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Research Reviews
Wine as a Proxy for Air Quality Data
Study
Tracing changes in atmospheric sources of lead contamination using lead isotopic compositions in Australian red wine
Authors
Kristensen LJ, Taylor MP, Evans AJ
Year
2016
Journal
Chemosphere. 2016 Jul;154:40-7
URL
https://www.ncbi.nlm.nih.gov/pubmed/27037773
Quotes
Wine lead concentrations mirror available lead-in-air measurements.
This study demonstrates wine can be used to chronicle changes in environmental lead emissions and is an effective proxy for atmospherically sourced depositions of lead in the absence of air quality data.
Commentary
Having established a way to measure trends in lead emissions into periods when primary data were not collected enables improved correlation with health outcomes.
Safe Gardening
Study
VegeSafe: A community science program measuring soil-metal contamination, evaluating risk and providing advice for safe gardening.
Authors
Marek Rouillon, Paul J. Harvey, Louise J. Kristensen, Steven G. George, Mark P. Taylor
Year
2017
Journal
Environmental Pollution, Volume 222, March 2017, Pages 557–566
URL
Quotes
The Australian soil lead guideline of 300 mg/kg for residential gardens was exceeded at 40% of Sydney homes.
Community engagement with VegeSafe participants has resulted in useful outcomes
Commentary
The outcomes included dissemination of knowledge, building raised beds and replacement of contaminated soil.
This program demonstrates that some risks from environmental lead can be successfully managed in the domestic environment. Programs such as this should be rolled-out across other affected communities world-wide.
Using Lichens and Fungi to Measure Atmospheric Lead
Study
Australian atmospheric lead deposition reconstructed using lead concentrations and isotopic compositions of archival lichen and fungi
Authors
Liqin Wu , Mark Patrick Taylor, Heather K. Handley, Michael Wu
Year
2016
Journal
Environmental Pollution, Volume 208, Part B, January 2016, Pages 678–687
URL
https://doi.org/10.1016/j.envpol.2015.10.046
Quotes
During the period of leaded petrol use in Australian automobiles from 1932 to 2002, total median lead concentrations rose.
Following the cessation of leaded petrol use, median total lead concentrations decreased sharply in the 2000s
Commentary
The study showed that overall lead levels have fallen, but the ratio of 206Pb to 207Pb has increased, and therefore concludes that lead emission from petrol is still a source of contamination.
The abstract does not state that 206Pb is predominant in tetra-ethyl lead, but this is assumed based on the statement ‘Lead isotopic characterization appears to be applicable as a “fingerprinting” tool for tracing the sources of Pb pollution’ in the paper ‘Lead Isotope Characterization of Petroleum Fuels in Taipei, Taiwan’ by Pei-Hsuan Yao, Guey-Shin Shyu, Ying-Fang Chang, Yu-Chen Chou, Chuan-Chou Shen, Chi-Su Chou,5 and Tsun-Kuo Chang, 2015. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4454928/)
Nrf2 Raising Agents, Detoxification and Cytoprotection
Study
Nrf2, a master regulator of detoxification and also antioxidant, anti-inflammatory and other cytoprotective mechanisms, is raised by health promoting factors.
Authors
Pall ML, Levine S
Year
2015
Journal
Acta Physiologica Sinica, February 25, 2015, 67(1): 1–18
URL
Quotes
Nrf2 is not a magic bullet but is likely to be of great importance in health promotion, particularly in those regularly exposed to toxic chemicals.
Commentary
This paper is long and complex with references to 141 other studies so extracting and understanding the essential facts is not easy. What follows is an attempt to summarise some key points and to express them in less scientific terms.
How Nrf2 Works
Nrf2 (nuclear factor erythroid-2-related factor 2) is a transcription factor. These are proteins that control the transcription of genetic information from DNA. Essentially, it seems that they turn genes on or off and control production of other proteins. [Ref: Khan Academy, https://www.khanacademy.org/science/biology/gene-regulation/gene-regulation-in-eukaryotes/a/eukaryotic-transcription-factors].
In the case of Nrf2, most related genes have a cytoprotective function, including toxic metals. The Medical Dictionary defines cytoprotective as “protecting cells from noxious chemicals or other stimuli.” [Ref: http://medical-dictionary.thefreedictionary.com/cytoprotective]
Diet for Raising Nrf2 Levels
It has been found that some nutrients can raise Nrf2. The following nutrients are listed in the report followed by some example foods. (This should not be considered dietary advice).
- Many phenolic antioxidants;
Examples - fruit, vegetable, grains, legumes, parsley, coffee, tea, juices, cider, red wine
[Ref: Livestrong http://www.livestrong.com/article/165497-list-of-high-phenol-foods/]
- Gamma- and delta-tocopherols and tocotrienols;
Examples - edible oils, seeds
[Ref: Tocopherols and Tocotrienols in Common and Emerging Dietary Sources: Occurrence, Applications, and Health Benefits; Fereidoon Shahidi and Adriano Costa de Camargo; International Journal of Molecular Science; 20 October 2016; www.mdpi.com/1422-0067/17/10/1745/pdf]
- Long chain omega-3 fatty acids DHA and EPA;
Examples - fatty fish (herring, salmon, mackerel, and tuna) and fish oils; walnuts, flaxseed oil, soybean, and canola oil
[Ref: Functional Foods Fact Sheet: Omega-3 Fatty Acids, International Food Information Council Foundation, http://www.foodinsight.org/Functional_Foods_Fact_Sheet_Omega_3_Fatty_Acids]
- Many carotenoids of which lycopene may be the most active;
Examples - tomatoes
[Ref: Dietary lycopene and tomato extract supplementations inhibit nonalcoholic steatohepatitis-promoted hepatocarcinogenesis in rats; Yan Wang, Lynne M. Ausman, Andrew S. Greenberg, Robert M. Russell and Xiang-Dong Wang; Int J Cancer. 2010 Apr 15; 126(8): 1788–1796.]
- Isothiocyanates from cruciferous vegetables;
Examples - brocolli, brussels sprouts, turnips, watercress, garlic oil
[Ref: Natural products for cancer prevention associated with Nrf2–ARE pathway; Kua, Kirberger, Yang and Chen; Food Science and Human Wellness Volume 2, Issue 1, March 2013, Pages 22-28]
- Sulfur compounds from allium vegetables;
Examples - garlic, onions, scallions, shallots, chives and leeks
[Ref: All You Need To Know About Allium Vegetables; Vegetable Expert; http://www.vegetableexpert.co.uk/all-you-need-know-about-allium-vegetables.html]
Examples - lemons, camphor, pine, cloves, fennel, thyme, oregano, roses, menthol, cannabis, ginkgo, turmeric, mustard seed
[Ref: What are Terpenes; Food Info, http://www.food-info.net/uk/qa/qa-fi69.htm]
[Ref: Terpenoid, Wikipeadia, https://en.wikipedia.org/wiki/Terpenoid]
Examples of diets containing these foods mentioned are known as ‘Mediterranean’ and ‘Okinawan’ as well as the ‘Paleolithic’ diet.
However, a study by Kordas, 2017, included the statement “An expectation that any nutrient-rich food will prevent lead absorption or increase lead excretion in children is not based on empirical evidence.” That is in children, but shows that further analysis and research may be needed. [Ref: The “Lead Diet”: Can Dietary Approaches Prevent or Treat Lead Exposure?; Katarzyna Kordas, 2017; The Journal of Pediatrics, Volume 185, Pages 224–231.e1]
Other Nrf2 Raising Factors
Other Nrf2 raising factors mentioned in the paper include:
This is where low doses of an agent appear to have a beneficial effects where high doses have toxic effects. This seems to be a controversial area - [Ref: If low-level exposure to pollutants is good for us, what does that mean for regulations? Kevin Elliott; Associate Professor, University of South Carolina; http://www.environmentalhealthnews.org/ehs/editorial/hormesis-op-ed]
The Pall and Levine paper refers to Mayer and Yamamoto, 2010. This paper discusses the evolution of Nfr2, but does conclude “The functions of Nrf2 thus suggest a hormetic factor that has evolved empirically over time.” [Ref: The rise of antioxidant signaling--the evolution and hormetic actions of Nrf2.; Maher J, Yamamoto M. ; Toxicol Appl Pharmacol. 2010 Apr 1;244(1):4-15; https://www.ncbi.nlm.nih.gov/pubmed/20122947]
Another paper (Wang, Wang, Wang, Wang, Lu, Yu and Tien, 2010) showed a hormetic effect in plants grown in lead-contaminated soils. They concluded that “traditional threshold models ought to be combined with hormesis effect in assessment of Pb-polluted soils”, but give a wide range for the ‘threshold’ level of lead contamination in soil from 25-125 mg kg(-1). [Ref. Hormesis effects and implicative application in assessment of lead-contaminated soils in roots of Vicia faba seedlings; Wang CR, Tian Y, Wang XR, Yu HX, Lu XW, Wang C, Wang H.; Chemosphere. 2010 Aug;80(9):965-71.; https://www.ncbi.nlm.nih.gov/pubmed/20591469]
This is further discussed by Gonick, 2011, where it is noted that lead-binding proteins increase in concentration after exposure to lead and that these proteins ‘segregate’ lead in several organs. This therefore seems to suggest that the body has some evolved protection against lead toxicity. [Ref: Lead-Binding Proteins: A Review; Harvey C. Gonick; Journal of Toxicology Volume 2011 (2011), Article ID 686050]
It seems that Nrf2 can be regulated by exercise. A paper discussing this is referenced in Pall and Levine’s work.
This is simply eating less calories.
It is also noted that too much Nrf2 for too long can have a negative effects.
Nrf2 and Lead
The paper does contain some lead specific discussions. Pall and Levine note that Nrf2 induces genes for metallothionein which has a role in chelation, transport and excretion of lead, and other heavy metals.
Curcumin
Pall and Levine also note that curcumin has been shown to lower hepatotoxicity of lead and that this is attributed to Nrf2 activation and direct chelation. It is a rather sad irony that turmeric, the source of curcumin, is sometimes contaminated by lead [Ref: US Food and Drug Administration; August 5, 2016; https://www.fda.gov/Safety/Recalls/ucm515328.htm?source=govdelivery&utm_medium=email&utm_source=govdelivery#recall-photos]
The benefits of turmeric are listed by Authority Nutrition [Ref 1], with reference to academic studies, and the related conditions are also those related to lead, e.g. brain disease, heart disease, Alzheimer’s (although the link to lead is disputed), depression, but also cancer and arthritis. They note that absorption of curcumin is greatly enhanced by bioprene/piperene (found in pepper) as supported by Prasad, Tyagi and Aggarwal, 2014 [Ref 2].
[Ref 1: Proven Health Benefits of Turmeric and Curcumin, By Kris Gunnars, BSc | Reviewed on June 9, 2017, https://authoritynutrition.com/top-10-evidence-based-health-benefits-of-turmeric/]
[Ref 2: Recent Developments in Delivery, Bioavailability, Absorption and Metabolism of Curcumin: the Golden Pigment from Golden Spice; Prasad, Tyagi and Aggarwal; Cancer Res Treat. 2014 Jan; 46(1): 2–18.; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3918523/]
It should be noted that there are some concerns about curcumin toxicity which would need further exploration.
Final Note
Pall and Levine conclude that “Nrf2 probably has a substantial role in producing resistance to toxic metal exposure” and note that there is much more information available that has not been referenced in the paper.
Another review of this study can be found at:
Diet And Lifestyle Promote Nrf2 – Science Again Supports What We Have Been Saying For A Long Time, Posted ByDr. Paul Anderson, https://www.consultdranderson.com/diet-lifestyle-promote-nrf2-science-supports-saying-long-time/. This is entitled “Nrf2, a master regulator of detoxification and also antioxidant, anti-inflammatory and other cytoprotective mechanisms, is raised by health promoting factors.”
Conclusion
From this brief analysis, it would seem that the human body has some mechanisms to respond to lead toxicity. These mechanisms can be related to the Nrf2 transcription factor which stimulates genes to produce proteins that bind to lead. Furthermore, it seems that the level of Nrf2 can be increased by the appropriate diet, exercise and eating less.
What is also interesting in the paper is the hormesis concept which a low level of toxin has a beneficial effect whereas a high level does not. Unfortunately, it seems to we have not yet quantified low and high.
It is no surprise that diet and exercise are beneficial to health. This paper explains how this might work and how it has relevance in lead poisoning prevention.
Lead Intake from Wine
Study
A human health risk assessment of lead (Pb) ingestion among adult wine consumers
Authors
Kevin M. Towle, Lindsey C. Garnick and Andrew D. Monnot
Year
2017
Journal
International Journal of Food Contamination20174:7
URL
https://foodcontaminationjournal.springeropen.com/articles/10.1186/s40550-017-0052-z
Quotes
Overall, findings suggest that Pb content in wine does not pose a health risk to adult wine consumers.
Commentary
It should be noted that this is a literature review rather than original research.
‘Truth About Lead’ Facebook Group
The following comment was made on the ‘The Truth About Lead’ Facebook group. “Again this is another example of why we need to look at lead levels and say 0 is the only safe level. I've read so many times that many products contain small levels of lead and are safe to ingest. In light of fact that lead does not pass through the body and settles into the bone and vital organs. A little bit of lead here a little there adds up over time in the body. The next thing you know your lead poisoned.”
From The Editor
“I find the article to be Amero-centric in the extreme and misleading by implying that a PbB below the CDC's current 5ug/dL carries no Pb-related health risk.
I defy anyone to find another country with a mean adult PbB baseline as low as the US level (used in this study) of 1.27ug/dL. That is, I contend that it would be easy in every country outside of the US to get from that country's mean adult PbB to the Lustberg and Silbergeld Pb-related adult health risk PbB of 1.9ug/dL - JUST by drinking wine!
I also understood from perhaps something Prof Chris Winder once wrote or said, that, biokinetic lead uptake models for alcohol (and cigarettes) need to take into account more than just the lead concentration in the drink (or cigarette) and the consumption (smoking) rate, because the alcohol (temperature of the smoke) can have other impacts on both the lead rate and metabolism of other relevant-to-lead nutrients eg Vit C. These factors were not mentioned in the description of the Pb exposure model used in the study, and further research measuring lead in blood and comparing that to Pb in wine actually being imbibed was not considered.”
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