may work, based on your genetics.
Vitamin A is a fat-soluble vitamin, so taking high doses of vitamin A for long periods of time could lead to toxicity. If you have questions on how much vitamin A, talk with a doctor or get a blood test done to determine your current vitamin A status. (UltaLabs has a serum vitamin A test for $63, and you can usually get a 20% off coupon for your first order.)
Light at different wavelengths has been shown to be effective for reducing bacteria and for reducing the inflammatory response.
Red light therapy was shown in a lab setting to reduce IL-1a in acne. [ref] If you have IL1A variants (above), this may be something to look into.
Light therapy in the blue wavelengths (449 nm, 50 uW/cm2 ) kills the bacteria that causes acne – in a lab setting. [ref]
The majority of studies on light therapy (red-blue wavelengths) show a benefit for acne. [ref] I don’t know that light therapy is a total cure for everyone, but it is a non-pharmacological approach worth checking out.
Bacteriophages, which are viruses that kill bacteria, are one exciting possibility for treating acne. There are phages that have been identified that kill P. acnes. Other bacteria can also weed out an overgrowth of P. acnes. [ref][ref]
There are creams available with bacteriophages that target acne bacteria. Here is a bacteriophage cream on Amazon (not necessarily a recommendation for it – just linking to it so that you can see what I’m talking about).
Hops extract may work as both an anti-inflammatory and as an antibiotic against P. acnes. [ref] While you may be thinking that beer is your best bet for hops… there are hops extract supplements available also.
Low zinc levels correspond with more severe acne, according to one study.[ref] Foods high in zinc include oysters, beef, crab, and turkey. If you think you are low in zinc, there are also supplements available on Amazon. The recommended upper daily limit of zinc in 40mg/day.
Here is an interesting paper on how our modern diet (refined carbs, trans fats, etc) is upregulating mTOR and downregulating FOXO1. The conclusion is that a Paleo-style diet or periodic calorie restriction may help with acne.
*The links to Amazon products are so that you see what is available and not an endorsement. I am a part of Amazon’s affiliate program. Thus, if you buy stuff on Amazon after clicking a link on my website, I will get a small portion of the sale (at no extra cost to you).