Can Fast Food Cause Acne

Do fat and sugar make pimples sprout?

NEW YORK. When Christmas is over and all the pralines, cakes and chocolate lice have been eaten, the after-effects of this gluttony made up of lots of sweet and greasy foods are often noticeable on the skin.

Sebum-filled pimples sprout unconcernedly on the face as they usually do not all year round, as if the body wanted to get rid of the excess fat and carbohydrates in this way.

Doctors made such observations more than a hundred years ago in adolescents when, thanks to industrialization, an ever larger part of the population was able to afford food that was high in sugar and fat.

And researchers have always found such consequences when indigenous peoples who did not know acne adopted a western lifestyle or the poor rural population moved to the city.

So it was suspected at a very early stage that there was a connection between acne and diet and it was recommended that severely affected pimple faces be more reluctant to feast on sweet and fatty foods.

However, as is well known, observations and personal experiences do not provide any scientific evidence for a long time, even if everyone believes they have already had such experiences.

So from a scientific point of view, what speaks for the fact that sweet fat in acne causes pimples to shoot out of the skin like a warm autumn rain mushrooms out of the forest floor?

Sebum bags under a magnifying glass

Strictly speaking, very little if you take the unwanted sebum bags under the microscope with the strict criteria of evidence-based medicine, have now found nutritionists working with Jennifer Burris from the University of New York.

There have been more than enough studies on the subject in the past hundred years, but most of them were methodologically so bad that one would rather spread a cloak of silence over them.

After all, after analyzing numerous databases, the US researchers found 27 studies that were worth a look (J Acad Nutr Diet 2013; 113 (3): 416).

In the 1920s, for example, it was believed that chocolate was not exactly cheap for pure skin. At that time, researchers recognized that this sugar and fat mixture increased blood lipid levels.

They suspected that the sebum glands also increase oil production as a result, making acne worse. In the 1930s there were reports of impaired glucose tolerance in acne patients, whereupon they were urgently advised to reduce their carbohydrate consumption.

First observation and case-control studies in the 1940s and 50s also indicated a connection between acne and high milk and fat consumption.

However, there was a lasting turning point in the 1960s, reports Burris' team.

In an experimental study in 1961, researchers found no improvement in acne with a reduction in carbohydrate consumption, nor could they determine any impaired glucose tolerance, and in a case-control study from 1967 there were no differences in sugar consumption between acne patients and healthy controls.

A study from 1969, which has been cited again and again, had a particularly large influence: in a double-blind, cross-over study, the study participants with mild to moderate acne were given an additional ration of chocolate or "placebo" over a period of four weeks.

After a short withdrawal phase, chocolate was exchanged for a placebo. The result: The researchers did not find any differences in the course of acne in either group.

However, the fat and sugar content of the "placebo bar" was no different from that of the chocolate. The study only found that the cocoa in chocolate does not cause pimples, but these and similar studies have been incorrectly cited over and over again as evidence that diet does not affect acne, writes Burris. The result: for over 40 years, the connection has hardly been investigated further.

Sugar and fries rather unfavorable

Only in the new millennium did researchers venture into the topic again. The triggers were large cohort studies, with which the connections between lifestyle and illnesses were raised to a new level of evidence.

With these data, the influence of diet on the incidence and course of acne could also be re-examined. In three such studies with almost 50,000 participants, the acne rate was significantly increased with high milk consumption.

Since these studies also have numerous limitations and sources of error, Burris et al. Do not see sufficient evidence to warn against milk in the case of acne.

The evidence on the influence of carbohydrates looks a little better. A team of researchers carried out several intervention studies on this a few years ago. For a few weeks, the participants were fed food that had a high or low glycemic load, i.e. either a particularly high or low amount of easily blood-permeable carbohydrates.

With a low glycemic load - i.e. little sugar and french fries - the acne actually weakened, and the insulin sensitivity also improved. Finally, concentrations of hormones and growth factors that promote sebum production were also lower than with a high glycemic load.

However, the participants with the low glycemic load also lost significant weight, which may have skewed the result. Even so, Burris and co-workers see these studies as the most compelling evidence to date of the benefits of a low-glycemic diet for acne.

The results were confirmed in a study from 2012. With a low glycemic load, both inflammatory and non-inflammatory skin lesions decreased and the size of the sebum glands decreased regardless of weight changes.

Diet recommendations make little sense?

In contrast, modern studies on fat consumption and acne are less consistent. In surveys and cohort studies, some study authors found that fatty fast food worsened acne, while others found no effect.

Fish appeared to have a protective effect in some studies, but omega-3 fatty acids showed no benefit in others.

After reviewing all of this data, Burris and her team assume that the diet does not trigger acne, but does influence its course.

Sweets and foods with a high glycemic index seem to have a particularly negative effect on sebum production, as does milk, although it is still unclear whether hormones, fat or milk proteins cause the pimples to grow.

However, nutritionists still do not see enough evidence to provide specific recommendations on diet for acne. As is so often the case, many more questions would have to be clarified in further studies.

Maybe the chances are not bad that you will be a little wiser at least by the end of this century.

Until then, you can continue to rely on your experience and trust that maybe not the acne, but at least the Christmas pimples will go away again if you can't see any chocolate or sweets for the next few weeks after the annual gluttony. (courage)