When it comes to choosing an effective fat burning supplements you want the best.
And rightly so; that’s all you should accept.
To compliment your diet and exercise regime and help you navigate towards your goals you need ingredients that are not only proven to work, but dosed properly as well.
In this article we take a look at a popular fat burner supplement – raspberry ketones. We tell you everything you need to know about this fragrant plant compound.
Why’s the science behind it limited, and why is it one to avoid if you’re looking for results?
Read on to find out more.
What Are Raspberry Ketones?
Raspberry ketones (RK) are plant compounds found in red raspberries, blackberries and cranberries.
It’s chemical name is 4-(4-hydroxyphenyl) butan-2-one.
RK first became popular in the perfume and cosmetics industry because of its sweet, aromatic properties. It has also previously been used in foods as candy, and is also added to scented candles and soaps too.
The raspberry ketones in your supplement were made in a lab
Although the smell of this nutrient might remind you of green fields full of vibrant, fresh raspberries, all commercial supplements containing the product are synthetic.
There’s nothing natural about it.
Manufacturers of the supplement quickly realized that it was expensive to harvest from fruits, but that using a process called catalytic hydrogenation could produce a 99% yield for practically zero costing comparison [1].
And after all, for many companies, profits come first unfortunately.
The chemical structure of raspberry ketones is similar to banned fat loss drugs
RK became popular as a fat loss supplement in the early 2000’s.
Because of various endorsements from celebrities and slightly less-than-ethical fitness trainers it quickly became the go-to fat burner for many people wanting to lose weight and drop body fat.
Why?
It has a structure quite similar to synephrine and ephedrine – both weight loss drugs banned by the FDA for causing severe adverse reactions.
After the ban of these two nutrients in 2004, raspberry ketones shot into the spotlight – simply because it was the nearest legal alternative.
That in itself is worrying.
Key Point: Raspberry ketones are structurally similar to banned weight loss drugs synphrine and ephedrine.
Do Raspberry Ketones Help With Weight Loss?
In recent years, raspberry ketones have become a popular fat burner supplement.
They’ve been endorsed by celebrities and had attention from a number of trainers and holistic health practitioners around the world. Even some medical professionals have jumped on the bandwagon, suggesting that they use RK products with their patients.
Many of these are actually paid by manufacturers of the product unsurprisingly.
No human data to draw upon
Raspberry ketones never actually been tested on humans in clinical trials.
The marketing behind the compound is quite clever.
The thought of raspberries conjure up images of nature and healthy nutrition and when you think of ‘ketones’ you might be reminded of the ketogenic diet that is sometimes used for fat loss.
Those two words placed together are a powerful marketing tool.
Let’s not forget though that it’s a synthetic drug. And has no human data profile to back it up.
What does the research say about raspberry ketones and weight loss?
All of the current research comes from petri-dish studies – not exactly reliable or valid.
And what’s worse is that these studies don’t exactly show any benefit either!
RK shown to stimulate glycerol release in cell cultures…
To date, the go-to study that’s often cited by supplement manufactures is this one that was published in Planta Medica [2].
It showed 10µM of RK increased glycerol release by 3 times as much.
That sounds good, right?
As a marker of fat burning, this looks promising at first glance.
But cell culture studies can often be unreliable and don’t necessarily cross over to human, or even animal studies that matter. They are only used as initial research projects for future funding into more comprehensive scientific testing.
…but primary fat cell research shows no increased fat burning
In a more transferable study [3], fat cells obtained from animals were again subjected to 10µM of RK.
These cells provide more realistic replication of human data, simply because they are better suited to show what goes off in in vivo processes.
Cell culture studies often suffer what’s called ‘genetic drift’, where cell strains can adapt and combine, and therefore skew study results. This fat cell research was the first paper that showed what might happen in the human body.
The results of this study showed that even high concentrations of raspberry ketones had no effect on lipolysis (fat burning).
A disappointing result.
No human studies makes raspberry ketones an unreliable supplement
The typical research cycle of a supplement goes like this: cell studies, animal studies and then finally, human trials. If the results of the initial research if seen to be safe and effective, ethics boards will clear the drug for human trials.
Again, that’s only if seen to be safe.
At present there’s absolutely no human data to draw upon. The only time RK has been used in human research is as a topical cosmetic, not an oral weight loss supplement.
Key Point: There are no human trials looking at raspberry ketones and weight loss. And the animal and cell studies that are available are less than convincing.
What Are Raspberry Ketones Side Effects?
Not only is RK an unreliable supplement for fat loss, it might not be safe either.
The effects of long-term use haven’t been verified and are unknown. The FDA currently labels RK as a ‘novel food’. This means that it has no significant history of consumption safety.
Remember, it’s structurally similar to two of the least safe weight loss drugs out there. Raspberry ketones side effects could be the same.
Many scientists have voiced their concerns over the safety of this supplement.
There’s currently no recommended dosage for humans, so when it comes to raspberry ketones side effects it’s pretty much guess and hope for the best.
Some manufacturers air on the side of caution by adding in only small amounts of the compound to a proprietary blend fat burner supplement. This in itself is problematic as it’s unlikely to have any effect on fat loss at all.
Some manufacturers of the supplement have decided to go for a larger dose, but at the risk of safety. Either way, it’s unlikely to sway cost-benefit in favor of the consumer.
So what are the raspberry ketones side effects?
Raspberry ketones side effects include jitters, rapid heart rate and elevated blood pressure. It appears to have a stimulatory effect similar on the autonomic nervous system.
If you suffer from heart disease, high blood pressure or respiratory illness then taking the supplement might aggravate your symptoms. It could also result in severe consequences.
Key Point: There’s no known recommended dosage, so when it comes to safety you’re pretty much flying blind.
Raspberry ketones side effects – Is it Safe?
When it comes to effective weight loss you need to put safety first.
Not only is the current cell and animal research on RK questionable, the lack of human research makes it hard to guess what an effective or safe dose would be.
We suggest that until more robust evidence is made available, you look elsewhere for a more effective fat burner supplement.
Smith, LR. Rheosmin (‘Raspberry Ketone’) and Zingerone, and Their Preparation by Crossed Aldol-Catalytic Hydrogenation Sequences. The Chem Educ. 1996; 1(3): 1-18
Park, KS. Raspberry ketone increases both lipolysis and fatty acid oxidation in 3T3-L1 adipocytes. Planta Medica. 2010; 76(15): 1654-8
Morimoto, C et al. Anti-obese action of raspberry ketone. Life Sci. 2005; 77(2): 194-204
