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Life Sciences => Physiology & Medicine => Topic started by: joblai on 26/04/2019 17:47:41

Title: Do Vegans produce more methane than meat eaters?
Post by: joblai on 26/04/2019 17:47:41
Due to the amount of pulses and fibre in their diet, are vegans more flatulent and emit more methane?
Title: Re: Do Vegans produce more methane than meat eaters?
Post by: Bored chemist on 26/04/2019 17:59:41
Probably not. And, to be sensible about it, you would need to account for the methane produced by the farm animals the non-vegans eat
Title: Re: Do Vegans produce more methane than meat eaters?
Post by: chris on 26/04/2019 18:23:38
According to my friend Giles Yeo, who appears on our show from time to time and recently agreed to go vegan for a BBC documentary, he did get very "windy" (his words); however, this did settle down with time, so the interpretation is that the transition in intake from meat-based diet to vegan diet applies different selection pressures to the microbiome, which initially rebels in a flatulent way...

Here's a reference: https://www.thenakedscientists.com/articles/questions/why-does-food-make-me-happy

Also, we did have a similar discussion about this topic previously, here: https://www.thenakedscientists.com/forum/index.php?topic=75298.0
Title: Re: Do Vegans produce more methane than meat eaters?
Post by: AnnaScott on 03/05/2019 21:34:37
It is well known that grassy food wanders in the stomach, when we eat a lot of fiber, we often fart. But poorly digestible meat products rot more, decompose for a long time, and therefore less gas is released during splitting.
Title: Re: Do Vegans produce more methane than meat eaters?
Post by: evan_au on 03/05/2019 23:25:07
Quote from: AnnaScott
poorly digestible meat products rot more
More than what? Fiber?

Digestible foods (whether animal or vegetable) are broken down into small molecules which can be absorbed into the gut. If you call this "rotting", they both rot equally.

Indigestible foods (whether animal or vegetable) are not broken down into small molecules which can be absorbed into the gut, and so pass through the digestive system. If you call this "rotting", they both rot equally.

But since humans generally avoid eating bones, vegetables contain a greater percentage of indigestible matter than meat.

Quote
grassy food wanders in the stomach
Why? It's the same distance from top to bottom of the stomach (and from mouth to colon).
Title: Re: Do Vegans produce more methane than meat eaters?
Post by: Bored chemist on 04/05/2019 02:46:39
It is well known that grassy food wanders in the stomach,
No.
That's just hokum.
Title: Re: Do Vegans produce more methane than meat eaters?
Post by: AnnaScott on 04/05/2019 09:29:24
My nutritionist says that flatulence - bloating and increased flatulence in the intestines can be caused by the specifics of nutrition: poor grinding of food in the mouth, respectively, poor digestion in the stomach, food is delayed in the intestine, causing putrefactive processes, producing gases. In this case, the processes of splitting go wrong and far from the molecules, there remains a lot of non-digestible food. Insufficient chewing and swallowing too fast, especially meat. The emergence of flatulence contributes to the food products with high gas-generating potential: onions, celery, cabbage, radishes, onions, carrot cucumbers, potatoes, apples, peaches, plums, grapes, bananas, pears, apricots. Meat eaters do not fart less because they consume less fiber, bran products, vegetables and fruits.
Title: Re: Do Vegans produce more methane than meat eaters?
Post by: alancalverd on 04/05/2019 11:02:33
Methane ain't the problem. Farm animals exhale CO2 while they are alive, and this accounts for about 25% of all anthropogenic emissions.

We probably fart less CH4 than the ruminants we eat, because we don't have the capacity for anerobic digestion of celluose.
Title: Re: Do Vegans produce more methane than meat eaters?
Post by: Bored chemist on 04/05/2019 14:51:29
food is delayed in the intestine, causing putrefactive processes,
The acidic conditions in the stomach would prevent putrefaction.