"Benefits of Flaxseed Meal for Weight Loss"
Canada now allows a health claim on the labels of products with flaxseeds,
saying that we know with sufficient certainty
that flaxseeds do indeed help lower cholesterol levels.
The products have to contain two tablespoons
and have to be relatively healthy in the first place,
so they can't like boast about the cholesterol-lowering effects
of a flaxseed-enriched meatball or something.
Such claims are based on studies like this:
double-blind, randomized, placebo-controlled trials.
Wait, how do you come up with placebo food?
I mean there are sugar pills for drugs,
but how can you slip spoonfuls of flax past someone?
The researchers made all these special products, snack bars, muffins, and bagels
so the research subjects unknowingly would be getting tablespoons
of ground flaxseeds, or just tablespoons of the control, whole wheat.
And they did this for a year!
No one knew who got which muffins until the code was broken at the end.
And the dietary flaxseed group saw a 15% reduction in LDL cholesterol
as early as one month into the trial, but only fell significantly lower
than the whole wheat group in those on cholesterol-lowering drugs.
In those off drugs, the whole wheat group's cholesterol went down too,
diminishing the efficacy of the flax in comparison.
That's why food placebos are so hard. Like in this study.
The reason they give for doing a so-called "open label" study where the study group
is aware that they're eating flax seeds is because
they couldn't come up with an inert placebo for flaxseeds.
I mean, whole wheat flour is a whole grain;
it could be beneficial in its own right,
and white flour could make the control group look even worse.
So what they did in this study was that overweight patients
were randomly assigned to receive
either lifestyle advice and daily ground flaxseeds
or just the lifestyle advice alone as the control group.
And, not surprisingly, body weight, waist circumference,
and body mass index decreased significantly in both groups.
Even without the lifestyle advice, just enrolling people in a study
where you know they're going to keep weighing you
can get people to lose weight,
though there was a significantly greater reduction
in the flaxseed group, and not just by a little.
The control group that just got lifestyle advice over a 12-week period
lost nearly seven pounds and an inch off their waist.
But the group that got the same advice plus spoonfuls of flax a day—
so, in effect, given more food to eat— lost over 20 pounds on average
over the same period and cut nearly four inches off their waist.
Those are extraordinary numbers for an intervention
that added rather than actively removed calories from the diet.
Was that just some crazy fluke?
How about flaxseed supplementation for non-alcoholic fatty liver disease?
Thanks to the obesity epidemic, that's now the most common liver disease,
recognized as a major public health problem around the world.
A high-fat diet is the most common cause,
but flaxseed fat may be better, compared to lard.
Well, that's not very helpful, so let's put it to the test.
Same as last time, lifestyle modification advice with or without flaxseeds.
They were told to just mix it with water and juice
and drink it down after breakfast, and...
body weight went down, along with liver inflammation and scarring
and fat inside the liver in both groups, but better in the flaxseed group.
And again, that extraordinary 20-pound weight loss,
telling people to add something to their diet.
So maybe that first study wasn't a fluke, or maybe they both were.
There have been dozens of randomized, controlled trials of flaxseeds
and weight loss, and as you can see most were more equivocal.
Here are those two recent 20-pound weight loss studies,
which appear to be the outliers.
But still, put all the studies together and you do see a significant reduction
in body weight, BMI, and waistlines following flaxseed supplementation
in randomized controlled trials,
though one would expect more like two pounds of weight lost rather than 20.