The Nutrition Science thread

[Rideski]

So I asked the brainy gf what attributed to red meat being deemed more cancerous than others and this is the reply I got. Thought some might find it interesting and or have opinions/facts to support or disagree.

Source:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4698595/

The possible factors from red meat consumption that could cause cancer:

1. N-nitroso compounds (NOCs)
2. Heterocyclic amines (HCAs)
3. Polycyclic aromatic hydrocarbons (PAHs)
4. Heme iron in red meat
5. PUFAs
6. Bile acids (made by the gut in response to the presence of dietary fat)
7. Other infectious agents

other helpful definitions to know:
mutagen: a chemical or physical agent that causes an error in DNA replication (can cause a mutation, hence the name), mutagens are also carcinogens...kind of like a precursor to a tumor forming. If you get enough mutations, you are more likely to have a tumor/cancer form

carcinogen: a chemical or physical agent that has the ability to cause cancer, could be due to damage to the genetic code or disruption of normal cellular processes

1. N-nitroso compounds (NOCs) -
production in meat occurs during meat processing, like making yummy bacon and sausage; mutagenic so potentially cancer causing; also formed by the body when meat is consumed

Evidence that it cause cancer:
article cites high NOCs in fecal samples of red meat eaters, NOCs are carcinogenic compounds so would lead to higher incidences of colorectal cancers in this group

2.& 3. Heterocyclic amines (HCAs) & Polycyclic aromatic hydrocarbons (PAHs) -
potent carcinogens produced during high temperature or open flame cooking; high temperatures cause chemical reactions in meat that produce HCAs & PAHs; high levels of these compounds found in well-done meats

Evidence that it cause cancer:
study that shows positive correlation between well-done meat eating and recurrence (returning colorectal cancers)

6. Bile Acids (BAs) -
dietary fat increases production of bile acids in the gut; animal meat contains a high amount of saturated fats (40-70%) causing increased bile acid (BA) production when eaten; small amount of metabolized bile acids (secondary BAs) can enter digestive tract and cause imbalance and dysfunction

Evidence that it causes cancer:
article cites that there are inconsistent results to show a link between high fat consumption and colorectal cancers...it does state that high fat diets can cause obesity, which can cause insulin resistance, which is linked to tumor growth
Chronic exposure to secondary BAs can cause disorder and inflammation that over time can potentially cause cancer to form.

Colorectal cancer due to red meat is caused by high temperature cooking (which causes carcinogens in the chemical process of cooking) and indirectly by high saturated fat, which can cause insulin resistance and inflammation over a longer period, causing cancer development.

Article found that showed no direct link between high saturated fat diets and intestinal cancers:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3023148/

This article basically says it is a combination of all of the factors (and gets down to details f cooking times, temps and types of meat - interesting!):
https://onlinelibrary.wiley.com/doi/...541-4337.12501


article here: https://www.sciencedirect.com/scienc...14000564#s0040

[Dantheman]

This article basically says it is a combination of all of the factors (and gets down to details f cooking times, temps and types of meat - interesting!):
https://onlinelibrary.wiley.com/doi/...541-4337.12501

"Therefore, it is difficult to conclude that dietary red meat is the main cause of colorectal cancer. Rather, there may be an intricate influence of multiple factors, including fruit and vegetable intake, alcohol consumption, smoking, overweight, obesity, and stress."

Pretty much. Red meat *might* exacerbate the risk of colorectal cancer in the context of a generally unhealthy lifestyle. It's not associated with any other kind of cancer.

[bagtagley]

Dan, what’s the latest on animal fats, particularly Omega 6 fatty acids?

[Dantheman]

O-6 in meat specifically? Honestly I haven't seen much on it lately, though I haven't really been looking. My general opinion is that unless you're eating a chicken thigh-based carnivore diet (which I wouldn't recommend) O-6 are just not a problem if you don't eat refined seed oils.

[Rideski]

Thanks Dan. Even though some of the science in the longer articles is out of my scope of knowledge I was still thinking there were big caveats as well. She had already called the friendly wager a draw when she wrote that.

[Dantheman]

All of those mechanisms could potentially have pro-cancer effects, it's just that some of them aren't meat-specific and/or don't matter in the context of a diet with lots of veggies and fruit, tubers, pulses, etc. As noted in those links, PAHs, acrylamides, and HCAs are produced when high-heat cooking anything and unfortunately we're also exposed to lots of them in the ambient environment. I can't recall the source, but I've read that they're poorly absorbed in your stomach and quickly neutralized in the stomach if eaten with dark green/blue/orange/red things.

As for NOCs, vegetables have tons of nitrates, orders of magnitude more than processed meat. AFAIK there's no evidence that eating, say, meat and celery (TONS of nitrate) together produces concerning levels of NOCs. If your breakfast consists of nothing but a half pound of bacon you should probably pump the brakes a little.

Maybe bile acids could be a problem on a long-term keto/carnivore diet (I don't recommend either), but otherwise it's doubtful if you eat roughage.

[Rideski]

I missed the previous memos veggies had nitrates. I’ll check that out. Yeah we both eat lots of good veggies for sure. Apparently with nitrates for free.

[fool]

I might have missed it...but what are the collective thoughts on collagen and BCAAs, especially in a post-workout protein shake? Unsure of the science - and who to trust - so figured the Mags like Dan might have some thoughts. Including if anything besides protein + carbs + electrolytes is critical in a post-workout shake (primarily after running/endurance activities).

[concretejungle]

I’ve added collagen to my coffee for the last six months (taken with vitamin C) and haven’t noticed anything. I also tried BCAA’s for long enough to notice zero difference. Your results may be different.


Sent from my iPhone using TGR Forums

[Dantheman]

I might have missed it...but what are the collective thoughts on collagen and BCAAs, especially in a post-workout protein shake? Unsure of the science - and who to trust - so figured the Mags like Dan might have some thoughts. Including if anything besides protein + carbs + electrolytes is critical in a post-workout shake (primarily after running/endurance activities).

For post-endurance recovery the answer is just moar carbs. The studies that showed 4:1 carb-protein to be optimal didn't control for total calories. When calories are held constant (i.e. 100 cals of carbs vs. 80 cals carbs+20 cals protein) carb-only performs better than carbs+protein. Fully explained here:




I haven't looked into BCAAs much. Collagen probably doesn't matter much for endurance recovery specifically. For general health it probably helps and I work it into meals when I can. The main beneficial thing you're getting from collagen/gelatin is glycine. There's good evidence that almost no one gets enough glycine for optimum health (https://link.springer.com/article/10...38-009-0100-9; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5350494/). Isolated glycine happens to very sweet, almost as sweet as sugar. I buy it in bulk powder and use it to sweeten things like beverages, oatmeal, etc. Basically anything where you can dissolve it in water, it doesn't work for baking.

[SkiBall]

PSA for anyone that needs, I just got some more of this amino and electrolytes that I kind like that is BOGO right now which is a good deal.
https://www.bodybuilding.com/store/e...ino-acids.html

And check out same brand Recovery Mode. I have made my own unscientific concoctions, mainly after big ski days, and this stuff seems to do a good job plus some protein.
https://www.bodybuilding.com/store/e...-recovery.html

[Norseman]

1000 yr old poops rehydrated, DNA fragments from 38% novel gut bacteria found

https://www.sciencemag.org/news/2021...n-gut-bacteria

[babybear]

1000 yr old poops rehydrated, DNA fragments from 38% novel gut bacteria found

https://www.sciencemag.org/news/2021...n-gut-bacteria

holy sh*t that is neat
Feces is not considered "human remains" under federal law

this book "I Contain Multitudes" was good

[Jacques Strap]

collagen and BCAAs, especially in a post-workout protein shake

As far as BCAAs go, as long as you are getting enough high quality protein in your daily diet, you don't need to waste money on BCAAs. They're not a scam, they're just unnecessary and redundant, especially at their price.

I agree completely with Dan re: collagen and post-workout recovery.

[thefortrees]

For post-endurance recovery the answer is just moar carbs. The studies that showed 4:1 carb-protein to be optimal didn't control for total calories. When calories are held constant (i.e. 100 cals of carbs vs. 80 cals carbs+20 cals protein) carb-only performs better than carbs+protein. Fully explained here:




I haven't looked into BCAAs much. Collagen probably doesn't matter much for endurance recovery specifically. For general health it probably helps and I work it into meals when I can. The main beneficial thing you're getting from collagen/gelatin is glycine. There's good evidence that almost no one gets enough glycine for optimum health (https://link.springer.com/article/10...38-009-0100-9; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5350494/). Isolated glycine happens to very sweet, almost as sweet as sugar. I buy it in bulk powder and use it to sweeten things like beverages, oatmeal, etc. Basically anything where you can dissolve it in water, it doesn't work for baking.

So you’re saying I’ve been doing it right by drinking a few (or more) beers at the end of a big day.

[Dantheman]

So you’re saying I’ve been doing it right by drinking a few (or more) beers at the end of a big day.

I've seen studies where NA beer outperformed fancy recovery drinks. Unfortunately the data is very clear that even small quantities of alcohol impair recovery.

[Rideski]

I saw a recommendation for a book called
How not to diet

Anyone read it? Forward sounds good.

[Game Over]

Can we talk about dairy?

Iceman posted this in the ice cream thread…

https://www.health.harvard.edu/blog/...-2019102118028

My vegan buddy can’t process it and is going on and on about prostate cancer. That the science has a bias.

Sent this as a example of a horrible biased study

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6683061/

Is there anything to this cancer noise with high amounts of 2% and full fat?

Kinda seems like he’s in denial. It’s eye opening considering the dude is a Dr. and is of course very critical of unvaccinated-> science deniers and all that 🤔

[old_newguy]

Anyone have any thoughts on the viability of a gluten free (because of diagnosed celiacs) and lacto-ovo vegetarian diet? Cookbooks with decent recipes?

I'm trying to figure out how to get enough iron, B12, protein etc.

We already eat a significant amount of "whole foods", salads, etc and don't eat a lot of processed foods and have had limited red meat intake for years, so have relied on chicken/fish alot. I'm not super interested in eating a bunch of hyper-processed fake meat products, but we do eat tofu somewhat regularly. Aside from the GF thing we aren't super hardcore about it, so will eat whatever is available at other peoples houses or when eating out. I'm thinking we probably need to be regularly (2x/wk) eating fish to make this work.

(Maybe we can leave the "why wouldn't you want to eat meat" argument aside, it's boring. I'm just curious if it's possible to eat a healthy, balanced diet while being GF and vegetarian.)

[Mazderati]

Don't sleep on sardines and shellfish.

[Dantheman]

Celiac here (technically, dermatitis herpetiformis), been strict GF for almost a decade. Nutritionally, this part is easy AF. There are no nutrients in gluten grains that aren't easily acquired through other sources. I eat a lot of potatoes, sweet potatoes/other tubers, corn tortillas and GF oats.

For the vegetarian part, I'd run your current diet through something like MyFitnessPal. Then, run it again without the animal foods you're going to drop and with the subs you already have in mind. That should give you a pretty good idea of how far short you might end up on iron, B12, protein etc. If the results indicate sub-optimal intake of any of those three:

Eat more eggs. Eggs are rich sources of B12 (two eggs = ~50% of RDI), and worst-case B12 supplements are cheap and don't carry any risks.

You may be fine on protein. You definitely want your protein intake above 0.5 g/lb BW/day, but there is no need at all to go above 1 g/lb BW/day. You very well may get there with eggs and dairy alone, but if you're short you can add some whey protein or something.

Likewise, you may not need any additional iron. Adult men only need about 8-10 mg/day and excessive iron is more common than iron deficiency. Eggs are also a good source and iron-rich plant foods are plentiful (though non-heme iron in plants is less bioavailable).

DHA/EPA will be an issue without fatty fish. Flax/hemp/chia/walnuts can help since they supply a lot of ALA, but conversion of ALA to DHA/EPA is not good enough to be relied on entirely (even Michael Greger has begrudgingly admitted this in recent years). You can find eggs that are enriched in DHA (they put seaweed in the chicken feed), or take algae-based DHA/EPA supplements.

[TBS]

Checking in with my story.

Used to race bicycles, retiring from the road at age 41 and MTB racing at 45.
Problem - I didn’t modify my diet after I quit racing and reduced saddle time.
Gained 60lb over the next 20 years.

I was diagnosed type 2 diabetic 4/18/21 with A1c = 6.7 and carrying 240lb on a 6’0” frame

Got a new doc who described my two choices in stark terms
1. Keep doing what you’re doing and die a slow horrible death as you go blind and appendages are amputated.
2. Change your diet

She also set me up with a Diabetes specialist, who is T1D, and was Div 1 track athlete (Ashton Eaton’s coach in field events), and well-known in diabetes management circles across the globe.

New diet targets
Max 2,000 calories and 200g of carbs per day.
No food with glycemic index > 55.
No liquid carbs (beer, fruit juices).
Animal fat in moderation, except eat all the salmon I want
Eat all the protein and HDL I wanted.
Make sure to eat some fats with carbs to slow down carb metabolism and insulin response.
Try to keep my eating in an 8 hr window but don’t stress it.

She told me to never try a diet with less than 100g carbs per day. Because I’ll never stick with that.

It was hard for a couple of weeks but now I’m at about 1800 cal and 150g carbs. And burning about 1000cal/day exercising (MTB rides, hike/wade/flyfish, now skiing)

Last weeks blood test came back with A1c = 5.9 (I.e. normal) and weight = 201.

I feel a shitload better - not carrying around the equivalent of a 5gal bucket of water in extra weight will do that. Riding way faster and stronger, and my first two ski days were a lot easier to recover from.

We are now working on an eating plan for skiing. Current plan is Meat/cheese/avocado omelette first off in AM (0600), Overnight Oats(*) with blueberries in the car an hour before lifts spin. Some meat, an apple and carrots/peanut butter midday with protein bars (200 cals, 15g carbs) to fill in if hungry. Eat dinner early (like 4pm).

I have a continuous glucose monitor on my desk. As soon as my legs recover from the Alzheimer’s of muscle memory, I’m hooking myself up for a couple of weeks to see in real time how food intake works for/against me on a long day.

One man’s experience. YMMV

(*) Overnight Oats - put rolled or steel cut oats in a pint jar. Add equiv amount of milk (I’m using almond milk) a sweetener (2 tsp stevia) and blueberries. Put in refrig overnight.

Prepping this way makes a portion of the carbs in the oatmeal resistant to metabolism in your gut. Instead, these carbs go to your large intestine where they feed the gut bacteria. And since you have more gut bacteria than human cells in your body, eating overnight oats makes you less human!

[Dantheman]

Congrats! I'm a pretty fit guy and carrying a 40 lb pack around 24/7 would crush me.

[Danno]

Nice work, TBS! I call bullshit on the "never try a diet with less than 100g carbs per day. Because I’ll never stick with that." though, because I have been doing that for 3.5 years now. I probably have a handful (10-20?) of days a year where I go over 100g carbs.

[Dantheman]

Nice work, TBS! I call bullshit on the "never try a diet with less than 100g carbs per day. Because I’ll never stick with that." though, because I have been doing that for 3.5 years now. I probably have a handful (10-20?) of days a year where I go over 100g carbs.

There's a small percentage of people who are the exception that proves the rule.