Losing Weight: How medicinal plants can make all the difference
Obesity is connected to a larger health crisis in the Western world. In New Zealand, one third of adults are obese, and a further 34% are overweight (New Zealand Ministry of Health, 2014b). Children are increasingly becoming part of these statistics as well, with 11% of children in New Zealand obese, and 22% overweight.
Problems associated with excess weight such as elevated blood glucose levels and dyslipidaemia can lead to co-morbidities including insulin resistance, metabolic syndrome, Type II Diabetes Mellitus (T2DM), atherosclerosis, and increased risk of cardiovascular disease and stroke (New Zealand Ministry of Health, 2014a).
Although weight is one of the most important modifiable risk factors for preventing these diseases, losing weight is often difficult for people. Medicinal plants which modulate key physiological functions can support weight loss and management by:
- inhibiting adipogenesis (the creation and growth of fat cells)
- improving blood glucose control, which can reduce cravings and excess sugar and carbohydrate consumption
- improving metabolism of fats via improved digestion, elimination (bowels and kidneys), and liver function
- supporting cardiovascular health, leading to improved energy levels and better health overall
- providing nutrients to the body, which can ameliorate cravings caused by deficiencies or imbalances
These medicinal plants can help to improve outcomes and may also be able to treat or support overt disease, such as those mentioned above. Many of these medicinal plants have longstanding traditional use in weight loss or its consequences eg: diabetes and cardiovascular disease. This article looks at the wealth of contemporary science research which has confirmed the efficacy of these medicinal plants.
Yerba Maté (Ilex paraguariensis)
Although Yerba maté originates in South America, European medical text books discuss Ilex species from as early on as the 1600s, as it was recognised as a valuable medicinal plant. It is commonly drunk throughout the day as a tea in many parts of South America, and has gained huge popularity worldwide as a coffee or tea substitute (Bracesco, Sanchez, Contreras, Menini, & Gugliucci, 2011; De Morais et al., 2009; Kang et al., 2012; Klein et al., 2011).
There has been a great surge of research into the medicinal properties of Yerba maté in the last 20 years. Constituents that have been identified include alkaloids (methyl xanthines such as theobromine and theophylline), flavonoids, tannins, chlorogenic acid, triterpene saponins, as well as numerous vitamins and minerals. Accordingly, Yerba maté acts as an antioxidant, has anti-inflammatory and anti-glycation effects, and also has weight reduction properties.
Antioxidant Properties, Dyslipidaemia, and Atherosclerosis
Yerba maté’s antioxidant properties may be responsible for many of its therapeutic actions. Its polyphenol levels exceed those of green tea, and studies show that these compounds are easily extracted in hot water and bioavailable (Gugliucci, 1996; Gugliucci & Stahl, 1995). Early in vitro studies demonstrated the free radical and metal scavenging abilities of Yerba maté; with a focus on its ability to prevent low-density lipoprotein (LDL) oxidation, as well as its ability to inhibit advanced glycation end-products (AGEs), which are associated with oxidation and highly implicated in the pathogenesis of diabetes and other chronic diseases (Klein et al., 2011; Uribarri et al., 2010).
In vivo and human trials have confirmed the clinical efficacy of Yerba maté. Several studies have shown that Yerba maté improves lipid profiles- including triglycerides, LDL, and HDL (high-density lipoprotein) levels and ratios, in both healthy individuals and those with dyslipidaemia (Bracesco et al., 2011; De Morais et al., 2009; Kang et al., 2012; Klein et al., 2011). Its anti-inflammatory properties have been shown to inhibit a number of inflammatory cytokines, which also play a part in the pathogenesis of atherosclerosis. Yerba maté has also been shown to protect fatty acids from oxidation, most notably in the liver (Bracesco et al., 2011). The combination of these actions indicate its suitability in preventing or treating dyslipidaemia and atherosclerosis.
Diabetes and Blood Glucose Control
Type II Diabetes Mellitus and its precursor, insulin resistance, are also conditions where Yerba maté may be able to help. A 2011 pilot study which looked at glycaemic and lipid profiles of Type II Diabetic and pre-diabetic individuals found that 3 cups of Yerba maté tea, over 60 days, significantly reduced levels of fasting glucose, glycated haemoglobin (HbA1c), as well as LDL cholesterol. In the pre-diabetic group, lipid profiles were improved, and HbA1c was lowered when combined with dietary intervention, while dietary intervention alone did not promote a significant change in lipids or glycaemic control in either group (Klein et al., 2011).
The mechanisms of action that have been investigated suggest that Yerba maté may be able to modulate glucose absorption by reducing expression of the intestinal glucose transporter SGLT1 (Oliveira et al., 2008). Several of the constituents of Yerba maté, including chlorogenic acid, gallic acid, and caffeic acids, have been studied individually, and have been shown to improve blood glucose by modulating hepatic enzymes, and by improving glucose uptake by hepatocytes (Klein et al., 2011).
Clinically, reducing weight helps to reduce the risk of both T2DM and cardiovascular disease. Aside from its ability to support parameters such as lipid profiles and blood glucose, Yerba maté has also been shown to help with weight reduction (Andersen & Fogh, 2001; Bracesco et al., 2011; Dickel, Rates, & Ritter, 2007; Kang et al., 2012; Klein et al., 2011). It has been shown to delay gastric emptying, which can lead to increased feelings of satiation. It may also interfere with uptake of dietary fat due to its saponin content. (Bracesco et al., 2011; Sugimoto et al., 2009).
A 2012 animal study obtained positive results, and elucidated some of the mechanisms of action, indicating that Yerba maté consumption reduces the growth rate of adipocytes, and inhibits visceral fat accumulation (Kang et al., 2012).
Two human trials have shown that Yerba maté helps to manage healthy weight (Anderson & Fogh, 2001; Klein et al., 2011). The 2001 study, which used a preparation that also included guarana and damiana, found that the combination helped to reduce weight in overweight patients by about 0.75kg/week, which is a safe and sustainable amount, and is also sufficient to improve biomarkers of disease such as blood pressure, blood glucose, and lipids. This study also showed that the preparation helped participants maintain their weight loss for a further 12 months (Anderson & Fogh, 2001). The 2011 trial showed that individuals with pre-diabetes who drank Yerba maté tea had a significant reduction in body weight and BMI after 60 days of drinking the tea (Klein et al., 2011).
Olive Leaf (Olea europaea)
In Europe, various parts of the olive tree Olea europaea has been used extensively for both culinary and medicinal purposes. Research into the “Mediterranean diet”, with its high amounts of fresh fruit and vegetables, fish, legumes, olives and olive oil, has substantiated claims that this diet is beneficial for weight management, as well as being preventative against cardiovascular disease and diabetes (Drira, Chen, & Sakamoto, 2011; Widmer et al., 2013).
Olea europaea is full of phenolic compounds, which is where the majority of its beneficial properties are believed to come from (Omar, 2010). In the leaf, which is the part that herbalists use medicinally, the constituents which have been the most widely researched include oleuropein and hydroxytyrosol, as well as rutin, luteolin, catechin and apigenin (Bone, 2003; Braun & Cohen, 2010; Everson, 2013; Omar, 2010).
Much research has focussed on olive leaf’s effects on the cardiovascular system. Its hypotensive, lipid lowering, antithrombotic, anti-atherogenic, anti-inflammatory and hypoglycaemic actions indicate it is well suited to treating complex and often interconnected conditions such as hypertension, atherosclerosis, heart disease, metabolic syndrome, and type II diabetes, as well as the sub-clinical manifestations of these disorders (Bone, 2003; Braun & Cohen, 2010; Omar, 2010)
Hypertension and Atherosclerosis
Elevated blood pressure is a risk factor for thrombosis, embolism, heart attack, and stroke, and can also contribute to heart and kidney failure (Bone, 2003; Braun & Cohen, 2010; Sarris & Wardle, 2014).
Common conventional treatment of hypertension includes angiotensin-converting enzyme (ACE) inhibitors, thiazide diuretics, or calcium channel blockers (Sarris & Wardle, 2014; Susalit et al., 2011). Diet and lifestyle changes can also contribute greatly to reducing elevated blood pressure.
In vitro, in vivo and clinical trials have shown that both olive oil and olive leaf can lower blood pressure. A 2011 double-blind, randomised clinical trial compared the efficacy of olive leaf extract with Captopril, an ACE inhibitor on stage-1 hypertensive participants. After 8 weeks of treatment, both groups had significantly reduced both systolic and diastolic blood pressure. There were not significant differences between the two groups, demonstrating that olive leaf is as effective as Captopril for reducing blood pressure. The olive leaf group also experienced a significant reduction in blood lipid levels which was not seen in the Captopril group (Susalit et al., 2011). This was especially noted in those with higher baseline levels of triglycerides and LDL-cholesterol. As these two risk factors are often seen concomitantly (hypertension and elevated blood lipids), using olive leaf could potentially reduce the need for multiple medications.
Olive leaf has been studied specifically for its use in treating and preventing atherosclerosis as well. Current conventional treatment strategies mainly focus on lowering blood lipid levels, however olive leaf provides a variety of actions which can support healthy vasculature, by improving endothelial function, reducing oxidative stress and inflammation, as well as reducing elevated blood lipids (Ahmadvand, Noori, Dehnoo, Bagheri, & Cheraghi, 2014; Omar, 2010; Wang et al., 2008; Widmer et al., 2013)
Blood Glucose Control and Weight Loss
A study published in 2013 which was conducted in New Zealand investigated the effects of olive leaf extract on blood glucose control in a group of overweight, middle-aged men (de Bock et al., 2013). In this double-blind, placebo controlled crossover trial, after 12 weeks of supplementation with olive leaf, two aspects of glucose regulation were improved: insulin sensitivity, and insulin secretion via the pancreatic beta cells.
Furthermore, the improvement was on par with results seen with current diabetic medications, such as metformin. Importantly, most diabetic medication work only on either insulin sensitivity or secretion, not both (de Bock et al., 2013). While the participants in this study were not yet diabetic, a previous clinical trial has shown that olive leaf improved glycaemic control (as measured by glycated haemoglobin- HbA1c) in people with type 2 diabetes (Wainstein et al., 2012).
Overall, these studies show that olive leaf is beneficial in improving blood glucose regulation via multiple mechanisms. As problems with sugar and carbohydrate cravings (signs of dysregulated blood glucose) are often cited by people trying to lose weight, olive leaf has a clear purpose in these cases.
Looking at weight loss itself, early in vitro and animal studies have found promising results and are elucidating mechanisms by which olive leaf may be helpful (Drira et al., 2011; Shen, Song, & Keum, 2014). A 2011 study showed that olive leaf inhibits the differentiation of adipocytes, and reduces triglyceride accumulation. As reactive oxygen species assist with adipocyte differentiation by accelerating cell cycle progression, the antioxidant content of olive leaf may be responsible for inhibiting this process (Drira et al., 2011).
An animal study conducted last year showed similar results, concluding that olive leaf significantly decreased weight gain, visceral fat, and blood lipid levels in mice fed a high-fat diet (Shen et al., 2014). While further clinical trials are warranted, this research indicates that olive leaf may be helpful in reducing obesity.
Cinnamon (Cinnamomum zeylanicum)
Another medicinal plant with great promise in supporting healthy weight management or loss via its blood sugar regulating properties is cinnamon. Cinnamon has a long history of use in traditional medicine worldwide, with ancient Chinese texts mentioning it as a medicinal treatment as early as 2700BC. It is also valued for its ability to stimulate and warm the digestive system, helping to relieve cramps, colic, wind, and nausea (Bone, 2003; Braun & Cohen, 2010).
Cinnamon contains an essential oil which consists of high levels of cinnamaldahyde. This constituent has been cited as being responsible for cinnamon’s broad-spectrum antibacterial and anti-fungal actions (Braun & Cohen, 2010). It is possible that this antimicrobial action may contribute to cinnamon’s ability to help with digestion and weight loss, as overgrowth of pathogenic microbes have been shown to influence energy metabolism (Deweerdt, 2014).
Blood Glucose Control, Metabolic Syndrome, and Type II Diabetes
As obesity levels rise, so too do health conditions such as metabolic syndrome, type 2 diabetes and cardiovascular disease (Rafehi, Ververis, & Karagiannis, 2012). In the last 10 years, research into cinnamon’s effect on diabetic biomarkers such as glycaemic control and blood lipid levels has exploded. A 2003 randomised, placebo-controlled trial of 60 people with type 2 diabetes was the first study to investigate the effects of cinnamon on glucose and lipid levels in humans (Khan, Safdar, Ali Khan, Khattak, & Anderson, 2003). The results of this study demonstrated that varying doses of cinnamon (between 1 and 6 grams) all had a positive effect on the parameters studied. This trial spurred on further research to see if these results were replicable.
Since then, several clinical trials have been conducted, and a 2013 systematic review and meta-analysis, which analysed 10 randomised-controlled trials (n= 543 patients), concluded that “the consumption of cinnamon is associated with a statistically significant decrease in levels of fasting plasma glucose, total cholesterol, LDL-C, and triglyceride levels, and an increase in HDL-C levels” (Allen, Schwartzman, Baker, Coleman, & Phung, 2013).
The mechanisms of action appear to be, like in all whole plants, multifaceted. Cinnamon works by improving insulin secretion and sensitivity, enhancing insulin signalling, and by acting as an insulin mimetic. Cinnamon also improves glucose uptake by peripheral tissues via GLUT4 glucose transporter (Bandara, Uluwaduge, & Jansz, 2012).
Although most studies have focussed on cinnamon’s ability to regulate blood glucose, it has also been found to work as an antioxidant and have a positive effect on blood lipids (Bandara et al., 2012).
Dandelion root (Taraxacum officinale)
Dandelion root has an affinity to the digestive system and liver, and has long been used by medical herbalists for improving digestion and constipation, as well as supporting liver and gallbladder function (Bone, 2003; Braun & Cohen, 2010).
Dandelion has an excellent part to play in supporting weight management via its detoxifying, antioxidant, anti-inflammatory, hypolipidaemic, and hypoglycaemic effects, as well as its role in digestion and elimination (González‐Castejón, Visioli, & Rodriguez‐Casado, 2012; You et al., 2010).
Dandelion contains many nutrients, including the minerals potassium, iron, magnesium, zinc, manganese (Braun & Cohen, 2010). It also contains sesquiterpene lactones, phenylpropanoids, triterpene saponins, and polysaccharides (Sweeney, Vora, Ulbricht, & Basch, 2005; Yarnell & Abascal, 2009). One of these polysaccharides, inulin, appears to play a specific role in dandelion’s ability to support healthy weight.
The root is a good source of inulin, a prebiotic oligosaccharide which has a positive effect on lipid metabolism due to its ability to improve beneficial gut bacteria (Grela, Sobolewska, & Rozinski, 2014). As mentioned previously, gut flora, can have either a positive or negative effect on energy metabolism. Indirectly, gut bacteria can also influence energy intake and behaviour as beneficial bacteria are responsible for metabolising and even producing some essential nutrients (Deweerdt, 2014). Nutrient deficiencies or imbalances can lead to cravings. Inulin is best extracted in water.
In vitro research also demonstrates that dandelion root has a direct effect on adipogenesis and lipid metabolism, by inhibiting adipocyte growth and differentiation. Interestingly, a 2014 study which compared different extracts of dandelion root, found that the raw, whole plant extracts were more efficacious at inhibiting adipogenesis than their purified counterparts (Gonzalez-Castejon, Garcia-Carrasco, Fernandez-Dacosta, Davalos, & Rodriguez-Casado, 2013).
Dandelion’s beneficial effect on cholesterol was shown to be due to its ability to support the liver and reduce fatty acid synthesis as well as improve cholesterol elimination; thereby reducing the cholesterol that is deposited in the tissues (Grela et al., 2014).
Another study which support the use of dandelion for its metabolic effects includes an animal study which found that mice fed a high fat diet who were also supplemented with dandelion had significantly reduced hepatic lipid accumulation compared with those fed a high fat diet alone (Davaatseren et al., 2013). Dandelion supplementation also inhibited blood lipid levels, insulin levels, and fasting glucose (Davaatseren et al., 2013). This further confirms the hypolipidaemic and hypoglycaemic actions of dandelion.
Nettle Leaf (Urtica dioica)
Most herbalists are aware of nettle’s use in atopy, as a diuretic and kidney plant, for arthritis support and as a nutritive (Bone, 2003). However, recent research has highlighted nettle’s traditional role in insulin resistance, metabolic syndrome, and type II diabetes (Abo-elmatty, Essawy, Badr, & Sterner, 2013; Ahangarpour, Mohammadian, & Dianat, 2012; Golalipour & Khori, 2007; Kianbakht, Khalighi-Sigaroodi, & Dabaghian, 2013; Namazi, Esfanjani, Heshmati, & Bahrami, 2011; Namazi, Tarighat, & Bahrami, 2012; Upton, 2013).
Rich in vitamins, minerals, and trace elements, nettle is a nourishing plant which provides micronutrients needed in a balanced diet. Nettle also has a stimulating effect on the kidneys and bladder, helping to ease water retention and cleanse the body of toxins and wastes. It is high in antioxidants, and these have been shown to directly support the enzymes in Phase I and Phase II liver detoxification (Upton, 2013). These actions, combined with its ability to support blood glucose levels, make it an ideal plant to support metabolic issues such as obesity and type 2 diabetes. Nettle’s rich nutrients are best absorbed as a hot water extract.
A group of researchers from Pakistan carried out a clinical trial on people with type 2 diabetes, investigating the effects of nettle on insulin sensitivity, inflammatory markers, and oxidative stress. Problems with poor glucose control and hyperglycaemia, inflammation and oxidative stress are risk factors for cardiovascular disease. This randomised, double-blind, placebo-controlled trial showed improvements in both inflammatory markers and oxidative stress (Namazi et al., 2011; Namazi et al., 2012). Previous studies have also shown improved insulin secretion and sensitivity, and a larger trial done in 2013 showed improved glycaemic control in type II diabetic patients who required insulin to control their condition (Ahangarpour et al., 2012; Domola, Vu, Robson-Doucette, Sweeney, & Wheeler, 2010; Golalipour & Khori, 2007; Kianbakht et al., 2013). These studies confirm the usefulness of nettle in conditions with dysregulated blood glucose.
Mint (Mentha spp.)
The mint species help with the proper digestion of food to lessen storage. Proper digestion also ensures that the body is absorbing the nutrients it requires, which can reduce cravings when they are driven by nutrient deficiencies or imbalances. Improperly digested food can also cause bloating, which can lead people to believe that they are carrying more weight around the middle than they actually are.
Mint species contain volatile oils which have an antispasmodic and carminative action on the smooth muscle of the digestive system (Bone, 2003; Braun & Cohen, 2010). Traditionally used to aid digestion and treat cramps in the digestive tract, gallbladder, and bile ducts, mint eases bloating, stomach upsets, flatulence, and inflammation in the stomach and bowels.
Our solution for weight loss support
Weight loss is complicated, and can be driven by many different factors. Traditionally, plant medicine has played a supportive role in weight loss and management, which is now confirmed through contemporary research. However, it is vital to take the basics into account - a healthy diet, adequate activity, adequate rest and stress reduction are all a necessary part of any weight loss plan.
Artemis founder and medical herbalist, Sandra Clair, developed Slim and Trim Tea to support weight loss. This formula is traditional plant medicine to support these internal mechanisms. It helps manage cravings, supports normal blood sugar levels and detoxification. It helps your body digest food properly and metabolise fat efficiently.
Weight management is a long-term thing and making healthy lifestyle choices will always be part of it. There are no quick fixes. We certainly aren’t promising that with Slim and Trim Tea. However, if you do the good work up front, Slim and Trim Tea will support your system so your healthy choices pay off.