Glucose and Healthy Skin: An Introduction
Research shows that persistently elevated glucose levels can both accelerate aging of the skin and create conditions that lead to acne. This means that monitoring glucose levels with a metabolic tracking tool like Levels can provide actionable insights, grounded in personal data that may lead to clearer, more youthful-looking skin.
Aging & Wrinkles
Skin aging and wrinkling are due to a wide variety of dysfunctions in cellular processes. These include the thinning of skin layers, the reduction and diminished function of structural proteins like collagen and elastin, reduced blood flow, decreased pigment production, and a diminishment in cell turnover and replication.
Excess sugar in the body appears to speed up these processes. This is due in part to “glycation,” the process by which a glucose molecule bonds with proteins, fats, or DNA in a cell, forming what are called “Advanced Glycation End products” (aptly abbreviated “AGEs”), with altered ability to perform normal functions.
Glycation can affect tissues all over the body, but the skin is particularly susceptible because of how collagen interacts with sugar. Collagen is the most plentiful protein in the human body, and plays an important role in the structure and resiliency of your skin.
Glycation alters normal collagen function by causing cross-linking of the protein, which results in stiffness of the skin. It also changes the molecular charge of collagen, which prevents the protein from interacting normally with cells and proteins around it. Lastly, glycated collagen is resistant to being broken down, impairing the normal turnover process.This glycation can have long term consequences. Because collagen has a very slow turnover rate (on the order of decades), once it becomes glycated and dysfunctional, the consequences can last for years.
Glycation can affect other proteins in the skin, including vimentin and cytokeratin.These proteins are also critical for structural support of skin cells, but glycation reduces the cells’ ability to contract, preventing the skin from moving properly.
The good news is that there are multiple ways to reduce glycation in the body, including diet and lifestyle changes that support metabolic fitness. In fact, studies have shown that tight glycemic control over a period of just 4 months can reduce glycated collagen by 25%.
The relationship between glucose, insulin and acne is well-established, and elevated glucose and insulin are both implicated in the development of acne.
Insulin and insulin-like growth factor-1 (IGF1) can both contribute to the development of acne. These hormones stimulate oil production in the hair follicle, as well as increase the production and activity of androgens, commonly known as male hormones.
Multiple studies have shown that raised blood sugar also leads to increased acne. A 2007 study followed two groups of male patients between the ages of 15-25 over 12 weeks; the first group consumed a low-glycemic-load diet, meaning diets with less propensity to spike blood sugar. The other group’s diet emphasized carbohydrate dense foods without reference to glycemic index.
The low-glycemic-load diet not only showed a significantly greater reduction in acne lesions, (see Figure 1) but also a reduction in weight and improvements in insulin sensitivity (the ability of the body’s cells to efficiently use available insulin) when compared with the group following the carbohydrate-dense diet.
A 2012 study took this research further by putting participants on a low glycemic load diet for 10 weeks while also taking skin biopsies. The study also included a control group who were instructed to eat high-carbohydrate foods daily. Looking at each groups’ skin under the microscope before and after the intervention showed significant differences.
At 10 weeks, the low-glycemic group had significantly fewer non-inflammatory and inflammatory acne lesions, and (See Figure 2) smaller sebaceous (oil producing) glands. There was also less evidence of SREBP-1, a protein that activates oil production in the skin, and IL-8, an inflammatory molecule – both of which have strong associations with acne.
It’s interesting to note that those who followed low-glycemic dietary recommendations saw significant acne improvements, even without limiting other foods known to contribute to acne, including dairy.
Diets with a high glycemic impact also lead to overactivation of the mTOR genetic signalling pathway, leading to increased oil production and cell proliferation, both of which contribute to acne. The genetic pathways that link glucose and acne are still being uncovered, but they continue to contribute even more insight into how dietary choices can benefit skin health.
The skin is the largest organ in the body, and the health of our skin is a clue to our overall well being. Reducing premature wrinkles and acne is a concern for many, and it’s important to think about the underlying biology when approaching how to prevent and treat these conditions. When we better understand the underlying mechanisms that link glucose, acne, and wrinkles, we have even more reasons to strive for dietary choices that optimize our glucose levels, minimize glucose spikes, and improve metabolic fitness.
Research has shown, however, that two individuals may respond completely differently to the same food in terms of how much their glucose rises, so how do we know what to eat to optimize our glucose levels? Fortunately, continuous glucose monitoring programs like Levels allow us to track our own personal glucose response to various foods and lifestyle decisions and can enable us to more precisely adhere to a truly personalized “low-glycemic” diet. The metabolic awareness we develop by monitoring our own biological information in real-time can aid in optimizing many aspects of our health, including our skin.