Mixed news for flavonoids.

[pjoshea13]

New meta-analysis below [1].

The flavonoid family (Anthocyanidins, Anthoxanthins, Flavanones, Flavanonols, Flavans, & Isoflavonoids) include members that have hormone-like properties. "This meta-analysis was aimed to explore the association between flavonoids intake and {hormone-related cancer} HRC risk among observational studies."

Wikipedia [2]:

"Clinical studies investigating the relationship between flavonoid consumption and cancer prevention or development are conflicting for most types of cancer, probably because most human studies have weak designs, such as a small sample size. There is little evidence to indicate that dietary flavonoids affect human cancer risk in general, but observational studies and clinical trials on hormone-dependent cancers (breast and prostate) have shown benefits. A recent review has suggested that dietary intake of flavonoids is associated with a reduced risk of different types of cancer, including gastric, breast, prostate, and colorectal cancer"

From the new paper:

"The present study suggests evidence that intake of total flavonoids, flavonols, flavones, flavanones, flavan-3-ols and isoflavones would be associated with a lower or higher risk of HRCs, which perhaps provides guidance for diet guidelines to a certain extent."

"All included studies were rated as medium or high quality. Higher consumption of flavonols (OR = 0.85 ...), flavones (OR = 0.85 ...) and isoflavones (OR = 0.87 ...) was associated with a decreased risk of women-specific cancers (breast, ovarian and endometrial cancer), while the higher intake of total flavonoids was linked to a significantly elevated risk of prostate cancer (OR = 1.11 ...)"

Note that soy products would account for a significant intake of isoflavones. Genistein (a phytoestrogen) has been shown to have a biphasic effect on PCa cells - being growth-promoting at physiological levels & growth-inhibiting at pharmaceutical levels.

i.e. perhaps prudent to avoid dietary soy. If using supplements, go big.

-Patrick

[1] pubmed.ncbi.nlm.nih.gov/355...

(90 papers are referenced)

Nutr J

. 2022 May 11;21(1):27. doi: 10.1186/s12937-022-00778-w.

Consumption of flavonoids and risk of hormone-related cancers: a systematic review and meta-analysis of observational studies

Fubin Liu 1 2 3 , Yu Peng 1 2 3 , Yating Qiao 1 2 3 , Yubei Huang 1 2 3 , Fengju Song 1 2 3 , Ming Zhang 4 , Fangfang Song 5 6 7

Affiliations collapse

Affiliations

1 Department of Epidemiology and Biostatistics, Key Laboratory of Molecular Cancer Epidemiology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, 300060, China.

2 Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin, 300060, China.

3 Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, 300060, China.

4 Shenzhen Prevention and Treatment Center for Occupational Diseases, Shenzhen, 518020, Guangdong, China. [e-mail].

5 Department of Epidemiology and Biostatistics, Key Laboratory of Molecular Cancer Epidemiology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, 300060, China. [e-mail].

6 Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin, 300060, China. [e-mail].

7 Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, 300060, China. [e-mail].

PMID: 35545772 DOI: 10.1186/s12937-022-00778-w

Abstract

Background: Flavonoids seem to have hormone-like and anti-hormone properties so that the consumption of flavonoids may have potential effects on hormone-related cancers (HRCs), but the findings have been inconsistent so far. This meta-analysis was aimed to explore the association between flavonoids intake and HRCs risk among observational studies.

Methods: Qualified articles, published on PubMed, EMBASE, and China National Knowledge Infrastructure (CNKI) from January 1999 to March 2022 and focused on relationships between flavonoids (total, subclass of and individual flavonoids) and HRCs (breast, ovarian, endometrial, thyroid, prostate and testicular cancer), were retrieved for pooled analysis. Random effects models were performed to calculate the pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs). Funnel plots and Begg's/Egger's test were used to evaluate the publication bias. Subgroup analyses and sensitivity analyses were conducted to explore the origins of heterogeneity.

Results: All included studies were rated as medium or high quality. Higher consumption of flavonols (OR = 0.85, 95% CI: 0.76-0.94), flavones (OR = 0.85, 95% CI: 0.77-0.95) and isoflavones (OR = 0.87, 95% CI: 0.82-0.92) was associated with a decreased risk of women-specific cancers (breast, ovarian and endometrial cancer), while the higher intake of total flavonoids was linked to a significantly elevated risk of prostate cancer (OR = 1.11, 95% CI: 1.02-1.21). A little evidence implied that thyroid cancer risk was augmented with the higher intake of flavones (OR = 1.24, 95% CI: 1.03-1.50) and flavanones (OR = 1.31, 95% CI: 1.09-1.57).

Conclusions: The present study suggests evidence that intake of total flavonoids, flavonols, flavones, flavanones, flavan-3-ols and isoflavones would be associated with a lower or higher risk of HRCs, which perhaps provides guidance for diet guidelines to a certain extent.

Trial registration: This protocol has been registered on PROSPERO with registration number CRD42020200720 .

Keywords: Flavonoid subclasses; Flavonoids; Hormone-related cancers; Meta-analysis; Observational studies.

© 2022. The Author(s).

*****

[2] en.wikipedia.org/wiki/Flavo...

[MrG68]

You see, this is the problem...

Eggs are great for you. Tomorrow: eggs promote angiogenesis.

Red meat causes cancer. Tomorrow: red meat is essential to treat cancer.

It just goes on and on in circles depending on things like who wrote the article, who are the sponsors and conflicts of interest, use of regression models etc etc. It's endless.

You can collect all the studies you like and form some kind of meta analysis based on some super dooper modeling techniques and get garbage out. For every negative article, you can find the opposite with a few clicks.

Try to focus on the best form of studies that you can. Randomized, double blinded, placebo, added control group type studies are FAR superior to anything with types like regression, multivariable reports - IMO.

You need to be VERY cautious about reading articles where you just read the abstract and results.

I would not consider looking for a single panacea to help with any form of cancer. If things were as simple of removing soy products from your diet, don't you think that this would have been discovered by now? Your body is INCREDIBLY complex. Its has a multitude of complex pathways interlinked with biochemical reactions. On top of that, you're genome is totally unique with billions and billions of differences all dependent on a changing environment. Even your diet, has an effect because it affects your gene expressions. Don't believe me? Try not supplementing with vitamin D3 in a location with poor sun exposure. Good luck identifying anything that involves reduction techniques.

A better way is to look at your situation in the whole and come up with a more holistic approach.

For me, I try to target inflammation since its implicitly linked to cancer.

Just my opinion, I'm not trying to fight anyone or prove anyone wrong.

[LearnAll in reply to MrG68]

"Holistic approach"...Absolutely !

[Ashikpong in reply to MrG68]

It just goes on and on in circles depending on things like who wrote the article, who are the sponsors and conflicts of interest, use of regression models etc etc. It's endless. Said it all!

[j-o-h-n]

No ands, ifs or oids.......

Good Luck, Good Health and Good Humor.

j-o-h-n Saturday 05/14/2022 1:16 PM DST

[Graham49]

Patrick

The results from this study seem very controversial with regard to anthocyanidins and flavan -3-ols.

From the study:

"Prostate cancer

Figure 2E and Supplementary Table S4 demonstrated the summarized risk estimates for six cohort and six case–control studies [31, 69,70,71,72,73,74,75,76,77,78,79,80,81] on consumption of flavonoids and prostate cancer risk. We observed an increased risk of prostate cancer by higher intake of total flavonoids (OR = 1.11; 95% CI, 1.02–1.21; I2 = 0%; p = 0.484), which was more pronounced in cohort studies. And, this positive relationship was found only in non-Asia populations (Supplementary Table S6). Of note, for the anthocyanidins and flavan-3-ols subclass, the higher intake category presented a markedly elevated prostate cancer risk compared to the lower intake category in prospective studies. For individual compounds, no significant association was attained in our analysis."

From Wiki

Anthocyanidins

"are responsible for red, blue, or black color of many fruits (like grapes and blueberries), ......"

Flavan-3-ols are abundant in teas derived from the tea plant Camellia sinensis, as well as in some cocoas......"

[pjoshea13 in reply to Graham49]

Graham,

I would still have a dish of low-bush blueberries everyday if I could. Finding only for non-Asians? Perhaps due to detection bias?

If the study is correct, perhaps Woody Allen's "Sleeper" had it right?:

"Before we found out that everything we thought was bad for us was actually good for us"

-Patrick