The five best anti-aromatase substances

Aromatase: definition and biological function

What is aromatase?

Aromatase is an enzyme complex responsible for catalysing the conversion of androgen hormones into oestrogens. More specifically, it converts androstenedione into oestrone and testosterone into oestradiol (1). It is found in various tissues and organs in the body including the gonads (testes and ovaries), the brain, fatty tissue, the placenta, blood vessels, skin and bones.

Does aromatase have any benefits?

Aromatisation is a natural process which is initially beneficial: it finetunes male and female hormone balance.

In particular, it allows menopausal women - once menstruation has ceased - to continue benefiting from a certain level of oestrogen (needed for bone health, amongst others) from testosterone produced by the adrenal glands. In men too, it provides the small amount of oestrogen required for good quality spermatogenesis, amongst others (2-3).

But when aromatase activity goes into overdrive – something which happens much more frequently with age – this balance is disrupted, causing hormone problems with various repercussions.

Benefits of inhibiting aromatase in men

Excessive aromatisation in men precipitates a drop in testosterone levels which already start to fall naturally from the age of 30-40. Depending on the individual, this leads to abdominal fat gain, gynaecomastia (increase in breast tissue), loss of libido, enlarged prostate, mood swings and/or lack of energy (4-5). Partially inhibiting aromatase helps to stabilise levels of androgen hormones and maintain metabolic, emotional and sexual health.

Aromatase and female cancers: what’s the connection?

In women, a number of studies suggest aromatase plays a role in the development of certain hormone-dependent cancers (breast, ovaries …), since oestrogens directly stimulate hormone-sensitive tumour cell receptors and contribute to their growth. Anti-aromatase drugs (letrozole, anastrozole, exemestane…) have, for several years, been showing promised in hormone therapy as an adjuvant treatment for breast cancer in post-menopausal women (6).

What can you do to fight aromatase naturally?

Anti-aromatase and diet

Several studies have highlighted the benefits of plant antioxidants in the aromatase inhibition mechanism (7). It would therefore make sense to prioritise a diet high in fruit and vegetables, preferably organic to reduce exposure to xenobiotics (such as synthetic pesticides) which are thought to be endocrine-disruptors.

Studies on women with oestrogen-dependent endometrial tumours suggest that overproduction of insulin may stimulate the aromatisation process in situ (8). This makes a case for reducing consumption of refined sugars and foods with a high GI index in order to maintain stable blood sugar levels. It's worth noting that alcohol also stimulates overexpression of aromatase (9).

Lose weight to reduce aromatisation

More generally, any diet and lifestyle measure aimed at reducing fat mass - lowering sugar and saturated fat intake, taking regular exercise, getting sufficient sleep - are also to be encouraged, since adipose cells accumulate a high proportion of aromatase (10).

What about stress?

While the impact of stress on aromatase in humans is not yet clearly established, a study of male quail birds exposed to acute stress found an in increase in cerebral aromatase in the medial preoptic nucleus (the region governing reproductive behaviour) (11). Chronic stress is also known to disrupt the hypothalamic-pituitary-gonadal (HPG) axis and the release of testosterone (12). All the more reason, then, to embrace relaxation techniques (yoga, meditation, sophrology ...) to manage your emotions as well as possible.

What are the best natural anti-aromatase substances?

Chrysin

Along with apigenin, chrysin has been shown in in vitro studies to be one of the most promising flavonoids for fighting aromatase (13). Isolated from blue passion flower (Passiflora caerulea), chrysin is believed to bind directly to aromatase, blocking its catalytic activity, though the extent of this ability needs to be further investigated in humans (you can find this substance in the supplement Chrysine) (14-15).

Paris (or button) mushrooms

The potential of Paris mushrooms (Agaricus bisporus) to inhibit aromatisation was highlighted in a mouse model analysis. Its fatty acids (more specifically conjugated linoleic acid and its derivatives) appear to be able to bind to active sites of aromatase via a competitive mechanism (16).

Resveratrol

Dubbed the star molecule of longevity (for its leading role in the ‘French Paradox’), the antioxidant resveratrol continues to fascinate scientists. Researchers have for some years been interested in its presumed antioestrogen action. Its effects on aromatase have also been compared with those of selective oestrogen receptor modulators, a group of clinically-used anti-aromatase treatments (the supplement Resveratrol is standardised to contain 10% resveratrol, making it the most potent such extract on the market) (17).

Zinc

Zinc is an essential trace element which helps to maintain normal testosterone levels. Animal studies confirm that a zinc-deficient diet is associated with greater conversion of testosterone into oestradiol, a marker of increased aromatase activity (18). The best dietary sources of zinc include oysters, cheese, red meat, offal and cocoa, but taking a highly-absorbable zinc supplement is also an easy way of optimising intake (one such product is Zinc Orotate).

Turmeric

Ayurveda’s favourite rhizome, turmeric may still have a few secrets to reveal. One study investigating how its curcuminoids affect the aromatisation of androstenedione (19) found that their molecular conformation had striking similarities with those of steroid substrates, which could make it easier for them to bind to active aromatase sites (combined with phosphatidylcholine, the curcuminoids in Super Curcuma are absorbed 29 times better than those in standard supplements) (20).

Are there specific anti-aromatase supplements?

If you’re keen to restore optimal hormone balance in your body, there are certain supplements that specifically target the problem of aromatase by combining several of the above-mentioned compounds. One example is Natural Anti Aromatase Support, in which the strength of chrysin and Paris mushroom is paired with a whole host of natural and scientifically-studied regulatory compounds: naringin, genistein, quercetin, Epilobium parviflorum, diindolylmethane (21-23)… However, if you have a health condition, make sure you seek medical advice before starting supplementation.