Unless you've been living under a rock somewhere for the
last several years, you've probably heard about the health
benefits of eating fatty fish or taking fish oil
supplements. Well, it looks like you might be able to add
fat loss alongside the other benefits like heart, blood
(cholesterol/triglycerides), brain, skin and joint health -
and the rest of the list, which is too long to print here.
The biologically active ingredients that seem to make fatty
fish so beneficial are are the long chain omega-3 (n-3)
fatty acids, EPA and DHA. At least a half a dozen human
studies and more than two dozen animal studies have been
completed in the last 10 years which suggest that these
omega-3 fatty acids found in fish may help you lose more
fat. However, the fat loss benefit is not as much as some
people want you to believe…
The results of two new studies on fish oil and fat loss
were just released earlier this year. In one study
published by the International Journal of Obesity,
researchers from Reykjavik Iceland tested the effects of
fish or fish oil consumption equivalent to 1.5 grams of
combined EPA/DHA on body weight and body composition as
part of a calorie restricted diet. (1)
The subjects were 324 young overweight men and women who
followed one of four experimental protocols for 8 weeks:
(1) sunflower oil capsules (control)
(2) lean fish
(3) fatty fish (salmon)
(4) fish oil capsules
The researchers reported the following results:
"In young, overweight men, the inclusion of either lean or
fatty fish, or fish oil as part of a hypoenergetic diet
resulted in 1 kilogram more weight loss after 4 weeks than
a similar diet without seafood or supplement of marine
origin. The addition of seafood to a nutritionally balanced
energy-restricted diet may boost weight loss."
It should be noted that the study was supported by the
Seafood Plus organization and there were some limitations
in the design that could have influenced the subject's
compliance.
The second study, conducted at the University of South
Australia and published in the American Journal of Clinical
Nutrition (2) investigated the effect of combining fish oil
supplements with regular aerobic exercise.
In a 12 week placebo-controlled study, the subjects were
divided into four groups:
(1) sunflower oil
(2) sunflower oil plus exercise
(3) fish oil
(4) fish oil plus exercise.
The fish oil groups were given 6 grams of high DHA fish oil
per day, which contained a total of 1.9 grams of long chain
omega-3 fatty acids. The exercising groups performed
aerobic exercise three days per week for 45 minutes.
As you might expect, the fish oil plus exercise group came
out with the best results:
• minus 1.2% body fat (compared to no decrease in the other
groups)
• minus 2 kilograms/4.4 lbs (compared to no decrease in the
non exercise group).
Unfortunately, there was a limitation in this study as
well: The food intake of the subjects was self reported,
which is known to be notoriously inaccurate.
There have been several other human studies on fish oil and
fat loss in the last ten years or so and the majority of
the findings have been positive. The research is compelling
and there have been numerous, and very plausible mechanisms
of action proposed.
However, more and more often, I am hearing people in the
health, fitness and nutrition industries making some pretty
bold and I daresay, premature and outrageous claims about
what fish oil can do for fat loss; claims which are not
supported by the research.
The studies on fish oil and fat loss are encouraging, but
the vast majority of research has been on animals (rats,
mice and hamsters) and there have been limitations in
nearly all the human studies so far, including:
small sample sizes, short study durations, statistically
insignificant results, lack of randomization, no control
groups, imprecise body composition testing, measurement
errors, self-reporting of food intake, low compliance
control and fish industry or supplement industry-sponsored
bias.
Even if you take the results of the existing research at
face value, the fat loss really isn't all that impressive -
an extra pound here, an extra kilo there.
Many of the research results barely reach statistical
significance, and you even have to wonder if these small
improvements in fat loss are simply correcting omega-3
deficiency or fixing omega-3 and omega-6 imbalance…
therefore, will they continue over a longer time period or
is this a one time improvement?
One of the earlier studies showed the same kind of
measurable but modest results: The fish oil group that took
1.8 grams of combined EPA/DHA daily lost 2 pounds and the
non fish oil group lost only 0.7 pounds after 3 weeks (3).
Of course, you'll probably take all the fat loss help that
you can get, and since there are already enough good
reasons to eat fatty fish for cardiovascular disease
prevention and other health benefits, it's really a no
brainer to eat fish such as salmon, trout, mackerel or
sardines at least twice a week. (By the way, with the
exception of King Mackerel, these are species which have
not been reported as having problems with mercury
contamination).
Alternately, you can use a fish oil supplement to get the
equivalent in omega-3 fatty acids as found in the fish. Non
fish eaters or vegetarians can use flaxseed oil, a
plant-based source of Alpha Linolenic Acid (ALA) which
converts in the body to EPA and DHA (the efficiency and
amount of conversion has been a subject of controversy,
however).
Based on the three studies cited above, it looks like 1.5
to 2.0 grams per day of combined DHA/EPA is the right dose
when fat loss is the goal (although some suggest you should
consider body weight when choosing the dosage, i.e., 1 gram
total fish oil for each 20 lbs body weight, so a big guy
might go with as much as 3.0 grams)
Most fish oil capsules come in 1,000 mg size at a 30%
concentration, so if you took five 1000mg capsules a day (5
grams of total fish oil), that would give you 1.5 grams of
EPA/DHA; about the same as you'd get in 3 ounces (85 g) of
salmon.
Note: other studies on fish oil and fat loss tested 3.0 to
4.0 g/day of EPA/DHA, but the American Heart Association
has warned against taking more than 3 g EPA/DHA per day
without a physician's supervision, as there may be
potential contraindications or side effects such as
increased bleeding time. Based on the research, more fish
oil will NOT burn more fat, so be wary of the "mega dose
gurus."
Another tip: Don't fall for the "premium price" necessarily
means better quality party line. Quality and purity are
important, but you can get molecularly-distilled, mercury,
PCB, Dioxin, Organochlorine-free, 3rd party
tested-to-meet-label-claims fish oil for less than ten
bucks per bottle of 400 (one gram) capsules… yet I have
seen "fish oil gurus" selling the exact same thing for $50
to $60 claiming that everyone else's products were
"contaminated" and "inferior" in quality. If that's true,
then I'd like to see those products submitted to consumer
lab for voluntary 3rd party independent analysis and head
to head comparison on purity AND cost effectiveness. If
they come out superior and cost effective, I will gladly
publicize the results myself.
The bottom line is it looks like fish oil may be a
legitimate help to your fat loss efforts, especially when
combined with exercise, as there may be an important
synergy there. However, the idea that fish oil is some kind
of miracle fat burner is just not true.
Like Mulder on the X-files, "I want to believe"… but we
need much, much more research before we can say for certain
exactly how much body composition improvement you can
really expect from eating fatty fish or taking fish oil
supplements.
References:
(1) Hill AM. Combining fish-oil supplements with regular
aerobic exercise improves body composition and
cardiovascular disease risk factors. Am J Clin Nutr. 86(5):
1267-1274. 2007
(2) Thorsdottir I et al. Randomized trial of weight loss
diets for young adults varying in fish and fish oil
content. Int J Obesity. May 2007. pp 1-7
(3) Couet C. Effect of dietary fish oil on body fat mass
and basal fat oxidation in healthy adults. Int J Obes. 21:
637-643. 1997
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Tom Venuto, CSCS, CPT, is a natural bodybuilder, fat loss
expert, independent nutrition researcher and author of
"Burn the Fat, Feed The Muscle," which teaches you how to
get lean without drugs or supplements using secrets of the
world's best bodybuilders and fitness models. Learn how to
get rid of stubborn fat and increase your metabolism by
visiting: http://www.burnthefat.com and
http://www.burnthefatinnercircle.com
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