It is becoming increasingly evident that the UK is in the grip of an obesity epidemic. Our lifestyles are becoming increasingly sedentary to the point that not even a morning coffee requires exercise, I recently experienced my first drive through Costa Coffee! My routine morning latte can now be ordered, collected and consumed all without the removal of my seat belt. Convenience focussed lifestyles have made weight gain far easier than ever, resulting in 44% of men and 33% of woman in the UK being classed as clinically obese. In addition, the incidence of childhood obesity has dramatically increased, with 31.2% of children aged 2 to15 being classed as either obese or overweight in 2004.
It is well understood that a combination of a balanced diet and plenty of exercise is the key to maintaining a healthy body weight, but why is obesity such a big issue despite the solution appearing incredibly obvious? It is the distaste for exercise? Our drinking culture? Our busy lifestyles that leave little time for exercise? Our lack of awareness on calorific content of foods? The answer is that people find it hard and unpleasant adapting to a healthier lifestyle, and once in an unhealthy routine, its very hard to break the routine. It is obvious that a large chunk of the population is struggling to commit to the lifestyle changes that rewards weight loss.
Nutraceuticals are part of a growing sector of the food supplements market, and are becoming increasingly popular due to their convenience and low side effects. Nutraceuticals are defined as supplements derived from specific food sources that have medical or health benefits in addition to the basic nutritional content. However, there is a significant difference between the level of good quality evidence associated with the specific Nutraceuticals claimed to aid fat loss in combination with increased exercise and maintenance of a balanced diet.
1. L Carnitine is commonly found in dairy products and red meats and is an example of a Nutraceutical with claims to reduce body fat. L Carnitine functions as a co factor in the process of fatty acid oxidation for cellular energy production. In theory, a reduction of L Carnitine mediated enzyme activity results in reduced fatty acid oxidation in muscle tissue, resulting in increased fat storage. Consumption of additional L-Carnitine in obese patients should increase the rate of fatty acid metabolism in the liver and muscle and therefore reduce fat storage. However, there is little firm evidence to support its use for weight loss because the studies to support this ingredient are either based on animal models or use human subjects with statistically insignificant numbers.
2. Dehydroepiandrosterone (DHEA) is an endogenous adrenal hormone and functions as a PPAR alpha-receptor agonist, with peak blood levels experienced at 20 years of age and then rapidly diminishing after 25 years of age. In a randomised, double blind, placebo controlled, six-month trial of men and woman over 65, a daily dose of 50mg DHEA reduced visceral and subcutaneous fat significantly, with no significant adverse effects reported. DHEA has solid evidence supporting it as an effective weight loss aid. However, it’s safety in long term use has not been fully validated particularly relating to its effects on estradiol and testosterone levels
3. Bergamot (Citrus bergamia Risso et Poiteau) belongs to the family Rutaceae, genus Citrus, and is an endemic plant from the Calabrian region in Italy. Bergamot juice was traditionally recognized by the local population of Calabria, as a remedy for “fatty arteries” and heart problems. The medical uses of bergamot derivatives, forgotten for decades, but are now being researched by centres in Rome, Calabria and Australia. Several published human clinical trials have highlighted the effectiveness of 37% strength Bergamot fruit extract against several parameters associated with obesity. In one large-scale human trial consisting of 107 participants, the group receiving Bergamot Polyphenol fraction (BPF) 650 mg twice a day for 120 consecutive days exhibited a significant reduction of fasting plasma glucose, serum LDL cholesterol and triglycerides alongside with an increase of HDL cholesterol was found. This effect was accompanied by significant reduction in belly fat in and around the liver supported by CT scans of the patients before and after 4 months of treatment.
4. Green Tea is increasingly becoming the target of weight loss claims. Moreover, green tea contains catechin polyphenols including epigallocatechingallate (ECGC) which have been shown to inhibit catechol ortho-methyltransferase (COMT), an enzyme responsible for the degradation of noradrenalin (which has an important role in the control of thermogenesis and fat metabolism). In addition to this, Tea catechin have been shown to cause loss of appetite, which might involve neuropeptides other than leptin. A small cross over study featuring 10 male adults indicated that green tea extract increased 24 hour energy expenditure without increasing the heart rates of the volunteers, which is surprising as other substances that increase energy expenditure (ephedrine) also increase heart rate, increasing the risk of adverse cardiovascular effects. This study did not measure weight loss as a parameter and further clinical trials need to be conducted in order to evaluate the complete efficacy of green tea as a weight loss tool. Green tea is widely consumed worldwide and is considered safe to use if the equivalent of 5 cups daily is not exceeded. It can easily be incorporated into an everyday lifestyle without the trouble of buying and taking capsules and tablets.
5. Conjugated Linoleic acid (CLA) is a collective term to describe a mixture of positional and geometric dienoic linoleum acid isomers with conjugated double bonds. CLA isomers are found in dairy and meat products. The different mechanisms thought to be responsible for the activity of CLA are increasing energy expenditure, reduced fat cell size, increasing apoptosis of fat cells, and the inhibition of lipogenesis in the liver or increasing fat oxidation. A year long randomised, double blind, placebo controlled study into the effects of CLA on body fat mass concluded that long-term supplementation of CLA in healthy over-weight adults significantly reduced body fat mass. Adverse effects were mainly gastrointestinal and classed as just ‘mild’ or ‘moderate’. Several human trials have been reported in which no adverse effects occurred when high quality CLA was taken at doses of 3-6g per day. It is necessary for more extensive clinical trials to be conducted to monitor the safe use of CLA for weight management in humans.
In conclusion, the effectiveness of Nutraceuticals on reducing body weight is highly dependent the level of good clinical evidence supporting same strength of ingredient. This must be considered alongside the level/type of calorific intake and amount of daily exercise. Moreover, the concept of a ‘magic pill’ that reduces body weight without amendments to lifestyle is far from realistic.