Conjugated Linoleic Acid for Weight Loss?

You asked us to evaluate the use of CLA for weight loss, so that’s today’s main feature!

First, what is CLA?

Conjugated Linoleic Acid (CLA) is a fatty acid made by grazing animals. Humans don’t make it ourselves, and it’s not an essential nutrient.

Nevertheless, it’s a popular supplement, mostly sold as a fat-burning helper, and thus enjoyed by slimmers and bodybuilders alike.

❝CLA reduces bodyfat❞—True or False?

True! Contingently. Specifically, it will definitely clearly help in some cases. For example:

• This study found it doubled fat loss in chickens
• It significantly increased delipidation of white adipose tissue in these mice
• The mice in this study enjoyed a 43–88% reduction in (fatty) weight gain
• Over the course of a six-week weight-loss program, these mice got 70% more weight loss on CLA, compared to placebo
• In this study, pigs that took CLA on a high-calorie diet gained 50% less weight than those not taking CLA
• On a heart-unhealthy diet, these hamsters taking CLA gained much less white adipose tissue than their comrades not taking CLA
• Another study with pigs found that again, CLA supplementation resulted in much less weight gained
• These hamsters being fed a high-cholesterol diet found that those taking CLA ended up with a leaner body mass than those not taking CLA
• This study with mice found that CLA supplementation promoted fat loss and lean muscle gain

Did you notice a theme? It’s Animal Farm out there!

❝CLA reduces bodyfat in humans❞—True or False?

False—practically. Technically it appears to give non-significantly better results than placebo.

A comprehensive meta-analysis of 18 different studies (in which CLA was provided to humans in randomized, double-blinded, placebo-controlled trials and in which body composition was assessed by using a validated technique) found that, on average, human CLA-takers lost…

Drumroll please…

00.00–00.05 kg per week. That’s between 0–50g per week. That’s less than two ounces. Put it this way: if you were to quickly drink an espresso before stepping on the scale, the weight of your very tiny coffee would cover your fat loss.

The reviewers concluded:

❝CLA produces a modest loss in body fat in humans❞

Modest indeed!

See for yourself: Efficacy of conjugated linoleic acid for reducing fat mass: a meta-analysis in humans

But what about long-term? Well, as it happens (and as did show up in the non-human animal studies too, by the way) CLA works best for the first four weeks or so, and then effects taper off.

Another review of longer-term randomized clinical trials (in humans) found that over the course of a year, CLA-takers enjoyed on average a 1.33kg total weight loss benefit over placebo—so that’s the equivalent of about 25g (0.8 oz) per week. We’re talking less than a shot glass now.

They concluded:

❝The evidence from RCTs does not convincingly show that CLA intake generates any clinically relevant effects on body composition on the long term❞

A couple of other studies we’ll quickly mention before closing this section:

• CLA supplementation does not affect waist circumference in humans (at all).
• Amongst obese women doing aerobic exercise, CLA supplementation has no effect (at all) on body fat reduction compared to placebo

What does work?

You may remember this headline from our “What’s happening in the health world” section a few days ago:

Research reveals self-monitoring behaviors and tracking tools key to long-term weight loss success

On which note, we’ve mentioned before, we’ll mention again, and maybe one of these days we’ll do a main feature on it, there’s a psychology-based app/service “Noom” that’s very personalizable and helps you reach your own health goals, whatever they might be, in a manner consistent with any lifestyle considerations you might want to give it.

Curious to give it a go? Check it out at Noom.com (you can get the app there too, if you want)

Gluten: What’s The Truth?

We asked you for your health-related view of gluten, and got the above spread of results. To put it simply:

Around 60% of voters voted for “Gluten is bad if you have an allergy/sensitivity; otherwise fine”

The rest of the votes were split fairly evenly between the other three options:

• Gluten is bad for everyone and we should avoid it
• Gluten is bad if (and only if) you have Celiac disease
• Gluten is fine for all, and going gluten-free is a modern fad

First, let’s define some terms so that we’re all on the same page:

What is gluten?

Gluten is a category of protein found in wheat, barley, rye, and triticale. As such, it’s not one single compound, but a little umbrella of similar compounds. However, for the sake of not making this article many times longer, we’re going to refer to “gluten” without further specification.

What is Celiac disease?

Celiac disease is an autoimmune disease. Like many autoimmune diseases, we don’t know for sure how/why it occurs, but a combination of genetic and environmental factors have been strongly implicated, with the latter putatively including overexposure to gluten.

It affects about 1% of the world’s population, and people with Celiac disease will tend to respond adversely to gluten, notably by inflammation of the small intestine and destruction of enterocytes (the cells that line the wall of the small intestine). This in turn causes all sorts of other problems, beyond the scope of today’s main feature, but suffice it to say, it’s not pleasant.

What is an allergy/intolerance/sensitivity?

This may seem basic, but a lot of people conflate allergy/intolerance/sensitivity, so:

• An allergy is when the body mistakes a harmless substance for something harmful, and responds inappropriately. This can be mild (e.g. allergic rhinitis, hayfever) or severe (e.g. peanut allergy), and as such, responses can vary from “sniffly nose” to “anaphylactic shock and death”.
  • In the case of a wheat allergy (for example), this is usually somewhere between the two, and can for example cause breathing problems after ingesting wheat or inhaling wheat flour.
• An intolerance is when the body fails to correctly process something it should be able to process, and just ejects it half-processed instead.
  • A common and easily demonstrable example is lactose intolerance. There isn’t a well-defined analog for gluten, but gluten intolerance is nonetheless a well-reported thing.
• A sensitivity is when none of the above apply, but the body nevertheless experiences unpleasant symptoms after exposure to a substance that should normally be safe.
  • In the case of gluten, this is referred to as non-Celiac gluten sensitivity

A word on scientific objectivity: at 10almonds we try to report science as objectively as possible. Sometimes people have strong feelings on a topic, especially if it is polarizing.

Sometimes people with a certain condition feel constantly disbelieved and mocked; sometimes people without a certain condition think others are imagining problems for themselves where there are none.

We can’t diagnose anyone or validate either side of that, but what we can do is report the facts as objectively as science can lay them out.

Gluten is fine for all, and going gluten-free is a modern fad: True or False?

Definitely False, Celiac disease is a real autoimmune disease that cannot be faked, and allergies are also a real thing that people can have, and again can be validated in studies. Even intolerances have scientifically measurable symptoms and can be tested against nocebo.

See for example:

• Epidemiology and clinical presentations of Celiac disease
• Severe forms of food allergy that can precipitate allergic emergencies
• Properties of gluten intolerance: gluten structure, evolution, and pathogenicity

However! It may not be a modern fad, so much as a modern genuine increase in incidence.

Widespread varieties of wheat today contain a lot more gluten than wheat of ages past, and many other molecular changes mean there are other compounds in modern grains that never even existed before.

However, the health-related impact of these (novel proteins and carbohydrates) is currently still speculative, and we are not in the business of speculating, so we’ll leave that as a “this hasn’t been studied enough to comment yet but we recognize it could potentially be a thing” factor.

Gluten is bad if (and only if) you have Celiac disease: True or False?

Definitely False; allergies for example are well-evidenced as real; same facts as we discussed/linked just above.

Gluten is bad for everyone and we should avoid it: True or False?

False, tentatively and contingently.

First, as established, there are people with clinically-evidenced Celiac disease, wheat allergy, or similar. Obviously, they should avoid triggering those diseases.

What about the rest of us, and what about those who have non-Celiac gluten sensitivity?

Clinical testing has found that of those reporting non-Celiac gluten sensitivity, nocebo-controlled studies validate that diagnosis in only a minority of cases.

In the following study, for example, only 16% of those reporting symptoms showed them in the trials, and 40% of those also showed a nocebo response (i.e., like placebo, but a bad rather than good effect):

Suspected Nonceliac Gluten Sensitivity Confirmed in Few Patients After Gluten Challenge in Double-Blind, Placebo-Controlled Trials

This one, on the other hand, found that positive validations of diagnoses were found to be between 7% and 77%, depending on the trial, with an average of 30%:

Re-challenge Studies in Non-celiac Gluten Sensitivity: A Systematic Review and Meta-Analysis

In other words: non-Celiac gluten sensitivity is a thing, and/but may be over-reported, and/but may be in some part exacerbated by psychosomatic effect.

Note: psychosomatic effect does not mean “imagining it” or “all in your head”. Indeed, the “soma” part of the word “psychosomatic” has to do with its measurable effect on the rest of the body.

For example, while pain can’t be easily objectively measured, other things, like inflammation, definitely can.

As for everyone else? If you’re enjoying your wheat (or similar) products, it’s well-established that they should be wholegrain for the best health impact (fiber, a positive for your health, rather than white flour’s super-fast metabolites padding the liver and causing metabolic problems).

Wheat itself may have other problems, for example FODMAPs, amylase trypsin inhibitors, and wheat germ agglutinins, but that’s “a wheat thing” rather than “a gluten thing”.

That’s beyond the scope of today’s main feature, but you might want to check out today’s featured book!

For a final scientific opinion on this last one, though, here’s what a respected academic journal of gastroenterology has to say:

From coeliac disease to noncoeliac gluten sensitivity; should everyone be gluten-free?