Grapefruit - Yes/No

[jaywills]

What is the general consensus on Grapefruit?

Other than a line stating it is Estrogenic, I cannot find any mention of this fruit throughout Ray Peats articles/ this forum.

However, Functional Alps seem to favor its ability to aid the liver:

http://www.functionalps.com/blog/2011/1 ... -estrogen/

 

[Zachs]

Seems like oranges and lemons would be a better combo for sugar, minerals and liver function.

 

[DaveFoster]

Flavonoids in grapefruit juice inhibit the in vitro hepatic metabolism of 17 beta-estradiol.
Naringenin, quercetin and kaempferol, which may be found in glycoside form in natural compounds such as grapefruit, are potent inhibitors of cytochrome P-450 metabolism. The influence of these flavonoids on the metabolism of 17 beta-estradiol was investigated in a microsome preparation from human liver. The flavonoids were added in concentrations of 10, 50, 100, 250 and 500 mumol/l to the microsome preparation. The metabolism of 17 beta-estradiol was concentration dependently inhibited by all the flavonoids tested. Addition of the flavonoids to the microsome preparation did not influence estrone formation, while a potent inhibition of estriol formation was observed. At the highest concentrations tested of the respective flavonoid, there was approximately 75-85% inhibition of estriol formation. However, naringenin was a less potent inhibitor of 17 beta-estradiol metabolism as compared to quercetin and kaempferol. The most likely mechanism of action of the flavonoids on 17 beta-estradiol metabolism is inhibition of the cytochrome P-450 IIIA4 enzyme, which catalyzes the reversible hydroxylation of 17 beta-estradiol into estrone and further into estriol. These hydroxylation processes represent the predominant steps of the hepatic metabolic conversion of endogenous as well as exogenous 17 beta-estradiol. This interaction would be expected to inhibit the first-pass metabolism of 17 beta-estradiol, and this has recently been demonstrated after oral administration of 17 beta-estradiol to women.

If consumption of grapefruit inhibits the P-450 IIIA4 enzyme, and this enzyme catalyzes estrogen hydroxylation in the liver, then it follows that there would be a net decrease in estrogen deactivation in the liver. Thus, the liver undergoes fewer metabolic processes in this context, so of course the impact on the liver will be less.

I may be missing a major piece here, but why would you want to increase the amount of estradiol in your system by inhibiting your liver's ability to hydroxylate?

 

[Westside PUFAs]

However, Functional Alps seem to favor its ability to aid the liver:

No that is not what his post implies. The goal is to reduce estrogen and support the liver, not the opposite.

 

[Peatit]

Seems like oranges and lemons would be a better combo for sugar, minerals and liver function.

I don't understand why other citrus fruits (so oranges, lemons or orange juice) would have a different (activating or at least non inhibiting) mechanism of action on cytochrome P-450 IIIA4 insofar in the studies mentioned, the compounds involved are present in all citrus fruits (naringenin, quercetin and kaempherol)

 

[mt_dreams]

I don't understand why other citrus fruits (so oranges, lemons or orange juice) would have a different (activating or at least non inhibiting) mechanism of action on cytochrome P-450 IIIA4 insofar in the studies mentioned, the compounds involved are present in all citrus fruits (naringenin, quercetin and kaempherol)

Grapefruit have roughly 10-15x the amount of naringenin than lemons & oranges. Oranges having roughly 7% compared to grapefruit, while lemons are probably closer to 10% range of grapfruit. Re grapefruit, the white ones have roughly double of this compound compared to the pink variety.

 

[Peatit]

I don't understand why other citrus fruits (so oranges, lemons or orange juice) would have a different (activating or at least non inhibiting) mechanism of action on cytochrome P-450 IIIA4 insofar in the studies mentioned, the compounds involved are present in all citrus fruits (naringenin, quercetin and kaempherol)

Grapefruit have roughly 10-15x the amount of naringenin than lemons & oranges. Oranges having roughly 7% compared to grapefruit, while lemons are probably closer to 10% range of grapfruit. Re grapefruit, the white ones have roughly double of this compound compared to the pink variety.

Thank you for the explanation. What about mandarin oranges?

 

[Parsifal]

I'm a bit lost, I thought that naringenin was good and anti-oestrogenic but it seems higher in grapefruit that is highly oestrogenic.

 

[ecstatichamster]

it's a mixed bag with naringenin, it seems to be a phytoestrogen that in some cases can lower estrogen levels. I don't think huge amounts are healthy. It is like quercetin to me, has benefits but also definitely has an estrogenic effect on me (quercetin does). So I am not big on grapefruits these days.

 

[beachbum]

If consumption of grapefruit inhibits the P-450 IIIA4 enzyme, and this enzyme catalyzes estrogen hydroxylation in the liver, then it follows that there would be a net decrease in estrogen deactivation in the liver. Thus, the liver undergoes fewer metabolic processes in this context, so of course the impact on the liver will be less.

I may be missing a major piece here, but why would you want to increase the amount of estradiol in your system by inhibiting your liver's ability to hydroxylate?

I know this is an old thread, but confused on the answer here. how does grapefruit estrogen an liver.

EDIT: NEVERMIND I FOUND MY ANSWER

 

[ddjd]

EDIT: NEVERMIND I FOUND MY ANSWER

please do share it

 

[BearWithMe]

This study seems to indicate that grapefruit decrease both E1 and E2, while increasing DHEA-S and E1S

The Effect of Grapefruit Intake on Endogenous Serum Estrogen Levels in Postmenopausal Women

Although grapefruit intake leads to elevated serum estrogen levels when hormones are taken orally, there are no published data on the effect on endogenous levels. We conducted a pilot dietary intervention study among healthy postmenopausal volunteers ...

www.ncbi.nlm.nih.gov

 

[Peatness]

I read this recently in the notes @-Luke- posted of the Ray and One Radio Network interviews.

- 01:20:50 - Would grapefruit (juice) have the same anti-estrogenic effects like orange juice? There were a few publications that found an increase in estrogen with grapefruit juice. But later publications found that that wasn't accurate. They have probably used unripe grapefruits. Good, ripe grapefruits are very sweet and have a pro-thyroid effect like orange juice. When the thyroid is working right, your estrogen is kept at a minimal level, except in the one or two days around ovulation.

 

[Jonk]

I found this PDF on liver detox posted by the user @Amazoniac, http://balancedconcepts.net/liver_phases_detox_paths.pdf. It details the two different phases of liver detox. Apparently grapefruit slows down phase I but promotes phase II. So maybe it's individual if it has an estrogenic effect depending on liver status.

 

[Tiffany]

I found this PDF on liver detox posted by the user @Amazoniac, http://balancedconcepts.net/liver_phases_detox_paths.pdf. It details the two different phases of liver detox. Apparently grapefruit slows down phase I but promotes phase II. So maybe it's individual if it has an estrogenic effect depending on liver status.

I'm not proficient enough in hormone biochemistry to understand your reference so I hope you will assist me. I will keep it simple. I went through early menopause at age 43. Since puberty I've had the E-dominant figure, despite being a "healthy weight". When I lose enough weight for thighs to look lean and toned, my arms are too skinny (strangers will tell me I need to eat more). I find grapefruit causes me to shed mid-section fat in an obvious way after having 1-2 grapefruits per day for a few days. I'm not decreasing other foods in a way that calories would be less overall. I cannot tell if eating GF is affecting thigh/bottom fat because I go by how my waistbands fit. I have never continued to consume them more than 5 days in a row.

Do you think if I lose mid-section fat, this is an indicator that it's lowering overall estrogen (or lowering it's negative effect)? I appreciate your (and anyone else on the thread) weighing in on this.

I would like to do a trial where I eat GF for a week or two and measure my waist and thighs. As long as I am shedding fat from these areas, would that indicate that I can safely eat grapefruit (in terms of estrogen toxicity, only) more regularly?. I was thinking I would like to have GF 2 days per week or one week per month. My body craves them when I have them in the fruit basket. I will especially crave them right before bedtime (even if I have just eaten).

Has anyone else had this effect?

 

[LA]

I'm not proficient enough in hormone biochemistry to understand your reference so I hope you will assist me. I will keep it simple. I went through early menopause at age 43. Since puberty I've had the E-dominant figure, despite being a "healthy weight". When I lose enough weight for thighs to look lean and toned, my arms are too skinny (strangers will tell me I need to eat more). I find grapefruit causes me to shed mid-section fat in an obvious way after having 1-2 grapefruits per day for a few days. I'm not decreasing other foods in a way that calories would be less overall. I cannot tell if eating GF is affecting thigh/bottom fat because I go by how my waistbands fit. I have never continued to consume them more than 5 days in a row.
Do you think if I lose mid-section fat, this is an indicator that it's lowering overall estrogen (or lowering it's negative effect)? I appreciate your (and anyone else on the thread) weighing in on this.
I would like to do a trial where I eat GF for a week or two and measure my waist and thighs. As long as I am shedding fat from these areas, would that indicate that I can safely eat grapefruit (in terms of estrogen toxicity, only) more regularly?. I was thinking I would like to have GF 2 days per week or one week per month. My body craves them when I have them in the fruit basket. I will especially crave them right before bedtime (even if I have just eaten).
Has anyone else had this effect?

I viewed your posting as I was wondering if it would be another study on the reactions of certain medications to grapefruit consumption, such as this:

Grapefruit and medication: A cautionary note - Harvard Health

Grapefruit and grapefruit juice are healthful, providing enough nutrients to earn the American Heart Association's "heart-check" mark. But grapefruit and medication can sometimes make a dangerous c...

www.health.harvard.edu

From my non-professional observations most people 'seem' to acquire a pot-belly from eating too much starch. Some eat too much starch due to having the munchies from smoking too much 'weed'.

Have you read the Ray Peat book on Female Hormones in Context?
I typed out the important page regarding starch on this thread:

What fruit work best for you? (for those who are starch free)

Title says, wonder what fruit work best for you. So far i am doing best with: papaya, mango, grapes, pineapple, melon, anything else which work good?

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