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Science Forum Index » Medicine - Cancer Forum » High Protein Diets May Boost Cancer Risk
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| Roman Bystrianyk |
 Posted: Fri Dec 08, 2006 9:20 am |
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Steven Reinberg, "High Protein Diets May Boost Cancer Risk", Washington
Post, December 7, 2006,
Link:
http://www.washingtonpost.com/wp-dyn/content/article/2006/12/07/AR2006120700845.html
Eating a low-protein diet may protect against certain cancers, while a
diet high in protein may increase the risk for malignancies, a new
study suggests.
The results of this preliminary study show that lean people on a
long-term, low-protein, low-calorie diet or who participate in regular
endurance exercise training have lower levels of plasma growth factors
and certain hormones such as insulin-like growth factor 1 (IGF-1).
These substances have been linked to an increased cancer risk,
especially premenopausal breast cancer, prostate cancer and certain
types of colon cancer.
"We know there is a link between nutrition and cancer," said lead
author Dr. Luigi Fontana, an assistant professor of medicine at
Washington University in St. Louis. "There are certain cancers that are
linked with levels of IGF-1, which is an important growth factor that
stimulates the proliferation of cells."
If there are high levels of IGF-1, there's a greater chance that
mutated cells will become cancer cells, said Fontana, who's also an
investigator at Istituto Superiore di Sanita, in Rome, Italy. "We found
that people following a low-calorie, low-protein diet have lower IGF-1
than lean athletes who eat a Western diet. This suggests that low
protein intake may reduce IGF-1, independent of body weight," he said.
The study is published in the December issue of theAmerican Journal of
Clinical Nutrition.
For the study, Fontana's team looked at three groups of people. The
first, made up of 21 lean men and women, ate a low-protein,
low-calorie, raw food, vegetarian diet. The second group of 21 people
did regular endurance running, averaging about 48 miles a week. These
runners ate a standard Western diet that included more calories and
protein than the first group. The third group included 21 sedentary
people who also consumed a standard Western diet, higher in sugars,
processed refined grains and animal products.
People in the first group averaged a daily intake of 0.73 grams of
protein per kilogram of body weight. The runners ate 1.6 grams, and
sedentary people ate 1.23 grams of protein a day. The recommended daily
allowance for protein intake is 0.8 grams, Fontana said. That's about
three ounces of protein per day for a 220-pound man.
The researchers found that people in the first group had significantly
lower blood levels of IGF-1 compared with the runners or the sedentary
people. High levels of IGF-1 have been linked to premenopausal breast
cancer, prostate cancer and certain types of colon cancer.
In addition, lower IGF-1 levels are associated with increased life span
in animals, Fontana noted.
Fontana thinks that if people ate more whole grains, beans, fruits and
vegetables and far fewer animal products, they would be healthier. He
recommends fish, low-fat dairy products and, occasionally, some red
meat. This type of diet reduces total calories and the amount of
protein consumed, and it also might result in lower levels of IGF-1.
"Many people in the United States and Italy are eating 50 percent more
protein than what is recommended," Fontana said. "If we eat 50 percent
more calories than recommended, we become overweight and obese. What
happens if you eat 50 percent more protein than required -- we don't
know."
He speculated that eating too much protein increases the risk for
cancer and also accelerates aging, "but we need more studies to see if
my hypothesis is true or false."
One expert also thinks that a high-protein diet increases the risk for
certain cancers.
"We recently published a paper that also shows that a high-protein diet
is bad for you. It reduces survival; it increases the risk of cancer,"
said Dr. Dimitrios Trichopoulos, the Vincent L. Gregory Professor of
Cancer Prevention at the Harvard School of Public Health's Department
of Epidemiology.
In that study, published online in the Nov. 29 issue of theEuropean
Journal of Clinical Nutrition, the researchers collected data on the
diets of 22,944 healthy adults and found that eating diets low in
carbohydrates and high in protein was associated with increased
mortality.
Trichopoulos thinks that levels of IGF-1 may be the reason for the
increased cancer risk. However, other factors may be at work, he added.
Despite his and Fontana's findings, Trichopoulos isn't ready to
recommend a low-protein diet to reduce the risk of cancer or to live
longer. Another recent study contradicted this finding, Trichopoulos
said. "At this stage, we should wait for clarification," he said.
More information
The American Cancer Society can tell you more about cancer and diet.
SOURCES: Luigi Fontana, M.D., Ph.D., assistant professor of medicine,
Washington University, St. Louis, and investigator, Istituto Superiore
di Sanita, Rome, Italy; Dimitrios Trichopoulos, M.D., Vincent L.
Gregory Professor of Cancer Prevention, Department of Epidemiology,
Harvard School of Public Health, Boston; December 2006,American Journal
of Clinical Nutrition; Nov. 29, 2006, online edition,European Journal
of Clinical Nutrition |
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| Matti Narkia |
| Posted: Fri Dec 08, 2006 10:28 am |
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Guest
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On 8 Dec 2006 05:20:51 -0800, "Roman Bystrianyk"
<rbystrianyk@gmail.com> wrote:
Quote: Steven Reinberg, "High Protein Diets May Boost Cancer Risk", Washington
Post, December 7, 2006,
Link:
http://www.washingtonpost.com/wp-dyn/content/article/2006/12/07/AR2006120700845.html
Eating a low-protein diet may protect against certain cancers, while a
diet high in protein may increase the risk for malignancies, a new
study suggests.
The results of this preliminary study show that lean people on a
long-term, low-protein, low-calorie diet or who participate in regular
endurance exercise training have lower levels of plasma growth factors
and certain hormones such as insulin-like growth factor 1 (IGF-1).
These substances have been linked to an increased cancer risk,
especially premenopausal breast cancer, prostate cancer and certain
types of colon cancer.
The reference for the study is
Trichopoulou A, Psaltopoulou T, Orfanos P, Hsieh CC, Trichopoulos D.
Low-carbohydrate-high-protein diet and long-term survival in a general
population cohort.
Eur J Clin Nutr. 2006 Nov 29; [Epub ahead of print]
PMID: 17136037 [PubMed - as supplied by publisher]
<http://www.nature.com/ejcn/journal/vaop/ncurrent/abs/1602557a.html>
I am very skeptical about this study. Usually
low-carbohydrate-high-protein diet has meant and probably still means
high consumption of red meat and low consumption of vegetables and
fruit, which is not a good recipe for health. If, however, fatty fish,
legumes and nuts are used as sources of protein and diet contains
plenty of low carbohydrate vegetables and fruit (such as avocado and
water melon, for example), I believe that
low-carbohydrate-high-protein diet could be very healthy indeed. In
this particular study the outcome was probably caused by what foods
were in the diets and not by the ratios of the macronutrients in the
diets. It is good to remember that we (our ancestors) have been
evolutionary adapted to low-carbohydrate-high-protein diet for over
two million years and the switch to high carbohydrate diet happened
only after the invention of agriculture about 10 000 - 15 000 years
ago - a very short time from evolutionary perspective. In this light
_healthily composed_ low-carbohydrate-high-protein diet is still
probably the genetically most suitable diet for a majority of people.
--
Matti Narkia |
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| Guest |
| Posted: Fri Dec 08, 2006 10:50 am |
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Recall the factors considered were amoung of protein, amount of
exercise, and calory intake. The answers one gets depends on the
questions asked. In this example the above were the questions with the
answer as presented. Protein is related to the level of the growth
hormone and that was the variable produced that was considered as
related to the cancer risk. All the considerations you mention would
tend to be averaged out. Recall the high exercise group and the low
exercise group had the same diet but with different results depending on
protein level.
"I am very skeptical about this study. Usually
low-carbohydrate-high-protein diet has meant and probably still means
high consumption of red meat and low consumption of vegetables and
fruit, which is not a good recipe for health. If, however, fatty fish,
legumes and nuts are used as sources of protein and diet contains plenty
of low carbohydrate vegetables and fruit (such as avocado and water
melon, for example), I believe that low-carbohydrate-high-protein diet
could be very healthy indeed. In this particular study the outcome was
probably caused by what foods were in the diets and not by the ratios of
the macronutrients in the diets. It is good to remember that we (our
ancestors) have been evolutionary adapted to
low-carbohydrate-high-protein diet for over two million years and the
switch to high carbohydrate diet happened only after the invention of
agriculture about 10 000 - 15 000 years ago - a very short time from
evolutionary perspective. In this light _healthily composed_
low-carbohydrate-high-protein diet is still probably the genetically
most suitable diet for a majority of people." |
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| Matti Narkia |
| Posted: Fri Dec 08, 2006 11:26 am |
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On 08 Dec 2006 14:50:09 GMT, coonskin@amestwp.com wrote:
Quote: Recall the factors considered were amoung of protein, amount of
exercise, and calory intake. The answers one gets depends on the
questions asked. In this example the above were the questions with the
answer as presented. Protein is related to the level of the growth
hormone and that was the variable produced that was considered as
related to the cancer risk. All the considerations you mention would
tend to be averaged out.
They don't.
--
Matti Narkia |
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| Guest |
| Posted: Fri Dec 08, 2006 12:07 pm |
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Quote: All the considerations you mention would
tend to be averaged out.
"They don't."
As mentioned, the two groups with the "unhealthy" diets as per your
speculation, had the hormone related to cancer risk correlated with
protein intake, diet was held constant in this case. That after all was
the question asked. Because outcomes in cancer level were not in
question we don't know how a "healthy" diet would affect cancer levels
which seemed to be the point you were making. |
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| Matti Narkia |
| Posted: Fri Dec 08, 2006 12:41 pm |
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On 08 Dec 2006 16:07:25 GMT, coonskin@amestwp.com wrote:
Quote: All the considerations you mention would
tend to be averaged out.
"They don't."
As mentioned, the two groups with the "unhealthy" diets as per your
speculation, had the hormone related to cancer risk correlated with
protein intake, diet was held constant in this case. That after all was
the question asked. Because outcomes in cancer level were not in
question we don't know how a "healthy" diet would affect cancer levels
which seemed to be the point you were making.
The study raises some questions, but doesn't give any answers. It was
an epidemiological study, which gives only statistical associations,
not causal relations. Higher IGF-1 levels have been associated also
with foods regarded as healthy such as fish and seafood, and with
useful minerals such as potassium and magnesium. Clearly we should not
eliminate or or reduce these. Even the news article recommended fish
and seafood, although they are heve been associated with higher IGF-1
levels. In some studies even carbohydrates have been associated with
higher IGF-1 levels. IGF-1 and growth hormone levels can also be too
low, Do we know what the optimal levels are? So the whole IGF-1 issue
is still somewhat vague and we cannot draw any firm conclusions at
this stage. Therefore it's possible that the mortality figures quoted
had more to do with the foods in the diets than with IGF-1 or with the
macoronutrient ratios, as I said. Often _modern_ low-carb-high-protein
diets are unhealthy because of their high red meat and low vegetable
content, and not because of their macronutrient ratio. Preagricultural
diet of our ancestors was low-carb-high-protein, yet not atherogenic,
because it contained also enough vegetables and the protein sources
were healthy, even the meat from hunted animals were healthier that
the meat from today's domesticated grain-fed animals.
--
Matti Narkia |
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| I.P. Freely |
| Posted: Fri Dec 08, 2006 4:42 pm |
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Matti Narkia wrote:
Quote: In this light
_healthily composed_ low-carbohydrate-high-protein diet is still
probably the genetically most suitable diet for a majority of people.
A few tenets I think we would generally agree on (and let's not get
caught up in Krebs cycle nuances; I'm talking generalities), then a
couple of questions:
1. We should all be physically very active -- plenty of load-bearing and
aerobic work/play -- if we want to optimize/maximize the quality and
length of our lives.
2. The most efficient fuel for that endeavor is carbs.
3. Our brains run on carbs.
4. Yes, fats and proteins can be converted to carbs, but only slowly and
inefficiently, at least relative to the rate it's needed for significant
work/play.
5. Buried in the depths of many of the low-carb diet books (e.g.,
Atkins, Sugarbusters) is this caveat, in one form or another: "This
concept is for borderline diabetics, aka metabolic syndrome X patients,
who are not athletic".
The questions:
Is it not possible, even likely, that a significant part of modern man's
greater longevity compared to that of cave men is due to the
introduction of agriculture into our diets in the form of fruits,
vegetables, and whole grains, and the resultant displacement of some of
the sat fats?
Don't these generalities and many more specific facts favor a more
balanced diet, rather than low-carb, as long as we avoid refined carbs?
I.P. |
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| TC |
| Posted: Fri Dec 08, 2006 5:00 pm |
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I.P. Freely wrote:
Quote: Matti Narkia wrote:
In this light
_healthily composed_ low-carbohydrate-high-protein diet is still
probably the genetically most suitable diet for a majority of people.
A few tenets I think we would generally agree on (and let's not get
caught up in Krebs cycle nuances; I'm talking generalities), then a
couple of questions:
1. We should all be physically very active -- plenty of load-bearing and
aerobic work/play -- if we want to optimize/maximize the quality and
length of our lives.
2. The most efficient fuel for that endeavor is carbs.
3. Our brains run on carbs.
4. Yes, fats and proteins can be converted to carbs, but only slowly and
inefficiently, at least relative to the rate it's needed for significant
work/play.
5. Buried in the depths of many of the low-carb diet books (e.g.,
Atkins, Sugarbusters) is this caveat, in one form or another: "This
concept is for borderline diabetics, aka metabolic syndrome X patients,
who are not athletic".
I think that you apply way more importance to carbs than necessary.
Talking about carbs being efficient fuel and fats and proteins being
inefficiently converted to carbs is really nothing more than exercises
in semantics and linguistic connotations.
There is no disadvantage to avoiding highly refined manufacture crap
carbs. Nor is there a disadvantage in eating a diet higher in fats and
proteins, especially relative to the SAD diet.
You would be better served by talking about the differences between
highly refined crap carbs versus real whole-food carbohydrate foods. Or
real animal-sourced fats compared to fake highly processed manufactured
vegetable sourced fats. Or fake highly processed soy proteins vs real
healthy animal-sourced proteins.
Grains and fruits are over rated in their vitamin content. And meats
are way under rated with regards to their nutrient density. And fruits
and grains, especially the refined grains and the genetically modified
modern extra sweet fruits add a great deal of unnecessary relatively
nutrient-poor carbs to the diet.
Balanced diets are overrated too. A large variety of nutrient poor
foods do not accomplish the goal of good overall nourishment, while a
smaller variety of nutrient-rich foods is does.
Quote:
The questions:
Is it not possible, even likely, that a significant part of modern man's
greater longevity compared to that of cave men is due to the
introduction of agriculture into our diets in the form of fruits,
vegetables, and whole grains, and the resultant displacement of some of
the sat fats?
Not really. At least not from a nutritional standpoint. From a
lifestyle standpoint it may have contributed in that man would have
been able to cut back physically dangerous activities such as hunting
larger and more dangerous animals. Life would have been easier on them
that way.
Quote:
Don't these generalities and many more specific facts favor a more
balanced diet, rather than low-carb, as long as we avoid refined carbs?
I.P.
Well, last time I looked, every single low carb diet forgoes only the
refined and the very starchy carbs. So the need for what you refer to
as balance is the very point when it comes to low carb. In other words,
a balanced diet is one without those foods that throw the diet out of
balance. And those foods are sugars, hfcs and refined grains. And some,
myself included, see no need for any grains at all or too many of the
sweeter fruits. Fruits are mostly water and sugars, and the longer
they've been farmed the sweeter and the less nutritious they are. As
I've said, fruits are highly overated for their nutrient density.
Low carb equals no refined carbs and more real whole food carbs.
TC |
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| italiangm |
| Posted: Fri Dec 08, 2006 6:39 pm |
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| Watermelon is not a low carb fruit. |
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| italiangm |
| Posted: Fri Dec 08, 2006 7:16 pm |
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I.P. Freely wrote:
Quote: 3. Our brains run on carbs.
Our brains run on glucose. Of the 3 macronutrients, carbs convert most
efficiently to glucose.
Quote: 4. Yes, fats and proteins can be converted to carbs
....you mean glucose...
Quote: but only slowly and inefficiently, at least relative to the rate it's
needed for significant work/play.
Sometimes slowly and efficiently can be used to one's advantage under
the proper conditions.
Quote: 5. Buried in the depths of many of the low-carb diet books (e.g.,
Atkins, Sugarbusters) is this caveat, in one form or another: "This
concept is for borderline diabetics, aka metabolic syndrome X patients,
who are not athletic".
People make choices about their energy expenditure, meal composition,
and calorie intake. It's nice to have more choices than 'be athletic',
especially for those who cannot or will not.
Quote: Is it not possible, even likely, that a significant part of modern man's
greater longevity compared to that of cave men is due to the
introduction of agriculture into our diets in the form of fruits,
vegetables, and whole grains, and the resultant displacement of some of
the sat fats?
It's more likely that modern man's longevity comes from better
sanitation, infection deterrence, fewer accidents with high mortality,
less wear and tear on load-bearing structures, and more accurate
diagnostic and treatment capabilities when something does go wrong.
Until better genetic detection and manipulation occurs however, I wish
folks wouldn't be so quick to pass on serious genetic defects onto
their children. Since science can keep them alive long enough to pass
the defect onto future children, our medical system will eventually
reach a tipping point.
Quote: Don't these generalities and many more specific facts favor a more
balanced diet, rather than low-carb, as long as we avoid refined carbs?
The assumptions being used to support the aforementioned generalities
are inaccurate.
However, what most nutritionists currently pass as a 'balanced diet'
that fit your description still have too many starches and calories for
the level of energy being expended, leading to trigyceride storage,
visceral adiposity, insulin resistance, impaired glucose tolerance, and
type 2 diabetes.. |
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| I.P. Freely |
| Posted: Fri Dec 08, 2006 8:28 pm |
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italiangm wrote:
Quote: I.P. Freely wrote:
3. Our brains run on carbs.
Our brains run on glucose. Of the 3 macronutrients, carbs convert most
efficiently to glucose.
4. Yes, fats and proteins can be converted to carbs
...you mean glucose...
And glucose is . . . a carb.
Remember, I'm talking generalities here, and as you say the path from
whole grains to glucose is shorter and more efficient than the path from
protein to glucose.
Quote: People make choices about their energy expenditure, meal composition,
and calorie intake. It's nice to have more choices than 'be athletic',
especially for those who cannot or will not.
Yes, but as your valid closing paragraph states, many/most people make
wrong choices (as evidenced, for example, by the 2/3 obesity rate in the
U.S.). Beyond opening their eyes to the fallacies of the stereotypical
low-carb mantra ("If I avoid carbs I will be lean and healthy") and/or
starvation diets in place of exercise, there's not much we can do for
them except treat the overeaters' health problems and help obsessive
dieters count the raisins and peas they consume.
Quote: Is it not possible, even likely, that a significant part of modern man's
greater longevity compared to that of cave men is due to the
introduction of agriculture into our diets in the form of fruits,
vegetables, and whole grains, and the resultant displacement of some of
the sat fats?
It's more likely that modern man's longevity comes from better
sanitation, infection deterrence, fewer accidents with high mortality,
less wear and tear on load-bearing structures, and more accurate
diagnostic and treatment capabilities when something does go wrong.
"MORE" likely, yes; I'm asking whether better diet may CONTRIBUTE an
appreciable part to modern man's increased longevity.
Quote: The assumptions being used to support the aforementioned generalities
are inaccurate.
They come from the world's universities and hospitals and the studies
they produce. I'm at their mercy for data.
Quote: However, what most nutritionists currently pass as a 'balanced diet'
that fit your description still have too many starches and calories for
the level of energy being expended, leading to trigyceride storage,
visceral adiposity, insulin resistance, impaired glucose tolerance, and
type 2 diabetes..
I agree the new food pyramid does exactly that, and it is my major beef
with the pyramid. But it's also one reason why I emphasize the
importance of relatively (to individual ability) hard physical work or
play in our lives. (The other reason is the many shortcomings of weight
control by food alone.)
And now that you mention triglycerides, let me ask whether they may
contribute to physical endurance in people whose cells burn fat before
sugar? I've asked that of many physicians and trainers with no answer
and minimal opinions.
I.P. |
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| Matti Narkia |
| Posted: Fri Dec 08, 2006 9:42 pm |
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On 8 Dec 2006 14:39:01 -0800, "italiangm" <italiangm@yahoo.com> wrote:
Quote: Watermelon is not a low carb fruit.
Depending on the source watermelon contains 7.1 - 7.8 g carbs/100 g.
For a fruit that's fairly low, IMHO. For the sake of comparison carb
content per 100 g of some common fruit from two different sources:
<http://www.fineli.fi/topfoods.php?compid=2034&fuclass=frufresh&specdiet=none&items=100&from=bottom&portion=100g&lang=en>
g/100g Food Name
0.8 Avocado, average, without skin and stone
3.9 Water melon, average, with peel
7.1 Water melon without peel
8.3 Mandarin without peel
9.4 Apple, imported, without skin
10.6 Apricot, average, without stone
11.2 Pineapple without skin
14.7 Grape, average, green/black
18.3 Banana without peel
40.7 Fig with skin
52.9 Exotic fruit average, mango, papaya, without skin
<http://www.nutritiondata.com/foods-009000000000005000000-w.html>
g/100g Food Name
6.6 Melons, casaba, raw
7.5 Watermelon, raw
7.8 Avocados, raw, Florida
8.5 Avocados, raw, all commercial varieties
11.4 Plums, raw
11.7 Oranges, raw, all commercial varieties
12.0 Clementines, raw
12.6 Pineapple, raw, all varieties
12.8 Apples, raw, without skin
13.3 Tangerines, (mandarin oranges), raw
14.5 Blueberries, raw
14.7 Kiwi fruit, (chinese gooseberries), fresh, raw
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Matti Narkia |
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| italiangm |
| Posted: Fri Dec 08, 2006 10:10 pm |
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100g of watermelon has a much higher glycemic index value than, say,
blueberries. Watermelon will also cause more insulin to be released to
cover the glucose hit than blueberries, and therefore more likely to be
stored as fat. |
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| Matti Narkia |
| Posted: Fri Dec 08, 2006 10:44 pm |
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On Fri, 08 Dec 2006 12:42:17 -0800, "I.P. Freely"
<fuhgheddaboutit@noway.nohow> wrote:
Quote: Matti Narkia wrote:
In this light
_healthily composed_ low-carbohydrate-high-protein diet is still
probably the genetically most suitable diet for a majority of people.
A few tenets I think we would generally agree on (and let's not get
caught up in Krebs cycle nuances; I'm talking generalities), then a
couple of questions:
1. We should all be physically very active -- plenty of load-bearing and
aerobic work/play -- if we want to optimize/maximize the quality and
length of our lives.
We should, I agree with you about that, but how many of us are when we
get older? If you look at the BMI statistics in various countries, you
get the impression that not many, otherwise the average BMIs wouldn't
be so high.
Quote: 2. The most efficient fuel for that endeavor is carbs.
It depends on the strenuousness of the physical activity. With
relatively low pulse rates typical for example for walking or slow
jogging, fat is the predominant fuel. When heart rate goes up carbs
become the the predominat fuel. And in very long endurance events, say
marathon running or longer, carb storages are exhausted and our bodies
again switch to burn fat.
Now, I'm not sure that a very strenuous exercise is the best type of
activity for elderly people, a bit lower heart rates may be more
suitable for them. Therefore their carb requirements are not nearly as
high as endurance athletes', they can manage very well with moderately
low-carb diet. So can younger people, who keep themselves in shape,
but are not professional endurance athletes. And even endurance
athletes need a fair amount for protein during the training period to
build up those muscles they need in their sport. And our ancestors,
who probably led physically active life hunting and gathering their
food, did cope with and adapted to a diet, where 22-40% of energy came
from carbs and 19-35% from protein.
Quote: 3. Our brains run on carbs.
On glucose, yes, but they can also use ketones as fuel, when there is
a shortage of glucose, and they do fairly well with ketones, too. Not
that there is any need for that, if one follows a diet to which are
evolutionary adapted, i.e. diet, where 22-40% of energy comes from the
carbs. That should be enough for our brains. I don't suggest that
anyone would completely cut out the carbs or even go below 22% of
energy from carbs, but remember, that it has never been shown that
carbs are essential for humans. Protein has been shown to be essential
(essential amino acids) and so has fat (essential fatty acids).
Quote: 4. Yes, fats and proteins can be converted to carbs, but only slowly and
inefficiently, at least relative to the rate it's needed for significant
work/play.
As I mentioned above, brain can also use ketones as fuel, although
there should be no need for that with a diet where 22-40% of energy
comes from the carbs.
Quote: 5. Buried in the depths of many of the low-carb diet books (e.g.,
Atkins, Sugarbusters) is this caveat, in one form or another: "This
concept is for borderline diabetics, aka metabolic syndrome X patients,
who are not athletic".
I don't know exactly what Atkins books say and even less about
Sugarbusters books, but I doubt that these diets are ideal low-carb
diets, and therefore should not be used as a reference.
Quote: The questions:
Is it not possible, even likely, that a significant part of modern man's
greater longevity compared to that of cave men is due to the
introduction of agriculture into our diets in the form of fruits,
vegetables, and whole grains, and the resultant displacement of some of
the sat fats?
I'm not promoting saturated fats. As I said protein in moderately
low-carb diet resembling preagricultural diet at least in the ratios
of macronutrients, could come from fatty fish, nuts and legumes, which
are very heart-friendly choices. Modern red meat is not healthy, IMHO,
and I don't eat it, if I can avoid it. In preagrigultural era the meat
was different and resembled probably today's game meat. It had most
likely less fat, less omega-6 fatty acids such as arachidonic acid,
and more omega-3 fatty acids. This together with the sufficient use of
vegetables was probaly at least part of the reason for the fact that
preagricultural diet was not atherogenic.
As for your question of longevity, we probably live longer now at
least partly for the same reasons, why the animals in the zoo
typically live longer than wild animals: we are better protected, we
are not hunted down by wild beasts, we get food even in the advanced
age, when we would no longer be able to hunt or gather our food, and
above all, we have medical care. I wonder how many of us would live to
the old age with no medical care at all?
Quote: Don't these generalities and many more specific facts favor a more
balanced diet, rather than low-carb, as long as we avoid refined carbs?
Who says which one is more balanced diet, high-carb diet or moderately
low-carb diet, to which we have adapted in the evolution? IMHO it is
the latter. But as long as we are physically active, keep our weight
normal, and make the right food choices, perhaps the risk of insulin
resistance or type 2 diabetes encoded in our genes does not
materialize even with the relatively high carb diet. But if we start
accumulating visceral fat, the risk increases, and the low-carb diet
would IMHO be preferable at least then when we cannot get rid of that
fat we have gathered.
--
Matti Narkia |
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| Jim Chinnis |
| Posted: Fri Dec 08, 2006 10:58 pm |
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Guest
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"italiangm" <italiangm@yahoo.com> wrote in part:
Quote: However, what most nutritionists currently pass as a 'balanced diet'
that fit your description still have too many starches and calories for
the level of energy being expended, leading to trigyceride storage,
visceral adiposity, insulin resistance, impaired glucose tolerance, and
type 2 diabetes..
....and heart disease.
--
Jim Chinnis Warrenton, Virginia, USA jchinnis@alum.mit.edu |
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