Peter Cobbold Posted June 2, 2021 Report Share Posted June 2, 2021 There is a shortage of grapefruit juice in the shops so folks may be drinking a lot more than normal. Grapefruit juice and the fruit contain natural ingredients that inhibit an enzyme in the gut and liver that metabolise many drugs and toxins. A single glass 250ml is all it takes to wipe out that enzyme ( CYP-4A). So if you are on drugs and have taken to drinking grapefruit it might pay to again read the instruction in the packet and avoid overdosing. More here; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3589309/ Peter Quote Link to post Share on other sites
OldBob Posted June 2, 2021 Report Share Posted June 2, 2021 Thanks Peter, I never did trust that vile stuff! Quote Link to post Share on other sites
Peter Cobbold Posted June 3, 2021 Author Report Share Posted June 3, 2021 7 hours ago, OldBob said: Thanks Peter, I never did trust that vile stuff! Bob, Tastes vary ! I am enjoying three glasses a day. it helps my PD drug to work by slowing its breakdown. So the shortage is a concern. Peter Quote Link to post Share on other sites
Nigel Triumph Posted June 3, 2021 Report Share Posted June 3, 2021 Just ate half a grapefruit for breakfast, now wondering how that compares to drinking a glass of juice. Nigel Quote Link to post Share on other sites
Lebro Posted June 3, 2021 Report Share Posted June 3, 2021 Shame, I like grapefruit Bob. Quote Link to post Share on other sites
Peter Cobbold Posted June 3, 2021 Author Report Share Posted June 3, 2021 Grapefruit is a good source of vitC, and unless taking drugs that are sensitive to its effects is probably harmless,even good as one of 5 a day. This article makes the point that a varied diet full of colourful fruit and veg is also likely to inhibit CYP3A4 and so act similary to g/f. --bottom p7 https://www.researchgate.net/profile/Albert-Wright/publication/333718915_Daily_Inhibition_of_the_Cytochrome_P450_enzyme_CYP3A4_alleviates_symptoms_of_Parkinson's_Disease/links/5d296842458515c11c2b18e0/Daily-Inhibition-of-the-Cytochrome-P450-enzyme-CYP3A4-alleviates-symptoms-of-Parkinsons-Disease.pdf CYP3A4 is in part under promotion by D3. As I am taking lots (10,000 IU pd) that may result in high CYP3A4 that in turn inactivates the DOPA before it can get to my brain. The g'f juise seems to be having an effect. much as the paper reports. Peter Quote Link to post Share on other sites
Peter Cobbold Posted June 3, 2021 Author Report Share Posted June 3, 2021 5 hours ago, Nigel Triumph said: Just ate half a grapefruit for breakfast, now wondering how that compares to drinking a glass of juice. Nigel The Tropicana juice I take says it is undiluted squeezed fruit. 100ml has an effect on me. Not sure how much juice the manufacturers extract per fruit but I guess they use high pressures. Peter Quote Link to post Share on other sites
Hamish Posted June 3, 2021 Report Share Posted June 3, 2021 i have heard that pineapple juice can affect medication too. luckily I'm not on medication so a can enjoy these fruits and juices. Quote Link to post Share on other sites
ntc Posted June 3, 2021 Report Share Posted June 3, 2021 If you have any underlying Liver problems known or not Grapefruit can be deadly. Quote Link to post Share on other sites
Peter Cobbold Posted June 3, 2021 Author Report Share Posted June 3, 2021 1 hour ago, Hamish said: i have heard that pineapple juice can affect medication too. luckily I'm not on medication so a can enjoy these fruits and juices. Yes indeed, best to avoid bingeing. All in moderation. Curious that so many colourful fruits and veg that are justifiably deemed healthy in our diet, eg Meditteranean should inhibit these CYP detoxifiyng enzymes. ( see p7 of the ref I cited earlier). They contribute about 1 gram daily, but all are much less potent than the grapfruit componenst which only need 20mg to wipe out the enzyme. Sevile oranges also contain it. Perhaps fruit evolved these toxins to avoid being eaten by just one animal, by making it feel ill after a few, so ensuring many animals get to sup and so spread seeds far and wide. But why our livers should detoxify these useful/beneficial anti-oxidants is a mystery to me. Peter Quote Link to post Share on other sites
Pogo Posted June 3, 2021 Report Share Posted June 3, 2021 One of the meds that I take warn me not to have grapefruit juice with it so I don't have it anymore, which is a shame as I actually used to like the odd grapefruit/grapefruit juice. Quote Link to post Share on other sites
SuzanneH Posted June 4, 2021 Report Share Posted June 4, 2021 15 hours ago, Pogo said: One of the meds that I take warn me not to have grapefruit juice with it so I don't have it anymore, which is a shame as I actually used to like the odd grapefruit/grapefruit juice. +1 Quote Link to post Share on other sites
PodOne Posted June 14, 2021 Report Share Posted June 14, 2021 Grapefruit juice is a well known one. However many common over the counter herbal supplements eg; Garlic, St Johns Wort, Gingko etc all have the potential to interact with a variety of prescription medications usually resulting in sub optimal dosing leading to poor clinical effect or at worse toxicity. So its always worth just checking yourself or better asking your local pharmacist about the potential interactions. Andy Quote Link to post Share on other sites
Waldi Posted June 20, 2021 Report Share Posted June 20, 2021 You should not eat/drink grape fruit if you use medication to lower cholesterol (statines). How do I know? Waldi Quote Link to post Share on other sites
Peter Cobbold Posted June 20, 2021 Author Report Share Posted June 20, 2021 I am deliberately drinking g/f juice a half hour before my l-DOPA for PD. It makes the pills more effective I find, as have others. My D3 supplements of 10,000 IU pd may have been promoting the liver and gut enzyme that inactivates DOPA. There is biochemical evidence for D3 promoting CYP3A4. I am now lowering D3 dosage towards physiological. But I suspect all the pharmacokinetics on DOPA - and all drugs - have been conducted on D3-deficient individuals, the norm in most nations. Peter Quote Link to post Share on other sites
HSM Posted June 21, 2021 Report Share Posted June 21, 2021 Hi Peter On the information leaflet in one of my bleed pressure medication tablets, it advises against grapefruit juice. But i stand to be corrected. Glad your keeping well Peter. Quote Link to post Share on other sites
Peter Cobbold Posted June 21, 2021 Author Report Share Posted June 21, 2021 4 hours ago, HSM said: Hi Peter On the information leaflet in one of my bleed pressure medication tablets, it advises against grapefruit juice. But i stand to be corrected. Glad your keeping well Peter. Hi Harvey, Yes, g/f juice blocks gut and liver enzymes that protect us from foreign chemicals, and drugs are foreign. So g/f juice acts to raise the effctive drug dose. Hope you are keeping well. I have yet to find the ideal combination of D3, omega-3, aspirin, lithium, etc for slowing the PD. But I find it fascianting to read the research, so there is a plus side to it. Peter Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.