Why do we have cellulite?

Cellulite is also referred to as superficial lipodystrophy. It is a abnormal accumulation of fats, water, or toxins . When these clusters enlarge, they form protrusions in the dermis and eventually distort it, giving the skin a grainy appearance. This results in the formation of dimples . The accumulation of fats or water occurs in the deep layer of the skin: the hypodermis. Once established, it is very difficult to eliminate cellulite.

Cellulite primarily appears on the thighs, buttocks, hips, and arms, but its area of occurrence depends on each individual's anatomy. While cellulite poses no health risks, it is often deemed unattractive. It affects almost exclusively women, among whom doctors consider it a normal physiological phenomenon. Indeed, nearly 9 out of 10 women are affected by it at some point in their lives, while only an average of 1 in 50 men develop cellulite. This can be explained, in part, by the difference in fat mass between men and women: approximately 15% in men versus 25% in women.

There are three types of cellulite : the cellulite adipose, the cellulite aqueous and the cellulite fibrous. Different forms of cellulite can also coexist: we then speak of cellulite mixed.

• Adipose cellulite manifests as a soft, painless dimple. It results from an excess storage of subcutaneous fats. These fats accumulate in the adipocytes, leading to an hyperplasia of these cells, or their proliferation. The hyperplasia of adipocytes is usually followed by their hypertrophy, meaning their swelling. The change in structure of the fat clusters distorts the dermis and impacts the appearance of the skin: it becomes "dimpled" and adipose cellulite sets in.

• The appearance of water cellulite is a result of water accumulation between the adipocytes of the hypodermis. The water retained in the skin tissues forms swellings and edemas. This type of cellulite is often located in the lower limbs (thighs, calves, and ankles). Water cellulite is primarily caused by a dysfunction in the venous and lymphatic circulations. The elimination of water and toxins is slowed down, causing them to stagnate in the connective tissue and distort the skin.

• Fibrous cellulite is embedded, hard, and painful to the touch. It sometimes takes on a purplish hue. The appearance of fibrous cellulite is due to the hardening of collagen fibers surrounding the fat cells. This phenomenon is caused by the glycation of these fibers, which is the deposition of sugars on their surface that alters their structure and leads to a loss of their function. When they harden, the skin is pulled downwards, which compresses the fat cells between the partitions of the hypodermis, forming skin depressions that are the origin of dimples.

Several internal factors can be responsible for the development of cellulite:

• Heredity:

  Heredity plays a role in the formation of adipose, aqueous, or fibrous cellulite. Indeed, certain genes determine a person's predisposition to store fats, and their ability to get rid of them more or less easily. The ATXN1 and UBE2E2 genes are particularly involved in adipogenesis, that is, the formation of adipocytes. A person who tends to store fats easily is thus more likely to develop adipose cellulite. Genetics can also promote the appearance of aqueous cellulite: the strength of veins and lymphatic vessels, closely linked to the efficiency of circulation, is partly dependent on our genetic heritage.

• Age:

  With age, we observe an increase in factors that cause cellulite, among which are a less efficient venous and lymphatic circulation and a progressive loss of the skin's mechanical properties. The synthesis of collagen fibers decreases and these become more rigid, due to the effect of glycation, which also reduces the elastic properties of elastin.

• Hormonal changes:

  During menopause, the production of progesterone tends to decrease. An imbalance between the levels ofestrogen and progesterone then occurs and can be responsible for an increase in the permeability of blood capillaries. An abnormal flow towards the adipose tissues is observed, which promotes the accumulation of water in the hypodermis and the appearance of aqueous cells.

• A diet too high in fats.

  An excessive intake of fats promotes their accumulation in adipocytes, leading to the emergence of adipose cellulite.

• An excessive consumption of salt.

  When tissues have a high concentration of salt, they attract and retain water, which limits its evacuation. This can be responsible for a venous insufficiency and promote the appearance of water cellulite.

• An overly sugary diet.

  The consumption of numerous sugary products contributes to the deposition of sugars on collagen fibers and to the phenomenon of glycation. The fibers are then likely to harden and form dimples.

• Sedentary lifestyle.

  Engaging in regular physical activity helps to regulate the balance between fat intake and fat expenditure. Moreover, remaining sedentary for extended periods increases the risk of developing a venous insufficiency and can lead to water retention.

• Wearing overly tight clothing.

  Wearing ill-fitting clothing can disrupt venous return. When veins lose their elasticity or the valves, which prevent blood from flowing backward, become less efficient, microcirculation slows down. Blood pools in the lower limbs, resulting in the dilation of blood vessels and an increase in their permeability. An unusual migration of water carried by the blood to the cells is then observed, causing tissue swelling. This manifests as the appearance of cellulite.

• Stress.

  When we are stressed, our body synthesizes cortisol, a hormone that promotes water retention and fat storage. Indeed, cortisol stimulates the synthesis of glucose by the liver from glycogen reserves. This then increases the blood sugar level. When stress is a daily occurrence, the body needs to increase its energy reserves to cope: it then seeks to develop its fat mass by amplifying the fat storage capacity of adipocytes.

• Tobacco.

  Nicotine, found in cigarettes, tends to cause vasoconstriction of the capillaries and disrupt microcirculation. The risk of developing aqueous cellulite is increased.

• VERGNANINI A. & al. Cellulite: a review. Journal of the European Academy of Dermatology and Venereology (2002).

• JIMENEZ REJANO J. Cellulite's aetiology: a review. Journal of the European Academy of Dermatology and Venereology (2013).

• KAMINER M. & al. Insights into the pathophysiology of cellulite: a review. Dermatologic Surgery (2020).