Re: Is it true that 40% of PUFA in fish oil is Arachidonic acid?
montygraham
AA.
Spence...
news:bbb7ba6f-02b0-4193...@h31g2000yqd.googlegroups.com...
> I have just read on Fox and Cameron's "Food Science, Nutrition and
> Health" (Hodder Arnold Publication) that 40% of PUFA in fish oil is
> Arachidonic acid.
>
> Is it true? I know there's some AA in fish oil but is it possible that
> it is 40%. If so, would that not be worrying?
And you didn't want this post archived for... what reason, exactly..??
Sp.
Taka
> x-no-archive:yes
>
> I have just read on Fox and Cameron's "Food Science, Nutrition and
> Health" (Hodder Arnold Publication) that 40% of PUFA in fish oil is
> Arachidonic acid.
>
> Is it true? I know there's some AA in fish oil but is it possible that
> it is 40%. If so, would that not be worrying?
Most of the fish like salmon on the market is grain fed and end up
with high levels of AA. All creatures including humans will take any
PUFAs you give them in the feed and desaturate them to the
corresponding LC-PUFAs. If you give them only saturated fat they will
make their own LC-PUFAs like the mead acid which are much safer due to
lower level of desaturation. Seaweed is rich in Omega-3 while grains
are rich in Omega-6.
FROM: http://products.mercola.com/salmon-oil/
"Farm-raised salmon and grain-fed beef have very high levels of
something called arachidonic acid. This fat comes from the omega-6
family and is highly inflammatory.
...
Foods high in omega-6 fatty acids or arachidonic acid -- like farm-
raised salmon or grain-raised beef -- can irritate the lining of your
blood vessels.
...
Not only could eating farm-raised salmon deprive you of the omega-3
essential fats you need -- you could be doing your body more harm than
good by consuming too many omega-6 fats."
Taka
Taka
Popular Fish, Tilapia, Contains Potentially Dangerous Fatty Acid
Combination
enlarge
Farm-raised tilapia, one of the most highly consumed fish in America,
has very low levels of beneficial omega-3 fatty acids and, perhaps
worse, very high levels of omega-6 fatty acids. (Credit: iStockphoto/
Olga Lyubkina)
ScienceDaily (July 10, 2008) — Farm-raised tilapia, one of the most
highly consumed fish in America, has very low levels of beneficial
omega-3 fatty acids and, perhaps worse, very high levels of omega-6
fatty acids, according to new research from Wake Forest University
School of Medicine.
The researchers say the combination could be a potentially dangerous
food source for some patients with heart disease, arthritis, asthma
and other allergic and auto-immune diseases that are particularly
vulnerable to an "exaggerated inflammatory response." Inflammation is
known to cause damage to blood vessels, the heart, lung and joint
tissues, skin, and the digestive tract.
"In the United States, tilapia has shown the biggest gains in
popularity among seafood, and this trend is expected to continue as
consumption is projected to increase from 1.5 million tons in 2003 to
2.5 million tons by 2010," write the Wake Forest researchers in an
article published this month in the Journal of the American Dietetic
Association.
They say their research revealed that farm-raised tilapia, as well as
farmed catfish, "have several fatty acid characteristics that would
generally be considered by the scientific community as detrimental."
Tilapia has higher levels of potentially detrimental long-chain
omega-6 fatty acids than 80-percent-lean hamburger, doughnuts and even
pork bacon, the article says.
"For individuals who are eating fish as a method to control
inflammatory diseases such as heart disease, it is clear from these
numbers that tilapia is not a good choice," the article says. "All
other nutritional content aside, the inflammatory potential of
hamburger and pork bacon is lower than the average serving of farmed
tilapia."
The article notes that the health benefits of omega-3 fatty acids,
known scientifically as "long-chain n-3 polyunsaturated fatty
acids" (PUFAs), have been well documented. The American Heart
Association now recommends that everyone eat at least two servings of
fish per week, and that heart patients consume at least 1 gram a day
of the two most critical omega-3 fatty acids, known as EPA
(eicosapentaenoic acid) and DHA (docosahexaenoic acid).
But, the article says, the recommendation by the medical community for
people to eat more fish has resulted in consumption of increasing
quantities of fish such as tilapia that may do more harm than good,
because they contain high levels of omega-6 fatty acids, also called
n-6 PUFAs, such as arachidonic acid.
"The ratio of arachidonic acid (AA) to very long-chain n-3 PUFAs (EPA
and DHA) in diets of human beings appears to be an important factor
that dictates the anti-inflammatory effects of fish oils," the
researchers write. They cite numerous studies, including a recent one
that predicts "that changes in arachidonic acid to EPA or DHA ratios
shift the balance from pro-inflammatory [agents] to protective
chemical mediators ... which are proposed to play a pivotal role in
resolving inflammatory response" in the body.
For their study, the authors obtained a variety of fish from several
sources, including seafood distributors that supply restaurants and
supermarkets, two South American companies, fish farms in several
countries, and supermarkets in four states. All samples were snap-
frozen for preservation pending analysis, which was performed with gas
chromatography.
The researchers found that farmed tilapia contained only modest
amounts of omega-3 fatty acids -- less than half a gram per 100 grams
of fish, similar to flounder and swordfish. Farmed salmon and trout,
by contrast, had nearly 3 and 4 grams, respectively.
At the same time, the tilapia had much higher amounts of omega-6 acids
generally and AA specifically than both salmon and trout. Ratios of
long-chain omega-6 to long-chain omega-3, AA to EPA respectively, in
tilapia averaged about 11:1, compared to much less than 1:1
(indicating more EPA than AA) in both salmon and trout.
The article notes that "there is a controversy among scientists in
this field as to the importance of arachidonic acid or omega-6:omega-3
ratios vs. the concentration of long-chain omega-3 alone with regard
to their effects in human biology." Those issues are raised in an
editorial in the same issue of the Journal.
The Wake Forest article anticipates that criticism and notes that one
human study involving AA showed a probable gene-nutrient connection to
coronary heart disease in a specific group of heart disease patients.
In another study, four subjects were removed after consumption of high
amounts of AA due to concerns about the effect of the acid on their
blood platelets.
Floyd H. "Ski" Chilton, Ph.D., professor of physiology and
pharmacology and director of the Wake Forest Center for Botanical
Lipids, is the senior author of the Journal article. He said that in
next month's Journal, he will publish a rebuttal to this month's
editorial.
"We have known for three decades that arachidonic acid is the
substrate for all pro-inflammatory lipid mediators," Chilton said in
an interview. "The animal studies say unequivocally that if you feed
arachidonic acid, the animals show signs of inflammation and get sick.
"A New England Journal of Medicine article three years ago said if you
had heart disease and had a certain genetic makeup, and you ate
arachidonic acid, the diameter of your coronary artery was smaller, a
major risk factor for a heart attack," said Chilton. "My point is that
it's likely not worth the risk in this or other vulnerable
populations."
Chilton said tilapia is easily farmed using inexpensive corn-based
feeds, which contain short chain omega-6s that the fish very
efficiently convert to AA and place in their tissues. This ability to
feed the fish inexpensive foods, together with their capacity to grow
under almost any condition, keeps the market price for the fish so low
that it is rapidly becoming a staple in low-income diets.
"We are all familiar with the classical Hippocratic admonition, Primum
no nocere, 'First, do no harm.' I think it behooves us to consider
this critical directive when making dietary prescriptions for the sake
of health," Chilton said.
"Cardiologists are telling their patients to go home and eat fish, and
if the patients are poor, they're eating tilapia. And that could
translate into a dangerous situation."
Taka
Is Farm-Raised Tilapia Really Bad News?
News reports all over the internet have heralded a recent study
published in the Journal of the American Dietetic Association showing
that farm-raised tilapia is very rich in the supposedly inflammatory
"bad fat" we know as arachidonic acid or, for short, AA.
For example, NewsWise.Com carried a story entitled "Researchers Say
Popular Fish Contains Potentially Dangerous Fatty Acid Combination"
that reported the following:
They say their research revealed that farm-raised tilapia, as well as
farmed catfish, "have several fatty acid characteristics that would
generally be considered by the scientific community as detrimental."
Tilapia has higher levels of potentially detrimental long-chain
omega-6 fatty acids than 80-percent-lean hamburger, doughnuts and even
pork bacon, the article says.
Doughnuts and hamburgers -- really? I would never have thought to lump
the two foods together, since one is a junk food made from refined
flour and fried in hydrogenated vegetable oil and the other is a
health food packed with all kinds of vitamins and minerals and healthy
fats, but somehow the authors of this study managed to do so.
In the original report, the authors stated that a serving of pork
bacon contains 191 mg of AA, a serving of ground beef contains 34 mg,
and a doughnut contains 4 mg, referencing the latest release of the
USDA nutrient database. Nevermind the fact that ground beef contains
eight times more AA than their theoretical doughnut, revealing the
latter to be a negligible source of this fatty acid, but this must
have been one imaginative doughnut because the even the cream filling
doughnuts listed in the USDA database seem to have only 1 mg of AA.
But let's move on to the crux of the matter.
I'm no advocate of fish farming, but my first reaction to this article
was that maybe I should start eating tilapia. Those of you who have
read my PUFA Report know I have a fairly high opinion of AA.
The current study did not take any measurements from wild tilapia, but
found that farm-raised tilapia was relatively low in total fat, had a
high proportion of saturated and monounsaturated fatty acids, and was
unusually rich in AA and low in the omega-3 fatty acid EPA, yielding a
very high ratio of AA to EPA, a supposed index of inflammatory
potential. Farm-raised salmon and other species, by contrast, were
much higher in total PUFA and EPA. Unfortunately, they did not measure
DHA.
This, they say, is very bad. AA is a substrate for inflammatory
compounds, which make it a contributor to heart disease and all kinds
of other illnesses.
The news article points out in a single sentence that the editorial
accompanying the report mentions the "controversy" about AA, but never
quotes it. Let me quote it here:
Nevertheless, in this reviewer's opinion, evidence from relevant human
studies that a higher consumption of arachidonic acid promotes
atherosclerosis and coronary heart disease is quite weak, and the
assertion that because a serving of tilapia contains more arachidonic
acid than hamburger or bacon it has greater "inflammatory potential,"
is based on a potentially flawed conception of the physiological
impact of dietary arachidonic acid.
Not only that, but, as I describe in my first PUFA Report, a
deficiency of AA leads to low levels of sex hormones, hair loss, scaly
skin, infertility, and, if the deficiency is moderate enough to allow
ovulation and thus pregnancy, extended labor that is torturous and
possibly fatal.
So, while it's true that many humans suffer from inflammatory
diseases, it's also quite true that many humans suffer from hair loss,
skin problems, infertility, and difficult labor. Could these, in some
cases, be tied to a deficiency of arachidonic acid? The research from
Harvard showing that the intake of milkfat is associated with
increased fertility certainly suggests that this is the case.
And what of the high ratio of AA to EPA in farmed tilapia? I'm not
concerned. As I pointed out in a recent newsletter, researchers at the
University of Connecticut last year showed that low-carb dieters
eating unlimited amounts of AA-rich foods like heavy cream had far
better reductions in inflammatory markers than low-fat dieters. What's
more, the reduction in inflammation was directly correlated to the AA-
to-EPA ratio in the bloodstream!
As described in my PUFA Report, I suspect that EPA does not even
belong in the mammalian body. Rather, the two fatty acids we want are
AA and DHA. EPA is mostly present when the human body cannot keep up
with processing the EPA from fish oils and the alpha-linolenic acid
from plant oils into the DHA it needs. The UConn study found that the
low-carb diet led to higher DHA levels and lower EPA levels,
suggesting better conversion of the fatty acids on the diet.
I am not ready to advocate farmed tilapia. I would want to see the
levels of other nutrients and how they compare to wild tialpia.
That said, if you suffer from hair loss or infertility or want to
boost your testosterone or prepare for a pregnancy, while liver and
egg yolks would be the best way to stock up on AA, we now know that a
serving of tilapia here and there might help give you a boost as well.
Taka
mossambicus) reveals physiological effects not mediated by
prostaglandins.
Anholt, R. D. van, Spanings, F. A. T., Koven, W. M., Bonga, S. E. W.
This study aims to clarify the role of the polyunsaturated fatty acid
arachidonic acid (ArA, 20:4n-6) in the stress response of Mozambique
tilapia (Oreochromis mossambicus). ArA is converted into eicosanoids,
including prostaglandins, which can influence the response to
stressors. Tilapia, a species able to form ArA from its precursor, was
supplemented with ArA for 18 days, after which they were confined for
5 min. Acetylsalicylic acid (ASA, COX-inhibitor) was subsequently
administered to distinguish ArA-mediated effects from enhanced
prostaglandin E2 (PGE2) synthesis. ArA supplemented fish had higher
ArA levels in gills and kidneys, and these levels were further
enhanced after ASA treatment. Levels of total monounsaturated and
polyunsaturated fatty acids as well as docosahexaenoic acid (DHA),
eicosapentaenoic acid (EPA), and ArA, were altered 24 h after
confinement, particularly in the kidneys. ArA supplementation had no
effect on basal cortisol levels, while ArA+ASA reduced basal cortisol
levels. ArA+ASA augmented the cortisol response to confinement. The
combination of ArA+ASA also elevated plasma basal prolactin (tPRL)177
and 3,5,3′-triiodothyronine (T3) levels. Neither ArA nor ASA affected
the stress-associated increases in plasma glucose and lactate. Na+, K+-
ATPase activity in the gills was reduced after ArA supplementation and
was even further suppressed by subsequent ASA treatment. In an
additional feeding trial, ArA supplementation enhanced the renal Na+, K
+-ATPase activity. In vitro, ArA was a potent inhibitor of the Na+, K+-
ATPase activity of gill and kidney homogenates. In contrast, PGE2 had
no effect on branchial ATPase, whereas the effect on renal ATPase
activity was concentration dependent. Modifying the dietary intake of
ArA alters the response of tilapia to an acute stressor and influences
osmoregulatory processes and it is unlikely that these effects are due
to an enhanced production of prostaglandins.
SOURCE: http://www.cababstractsplus.org/abstracts/Abstract.aspx?AcNo=20053003417
montygraham
depending upon amount ingested, antioxidants eaten at the same time,
other foods eaten at the same time (such as cooked meat fried in
certain oils generating high amounts HCAs). AA is mostly a problem
when your cells incorporate it, and the it gets made into dangerous
metabolites (such as LTB4) when there is a stressor (and having AA in
cells lowers the stress threshold). Biologist Ray Peat argues that
most AA as well as long chain omega 3s that are in your food never
gets to where it can be utilized, because it is so unstable. Instead,
it is the more stable and usually a lot more abundant omega 6,
linoleic acid, that causes the most common problems (lipid
peroxidation, oxidizing LDL, being made into AA, etc.). Anyway,
there is no mystery. If you go to the USDA's site, you get the
following breakdown for salmon oil, per 4.5 ml:
Proximates
Water
g
0.00
Energy
kcal
41
Energy
kJ
170
Protein
g
0.00
Total lipid (fat)
g
4.50
Ash
g
0.00
Carbohydrate, by difference
g
0.00
Fiber, total dietary
g
0.0
Minerals
Calcium, Ca
mg
0
Iron, Fe
mg
0.00
Magnesium, Mg
mg
0
Phosphorus, P
mg
0
Potassium, K
mg
0
Sodium, Na
mg
0
Zinc, Zn
mg
0.00
Copper, Cu
mg
0.000
Manganese, Mn
mg
0.000
Selenium, Se
mcg
0.0
Vitamins
Vitamin C, total ascorbic acid
mg
0.0
Thiamin
mg
0.000
Riboflavin
mg
0.000
Niacin
mg
0.000
Pantothenic acid
mg
0.000
Vitamin B-6
mg
0.000
Folate, total
mcg
0
Folic acid
mcg
0
Folate, food
mcg
0
Folate, DFE
mcg_DFE
0
Vitamin B-12
mcg
0.00
Vitamin A, RAE
mcg_RAE
0
Retinol
mcg
0
Vitamin A, IU
IU
0
Lipids
Fatty acids, total saturated
g
0.894
14:0
g
0.148
16:0
g
0.443
18:0
g
0.191
Fatty acids, total monounsaturated
g
1.307
16:1 undifferentiated
g
0.217
18:1 undifferentiated
g
0.764
20:1
g
0.174
22:1 undifferentiated
g
0.152
Fatty acids, total polyunsaturated
g
1.815
18:2 undifferentiated
g
0.069
18:3 undifferentiated
g
0.048
18:4
g
0.126
20:4 undifferentiated
g
0.030
20:5 n-3
g
0.586
22:5 n-3
g
0.135
22:6 n-3
g
0.820
Cholesterol
mg
22
The site is at: http://www.nal.usda.gov/fnic/foodcomp/search/