Many people think that acne is a natural result of being a teenager. Yet the teenagers in many parts of the world are remarkably free of acne. The low rate of acne in those populations is not due to their genes. It is due to their low-fat, heavily plant-based diet. When people from those countries grow up in the United States, they generally eat a typical American diet which is rich in fat and animal-source foods. As a result, they too tend to get acne in their teenage years.
The rich, fatty, American-style diet increases your risk of acne. It supplies a lot of fat, which can make your skin oily. It also contains lots of animal-source foods, which can lead to an overload of two types of hormones: male sex hormones (androgens) and a growth hormone called insulin-like growth factor 1 (IGF-1). These two hormones work together to cause acne. That’s why acne tends to start when children go through puberty.
What is acne?
Acne arises in the hair follicles (pores). Part of the problem is that the oil glands in the pores produce too much oil. Another part of the problem is that the skin cells that line the pores divide too fast. (That problem is called hyperkeratosis.) As these extra skin cells die off, they are shed into the pore. There, they combine with excess oil to block the pores. One of these blockages is called a comedo. (The plural form of the word is comedones.)
A closed comedo, or whitehead, is covered by a layer of skin cells. In contrast, a blackhead is an open comedo. The tip of the open comedo turns dark because it is exposed to oxygen. The blackhead might look like dirt embedded in the skin, but the blackhead was actually produced in the pore.
The role of bacteria
A bacterium called Propionibacterium acnes can feed on the oil and protein in the comedo. If the skin is very oily and is shedding a lot of dead skin cells, the Propionibacterium acnes can multiply rapidly. These bacteria produce enzymes to digest the oil and dead skin cells in the comedo. However, these enzymes can also attack the live cells of the skin. This damage will cause inflammation and will attract white blood cells. If a large enough number of white blood cells gather in an area, they become visible as pus. The resulting pimple is a pustule.
In a particularly bad pimple, the infection goes deep into the skin, causing a cyst: a red, tender bump that can be filled with pus. A bad case of acne can lead to severe, permanent scars. A case of acne may be only skin-deep, but it can cause severe suffering at a time in life when people are emotionally fragile.
Treating the symptoms of acne
For many patients, the first step in managing acne is to apply some sort of product to the skin. These treatments can work in several different ways:
- Reduce the amount of oil produced in the pores (sebostatic effect)
- Suppress the growth of the cells that line the pores (antihyperkeratotic effect)
- Remove or break up the comedones, so that they stop blocking the pores (comedolytic effect)
- Kill bacteria, such as Propionibacterium acnes (bactericidal effect)
Note that some products can have more than one of these effects. For example, benzoyl peroxide has sebostatic, comedolytic, and bactericidal effects. In contrast, the mechanism of action of some acne medications, such as tretinoin (Retin-A) is uncertain.
Sometimes, people take pills to treat acne. Antibiotics can kill the bacteria that are causing inflammation. If a severe case of acne is not responding to other treatments, the doctor may prescribe a drug called isotretinoin (Accutane). Accutane is highly effective against acne. However, it can cause severe side effects, including suicidal depression. Accutane can also cause severe birth defects among the babies of women who took even a small amount of it during pregnancy. For this reason, Accutane is available only through a program that is designed to ensure that pregnant women never take this product and that women do not become pregnant while taking the product.
Removing the cause of acne
Before you consider taking pills to control your acne, you may consider switching to a healthier diet. A low-fat, plant-based diet works in two ways to fight acne.
- It reduces the amount of oil produced in the skin.
- It reduces your skin’s exposure to anabolic (growth promoting) hormones.
The rich, fatty American diet, with its heavy emphasis on animal foods, promotes acne for the following reasons:
- It contains lots of fat. Most of the oil in your skin came directly from the fat in your food.
- Animal products, even if they are organic, contain the animal’s natural hormones. In particular, dairy foods contain a lot of estrogen because a lot of the milk comes from pregnant cows.
- The heavy load of animal protein provides a big dose of an amino acid called leucine. This big dose of leucine causes your liver to produce large amounts of a growth hormone called insulin-like growth factor 1 (IGF-1).
Why vegans get less acne
A low-fat, plant-based diet tends to suppress acne:
- Plants do not have the same hormones that animals have. As a result, you won’t get a big dose of steroid hormones from your food.
- Plants do contain some substances that have an estrogen-like effect. However, these phytoestrogens tend to be weaker than your body’s own estrogen. As a result, they can actually end up decreasing the effect of your body’s own estrogen.
- Plants contain dietary fiber, which helps you excrete excess steroid hormones.
Because there is less oil and less overgrowth of skin cells, the pores are less likely to become blocked. Also, there is less oil and protein to feed the Propionibacterium acnes bacteria. As a result, the skin clears up naturally.
A low-fat, plant-based diet is also good for people who don’t have acne. Excess fat in the diet can also lead to clogging of the arteries, which can lead to heart attacks and strokes, which are major causes of death and disability in the United States. Excess amounts of the anabolic hormones (including the sex hormones and IGF-1) can also increase the risk of many cancers, especially cancers of the breast and prostate. That is why breast and prostate cancer are rare in the societies that are also largely free of acne.