Grapefruit is one of my favourite foods. Every Winter I look forward to this tart, fragrant fruit arriving in my supermarket.

Last week I was about to tuck into some juicy grapefruit for breakfast, when an app I have been trialing for nutrition and lifestyle change advised me I’d best avoid it.

On looking further into the reasons why the app recommended this, I was surprised to learn that grapefruit can increase estrogen levels and cause toxicity.

I was aware that grapefruit caused problems with oral hormones (tablets) , but not with transdermal oestrogen replacement (patches and gels).

So in the interests of all menopausal women on MHT, I researched extensively this week to sort out if we need to be concerned about grapefruit with transdermal treatment rather than just the oral MHT tablets!

There are natural chemicals in grapefruit called naringenin, quercetin and kaempferol that affect the enzymes the liver uses to process and eliminate estrogen.

To put it simply, they compete with the estrogen for enzymatic breakdown, leading to higher oestrogen levels and potentially side effects/toxicity.

In one study, the average peak oestrogen level in the blood after drinking grapefruit juice increased significantly to 137%, while the maximum peak seen in one person was over 200%!

This is especially important for women on oral MHT tablets and also for women who have had breast cancer who ideally want to avoid high oestrogen levels.

The safety of grapefruit in transdermal patches and gels is a trickier question to answer.

There’s not a lot of research that has been done on this topic.

Theoretically, if the breakdown and metabolism of estrogen is affected in the liver, there is concern that even transdermal oestrogen or endogenous (produced by our own body) estrogen could be affected, but there’s just no good study that has been done on this yet.

TIP: Avoid grapefruit and its juice, and supplements containing grapefruit extracts if you have a history of breast cancer, are on tamoxifen or oral MHT tablets.

It’s possible that if you are on transdermal MHT, your estrogen levels could also be affected, so I would advise infrequent use or avoid. If you do decide to eat grapefruit, monitor for estrogen side effects (including breast tenderness, mood changes, and nausea).

If you’re wanting personalised rather than general advice and support about MHT and the menopause transition, contact me at [email protected]

We’ve now sold around half the tickets to the Menopause Workshop on 11th October in Alexandra, so if you and your friends are wanting to come, be in quick!

Click the link below to access more info about what we’ll be covering and to buy tickets.

Stay happy and healthy!

Erika.

PS: Me after realising it might not be best to eat my grapefruit after all: