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Let me introduce myself. My name is Mark Sisson. I’m 63 years young. I live and work in Malibu, California. In a past life I was a professional marathoner and triathlete. Now my life goal is to help 100 million people get healthy. I started this blog in 2006 to empower people to take full responsibility for their own health and enjoyment of life by investigating, discussing, and critically rethinking everything we’ve assumed to be true about health and wellness...

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March 19, 2018

Dear Mark: Vitamin B and Lung Cancer, Folate Stability in Liver, and Less DNA Damage on No Produce

By Mark Sisson
19 Comments

Dear_Mark_Inline_PhotoFor today’s edition of Dear Mark, I’m answering three questions from readers. First, what do I make of the recent study showing a link between lung cancer in men and supplementation with vitamin B6 and vitamin B12? Next, how stable is folate in liver? Other foods with high folate content before cooking, like legumes and greens, lose a lot during cooking. And finally, what’s my take on the old study where subjects’ markers of oxidative damage improved after eating a diet bereft of produce?

Let’s go:

Mark, I wonder if you’ve seen the study linking lung cancer in men with vitamin B supplementation: http://ascopubs.org/doi/abs/10.1200/JCO.2017.72.7735

What do you think?

Interesting study, thanks.

Supplementation with vitamin B6 or B12 was not associated with lung cancer risk in women.

Supplementation with vitamin B6 or B12 was associated with lung cancer risk in men, but only if those supplements were taken separately. If they supplemented with either vitamin as part of a multivitamin, the risk disappeared.

In other studies, vitamin B6 appears to be protective against most types of cancer, including lung cancer. Circulating levels of vitamin B6 protect against lung cancer. People with low “functional” vitamin B6 status—meaning they have low levels of active vitamin B6—have a greater risk of lung cancer.

Here’s what I think is going on: The study is capturing people with vitamin issues and disorders that cause deficiencies. People who take high dose vitamin B6 or B12 are more likely to have those disorders. They’re more likely to have low levels of the vitamins. They’re more likely to be prescribed vitamin supplements to make up for the deficiency. They’re probably even more likely to be unhealthy; many people take vitamins as an antidote to poor health.

Maybe supplementing isn’t good enough to overcome the inherent deficiency, or the condition causing the deficiency. Maybe these people aren’t converting supplemental vitamin B6 into the active, “functional” form that protects against cancer. Many of the participants were smokers at baseline, and the vitamin-mediated risk of cancer went up in those who smoked. Maybe they’re taking vitamins in response to an underlying disease state.

Those underlying disease states change how vitamin B6 acts in the body. In one study, “functional” B6 status was protective against lung cancer, while another type of biomarker measuring the catabolism of B6 due to inflammation, was linked to a rise in lung cancer. Low-grade inflammation is often high in states of disease or general unhealthiness, and B6 catabolism is a strong predictor of all-cause mortality.

It does seem that cooking affects these folate sources differently. If you compare cooked (boiled, drained) legumes, lentils come out on top! (Although liver is still king.)

This is true.

Animal-sourced folate is quite stable whether you freeze it or cook it.

I should say that overcooking your liver will deplete the folate. 12 minutes of frying in corn oil until 158°F/70°C caused a 50% loss of folate. 16 minutes of broiling until 158°F/70°C caused a 40% loss. That’s an obscene amount of cooking. Cooked liver should be pink inside. Creamy, not grainy. Even then, you still maintain at least half of the already generous amount of folate.

Older studies got better results, with fried beef liver losing between just 11-15% of folate. They probably weren’t overcooking it.

A ghost said:

I’d love to hear your opinion on this study:
https://www.ncbi.nlm.nih.gov/pubmed?Db=pubmed&Cmd=ShowDetailView&TermToSearch=12064344&ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum

Man, I wish I could get my hands on the full study. I’ll comment, but keep in mind that I’m only going off the abstract. Consider this fun speculation, not iron-clad conclusion.

Researchers took 8 smokers and 8 non-smokers, removed all concentrated sources of flavonoids from their diet, and fed them meat patties dosed with green tea extract for 10 weeks. This amounted to a “fruit-and-vegetable-free diet,” as produce is the richest source of flavonoids.

Green tea extract had some positive effects on postprandial oxidative stress, but they didn’t last. The half life of the extract in the body was 2 hours. As the subjects peed it out, the antioxidant capacity returned to normal.

What’s weird is that oxidative damage to DNA, lipids, and blood proteins all decreased over ten weeks despite the subjects eating no produce and the green tea extract only improving antioxidant capacity for a few hours postprandial.

Maybe the diet was dense with vitamins and minerals. After all, vitamins and minerals serve antioxidant functions and provide building blocks for the production of endogenous antioxidants like glutathione.

Maybe most of the oxidative damage our DNA, lipids, and blood proteins face occurs immediately after eating. If so, the postprandial increase in antioxidant capacity could have made all the difference.

We don’t know enough about the rest of the diet to say anything else or do anything but make guesses. They weren’t only eating the green tea meat patties. They ate other stuff, too—a “strictly controlled diet” absent fruits and vegetables. I really wish I could get my hands on the full paper.

That’s it for today, folks. Help out down below if you have anything to add, ask, or proclaim!

Take care, be well, and Grok on.

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19 Comments on "Dear Mark: Vitamin B and Lung Cancer, Folate Stability in Liver, and Less DNA Damage on No Produce"

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Elizabeth Resnick
2 months 5 days ago
As far as the folate loss when cooking liver, I eat it raw. Totally gross, I know. I buy pastured beef liver from a local farmer and cut it into small pieces. Put in the freezer on a parchment lined baking sheet until frozen then pack up in a ziploc. Take one or two out in the morning and let it partially thaw while I’m doing my morning routine. Then I just swallow the liver whole. I take it with lemon water which helps to cut the taste. There is no point in cooking liver since I don’t know anyone… Read more »
Tiffany
Tiffany
2 months 5 days ago

That’s a great idea! Cutting it up does sound like a pain though. I buy a liverwurst from whole foods by wellshire farms that has no sugar or grains added but I fry it in a pan until almost black before eating, so I imagine I decrease the folate content by quite a lot.

Elizabeth Resnick
2 months 5 days ago

Hey Tiffany, I wish I could find clean liverwurst…I actually enjoy that! But it’s hard to find in grocery stores around me, and usually has some crappy ingredients.

HDA
HDA
2 months 4 days ago

US Wellness Meats has a clean liverwurst.

Elizabeth Resnick
2 months 4 days ago

I may have to order some!

Tiffany
Tiffany
2 months 4 days ago

Yeah it is literally the only pre-cooked liver product I’ve found that doesn’t have corn, wheat, sugar, or any other crap. It has nonfat dry milk but that’s okay with me. The brand is exclusive to Whole Foods, if you live near one. 🙂

Elizabeth Resnick
2 months 4 days ago

I FINALLY have a whole foods opening kind of near me…will definitely get some. And love that this community exists…where else could we be having such an in depth convo about liver lol?!

Tiffany
Tiffany
2 months 1 day ago

Exactly! MDA is just wonderful. 🙂

Shary
Shary
2 months 5 days ago

Elizabeth, you’ve got more fortitude than I have. I don’t mind cooked chicken liver, but I find the taste and texture of ruminant liver flat-out disgusting, even when cooked. Incidentally, according to several websites I looked at, chicken liver compares favorably to beef liver with regard to nutrients. I think I’ll just stick with chicken liver pates, which even my ultra-picky family members will eat.

Kelly
Kelly
2 months 5 days ago

I eat grass-fed-beef liver raw, too. However, since I’ve always loved the taste of liver (since I was a kid), I eat it in quantity. I have about 40-50 grams at a sitting and chew it up, savoring the flavor. My guess is that my affinity for liver comes from my MTFHR mutation… it’s just my body craving a good source of vitamin B. We eat fish raw, why not meat?

Elizabeth Resnick
2 months 5 days ago

Wow, Kelly, glad I’m not the only one. But I can’t imagine chewing it up…I just try to get it down as fast as possible!

Ken Zahringer
Ken Zahringer
2 months 5 days ago

Check your inbox for full paper.

Tiffany
Tiffany
2 months 5 days ago

What about the folate in sunflower seeds and leafy greens? How much does cooking affect those?

John
John
2 months 5 days ago

The full paper is available for download by clicking “Full Text Links” in the upper right of the PubMed page, then clicking the PDF symbol button to the lower left of the extract at the BJN site.

Chupo
Chupo
2 months 4 days ago

I hope he reads it. It had nothing to do with GTE as the effects were seen during the control period when it wasn’t given.

Rémy ROCHE
Rémy ROCHE
2 months 5 days ago

Green tea has polyphenols, so they exert a hormetic response. Having them in the body even just a few hours a days should be enough to upregulate the body’s antioxidant production, explaining the positive results?

Here’s the full study: https://www.cambridge.org/core/services/aop-cambridge-core/content/view/D0B0C9719378E7002F87734DA6D91798/S0007114502000673a.pdf/green_tea_extract_only_affects_markers_of_oxidative_status_postprandially_lasting_antioxidant_effect_of_flavonoidfree_diet.pdf

Time Traveler
Time Traveler
2 months 5 days ago

Hey Mark, here’s the link to the full smokers study, if you wish analyze thoroughly. It took me 2 seconds to find (-:

http://doc.rero.ch/record/301928/files/S0007114502000673.pdf

Steph Windmill
Steph Windmill
2 months 4 days ago

For some years now I’ve been whizzing Ox Liver up in the blender and then adding it to vats of chilli or bolognaise. It gives an additional meaty taste, but I’ve been mostly (and smugly!) doing it for the nutrition. Based on the idea that pan-frying depletes folate, is the 2+ hours of cooking time I’m giving this dish going to make adding the liver completely redundant on the nutrition front?!

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