… what’s more, this “epidemic disease” remains greatly undiagnosed”
Prof Theesan Bahorun – University of Mauritius
“3-4 cups of green tea and 6 grams of fermented papaya can greatly reduce the risk of developing type 2 diabetes”
A study on the “Clinical effects of Fermented Papaya Preparation/Green Tea on pre-diabetes” was conducted by Prof Theesan Bahorun of the University of Mauritius, from November 2010 to March 2011 involving some 150 pre-diabetic Mauritians.
The study’s results suggest that consumption of Fermented Papaya Preparation and of green tea taken for a period of 14 weeks would improve the health status of pre-diabetic patients and that a continued daily intake of FPP and green tea can positively alter the antioxidant status of pre-diabetics and provide a protective barrier to cells targeted by oxidative stress damage. Low doses of FPP may also be a suitable complement to good oral hygiene practice for the effective prevention of dental caries, plaque and gingivitis.
Prof Bahorun has been appointed National Research Chair in Applied Biochemistry since January 2012 and is based at the ANDI Centre of Excellence for Biomedical and Biomaterials Research, UOM, where he heads the Biopharmaceutical unit. His responsibilities centre on providing leadership in developing research themes linked to biomedical, pharmaceutical and functional food sciences, in mentoring students in research, exploring connections with the biochemical, biomedical and pharmaceutical research community and exploring funding opportunities to support research and development. Mauritius Times spoke to him about the findings of the present study, which benefited from support from the Mauritius Research Council under its Research Grant Scheme.
* According to CSO Mauritius, data relating to 2012 reveal that death caused by diabetes mellitus touches some 23.9% of the male population and 29.2% of women. Do you consider this to be alarmingly high and would therefore warrant research?
Although Mauritius no longer features amongst the top 10 countries with the highest prevalence of diabetes in the world, our tiny island still ranks 5th in the region of South East Asia with an overall prevalence of 15.5%, which is quite daunting. This still implies that at least 1 in every 2 adults is either diabetic or has a very high risk at developing diabetes in the near future. What’s more, this “epidemic disease” remains greatly undiagnosed despite numerous screening measures undertaken by the Government. There are over 120,000 adults in Mauritius who have type 2 diabetes, but are simply unaware! So the figures you state from CSO may well be underestimates!
Although medical practitioners clearly emphasize that a low fat diet, regular exercise and weight control are vital for the prevention of diabetes, it can be anticipated that a high proportion of those at risk will continue to eat non-cautiously and shun exercise. Considering the tremendous cost involved in terms of human suffering and monetary resources, we at the ANDI Centre of Biomedical and Biomaterials Research (University of Mauritius) are trying to identify practical, safe and cost-effective functional foods that can effectively curb the risk of developing type 2 diabetes and secondary complications. These functional foods should be locally available and easily accessible to the Mauritian population and cause no side effects on consumption.
* Can you tell us briefly about the causes and risk factors of diabetes?
Several factors contribute to this high rate of diabetics in Mauritius: we have a rapidly growing population which is ageing prematurely due to numerous environmental assaults on the body (pollution, exposure to sun, alcohol, tobacco smoke…), the majority of Mauritians are of Asian origin (ethnicity is a strong genetic factor), leading an increasingly sedentary and Westernised lifestyle and consuming unhealthy high fat/sugar/salt diets on a daily basis.
However, other factors such as sleeplessness, physical and metabolic stress and low consumption of antioxidant rich fruits, vegetables, spices and condiments also have an important role to play in causing the onset of diabetes.
The phenomenon of “oxidative stress” is of great interest to the scientific community. There is a plethora of scientific studies that clearly show a link between oxidative stress interfering with the proper functioning of the pancreas, the organ which produces insulin and controls the level of sugar in the blood.
* Does your research in this particular subject suggest that no such research has been undertaken elsewhere?
First I must point out that this research has been a collaborative venture between my group at ANDI centre for Biomedical and Biomaterials Research and the Cardiac Centre SRRN Hospital, the Mauritius Research Council, Apollo Bramwell Hospital, Société Usinière de St Aubin, Osato Research International, University of Réunion, the Tertiary Education Commission, the University of Mauritius and the Touro College of Pharmacy, New York. Indeed there has been a lot of research regarding the potential applications of functional foods in the management of diabetes. Green tea has been advocated mostly in cancer studies with less emphasis for diabetes, and fermented papaya studies have been so far limited mainly to animal studies. The originality of our work lies essentially in the targeting of pre-diabetics who represent a unique population not on any anti-diabetic drugs. The way the clinical trials and subsequent molecular works were designed and conducted have allowed the generation of important sets of data that open avenues for application, and further more focused research on the mechanisms of actions of these functional foods
* How will the findings of your research help the diabetic as well as the non-diabetic patient?
The findings of our research, which was carried out on a multi-ethnical pre-diabetic Mauritian population, have comprehensively shown that drinking 3-4 cups of green tea (infused for 6 minutes, with no added sugar and no added milk) and 6 grams (2 sachets) of fermented papaya preparation (FPP) to be taken on a daily basis, before mealtimes (as part of a healthy, well-balanced diet and an active lifestyle) can greatly reduce the risk of developing type 2 diabetes or any secondary complications related to uncontrolled diabetes.
They also showed that green tea and FPP could significantly improve the functioning of major organs, such as the liver and kidney; reduce biomarkers of inflammation (“c-reactive protein” and “uric acid”) and also greatly boost the overall functioning of the immune system. We also noted a significant improvement in the lipid profile and waist-hip ratio. These are all important findings because they clearly show that green tea and FPP reduce risk factors for diabetes, cardiovascular and neurodegenerative diseases without medical intervention.
So, whether you are diabetic or non-diabetic- consuming such functional foods on a daily basis will definitely improve your overall health and well-being.
* Which varieties of green tea and papaya are most effective in the treatment of diabetes or for pre-diabetics? Is the Mauritian variety, both of green tea and papaya more suitable in this respect?
We have used in this study local green tea which has been analysed prior to the clinical trials. Biochemical analyses have shown high levels of “polyphenols” responsible for the antioxidative propensity of green tea. I must add that the amounts of these prophylactic substances and their measured activities are higher than those measured in the same systems on other green teas in the world.
FPP is manufactured by a Japanese company called Osato Research International which has been also a partner on this project. It’s made from the yeast fermentation of ripe pulp of Carica papaya that has been grown in Hawaii, USA. Although it has not yet been confirmed, I suspect the variety of papaya used in the manufacture of FPP is Hawaiian Solo.
Here, in Mauritius we also have a variety of papaya called “Solo” which bears many common characteristics to that of “Hawaiian Solo”. We are currently investigating the biochemical and molecular activities of both fresh ripe and unripe Solo papaya. The results look very interesting so far.
* What about the green tea that is imported from places like China and Korea and sold in the local market?
We have not worked on these teas. Also there is little scientific information (varieties, cultivars, composition, activities, etc…) about these teas which are commercialised in Mauritius
* Your research has also indicated that fermented papaya FPP helps in the prevention of dental carries, plaque and gingivitis. Tell us more about it.
The World Health Organization clearly recognizes diabetes to be one of the common risk factors to prevalence of oral health complications such as plaque formation, dental caries, bad breath and gingivitis (inflammation of the gums). This link between diabetes and oral health complications arise from the several characteristics that diabetics present, namely:
- high blood sugar levels (causes dry mouth syndrome which makes pH of mouth acidic, oral bacteria grow well in acidic conditions)
- low blood supply (a low supply of blood and nutrients to the gums will greatly slow healing of gums and ulcers in the mouth)
- reduced immune defence system (healing of ulcers and inflamed gums is slowed down, infections in the mouth will be more persistent)
- reduced collagen production (collagen is important for teeth-to-gum attachment. Low collagen will cause loose, weak and brittle teeth and premature loss of teeth)
If an individual does not control his diabetes, then all these factors will indirectly trigger the growth of several types of bacteria in the mouth and cause dental carries, plaque and gingivitis. Diabetics are much more susceptible to oral health complications than non-diabetics.
The findings of our preliminary study showed that small doses of FPP (0.05 mg/ml) could greatly reduce the growth and attachment of common strains of in bacteria in the mouth known to form plaque on teeth, gums and on the tongue (Streptococcus mutans, Streptococcus mitis, Lactobacillus acidophilus). We also found that small doses of FPP could reduce the production of bacterial acid. It is these carboxylic acids released from bacteria that cause erosion of tooth enamel the underlying cause of dental caries.
* Literature relating to your research states that “oxidative stress is a hallmark in the degenerative diseases such as diabetes”. What does this mean in layman’s language?
We all consume oxygen in order to produce energy to survive, but a by-product of this oxygen consumption is oxygen free radicals, which are very reactive molecules. These oxygen free radicals are also produced by our immune system during “oxidative burst” which allows our body’s white blood cells to eliminate bacteria and viruses. These radicals normally removed from our body by a complex but efficient “anti-oxidative system” that is mainly composed of enzymes and vitamins (A, C, E) and minerals (selenium, zinc, copper) derived from our diet. However, during diabetes there is a dramatic increase of oxygen free radicals released into the blood, mainly due to abnormal low-grade inflammation. This overburdens the anti-oxidative system and the excess of non-eliminated free radicals is responsible of “oxidative stress”. It is this oxidative stress that greatly affects major organs by causing oxidative damage of cellular DNA, proteins and lipids and disrupts vital biochemical and molecular pathways. Untreated oxidative stress is the ultimate cause of secondary complications observed in type 2 diabetes: atherosclerosis, kidney failure, liver disease, cataracts, stroke, Alzheimer’s disease, etc…
* There may be other natural agents, just like the Mauritian variety of green tea, that may be helpful for the treatment of other diseases. Have they been identified and will research be undertaken?
We have been working in this area for a number of years now and we have identified a high number of plant-derived extracts/dietary factors/functional foods with high potential use in diabetes, cardiovascular disease and cancer. We have clearly demonstrated the effects of black tea in reducing markers of oxidative stress in cardiovascular diseases more particularly triglycerides, uric acid, cholesterol and inflammatory proteins. Mauritian citrus species (tangelo, tangor and others) contain a high concentration of flavonoids with potent antioxidative capacity of interest in the management of diabetes. We have used diabetic cell models to generate these interesting data. This work is ongoing in collaboration with the University of Reunion (groupe GEICO). We have also analysed a high number of endemic plants and we have now a shortlist that can go into anti-cancer studies at our Research Centre (ANDI Centre for Biomedical and Biomaterials Research). Work is also ongoing at our centre on mushroom extracts which are highly antioxidant with anti-inflammatory potential. We are currently working on a liver cancer animal model and testing the efficacy of green tea, fermented papaya and mushroom extracts.