Stretch Marks: Are They Caused by Genetics?

Stretch marks are the jagged red, purple, or silver stripes that appear on skin when it’s been stretched suddenly by rapid growth. Our skin is highly elastic, and collagen allows the skin’s surface to stretch during growth. But when stretching happens very rapidly, the production of collagen, the protein that makes up our connective tissue, is disrupted. This leaves a thinner outer layer of skin that eventually develops scar tissue when the inflammation lessens, leaving what is essentially scarring on the skin’s surface.

Before stretch marks appear, the symptoms may include itchiness and reddening of the skin. The marks begin as raised red or purple streaks and generally fade over time into silver. Stretch marks are likely to occur during pregnancy when the abdomen, breast and hip size increases very rapidly. A whopping 75% of pregnant women will develop stretch marks, though some will only develop minimal marks, and others will have a great number of very vivid stretch marks. Stretch marks are also common during puberty, weight gain, and body-building—all times when growth occurs quickly in a short amount of time.

The Role of Genetics in Stretch Marks

Why do some women develop large numbers of stretch marks during pregnancy, and others don’t? Genetics have been found to play a significant role in the severity of stretch marks a person is likely to develop. While it was long presumed that the tendency to develop stretch marks was a genetic trait that tends to run in families, thanks to a recent study by 23andMe, some genetic variations have been identified that clarify the role genetics can play in stretch mark development.

According to 23andMe, skin cells from people who tended to develop stretch marks had lower amounts of the skin protein responsible for elasticity and repair. When this skin is rapidly distended, it’s more likely to leave marks during repair. During the study, four genetic marker variations were discovered near the gene that encodes for the elastin protein, including the FN1 gene codes for fibronectin, an extracellular protein that binds to collagen to protect skin integrity. Skin biopsies performed on people with stretch marks show lowered amounts of fibronectin.

Men in the study were found to be less likely to develop stretch marks than women.

If you want to know your risk for developing stretch marks, you can use 23AndMe, AncestryDNA, and other genetic investigators to discover your own personal risk based on your genetic code.

How Does The Knowledge of This Genetic Connection Help?

While genetic heredity clearly plays a significant role in determining whether a person will be inclined to develop stretch marks, environmental factors also play a role. Knowing your risk allows you to tailor your skincare routine for the best outcome if you plan on becoming pregnant, are experiencing weight gain, or you are body-building.

Topical oils and moisturizers will help to ease the itching of stretching, but studies show that they really do very little to minimize the development of stretch marks. However, after stretch marks have developed, there are a variety of scar treatments and fade creams and lotions that can minimize the appearance of stretch marks.

What Creams and Gels Fade Stretch Marks?

Retinol or Retinoid creams applied topically are successful in helping to diminish the appearance of stretch marks by encouraging the skin cells to produce collagen, the critical protein responsible for maintaining skin’s elasticity and structural integrity.

Cocoa Butter has long been used to minimize the development and appearance of stretch marks, though studies seem to show mixed results in its effectiveness. Cocoa butter has been shown to help prevent the itching and tightness of skin during pregnancy, making it a popular choice for expectant moms.

While some choose to use laser technology to fade stretch marks, it really does little more than speed up the natural fading process. Most red or purple stretch marks fade to silver or white within six months to a year.

Another thing to consider when deciding how to handle your stretch marks is to simply embrace them. When they are the result of pregnancy at least, we know that these marks are not only worth it, many women consider them to be a badge of honor and accomplishment and proudly show them off on social media.

Resources— Medical News Today, 23AndMe, XCodeLife

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