1. What does sugar in diet do to our skin?
Sugar in diet is measured by the Glycemic Index (GI)– a value assigned to foods based on the effect they have on your blood sugar levels. Studies have suggested that diet, particularly dietary GI, may aggravate existing moderate-cystic acne. A high GI diet increases sebum production, contributing to acne formation. Additionally, high-glycemic foods can also accelerate aging theoretically via an increase in the breakdown of collagen fibers, a process known as glycation.
2. How exactly do low and high (GI) sugar in diet affect the body?
This is how sugar in diet works – carbohydrates with a low GI value are more slowly digested and absorbed, causing a lower and slower rise in blood sugar and, therefore, insulin levels. Conversely, consuming carbohydrates with higher GI translates to higher blood sugar and insulin levels. Insulin is a hormone responsible for the decrease in blood sugar levels. It also stimulates the synthesis of another group of hormones (known as androgens) which leads to high sebum production, a recognized correlation to acne severity.
3. How much sugar is too much, or should we cut it out completely?
I think it is very important, as part of a balanced diet, to incorporate all elements of the food pyramid. In my personal view, the presence of sugar in diet with natural foods such as fruits and honey is not something that is harmful. In fact, these sugars are essential for our body’s nutrition.
The problem arises when sugar is consumed in excess or when it is consumed in the form of refined artificial sugars. This is because one can easily down a lot more sugar without feeling full, for instance when one consumes a cake or a baked item. On the other hand, the amount of sugars present in natural fruits will lead to one feeling full before one consumes a real excess of it. The key thing here is balance. In terms of the actual scientific evidence, there are some conflicting viewpoints regarding this issue.
The main thing is that excess sugar in diet can definitely trigger conditions, such as metabolic syndrome which comes with an increase in risk of cardiovascular mortality and other conditions like diabetes. Another thing to take into consideration is inter-individual differences in metabolism and genetics.
The lifestyle of the individual plays a part as well. For example, someone who is very athletic would naturally need more sugar in diet for metabolism. Meanwhile, someone who is sedentary needs minimal calories in their diet and having excess sugars will just contribute to calorie intake and in turn obesity which is a risk factor for worsened skin diseases. Overall, I would strongly recommend a well-balanced diet and the limiting of artificial sugars as there are innate health risks with high sugar diets which include an increased risk of developing diabetes and pre-diabetes.
4. Is eliminating added sugar in diet effective for rosacea-prone skin?
Medical studies have not conclusively proven the link between a high sugar diet and the worsening of existing conditions, such as rosacea and eczema. Most of the studies have been focused on the role of a high sugar diet for patients with existing moderate to severe acne.
Theoretically, high sugar content does promote an inflammatory state and both rosacea and eczema are linked to underlying inflammation. Although there is a theoretical possibility that it could lead to worsening of the condition, it is not proven at this juncture. In fact, a German study specifically ruled out the worsening of eczema due to a high sugar diet.
In my personal clinical practice, I have not observed any such links. I do not routinely advise dietary modifications for people with these conditions. For acne however, I do recommend reducing the presence of trans-fat, dairy products and high sugar foods simply because they can potentially slow down the recovering process. Nevertheless, treating acne with dietary modifications alone does not work. It is more of an adjunct to medical treatments.
5. What are some guidelines to follow, if people do decide to reduce their sugar intake? For instance, is there certain fruit we should avoid, is alcohol a no-go too?
First of all, take sweets in moderation. This includes candies and baked goods which are particularly high in sugar content. Secondly, be aware beverages contain sugars as well. I would stick to plain water and perhaps an occasional natural fruit juice that doesn’t contain added sugars. However, diet alone is not sufficient. It is important to understand that you would need some form of energy output instead of just input. I would recommend an active lifestyle with a minimum of three exercise sessions a week, each with a duration of at least 20 minutes.