Freethought & Rationalism Archive

ps418 · 04-25-2003, 06:00 AM

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Nuno:
All in all, vegetarians have even been shown by research to have a HIGHER all cause mortality rate than meat eaters (1), so I do question how much healthier it really is.

Its questionable that vegetarians have higher mortality rates than meat-eaters. There are newer and larger epidemiological studies that show either little difference, or differences favoring vegetarians, such as the one below which is prospective (10 years), includes a huge sample (76,000), and suggests that while vegetarians die about 30% less frequently from ischaemic heart disease, there are "no significant differences between vegetarians and nonvegetarians in mortality from cerebrovascular disease, stomach cancer, colorectal cancer, lung cancer, breast cancer, prostate cancer, or all other causes combined."

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OBJECTIVE: To compare the mortality rates of vegetarians and non-vegetarians. DESIGN: Collaborative analysis using original data from five prospective studies. Death rate ratios for vegetarians compared to non-vegetarians were calculated for ischaemic heart disease, cerebrovascular disease, cancers of the stomach, large bowel, lung, breast and prostate, and for all causes of death. All results were adjusted for age, sex and smoking. A random effects model was used to calculate pooled estimates of effect for all studies combined. SETTING: USA, UK and Germany. SUBJECTS: 76,172 men and women aged 16-89 years at recruitment. Vegetarians were those who did not eat any meat or fish (n = 27,808). Non-vegetarians were from a similar background to the vegetarians within each study. RESULTS: After a mean of 10.6 years of follow-up there were 8330 deaths before the age of 90 years, including 2264 deaths from ischaemic heart disease. In comparison with non-vegetarians, vegetarians had a 24% reduction in mortality from ischaemic heart disease (death rate ratio 0.76, 95% CI 0.62-0.94). The reduction in mortality among vegetarians varied significantly with age at death: rate ratios for vegetarians compared to non-vegetarians were 0.55 (95% CI 0.35-0.85), 0.69 (95% CI 0.53-0.90) and 0.92 (95% CI 0.73-1.16) for deaths from ischaemic heart disease at ages <65, 65-79 and 80-89 years, respectively. When the non-vegetarians were divided into regular meat eaters (who ate meat at least once a week) and semi-vegetarians (who ate fish only or ate meat less than once a week), the ischaemic heart disease death rate ratios compared to regular meat eaters were 0.78 (95% CI 0.68-0.89) in semi-vegetarians and 0.66 (95% CI 0.53-0.83) in vegetarians (test for trend P< 0.001). There were no significant differences between vegetarians and non-vegetarians in mortality from the other causes of death examined. CONCLUSION: Vegetarians have a lower risk of dying from ischaemic heart disease than non-vegetarians.

Key et al, Mortality in vegetarians and non-vegetarians: a collaborative analysis of 8300 deaths among 76,000 men and women in five prospective studies. Public Health Nutr 1998 Mar;1(1):33-41.

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We combined data from 5 prospective studies to compare the death rates from common diseases of vegetarians with those of nonvegetarians with similar lifestyles. A summary of these results was reported previously; we report here more details of the findings. Data for 76172 men and women were available. Vegetarians were those who did not eat any meat or fish (n = 27808). Death rate ratios at ages 16-89 y were calculated by Poisson regression and all results were adjusted for age, sex, and smoking status. A random-effects model was used to calculate pooled estimates of effect for all studies combined. There were 8330 deaths after a mean of 10.6 y of follow-up. Mortality from ischemic heart disease was 24% lower in vegetarians than in nonvegetarians (death rate ratio: 0.76; 95% CI: 0.62, 0.94; P<0.01). The lower mortality from ischemic heart disease among vegetarians was greater at younger ages and was restricted to those who had followed their current diet for >5 y. Further categorization of diets showed that, in comparison with regular meat eaters, mortality from ischemic heart disease was 20% lower in occasional meat eaters, 34% lower in people who ate fish but not meat, 34% lower in lactoovovegetarians, and 26% lower in vegans. There were no significant differences between vegetarians and nonvegetarians in mortality from cerebrovascular disease, stomach cancer, colorectal cancer, lung cancer, breast cancer, prostate cancer, or all other causes combined.

Key et al, Mortality in vegetarians and nonvegetarians: detailed findings from a collaborative analysis of 5 prospective studies. Am J Clin Nutr 1999 Sep;70(3 Suppl):516S-524S.

Patrick

Godot · 04-25-2003, 06:11 AM

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Originally posted by Nuno Figueira
Can be, but there's actually a lot of debate if it's that counterproductive in the long run, and I haven't seen any research done with athletes in long term low carb diet. I can tell I never had any problems or drops of performance in my weightlifting activities when cutting carbs.

In the context of the advice given, you most certainly would not exhibit any loss in weightlifting performance due to a low CHO diet. Except in extreme circumstances, weightlifting is an anaerobic activity. It isn't an activity where glycogen depletion is really an issue, nor is substrate utilisation going to affect performance to an appreciable degree (if at all).
As an aside to all this, what tyoe of weightlifting are you involved in? Recreational? Bodybuilding? Traditional/Olympic?

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Phosphocreatine is also used.

The P-Cr energy system is only used for the initial ~10s burst of any activity. It is a negligible contribution WRT endurance activities. After that, it is depleted and the body shifts into the anaerobic glycolytic system until around the 90s mark. Subsequently, aerobic glycolysis takes over.
Lipid peroxidation occurs at lower exercise intensities, but the enzymatic pathways responsible for this are disabled due to the changes in pH associated with increasing intensity level.
In the absence of sufficient CHO stores for energy, the body will catabolise LBM and FM, but exercise intensity is sacrificed in the trade-off.

Nuno Figueira · 04-25-2003, 06:38 AM

Quote:

Originally posted by ps418
Its questionable that vegetarians have higher mortality rates than meat-eaters. There are newer and larger epidemiological studies that show either little difference, or differences favoring vegetarians, such as the one below which is prospective (10 years), includes a huge sample (76,000), and suggests that while vegetarians die about 30% less frequently from ischaemic heart disease, there are "no significant differences between vegetarians and nonvegetarians in mortality from cerebrovascular disease, stomach cancer, colorectal cancer, lung cancer, breast cancer, prostate cancer, or all other causes combined."

Key et al, Mortality in vegetarians and non-vegetarians: a collaborative analysis of 8300 deaths among 76,000 men and women in five prospective studies. Public Health Nutr 1998 Mar;1(1):33-41.

Key et al, Mortality in vegetarians and nonvegetarians: detailed findings from a collaborative analysis of 5 prospective studies. Am J Clin Nutr 1999 Sep;70(3 Suppl):516S-524S.

Patrick

Yes, I had read these. Notice I didn't say vegetarians HAD a higher mortality rate but that it WAS EVEN SHOWN that they did.

Personally, I would love to see the results between a controled trial between a vegetarian diet and a diet consisting of the typical hunther gatherer macro and micro nutrient intake, that is a diet with up to 65% of total calories from wild game animal sources and the rest from nuts, green veggies and fruit. Unfortunatelly all I have is comparisons with the SAD and to tell you the truth, given the concern most vegetarians I know have with other factors that increase health risks in the general population and the lack of concern of regular modern omnivores, I'm amazed they (vegetarians) don't score better in what concerns mortality rates from causes other than CVD.

Nuno Figueira · 04-25-2003, 06:47 AM

Quote:

Originally posted by Godot
In the context of the advice given, you most certainly would not exhibit any loss in weightlifting performance due to a low CHO diet. Except in extreme circumstances, weightlifting is an anaerobic activity. It isn't an activity where glycogen depletion is really an issue, nor is substrate utilisation going to affect performance to an appreciable degree (if at all).

I'm not quite sure I'm following you. Weightlifting, in typical bodybuilding fashion, involves a duration of sets anywere between 10 and 60 seconds, which does mean that although phosphocreatine will contribute with a significant portion of the energy used (in extreme lower rep ranges typical of powerlifting maybe even all energy), a good deal will be provided by ATP, which is synthetised out of glycogen, so glycogen depletion should actually be somewhat of a issue, depending on the duration of the sets in question.

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As an aside to all this, what tyoe of weightlifting are you involved in? Recreational? Bodybuilding? Traditional/Olympic?

Recreational I guess, but to most people I'm borderline obsessed with bodybuilding. I'm contemplating starting olympic lifting. There's kind of a Zen quality to all that effort given to momentarily lift all that weight off the ground that somewhat attracts me.

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In the absence of sufficient CHO stores for energy, the body will catabolise LBM and FM, but exercise intensity is sacrificed in the trade-off.

This one I believe is questionable. I'll get back to you on this.

ps418 · 04-25-2003, 06:57 AM

Quote:

Nuno:
Yes, I had read these. Notice I didn't say vegetarians HAD a higher mortality rate but that it WAS EVEN SHOWN that they did.

You mean, even after you had read about the results of the largest prospective study ever done of vegetarian vs nonvegetarian mortality rates, which contradicted your point, you still choose to cite a single, 30-year-old study, which seemed to support the opposite conclusion? Alright then.

Patrick

Gurdur · 04-25-2003, 07:21 AM

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Originally posted by Godot

I was merely responding with a little bit of sarcasm of my own.

Bit out of place, what ?
Next time, I suggest more humour !

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I couldn't stand living in Sydney; too big too much too fast.

Yes, I note a small inability of yours to keep up with the pace.....

Godot · 04-25-2003, 07:30 AM

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Originally posted by Nuno Figueira
I'm not quite sure I'm following you. Weightlifting, in typical bodybuilding fashion, involves a duration of sets anywere between 10 and 60 seconds, which does mean that although phosphocreatine will contribute with a significant portion of the energy used (in extreme lower rep ranges typical of powerlifting maybe even all energy), a good deal will be provided by ATP, which is synthetised out of glycogen, so glycogen depletion should actually be somewhat of a issue, depending on the duration of the sets in question.

If you really want to be pedantic about it, all useable energy is derived from ATP production and breakdown, regardless of the substrate in question. Besides, even the P-Cr system is replenished through the breakdown of ATP.
Glycogen depletion *can* be an issue in weightlifting, but the likelihood of it occuring is so small, I wouldn't even consider it an option. It would really only happen if an individual was consuming such a low volume of CHO that the cumulative effect of their daily activities led to depletion. It is even more insignificant when compared to the risk of glycogen depletion an endurance athlete runs if consuming insufficient CHO in their diet. A good part of peak athletic performance (from a nutritional point of view) is optimising intramuscular glycogen stores.

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Recreational I guess, but to most people I'm borderline obsessed with bodybuilding. I'm contemplating starting olympic lifting. There's kind of a Zen quality to all that effort given to momentarily lift all that weight off the ground that somewhat attracts me.

I'd recommend it. I picked it up a couple of years back because I wanted to try "something different." The rush is phenomenal.

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In the absence of sufficient CHO stores for energy, the body will catabolise LBM and FM, but exercise intensity is sacrificed in the trade-off.
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This one I believe is questionable. I'll get back to you on this.

Which part do you find questionable? The catabolism of body tissues when insufficient fuel stores exist? The body pulls what it needs indiscriminately, from wherever it can obtain the proper parts. This is part of the basis behind eating breakfast and for consuming a post-workout/training session meal.
Maybe you're questioning the drop-off in intensity resulting from altering substrate utilisation? My sources here are a few years old, any clarification would be lovely.
Not that you need the help, but I'd recommend looking at some exercise physiology texts to at least get you started (or to broaden your search). Wilmore & Costill, Tortorra et al., Foss & Keytian are all good options.

Dr Rick · 04-25-2003, 08:14 AM

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Originally posted by Gurdur
Till now I was completely unaware that a vegie diet could protect against sunstroke ?

Well, this is cutting edge-research I'm postin' here, Tim...

Rick

Nuno Figueira · 04-25-2003, 10:18 AM

Quote:

Originally posted by ps418
You mean, even after you had read about the results of the largest prospective study ever done of vegetarian vs nonvegetarian mortality rates, which contradicted your point, you still choose to cite a single, 30-year-old study, which seemed to support the opposite conclusion? Alright then.

Patrick

Yes yes, I've been a bad, bad boy......Shame on me...

Nuno Figueira · 04-25-2003, 10:27 AM

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Originally posted by Godot
I I'd recommend it. I picked it up a couple of years back because I wanted to try "something different." The rush is phenomenal.

I imagine. I'm seriously thinking about it. For now, the fitness gym I'm working out in doesn't even have olympic barbells and they would probably go crazy if I started droping barbells from overhead straight to the ground in that little crowded 30 square meter space they call the free weights section. As soon as I get my olympic weight set I'm having a go at it.

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quote:
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In the absence of sufficient CHO stores for energy, the body will catabolise LBM and FM, but exercise intensity is sacrificed in the trade-off.
--------------------------------------------------------------------------------

Which part do you find questionable? The catabolism of body tissues when insufficient fuel stores exist? The body pulls what it needs indiscriminately, from wherever it can obtain the proper parts. This is part of the basis behind eating breakfast and for consuming a post-workout/training session meal.
Maybe you're questioning the drop-off in intensity resulting from altering substrate utilisation? My sources here are a few years old, any clarification would be lovely.
Not that you need the help, but I'd recommend looking at some exercise physiology texts to at least get you started (or to broaden your search). Wilmore & Costill, Tortorra et al., Foss & Keytian are all good options.

Actually, thanks for the information. I wish I had some more time to learn about the physiological aspects that are pertinent to weightlifting and sports in general but at this moment of my life it's just not possible, which is a shame as I feel limited by the lack of a deeper understanding of how things really work at a celular level and all that stuff. But you can't have it all and I'm buzy enough going crazy learning how to program in Java and all my time is invested in this goal. Anyway, I enjoy discussing these things....

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