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 at the dermis level and eventually deform 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, although its area of occurrence depends on each individual's anatomy. While cellulite poses no health risk, it is often deemed unattractive. It almost exclusively affects 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, whereas only an average of 1 in 50 men develop cellulite. This can be largely explained by the difference in fat mass between men and women: approximately 15% in men compared to 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 presents itself as a soft and non-painful dimple. It results from an excess storage of subcutaneous fats. These accumulate in the adipocytes, leading to an hyperplasia of these cells, or their proliferation. The hyperplasia of adipocytes is usually followed by their hypertrophy, that is, 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 in the hypodermis. The water retained in the skin tissues forms swellings and oedemas. 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.

• The 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 fibres surrounding the fat cells. This phenomenon is caused by the glycation of these fibres, that is, the deposit of sugars on their surface which 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 at the origin of dimples.

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

• Hereditary Factors:

  Heredity plays a role in the formation of adipose, aqueous, or fibrous cellulite. Indeed, certain genes determine a person's predisposition to store fat, and their ability to get rid of it 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 fat 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 fibres decreases and they 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. A imbalance between the levels ofoestrogen 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 excessively high in fats.

  An excessive intake of fats encourages 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 restricts its elimination. This can lead to a venous insufficiency and promote the development of water-based cellulite.

• An excessively sugary diet.

  The consumption of numerous sugary products contributes to the deposition of sugars on collagen fibres and to the phenomenon of glycation. The fibres 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.

• The wearing of overly tight clothing.

  Wearing unsuitable clothing can disrupt venous return. When the veins lose their elasticity or the valves, which prevent the blood from flowing backwards, become less efficient, the microcirculation slows down. The blood stagnates in the lower limbs, resulting in the dilation of the blood vessels and an increase in their porosity. An unusual migration of water carried by the blood to the cells is then observed, causing the tissues to swell. This manifests as the appearance of cellulite.

• Stress.

  When we are stressed, our body synthesises 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 therefore seeks to expand 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).