Raspberry ketone is defined as a natural phenolic compound from red raspberries. The chances are high you’ve already heard or read something about this compound since it’s widely present in weight loss supplements. Raspberry ketones are branded as extremely beneficial for weight loss thus attracting thousands of people to buy products that contain them in a bid to lose extra pounds. The question is: do they really work? Keep reading to find an answer!
How do raspberry ketones work?
In order to discuss the efficacy of raspberry ketones for weight loss, it is necessary to learn how they work. Scientists who examined these compounds discovered that raspberry ketones resemble capsaicin, present in chili peppers, and synephrine, a stimulant. A growing body of evidence confirms that both these molecules have the potential to boost the metabolism which is important for weight loss.
Since raspberry ketones are similar to synephrine and capsaicin, it was only logical to assume they function the same way. A team of Korean researchers isolated fat cells from rats and made them grow in a test tube where they also added raspberry ketones. Their findings, published in the Planta Medica, showed the following:
- Raspberry ketones increased breakdown of fat (lipolysis), by making the cells more sensitive to the impact of fat-burning hormone norepinephrine
- They also promoted the release of hormone adiponectin
What is adiponectin? Your fat cells release this hormone which participates in regulating metabolism and blood sugar levels. For instance, thin people have higher adiponectin levels than overweight individuals, but according to a study published in the International Journal of Cardiology, weight loss supports the production of this important hormone.
Therefore, based on these conclusions it’s safe to say that raising adiponectin levels is essential for weight loss. Since raspberry ketones make fat cells release this hormone, then is it safe to conclude they can help you lose weight?
Raspberry ketones – how effective are they?
Raspberry ketones are one of the most common ingredients in weight loss supplements. Just browse these products and the chances are you’ll see this compound on the label. But, how effective are they?
The truth is, raspberry ketones have shown some promise in studies carried out on rats. For example, a study whose findings were published in the Life Sciences aimed to evaluate the efficacy of raspberry ketones by dividing mice into two experiments:
- First experiment – mice were fed high-fat diet including 2% of raspberry ketones for 10 weeks
- The second experiment – mice were given high-fat diet for 6 weeks and subsequently fed the same high-fat diet containing 1% of raspberry ketones for 5 weeks
Findings showed that mice in the raspberry ketone group weighed about 50g at the end of study while mice that weren’t given this compound at first weighed 55g. It is important to bear in mind that animals didn’t, actually, lose weight. They just gained less than expected.
The Journal of Medicinal Food published results of the study which included 40 rats that were, also fed a fattening diet. For the purpose of the research, rats were given raspberry ketones and scientists found that animals had increased adiponectin levels and were protected from the fatty liver. While these findings do seem promising, they’re not overly practical. Why? The reason is simple; rats received high dosages. In fact, you’d have to take 100 times the recommended amount just to reach the same dose that animals received in the study. It is impossible to get such a high dosage from dietary supplements.
Seriously, are raspberry ketones effective in humans?
You’ll be disappointed to know that the number of human studies on raspberry ketones is: zero! In fact, the only study that came close was the one wherein scientists aimed to determine the safety and efficacy of multi-ingredient supplement containing raspberry ketone, caffeine, capsaicin, ginger, and so on.
In the study, 70 participants were randomly assigned to multi-ingredient supplement or a placebo and underwent eight weeks of daily supplementation, a calorie restricted diet, and exercise training.
Although results showed that participants lost weight and fat mass, it’s impossible to tell whether raspberry ketones had anything to do with that, or if the beneficial effect was due to other compounds.
Despite the fact that raspberry ketones are a popular ingredient in weight loss supplement, it is impossible to tell whether they are truly effective. The major problem here is that there are no studies on humans which examined the efficacy of raspberry ketones only while research carried out on animals showed promising results. Unfortunately, raspberry ketones dosages in animal studies were too high and are impossible to obtain through supplements. If you want to lose weight, you should stick to the old but gold method combining regular physical activity and a well-balanced diet.
Please Note: Before following exercise routines or changing your fitness regime, please consult a certified fitness professional. Always talk with a medical practitioner before following dietary advice or taking supplements.