Does Greasy Food, Milk or Chocolate Cause Acne?

Answer: Not exactly. At least not in the way you might think.

Anecdotal associations between acne and particular foods like chocolate, ice cream and pizza have been discredited by scientific research.  But research does point to a connection between overall diet and the development of acne symptoms.

The Connection Between Acne and Overall Diet

Researchers have presented compelling evidence that people whose diets include lots of high glycemic index foods (foods that are high in sugar and simple carbohydrates) tend to experience acne at a greater frequency than those who have low glycemic index diets. However, there is no clear scientific consensus on why this connection exists. Some experts believe that high glycemic index diets may have negative impacts on hormone balance and the immune system.

Common Assumptions About Acne and Diet

There many widely held beliefs about the relationship between certain types of food and acne symptoms. Three of the common are:

Assumption #1: Eating Greasy Food Causes Greasy Skin

True or False?: Mostly False. The grease that you eat is not the same grease that makes your skin oily. Genetics, hormones, stress and environmental factors are much more important players than consumption of fatty or greasy foods when it comes to oily skin.

The substance that makes your skin feel and look greasy is not actually grease at all – it is a natural substance called sebum. The purpose of sebum is to moisturize and protect the skin.

Sebum is produced by a specialized structures called sebaceous glands, which are located deep inside of hair follicles. Sebum is produced from the break-down of sebocytes, which are the specialized cells that make up the sebaceous gland. Sebocytes are rich in lipids (fatty acids) and triglycerides (fats and oils). The sebocytes nearest to the hair follicle die and then dissolve, releasing their contents into the hair follicle. The faster the sebaceous gland proliferates (grows), the faster this process of cell death and sebum production takes place, and the more oily the skin becomes. But eating more grease and fat does not necessarily cause this process to happen any faster.

It is also important to point out that oil is a generic term for a diverse class of molecules. The oils (lipids and triglycerides) in sebum are not the same as the oils that you consume when you eat things like fried foods. There are a lot of intermediate steps between the consumption of dietary oil and the synthesis of sebum, and this makes a direct connection between the two unlikely.

Assumption #2: Chocolate Causes Acne

True or False?: Mostly False. Chocolate itself has not been shown to have a direct connection with acne symptoms. There have been at least two studies that directly examined the relationship between chocolate and acne. In both of these studies, the researchers found no correlation between chocolate consumption and acne.

However, many chocolate-containing products are also high in sugar and/or high-fructose corn syrup, and are therefore high glycemic index foods. Research has shown that diets high in sugar and simple carbohydrates may contribute to acne symptoms.

Chocolate is generally a mixture of ingredients, and different kinds of chocolate can have a dramatically different composition of ingredients, such as sugar. It is also possible for people to develop allergic reactions to particular foods, including chocolate, and these reactions can produce acne-like symptoms. However, most cases an allergic reaction would also have additional symptoms including, itching, hives, throat swelling, fever, rash, joint pain, etc.

Assumption #3: Milk Causes Acne

True or False?: Possibly True. There are a handful of studies that suggest a relationship between high levels of milk consumption and increased incidence of acne. The authors of these studies suggest that it is possible that hormones in the milk (or hormones stimulated by milk consumption) may be to blame.

A particular hormone called Insulin Growth Factor 1 (IGF-1) is present in milk may cause changes in metabolism and hormone balance that can impact acne symptoms. IGF-1 is a naturally occurring hormone, and it is present in all animal milks (even products made from animals that have not been treated with hormones).

Whether or not milk consumption actually causes acne symptoms (and whether this is true for all people) remains to be scientifically proven. People have blamed a lot of medical conditions on milk consumption. There is a large group of people who swear that by stopping milk consumption they were relieved of a range of medical problems, from respiratory infections to acne vulgaris. Not all of these claims are going to be true (at lesat for most people).

Milk consumption may also impact the balance of sex hormones, such as androgens and estrogens (male and female sex hormones). Several studies have demonstrated that elevated androgen levels are associated with more severe acne symptoms in some patients. It is also possible that people with certain types of milk allergies could exhibit acne-like symptoms.

In conclusion, there is some evidence that milk may contribute to symptoms of acne vulgaris, but the exact relationship between milk and acne is not well understood. Regardless, for many people it’s worth a shot to cut milk out of their diet for a few weeks and see if that helps improve their acne symptoms.

References

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The Clear Skin Diet. Logan, et al. 2007.
Glycemic Index and Glycemic Load of Foods. DietGrail. 2011.
Eat, Drink, and Be Healthy: The Harvard Medical School Guide to Healthy Eating. Willett, et al. 2005.
A systematic review of the evidence for ‘myths and misconceptions’ in acne management: diet, face-washing and sunlight. Magin, et al. 2005.
Diet and acne: a review of the evidence. Spencer, et al. 2009.
A low-glycemic-load diet improves symptoms in acne vulgaris patients: a randomized controlled trial. Smith, et al. 2007.
Does diet really affect acne? Ferdowsian, et al. 2010.
Effect of Chocolate on Acne Vulgaris. Fulton, et al. 1969.
Milk consumption and acne in teenaged boys. Adebamowo, et al. 2008.
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