Flavonoids Not Tied to Reduced Parkinson's Risk 2024

[Bolt_Upright]

Flavonoids Not Tied to Reduced Parkinson's Risk 2024 medscape.com/viewarticle/fl...

TOPLINE:

Higher intake of flavonoids shows no association with a later reduced risk for Parkinson's disease (PD), in a new study. The findings, which contradict earlier reports suggesting an association between flavonoids and PD risk, were not modified by the presence or absence of pesticide residues in fruits and vegetables, researchers reported.

METHODOLOGY:

• Investigators used data from the Nurses' Health Study and the Health Professionals Follow-Up Study, which included 80,701 women and 47,782 men who entered the study in 1984 and 1986, respectively, and were free of PD at baseline.

• Flavonoid intake was ascertained at baseline and every 4 years thereafter until 2016 using a Food Frequency Questionnaire.

• Investigators accounted for a range of confounders, including ethnicity, physical activity, body mass index, family history of PD, smoking, alcohol intake, and current use of multivitamins.

• The research updates a previous study by the same researchers that showed men with higher flavonoid intake had significantly lower PD risk and that anthocyanin (a flavonoid subclass) was inversely associated with PD risk. The current study included 10 more years of follow-up and 583 additional PD cases.

TAKEAWAY:

• During the 30- to 32-year follow-up, 1390 incident PD cases were identified (676 in females and 714 in males).

• Higher total flavonoid intake at baseline was not associated with a lower PD risk in either men or women (adjusted hazard ratio comparing highest to lowest quintile, 0.89 [95% CI, 0.69-1.14] and 1.27 [95% CI, 0.98-1.64], respectively).

• The researchers obtained similar findings for the various flavonoid subclasses including anthocyanin.

• Results remained similar, even after adjustment for and stratification by high-pesticide residue fruits and vegetables and even after the researchers restricted analyses to younger PD cases.

IN PRACTICE:

"These findings are in contrast with previously reported beneficial associations of dietary flavonoids among participants in these cohorts," the authors wrote. While this discrepancy could theoretically be explained if high flavonoid intake slowed the pathologic process of preclinical PD, investigators note the lack of association between flavonoid consumption and PD risk was consistent, even after adjusting for age at the time of diagnosis. This reduced the likelihood that the "aging of the cohort is a plausible explanation for the discrepancy with our previous report."

SOURCE:

Helena Sandoval-Insausti, of the Department of Nutrition, Harvard University T.H. Chan School of Public Health, Boston, Massachusetts, was the lead and corresponding author of the study. It was published online on January 24, 2024, in the Journal of Neurology, Neurosurgery and Psychiatry.

LIMITATIONS:

The study was observational and relied on participants' self-reported intake of flavonoids. Pesticide exposure was measured only indirectly by linking self-reported fruit and vegetable intake to pesticides, which could lead to misclassification.

DISCLOSURES:

The study was supported by the National Institutes of Health. The authors declared no competing relationships.

[Baca]

Bolt- Thank you for going through the documents and reporting the facts that is very important and helpful to me! Keep it up we all count on people like you to be informed.

[Esperanto]

Thank you? I'm not particularly happy about this. Flavonoids were a good excuse to add red wine and dark chocolate to our PD diet! 😅

[Bolt_Upright in reply to Esperanto]

Well there is no reason to believe everything you read

The study was based on self surveying.

[Gcf51]

In my opinion depends on the flavonoid. I would not stop quercetin or turmeric just because they contain flavonoids. Most if not all plant based supplements contain flavonoids

[Bolt_Upright in reply to Gcf51]

Definitely! This study is really only reporting on the ability of flavonoids in general to prevent PD. Says nothing about how they might help PD. Also, just because something has flavonoids in it does not mean it is the flavonoids that are helping. Turmeric has a lot of good things in it.

[gomelgo]

Super grateful to Bolt_Upright for the continued depth of research. And ... It's one study folks. I'm sure it has weight. However, I believe it's important to keep things in perspective. Currently listening to a great book: The Experience Machine, How Our Minds Predict and Shape Reality

By: Andy Clark

audible.com/pd/The-Experien...

Highly recommend for those who like to learn about the mind body brain connection.

[Bolt_Upright in reply to gomelgo]

The Experience Machine by Andy Clark review – how our brains really work theguardian.com/books/2023/...

A cognitive philosopher explains how prediction, rather than perception, is the mind’s secret weapon

[gomelgo in reply to Bolt_Upright]

I'm about a third of the way through. So thanks for that review. I haven't heard much about the mind, and wonder if, as I have heard in many other books, the mind and brain are used interchangeably here. There is also Jonathan Haidt's Righteous Mind, which has a similar focus which he metaphorically refers to as the elephant controlling the rider, aka confirmation bias, aka post hoc justifications or moral judgements. For me these are interesting ideas to ponder with regards to disease processes and placebo effects as well as possible explanations for why some treatments work for some people and not others.

[LAJ12345]

That was a very forward thinking study I must say! I would love to see more details of what form they were taking flavonoids in in the 1980s. I assume they weren’t for instance taking purified quercetin capsules as I doubt they would even be available commercially back then, so it must have been back solved based on the level of flavonoid in diet in the whole food they reported eating.

The fact diet was self reported might mean study is flawed. How many people romantically imagine they ate more vegetables and fruit and less junk than they actually did so as not to blame themselves and their lifestyle for their poor health. You know, the salad that is treated as garnish on a restaurant plate and left while the meat and potatoes (chips/fries) are all eaten? The fruit that is purchased meaning well, but left until it goes off and has to be thrown out.

I find it hard to believe a study that shows eating lots of brightly coloured fruit and vegetables doesn’t have health benefits over a diet that doesn’t. I think looking at health in western countries it is pretty obvious modern diet isn’t healthy at a population level.

I worked on flavonoids in my previous job as a chemistry technician in the 1980s. We were assisting botanists classify New Zealand native plants by their chemistry. It was pre internet of course. There was some talk of hesperidin being useful for a potential cancer drug but I never heard anything about other flavonoids being used as supplements. I guess back then it required the research scientists to look up the journals manually to see what was happening worldwide in their field. My scientist was very much into assisting the botanists. Other jobs I had involved extracting sea sponges for possible cancer curing compounds, and also seeds from various trees, then purifying enough of the compounds to send off for testing at cancer research in the US. Interesting work, but I got sick of being the technician doing all the boring smelly stuff in the noisy cold lab and not the scientist who sat in a warm office doing research 😄.

[psyche100]

This reports research into the beneficial effects of blueberries: healthunlocked.com/cure-par...

Perhaps it is better quality as it is experimental?

[MarkPrana in reply to psyche100]

Reassuring research into blueberries there psyche, thanks for bringing forward.

[MarkPrana]

Thanks for sharing Bolt, and for giving your balanced opinions on the wider conclusions around the efficacy (or not) of these health-giving compounds/supplements.

I take some comfort in the wider research into the MIND (aka Mediterranean+) diet.

It has, for example, has been associated with reduces 'dementia risk' + slower rate of 'biological aging'. Here, in what has been described as the 'Framingham Heart Study’s Offspring Cohort study', the researchers:

- Studied 1600 participants ave. ago ~60yrs

- Followed them over 30 years, starting in 1971

- Found 140 developed dementia

Ref: neurosciencenews.com/diet-a...

---

From a PD perspective, high adherence to a MIND diet was associated with later age of Parkinson's disease onset (delayed by about 15 to 17 years) in women, but interestingly not in men.

Ref: pubmed.ncbi.nlm.nih.gov/334...

Much more research needed but I won't lose hope that fruit/berries/Flavonoids will ultimately show benefit for PWP.

As the blueberry reference and video link above shows, there is a lot of cause for optimism and they are a tasty additions to our diets in their own right 😋

[Esperanto in reply to MarkPrana]

The MIND diet is a great choice and it is also easy to follow without many restrictions on your culinary choices. This was posted last year.

healthunlocked.com/cure-par...