What is acne?
It’s very frustrating, and can cause people a lot of anxiety. We link it to our age, hormones, our diets and mental state. In this article we’ll explore some of the scientific evidence behind acne and these factors. How does he scientific community define acne? In the literature it is referred to as a chronic (long-lasting) inflammatory disorder.
Tiny glands in the skin called sebaceous glands are affected by a variety of factors that can cause acne.
Sebaceous glands produce sebum. Sebum is an oily, waxy substance, and its main function is to moisturise our skin as well as make it water proof (-ish). Acne typically affects the sebaceous glands that respond to hormones. Not all sebaceous glands respond to hormones.
Unfortunately not just hormones affect our skin. Stress, environment, genetics, body weight as well as our diet has an impact. We’ll briefly touch on all of these aspects.
Why is acne an issue?
The long and short of it. Acne, spots, pimples, whatever you call them can affect our mental health long term. They are common during teen years and may linger in to adult hood.
Whether it is from having ‘bad’ skin as a teenager, adult acne, or the scars some people are left with. It’s not fun to deal with, and can cause mental health issues.
Almost half of high school students with acne (45%) have social phobia (anxiety) according to a systematic review. Having acne leads to a significant increase in depression and anxiety. Learning about evidence-based ways of dealing with acne could be beneficial for some in terms of managing mental health. A healthy diet also goes a long way to improving our mental health.
Current evidence behind what effects skin
Adolescents go through lots of changes due to their hormones, acne is also caused by some of these hormones. Recent literature has pinpointed insulin, insulin-like growth factor-1 and androgens as the main insstigators.
NB: You don’t want to get rid of these hormones, but they may be out of balance. Bringing them into balance may help reduce acne flare ups.
Hey that sounds familiar! And diet related…. Insulin is the hormone of plenty, a good descriptor as it’s a visual reminder of when Insulin is released into the blood. Insulin is released when you have access to food, aka a time of plenty.
What foods cause insulin to be released? Carbohydrates, which are usually part of every food, even if that food is more fat or protein, it will still be bound up with some carbohydrates. Increased production of insulin is associated with the western diet. We will touch on this and the diet connection later.
Insulin-like growth factor-1 (IGF-1)
This guy increases androgen hormone production, it also changes some rather long-winded technical sounding hormones that increase triglycerides (fats) and the desaturation of some fatty acids in the sebum. Sebum is secreted by sebaceous glands. This can increase inflammation and causes acne to form.
What foods increase insulin and IGF-1?
Foods that increase insulin are all foods containing carbohydrates, while foods that increase IGF-1 include milk and dairy products, this may also include whey protein supplements.
Insulin and IGF-1, both activate something called PI3K. PI3K is an intracellular (inside the cell) pathway, P13K activation leads to the production of androgens. We don’t have to worry about specifics the key take away is the end result, which leads to increased production of cells in sebaceous glands. Increasing of cells in the glands also linked to acne.
Considered the main trigger of acne in puberty, androgens and IGF-1 have a close relationship. IGF-1 increases androgen production.
Androgens, according to a 2014 study increase sebaceous glands size, as well as stimulating sebum production. Research has also found that acne prone skin has more receptors for androgens. Receptors are little molecules that are like key holes (molecules are very physical) and fit the the specific key shape of androgens. Androgens will slot into the little key hole shape specifically for them.
If two people produce the same amount of androgens, but they have different number of androgen recpetors, we get two different results.
Person A has more receptors, and as such may get more incidences of acne.
Person B has less receptors, and will have less incidence of acne. The take away from this is, you may not produce more hormones than the next person (although we are all different), it may literally be skin deep. There may be more receptors. Because of this diet may be more of a concern, as well as skin care routine.
Estrogen, progesterone and polycystic ovary syndrome (PCOS)
Women who live with polycystic ovary syndrome (PCOS) are more likely to experience acne.
The main hormone perpetrators in PCOS are:
- too much lutenizing hormone compared to follicle stimulating hormone
These imbalances cause an increase in the production of androstenedione. Androstenedione is an androgen hormone that can be changed into testosterone or some oestrogens.
Women who live with PCOS may also have low progesterone, while the roles of oestrogen in PCOS and acne still remain unclear. More research in this area needs to be done.
Unsurprisingly we can see that sex hormones and hormones we associate with diet are connected. A healthy diet, steering clear of smoking, alcohol and trying to do more resistance training are all great methods for women to manage PCOS.
Whether stress can cause acne is unclear. It can worsen acne, this is apparently an issue more for western women over 25. Further research in this area needs to be done however researchers acknowledge a link between stress maybe causing and exacerbating acne.
Vitamin D and sun exposure
Connections have been made in cohort studies, linking acne with vitamin D deficiency. The sun is the quickest way to top up vitamin D. People should remember that all sun exposure needs to be done safely.
Oral vitamin D tablets are very safe, and in some countries like Australia and New Zealand may be safer than UV exposure. Most weather apps let you know when UV is at its lowest. Why is it recommended that people get sun exposure when UV is low? Because it is the safest time.
There are suggestions of a link between coeliac disease, a genetic autoimmune and auto-inflammatory disease and acne. However further research in this area needs to be done.
This makes sense as undiagnosed or treated coeliac disease will put someone in a constant state of inflammation. As we defined acne earlier, as a condition of chronic inflammatory condition, we can conjecture there is a link between constant inflammation causing acne.
Obese and overweight
Directly linked with PCOS, and insulin resistance, obesity is also linked with increased prevalence of acne. Obesity is also linked with a state of constant inflammation.
According to a very recent systematic review, a high glycaemic load is the most likely reason for an acne flare up.
It also points to weaker evidence connecting dairy intake and acne. Some studies suggest the dairy connection is due to skimmed milk alone, while others suggest it is because dairy products can increase IGF-1.
Another review points to saturated fat also causing acne flare-ups.
A 2017 study in the journal Medicine points to the Western diet as a cause of acne. What does the Western diet look like?
High intakes of:
- meats and processed meats
- pre-packaged foods higher in salt, sugar and fat
- fried foods
- high fat dairy products
- refined grains
- corn and high fructose corn syrup
- high sugar drinks
Is all of this bad for you? Not at all, it is important to note that the study specifies ‘high intakes’. Eggs and lean meats are not a problem when eaten in moderation alongside whole foods such as vegetables, and at least two serves of fruit a day.
High fat dairy is usually not an issue when included in a healthy diet, and low-fat options are readily available. People should always check low-fat dairy products in case any sugar has been added.
Processed and pre-packaged foods will usually be higher in sugar, saturated, trans fat and salt as well as the refined grains. Foods that contain added sugars, or foods that have had extra processing are digested very quickly, causing a person’s blood glucose levels to rise. To counter the western diet, people can adopt a low glycaemic diet.
Insulin and blood glucose
As mentioned, recent evidence suggests there is a link between acne and insulin. What does insulin actually do to our blood glucose? We require a fairly steady blood glucose level, too much glucose in the blood is hyperglycaemia, and too little is hypoglycaemia. Both are dangerous to be in, and could lead to hospitalisation.
When our blood glucose levels rise, our body produces insulin, to drive the glucose into tissues that need energy. If the body cannot use the glucose for energy, it is then stored as fat.
The release of insulin happens every time we eat, and is normal. People who eat too much, too often or are insulin resistant, the body is in fact producing too much insulin, to constantly normalise lower blood glucose levels. This can lead to insulin resistance.
What is insulin resistance?
Insulin resistance is when a persons body becomes resistant to insulin. All tissues in the body that require glucose for energy have special insulin receptors on the outsides of their cells. Like other receptors, the insulin receptors are specific key hole shape, and insulin is the only key that fits that shape.
Insulin resistance causes some of these receptors to become faulty. Which means when insulin is released from the pancreas, it cannot bind properly to receptors.
The receptors are faulty, and the cells cannot take in the glucose they need. As the tissues cannot activate glucose transporters, which would bring glucose out of the blood and into the tissue. This whole process leads to elevated blood glucose levels.
So we have a two fold issue, either people are eating a western diet, and perhaps too much and lots of insulin is being dumped into the body to deal with the raised blood glucose which then starts a chain of chemical reactions that leads to overactive sebaceous glands.
Or, people are insulin resistant or become insulin resistant and the body has to produce more and more insulin to deal with the blood glucose and then the chemical reactions leading to acne occur. It can also be both!
What if you are insulin resistant or your diet isn’t great?
Change of diet.
Following a low-glycaemic diet as well as exercise will help in this area. The low glycaemic diet will make sure the release of glucose into the blood stream happens at a slow and steady pace, allowing insulin to deal with it, and hopefully reducing the bodies need to dump loads of insulin into the blood stream.
Acne is considered a risk indicator for people who are insulin resistance and obese. Adults with acne may find it useful to get their fasted blood glucose checked to see if insulin resistance is a concern, or if it is hormone related acne.
What does exercise do? Exercise stimulates glucose transporters to the surface of muscle tissue. Now those muscles can take in glucose from the blood. No insulin required (magic).
Exercises that specifically build muscle are really good for this, as it increases muscle mass and muscle cells. By exercising more and including resistance exercises (with weights or body weight), people can build insulin sensitivity (the opposite of insulin resistance). This happens because more muscle cells mean glucose transporters.
People can try a variety of exercises such as:
Yoga, weight training, Pilates, or boxing for something a bit more intense.
How to reduce androgens
People do need androgens, so we shouldn’t try to eliminate them, if you do have too many then specific eating patterns can help.
Androgens include testosterone, and the precursor for the hormone oestrogen. A study looking at people with elevated androgens found a low glycaemic diet helped lower androgen levels to a normal range. This study is from 2008 so it is quite old. As a low glycaemic diet seems to be the recommendation for treating acne it at least seems consistent with the evidence.
Another option is to increase foods that contain dietary phytoestorgens, as they can reduce testosterone levels. Phytoestrogens are found in these foods:
- soy products in the form of isoflavones
- chaste tree from the vitex genus, can be found in supplements (check with a doctor before taking)
- most fruits and vegetables and whole grains
What does all this mean? Overwhelmingly, if acne is hormone related, the evidence points to a low glycaemic diet and low dairy. If it isn’t hormone related, this method may also be effective.
Before cutting out dairy products such as milk, there are some important considerations. Milk is an excellent source of calcium, which is an important mineral for our bones and bone density.
Some populations groups will become vulnerable if they cut out dairy completely:
- pregnant and breastfeeding mothers
- infants, children and teenagers, as this is the most important period for developing good bone density
- anyone with osteoporosis or a below average bone density
- women who have had a hysterectomy or been through menopause
- older adults, due to age related de-mineralisation of bone
If acne is an issue and you are included in one of these groups, think before cutting out milk. Other options also include taking a calcium supplement, always consult a doctor before adding any supplements to the diet.
The evidence around diet and acne is not always clear, however some simple lifestyle changes may help reduce acne flare-ups
A low glycaemic diet is essentially a very healthy diet, focusing on lots of whole foods, especially vegetables, fruits, legumes and whole grains, as well as lean proteins, some dairy as well as nuts and seeds.
Other lifestyle factors such as managing stress, getting enough vitamin D and maintaining a healthy weight will also help.
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