How diet impacts oestrogen levels

There are many dietary influences on oestrogen levels. Any diet that contains high amounts of refined carbohydrates, low fibre and high saturated fat comes with a higher risk of oestrogen-dependent problems arising. You can develop relative oestrogen excess.

Research indicates that your diet choices can increase your risks of developing endometriosis.

An Italian study found that beef, other red meat, and ham increased the risk, while those with a high green vegetable and fresh fruit intake had less risk. Items that were not significantly correlated to endometriosis include milk, liver, carrots, cheese, fish, whole-grains, alcohol and coffee.

But why does this happen? And what else could happen with more oestrogen in your body than you should have?

The impact of saturated animal fats (like red meat) on oestrogen levels – it’s weird and interesting!

Saturated fat and oestrogen have long had a relationship, with one theory being that a high-fat diet impedes oestrogen clearance.

Your body uses several methods to clear away your ‘used up’ oestrogen via the liver and bowel and some tricky chemistry.

Oestrogen is joined (conjugated) to other molecules in the bowel (bile salts).

So you eat, bile is excreted into the bowel, joins onto oestrogens like a pod joining the mother ship. Once joined to the mother ship, the pod – oestrogen – can’t do anything. It’s stuck. The bowel moves the bile-oestrogen bundle along and you poop it out. Oestrogen: cleared.

Saturated animal fats encourage the growth of certain bacteria in the bowel, which produce enzymes that deconjugate (unbond/deconstruct) oestrogen from the bile salts.

The oestrogen swings loose from the mother ship and is now usable oestrogen once again. On its way out of the body, the loose oestrogen is inadvertently absorbed back through the bowel wall and recycled as if it nothing happened.

In a high saturated fat diet, oestrogen clearance is thus much less effective and oestrogen levels subsequently rise.

What foods are high in saturated animal fat?
  • Any cow, pig, sheep, chicken/bird meat
  • Chicken skin
  • Animal lard, dripping or fats
  • Cream, butter and cheese are all made almost exclusively of saturated animal fat
  • Dairy products
What to do if your diet is high in saturated animal fats and you are showing signs of oestrogen excess

Changing your diet to low-saturated-fat foods could make a huge difference to your oestrogen levels, so switch out fatty meats for lean cuts and vegetarian sources of protein.

It won’t take more than a week for your bacterial communities to change, particularly the more vegetarian your diet becomes. Fibre is also associated with greater oestrogen clearance because it keeps your bowels moving faster and more efficiently, so high-fibre low-fat will quickly result in far less oestrogen in your body.

The impact of fat intake on oestrogen levels

Those with a high-fat diet have repeatedly been shown to have higher blood levels of oestrogen than those on low-fat diets.

Part of this process involves the action of aromatase – the enzyme that converts testosterone to oestrogen inside fat cells. The more fat you have, the more oestrogen you have. But why?

More fat => more arachidonic acid => more prostaglandin E2 (PGE2) => more aromatase P450 activity => increased conversion of 19-carbon steroids to oestrogen

High-fat low-fibre diets can also exert an impact on sex-hormone binding globulin (SHBG) – the thing that binds to oestrogen, disabling it and escorting it safely out of the body.

Why does fibre matter?

Fibre – both soluble and insoluble – is not absorbed into the blood, but acts as a filler for the bowel. Fibre safely transports waste out when you go to the toilet. In a nutshell, fibre makes a good, solid poo.

Fibre creates the bulk that stops our intestinal contents being sticky and unformed. Fibre makes sure you have a bowel motion to transport waste products into the toilet, which includes the excretion of hormones.

If you don’t have enough fibre, then your waste products spend longer in the bowel, are sloppier and looser and stickier, offering greater opportunities for oestrogen to be reabsorbed and recycled.

Having enough fibre means more regular, full bowel movements to keep your intestines ‘clean’ and healthy. Do not underestimate the power of a good bowel movement.

How to keep your oestrogen in check using diet

  • Adopt the Mediterranean diet – one study showed the transition from animal fats and proteins to vegetable sources of fat and protein saw a reduction of total oestrogens of over 40 per cent
  • Increase fibre intake – studies show reductions in circulating hormones, including a precursor to oestrogen (androstenedione) – due likely to both bacterial colonies and increased transit time (food’s journey from mouth to toilet)
  • Have more vegetarian days – vegetarians on low-fat high-fibre diets have lower levels of oestrogen
  • Eat the skins – soluble fibre is found in peels and skins of fruits and vegetables
  • Reduce saturated fat intake – high saturated fat changes your bowel flora, increasing an enzyme that releases oestrogen back into your body; especially important postmenopause
  • Increase yoghurt, milk kefir, probiotic capsules or drinksLactobacillus acidophilus reduces enzyme activity that would otherwise result in increased oestrogen levels
  • Add prebiotics into your diet to increase lactobacilli numbers – inulin, lactulose
  • Increase phyto-oestrogens – phyto-oestrogens bind to oestrogen receptors in the same way as human oestrogen, but are about 300 times weaker, thus blocking human oestrogen from binding as often and reducing the impact of oestrogen on the body (best choices are soy products – tofu, soy grits, tempeh, soy milk and soy beans, plus freshly-ground flaxseed)
  • Eat more cabbage family vegetables – Brassicaceae family vegetables are found to improve liver clearance of oestrogens – broccoli, brussel sprouts, radicchio, cabbage
  • Eat enough protein – protein is required for metabolism of oestrogen via the liver (vegetable sources include dairy products, egg, grains, legumes, soy products, nuts and seeds) – a palm or fist-sized portion at every meal
  • Supplement with B6 and B12 and folate – thought to improve liver clearance of oestrogen
  • Alcohol – one drink per day has been shown to reduce oestrogen levels, but increases breast cancer risk

For further advice on your specific circumstances, see your healthcare practitioner.  

Jessica Lloyd - Vulvovaginal Specialist Naturopathic Practitioner, BHSc(N)

Jessica is a degree-qualified naturopath (BHSc) specialising in vulvovaginal health and disease, based in Melbourne, Australia.

Jessica is the owner and lead naturopath of My Vagina, and is a member of the:

  • International Society for the Study of Vulvovaginal Disease (ISSVD)
  • International Society for the Study of Women's Sexual Health (ISSWSH)
  • National Vulvodynia Association (NVA) Australia
  • New Zealand Vulvovaginal Society (ANZVS)
  • Australian Traditional Medicine Society (ATMS)