CYP19A1, also known as aromatase, is an important enzyme that produces estrogen. By controlling estrogen levels, CYP19A1 affects a variety of processes in the body, including fat production and distribution, bone density, female fertility, and brain function. Estrogen deficiency is associated with diseases such as osteoporosis, hardening of the arteries, and Alzheimer’s. Furthermore, CYP19A1 gene variants have been associated with migraines and the growth of estrogen-sensitive cancers. In this post, you will find information about aromatase function, gene variants, and factors that may affect its activity.
Many CYPs eliminate toxins and drugs from the human body. However, some, like CYP19A1, are not involved in detoxification but in steroid hormone production.
By controlling estrogen production, CYP19A1 affects a variety of processes in the body, such as:
CYP19A1 is also involved in the sexual development of the brain . How the brain develops and functions depends on the levels of sex hormones it is exposed to.
Furthermore, CYP19A1 also affects cognitive function. It is implicated in reading, speech, and language . Studies suggest estrogen has important roles in learning and memory by enhancing neuron structure and function .
Mutations in CYP19A1 have been associated with dyslexia (a study in 3423 subjects) .
Increased aromatase activity, resulting in higher estrogen, can promote the growth of estrogen-sensitive cancers.
To date, hundreds of CYP19A1 variants have been identified .
Clinical features of CYP19A1 deficiency include:
- maternal virilization in pregnancy (male-pattern hair growth and other masculine physical traits) due to the excess of androgens and lack of estrogens coming from the fetus. These resolve gradually after giving birth .
- (in women) virilized external genitalia, hemorrhagic ovarian cysts in childhood, primary amenorrhea (absence of menstruation), no breast development, and decreased bone density .
- (in men) osteoporosis due to impaired bone mineralization. Also may have abnormal testis size and sperm production, metabolic syndrome-like stomach obesity, and insulin resistance .
In a study of 283 people ‘TT’ genotype was also associated with migraine susceptibility .
On the other hand, ‘CC’ genotype has been associated with higher apo B, insulin, BMI, and HOMA index (2250 subjects) .
A small study with 189 people has found a link between the ‘C’ variant may also be more prone to heart disease .
On the other hand, the ‘T’ variant for the rs4646 was associated with an advanced stage of breast cancer at the time of presentation and a more progressive disease in another study of 327 patients .
In one study, woman ‘AA’ carriers tended to have a higher bone mineral density (256 subjects) .
Interestingly, blood pressure was higher in men but lower in women with the ‘GG’ genotype (218 patients and 225 controls) . Another study confirmed that women ‘A’ carriers tend to have higher blood pressure (639 people) .
The ‘C’ variant produces 10–20% more estrogen in postmenopausal women .
Carrying an ‘A’, on the other hand, has been associated with endometrial cancer (10 studies, 4,998 cases, and 8,285 controls) .
One study in 286 women has found a link between rs700158 ‘G’ variant and preeclampsia (a pregnancy complication) .
rs11632903 and rs1902586 have been moderately associated with dyslexia in a study of 3423 people .
This variant (del/del) has been associated with melanoma (117 cases and 116 controls) .
Remember, these SNPs have only been found to be associated with certain health conditions. In other words, we only have one or two association studies suggesting that certain genetic variants are more common in people with certain conditions. However, more research will be needed to know what role, if any, these variants play in actually causing these conditions.
In addition, many of these conditions are complex and affected by a multitude of factors, including your lifestyle choices, and CYP19A1 may only play a small part.
Therefore, just because you have one of these SNPs or genotypes does not necessarily mean you are at an increased risk of developing any of these conditions.
- Dichlorodiphenyl ethylene (DDE, derived from DDT) 
- Olive tree leaves  and olive oil 
- Curcumin 
- Apigenin 
- Naringenin 
- Hesperetin 
- Chrysin 
- Kaempferol 
- Capsaicin 
- Mango peel 
- Lemons and limonoids found in lemons 
- Mangosteen 
- Ginkgo biloba [42, 43]
- Sumac sorghum bran extract 
- Licorice flavonoid isoliquiritigenin [45, 46]
- Biochanin A, from red clover (Trifolium pratense) 
- Hop flavonoids xanthohumol, isoxanthohumol, and 8-prenylnaringenin [48, 49]
- Lager beer, alcohol-free beer, stout beer, and xanthohumol-rich stout beer 
- Red wine [37, 41]
- Grape seed extract [50, 41]
- Tea [37, 41]
- Coffee 
- Cocoa 
- Collards (including cabbage and broccoli) 
- Tomato leaves 
- Stinging nettle root extract 
- Cigarette smoke and tobacco leaves 
- White button mushroom unsaturated fatty acids 
- Damiana (Turnera diffusa) 
It’s important to stress that what’s found in cell and animal studies, doesn’t always match what’s later found in humans. The findings from animal and cell studies are given solely for information purposes and will be updated as soon as new findings from human studies become available.