Debate rages on efficacy of weight loss therapies
In recent times, there has been an explosion in the sales of lightly regulated, under-researched herbal and dietary weight loss supplements.
According to the World Health Organisation (WHO), obesity worldwide has nearly tripled since 1975 and more people are now trying harder to lose weight.
Doctors now prescribe shedding extra kilogrammes to prevent and treat chronic diseases such as obesity, type 2 diabetes, hypertension, stroke, kidney failure, infertility and cancer.
According to a recent study, about 15 per cent of people in the United States have tried one of these dietary aids, the products of an industry valued at $140 billion in 2020. But there is insufficient evidence to recommend these supplements for weight loss.
Researchers recently presented the first global review in 19 years regarding the efficacy of herbal and dietary supplements for weight loss from the University of Sydney (USYD) in Australia to the European Congress on Obesity (ECO).
The research, which encompassed two literature reviews including 121 randomised placebo-controlled trials involving over 10,000 participants with overweight or obesity, found insufficient evidence that herbal and dietary supplements produce clinically significant weight loss.
Lead author of the study, Erica Bessell, said: “Our rigorous assessment of the best available evidence finds that there is insufficient evidence to recommend these supplements for weight loss. Even though most supplements appear safe for short-term consumption, they are not going to provide weight loss that is clinically meaningful.”
At issue are a range of pills, powders, and liquids marketed with the promise that they can help people lose weight. The products may include entire plants or products in which a plant is an active ingredient. They may also contain isolates from animal- and plant-based substances, such as fats, fibre, and protein.
“Over-the-counter herbal and dietary supplements promoted for weight loss are increasingly popular, but unlike pharmaceutical drugs, clinical evidence for their safety and effectiveness is not required before they hit the market,” Bessell said.
The first study involved a review of 54 trials that compared the effects of herbal supplements with those of placebos. The research involved 4,331 participants aged 16 years or above with overweight or obesity.
A weight loss of at least 2.494 kilogrammes (5.5 pounds) more than that achieved by a placebo was considered clinically meaningful.
Herbal supplements included in the analysis were: green tea; Garcinia cambogia and mangosteen (tropical fruits); white kidney bean; ephedra (a stimulant that increases metabolism); African mango; yerba mate (herbal tea made from the leaves and twigs of the Ilex paraguariensis plant); veld grape (commonly used in Indian traditional medicine); licorice root; and East Indian Globe Thistle (used in Ayurvedic medicine).
The analysis found that only one single agent, white kidney bean, resulted in a statistically, but not clinically, greater weight loss than placebo (-1.61kg; 3.5Ibs).
In addition, the researchers said, some combination preparations containing African Mango, veld grape, East Indian Globe Thistle and mangosteen showed promising results but were investigated in three or fewer trials, often with poor research methodology or reporting, and the findings should be interpreted with caution.
A new systematic review up to December 2019 also identified 67 randomised trials comparing the effect of dietary supplements containing naturally occurring isolated compounds to placebo for weight loss in 5,194 healthy overweight or obese adults (aged 16 years or older).
Dietary supplements included in the analysis were: chitosan (a complex sugar from the hard outer layers of lobsters, crabs, and shrimp that claims to block absorption of fat or carbohydrates); glucomannan (a soluble fibre found in the roots of the elephant yam, or konjac, that promotes a feeling of fullness); fructans (a carbohydrate composed of chains of fructose) and conjugated linoleic acid (that claims to change the body composition by decreasing fat).
The analysis found that chitosan (-1.84 kg), glucomannan (-1.27 kg), and conjugated linoleic acid (-1.08 kg) resulted in statistically, but not clinically, significant weight loss compared to placebo.
According to the researchers, some dietary supplements, including modified cellulose (plant fibre that expands in the stomach to induce a feeling of fullness) and blood orange juice extract, showed promising results but were only investigated in one trial and need more evidence before recommending them for weight loss.
Bessell added: “Herbal and dietary supplements might seem like a quick-fix solution to weight problems, but people need to be aware of how little we actually know about them.
“Very few high-quality studies have been done on some supplements with little data on long-term effectiveness. What is more, many trials are small and poorly designed, and some do not report on the composition of the supplements being investigated. The tremendous growth in the industry and popularity of these products underscores the urgency for conducting larger more rigorous studies to have reasonable assurance of their safety and effectiveness for weight loss.”
Meanwhile, scientists have validated more natural therapies that could help humans shed the extra kilogrammes and prevent the attendant obesity, type 2 diabetes, hypertension, stroke, kidney failure, infertility and cancer associated with weight gain.
Alligator pepper may provide next weight loss, energy-boosting drug
Can regular intake of alligator pepper be the next best and safest way to shed weight, burn body fats and boost energy levels?
Japanese researchers in a study published in the British Journal of Nutrition tested the traditional West African herbal remedy and found that it increases thermogenesis and stimulates brown adipose tissue loss. Thermogenesis is the process of heat production in organisms. It occurs mostly in warm-blooded animals.
The research comes from Japan’s Tenshi College School of Nursing and Nutrition. After significant laboratory testing on the medicinal herb called Aframomum melegueta, inclusive of breaking down its primary active constituents, the researchers tested the herb on 19 healthy young men. The study is titled ‘Grains of paradise (Aframomum melegueta) extract activates brown adipose tissue and increases whole-body energy expenditure in men.’
The researchers tested the 19 men for body fat content, energy expenditure and thermogenesis using positron emission tomography (PET) scans. A PET scan uses radiation, or nuclear medicine imaging, to produce 3-dimensional, color images of the functional processes within the human body. The thermogenesis testing included submitting the subjects to a cold environment for two hours while testing their energy output. After gaining baseline levels, the researchers gave an extract of Aframomum melegueta seed or a placebo to the 19 men for four weeks and then crossed the group over to test the placebo group with the herbal extract.
The researchers found that the extract resulted in a significant increase in energy expenditure and loss of brown adipose tissue ‘ fatty tissue known to be difficult to reduce. They also found that energy expenditure increased within two hours of the subject receiving the extract, while the placebo group showed no such increase.
The research, published in the British Journal of Nutrition, showed that alligator could be a significant weight loss aid. Brown adipose tissue can be difficult to reduce for those wanting to lose weight because it receives significant circulation. Some refer to brown fatty tissue as ‘baby fat.’
Black pepper could help in the battle against obesity
Black pepper could help in the fight against obesity, new research suggests. Piperonal, a compound in the seasoning, was found to ‘significantly reduce the harmful effects of a high-fat diet when fed to rats. In the Indian study, those given it as a supplement for six weeks had a lower body weight, body fat percentage and blood sugar levels as well as stronger bones compared to animals fed fatty foods only and no pepper.
The study was published in the journal Nutrition and Metabolism. In a separate study, the United Kingdom (U.K.) researchers at Imperial College London discovered mutations in a gene related to obesity and have suggested “obesity is not always gluttony’. Interestingly, the Indian researchers believe piperonal may counteract some of the genes that are associated with being severely overweight.
Extract of wild mango seed shows promise in obesity treatment
Can eating Ogbono soup help overweight persons shed some kilos, reduce abdominal fat, lower their cholesterol and chances of developing diabetes, heart diseases, cancer, stroke, kidney failure, high blood pressure?
A study published in Lipids in Health and Disease suggests that an extract derived from the seed (Ogbono) of West African mango may help overweight people shed kilogrammes, lower their cholesterol and chances of developing degenerative diseases.
Researchers in other studies found that the fruit of Irvingia gabonensis could be used to reduce abdominal fat, and stop diarrhoea and ulcer. Lab research has shown that extracts from the plant’s seed may inhibit body fat production, through effects on certain genes and enzymes that regulate metabolism.
A person is said to be obese when the ratio of the weight in kilogrammes over the height in square metres, that is the Body Mass Index (BMI), is more than 30; overweight when the BMI is between 25 and 30; and healthy weight when the BMI is between 20 and 25. The seed of Irvingia gabonensis is the basic ingredient of the popular tasty delicacy, Ogbono soup. The fruit looks like mango, but leaves a bitter aftertaste. The seed, slimy when it touches water, is used in cooking Ogbono soup.
Botanically called Irvingia gabonensis, West African mango or Wild mango is a fruit commonly eaten in Nigeria, and indeed the whole of West Africa. It is also called native mango, bush mango, dika nut tree, and dika bread tree. In Nigeria, it is pekpeara in Nupe; ugiri (tree or fruit) or ogbono (kernel or seed) in Igbo; oro (the tree) or aapon (the kernel) in Yoruba; ogwi (the tree or fruit) in Benin; goron or biri in Hausa; uyo in Efik.
The study is the first well-controlled clinical trial of the extract’s effectiveness as a weight-loss aid. But the findings suggest that Irvingia gabonensis could offer a “useful tool” for battling the growing worldwide problem of obesity and its related ills.
A few patients on the extract reported side effects, including headaches, sleep problems and gas, but the rates were similar in the placebo group.
Aloe vera juice for weight loss?
People looking for quick weight-loss solutions sometimes turn to herbal products, such as those containing Aloe vera. Although these products may produce short-term weight loss, they are not likely to result in permanent weight loss and may have a number of side effects. Most studies on Aloe vera and weight loss have used Aloe vera gel or supplements rather than Aloe vera juice, so it may not have the same effects.
An animal study published in Obesity Research & Practice in December 2008 showed a potential for plant sterols found in Aloe vera to improve body composition. In the study, obese rats given these plant sterols had lower levels of abdominal fat after 35 days than rats not given these sterols. This effect may also occur in people. A small preliminary study published in September 2013 in Nutrition found that obese people with diabetes or pre-diabetes who took an Aloe vera gel complex for eight weeks lost more weight and body fat than those not given this supplement. Larger long-term studies are needed to verify these effects.
Aloe vera may result in weight loss due to its laxative effect. Taking laxatives as a way to lose weight is a form of laxative misuse and can result in electrolyte imbalances that can cause numbness, weak muscles, seizures, irregular heartbeat, heart attacks and paralysis. Long-term laxative use can also interfere with your normal bowel function and cause incontinence or dependence on laxatives to have a bowel movement.
The grapefruit weight loss diet – fad or science?
Eat half a grapefruit before each meal and lose 4.53 kilogrammes (10 pounds) in 10 days! Citrus does have a few powerful antioxidants with known cholesterol and blood-pressure-lowering effects. But can it help with weight loss? A recent study looked at the age-old claim in an effort to get some answers.
Proponents of the diet claim that eating half a grapefruit before meals high in protein and fat produces a metabolic reaction that transforms even the meekest office worker into a magnificent fat-burning machine. The thermogenic powers supposedly stem from a special fat-burning enzyme in grapefruit that acts as a catalyst to help the body incinerate high-fat foods, which in turn results in fast weight loss.
Early studies did suggest that subjects on the grapefruit diet would lose weight, but this was most likely due to calorie restriction rather than any special fat-burning properties of the grapefruit itself. A recent study evaluating the satiating effects of eating or drinking something low in calories before meals compared grapefruit, grapefruit juice, and water. The subjects lost weight, although not a lot. But it didn’t matter which of the pre-meal snacks they had. All had some small effect.
However, a second study showed the opposite. Subjects who ate grapefruit lost more weight than those who ate a placebo. Citrus, and in particular, grapefruit, contains two of these superstars, flavonones called naringin and hesperidin. Studies conducted in mice and rats have confirmed that naringin and hesperidin act as antioxidants in the fight against free radicals, and reduce cholesterol and blood pressure.
Scientists have also looked at the effects of concentrated doses of naringin and hesperidin on rats. And at these high doses, we see even more evidence that phytochemicals lower cholesterol and blood pressure. Not only that but in rats, wait for it… naringin appears to stimulate fat breakdown.
To lose weight with exercise, aim for 300 minutes weekly
Can exercise help us shed kilogrammes? An interesting new study involving overweight men and women found that working out can help us lose weight, in part by remodeling appetite hormones. But to benefit, the study suggests, people most likely have to exercise a lot — burning at least 3,000 calories a week. In the study, that meant working out six days a week for up to an hour, or around 300 minutes a week.
The relationship between working out and waistlines is famously snarled. The process seems as if it should straightforward: People exercise, expend calories and, if life and metabolisms were just, develop an energy deficit. At that point, people would start to use stored fat to fuel their bodies’ continuing operations, leaving them leaner.
But human bodies are not always cooperative. Primed by evolution to maintain energy stores in case of famine, human bodies tend to undermine their attempts to drop kilogrammes. Start working out and one’s appetite rises, so one consumes more calories, compensating for those lost.
The upshot, according to many past studies of exercise and weight loss, is that most people who start a new exercise programme without also strictly monitoring what they eat do not lose as much weight as they expect — and some pack on kilogrammes.
To find out, he and his colleagues decided to repeat much of the earlier experiment, but with novel exercise schedules this time. So, for the new study, which was published in November in the journal Medicine & Science in Sports & Exercise, they gathered another group of 44 sedentary, overweight men and women, checked their body compositions, and asked half of them to start exercising twice a week, for at least 90 minutes, until they had burned about 750 calories a session, or 1,500 for the week. They could work out however they wished — many chose to walk, but some chose other activities — and they wore a heart rate monitor to track their efforts.
Meanwhile, researchers have shown that shedding weight restores sperm quality in men.
Indian scientists studied more than 1,200 men and found that too much extra weight was linked to a lower volume of semen, a lower sperm count and lower sperm concentration. In addition, sperm motility (the ability to move quickly through the female reproductive tract) was poor. The sperm had other defects as well, the researchers added. Poor sperm quality can lower fertility and the chances of conception.
The report was published in the journal Andrologia.
Meanwhile, some Nigerians have successfully used ketogenic or keto diet to achieve weight loss but leaving them with sagging skin. Recent studies have shown that ketogenic diet, which is high in fat, could also help beat epilepsy and seizures, increase lifespan, and boost memory. However, there are fears that these benefits may come at a cost- constipation and kidney stones.
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