Diabetes and Oral Health Part 2: Dietary Influences
© Juliette Reeves 2004

As a profession we are in a good position to detect undiagnosed systemic disease through changes in the oral tissues. Early detection remains the best strategy in avoiding diabetic complications. As a profession we are urged to keep our knowledge of this disease up to date and embrace a team approach in the management of the diabetic patient and their oral health.

Keywords: Diabetes Type I and Type II, insulin, hypoglycaemia, patient management, pharmacological management, nutritional management, diabetes and oral health.

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Diet and Lifestyle Factors

Type II diabetes is fundamentally affected by nutrition. The standard dietary advice remains largely unchanged. Research over the last two years confirms that a combination of exercise and specific changes to diet could prevent or dramatically reduce the risk of type II diabetes and heart disease.(1).Other research confirms that lifestyle factors such as smoking significantly exacerbates the aetiology of this disease (2). The following represents some of the latest research published over the last two years.
 
Dietary Factors

In a new study presented at the Endocrine Society annual meeting (3), Dr Greg Arsenis reported that replacing animal protein with vegetable protein helps reduce insulin resistance. This study concurs with a much earlier finding that diabetes is more common in beef eating populations than in vegetarian populations(4). Whilst Diabetes UK does not specifically recommend a vegetarian diet for diabetes, a reduction in red and white animal protein could be beneficial. It is widely accepted that insoluble fibre reduces cholesterol and glucose absorption, which may explain why decreasing animal protein and saturated animal fats in favour of vegetarian sources of protein helps reduce insulin resistance.

Research published in the American Journal of Clinical Nutrition(5,6) suggests consumption of omega 3 fatty acids lowers the risk of developing type II diabetes. The research also suggest that total fat and saturated and monounsaturated fatty acid intakes are not associated with risk of typeIIdiabetes in women, but that trans fatty acids increase and polyunsaturated fatty acids reduce risk. Substituting non hydrogenated polyunsaturated fatty acids for trans fatty acids would likely reduce the risk of typeIIdiabetes substantially.

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Consumption of soy protein has recently been shown to improve the blood lipid levels in Type II diabetes.(7)A dietary supplement of soy protein, isoflavones, and cotyledon fibre indicate beneficial effects of dietary supplementation on cardiovascular risk markers in type 2 diabetic subjects. Soluble fibre is desirable because it can actually reduce blood sugar rises after a meal, and lower serum cholesterol. Glucose and cholesterol molecules trapped in soluble fibre become less absorbable and so fewer of them enter the blood.

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Recent study has indicatedincreased lactose consumption as a risk factor in Type II diabetes (8). Increased intestinal lactase activity has been shown to occur in alloxan and streptozotocin diabetic rats. The objective of this study was to determine whether increased intestinal lactase activity is present in humans with diabetes mellitus. The researches concluded that diabetes is associated with increased intestinal lactase activity in humans. Consequently, there is a greater exposure to glucose and galactose in diabetic patients with high lactose consumption.

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In addition to eating regularly throughout the day at four hourly intervals, a new study has suggested that bedtime ingestion of slow-release carbohydrates leads to sustained nocturnal fatty acid suppression and improved glucose tolerance in type II diabetic patients(9). As adipocytes store more fat molecules, they release several products that can modify the body's sensitivity to insulin, such as free fatty acids which cause insulin resistance. Nocturnal fatty acid suppression by a complex carbohydrate bedtime snack, improved fasting and postprandial blood glucose concentrations in type II diabetic patients the next morning.
 
Micronutrient Supplementation

The intake of complex carbohydrates and grains has long been recommended for the diabetic patient. Recent study further confirms this fact and suggests magnesium deficiency as also showing a strong association with incidence of diabetes (10) . Early study has suggested intracellular magnesium as being a secondary messenger for insulin.(11) It has also been suggested that magnesium deficiency may be indicated in the pathopysiology of the disease (12).

The micronutrients needed to produce insulin from the pancreas are principally vitamin B6 and zinc. Glucose tolerance factor produced by the liver needs chromium and vitamin B3. Supplementing these can be helpful in managing blood glucose control, however this needs to be carefully monitored in patients receiving insulin. Vitamin C is important in diabetes as it strengthens blood capillaries which are often fragile, improves resistance to infection and reduce elevated cholesterol levels. Vitamin C is of particular value in smokers. Other nutrients include magnesium, zinc and potassium.

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New research has suggested the amino acids arginine and Taurine as being beneficialin the management of type II diabetes. The aim of this study(13) was to evaluate whether long-term administration of L-arginine acting through a normalization of NO/cyclic-guanosine-3',5'-cyclic monophosphate (cGMP) pathway was able to ameliorate peripheral and hepatic insulin sensitivity in the type II diabetic patient. L-Arginine was supplemented at 3 g three times per day. The study concluded that L-Arginine significantly improved but did not completely normalize peripheral and hepatic insulin sensitivity in type II diabetic patients.

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The effects of Taurine on insulin sensitivity were examined in a rat model of insulin resistance and type II diabetes.(14) Taurine, a potent antioxidant, has been reported to improve streptozotocin-induced diabetes mellitus, in which the development of diabetes results from an attack by oxygen free radicals on pancreatic ß cells. Taurine also increases the excretion of cholesterol via conversion to bile acid and may improve insulin resistance. The study found that Taurine effectively improves metabolism in rats by decreasing serum cholesterol and triacylglycerol, via increased secretion of cholesterol into bile acid and decreased production of cholesterol because of increased nitric oxide production. Further research is under way.

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New Medical Reports

A team of researchers has uncovered a new gene implicated in raising susceptibility to type II diabetes (15). The gene, calpain 10, was found to be strongly associated with the development of typeII diabetes in Mexican Americans, Pima Indians, and in Northern European groups. The researchers think that calpain 10 functions as a regulatory protein to modulate glucose response or insulin secretion and receptor interaction; however, its precise function has not yet been established. It remains to be seen if the association of calpain with type II diabeteswill be clinically beneficial. It may be used in the future as a marker gene for at risk populations, so that they can modify lifestyle factors such as diet and exercise and thereby reduce their risk.

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In Nature Medicine, two teams of scientists report the discovery of a compound that could able to reverse the effects of insulin resistance (16). This compound is called adiponectin. Kadowaki et al found that the hormone improved insulin resistance and lowered blood glucose levels in mice. They further discovered that adiponectin works by reducing triglyceride levels in skeletal muscle. Because of its ability to lower blood glucose levels, Kadowaki's team conclude that "adiponectin has potential as an anti-diabetic drug."

A separate team working at Albert Einstein College of Medicine in New York, led by Philipp E. Scherer, have also discovered that injection of adiponectin lowers blood glucose levels in obese and diabetic mice. It is clear more research is needed in this development.

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A new hormone has been identified that links obesity to type II diabetes(17) . It has been called resistin (for "resistance to insulin"), and, although first identified in mice, it has also now been found in humans. Its US discoverers believe that it goes some of the way to explaining how obesity predisposes people to diabetes.

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Environmental Influences

An increase in the incidence of Type II diabetes is being reported amongst children. Type IIdiabetes is being reported in children from the United States, Canada, Japan, Hong Kong, Australia, New Zealand, Libya, and Bangladesh (18). In Birmingham UK, the incidence of type II diabetes in children is also slowly increasing (19). The first case of childhood typeII diabetes in Birmingham was diagnosed in 1993,and since then 17children have presented with the disease, of whom 10 remain in the paediatric clinics. The condition presented insidiously without ketosis, and most of the children were asymptomatic at the time of diagnosis, not all of the children with typeIIdiabetes were overweight. The authors state that the rising prevalence of obesity and type II diabetes in children is an unforeseen consequence of worldwide industrialisation, with behavioural and environmental factors playing a significant role.

It is estimated that between 1995and 2025the number of people with diabetes will increase by 42% (from 51to 72million) in industrialised countries and by 170% (from 84to 228million) in industrialising countries(20). The British Medical Journal reports that over £7m will be spent over the next three years in Europe to find a cure for type 1 and typeII diabetes and lessen the impact of their complications(21).
 
References

1.Dr Kirsten McAuleyOtago UniversityDepartment of Human Nutrition Targeted Lifestyle Changes Could Turn the Tide Against Diabetes and Heart Diseases - Otago University Study: September 2001
2. S. Goya Wannamethee, A. Gerald Shaper, and Ivan J. Perry: Smoking as a Modifiable Risk Factor for Type 2 Diabetes in Middle-Aged Men : Diabetes Care 24:1590-1595, 2001
3. http://news.bbc.co.uk/hi/english/health/newsid_1407000/1407283.stm
4. Snowden. D.A., Phillips.R.L.: Does a vegetarian diet reduce the occurrence of diabetes? Am J. Pub Health. 1985; 75:507-12.
5. Clandinin.T., Wilke. M : Do trans fatty acids increase the incidence of type 2 diabetes?Am J Clin Nutr 2001 73: 1001-1002
6. Dietary fat intake and risk of type 2 diabetes in women : Am J Clin Nutr, 2001: Vol. 73, No. 6, 1019-1026.
7.Kjeld Hermansen, Mette Søndergaard, Lars Høie, et al : Beneficial Effects of a Soy-Based Dietary Supplement on Lipid Levels and Cardiovascular Risk Markers in Type 2 Diabetic Subjects : Diabetes Care 24:228-233, 2001
8.Gian Franco Meloni, Carla Colombo, Carlo La Vecchia, et al:High prevalence of lactose absorbers in Northern Sardinian patients with type 1 and type 2 diabetes mellitus. Am J Clin Nutr, 2001 :Vol. 73, No. 3, 582-585.
9. Mette Axelsen, Peter Lönnroth, Ragnhild Arvidsson Lenner, et al: Suppression of nocturnal fatty acid concentrations by bedtime carbohydrate supplement in type 2 diabetes: effects on insulin sensitivity, lipids, and glycemic control; Am J Clin Nutr, 2000: Vol. 71, No. 5, 1108-1114.
10.Katie A Meyer, Lawrence H Kushi, David R Jacobs et al: Carbohydrates, dietary fibre, and incident type 2 diabetes in older women : Am J Clin Nut, 2000 :Vol. 71, No. 4, 921-930.
11. Lostroh., Krahl: Magnesium, a second messenger for insulin: Ion translocation coupled to transport activity. :Adv Enz Regul 1974: 12:73-81.
12. Elamin, Tuvemo: Magnesium and insulin dependant diabetes mellitus. Diabetes Res Clin Prac 1990 : 10:203-9.
13. PierMarco Piatti, Lucilla D. Monti, Gianpietro Valsecchi, et al: Long-Term Oral L-Arginine Administration Improves Peripheral and Hepatic Insulin Sensitivity in Type 2 Diabetic Patients : Diabetes Care 2001 :24:875-880.
14.Yutaka Nakaya, Asako Minami, Nagakatsu Harada, et al: Taurine improves insulin sensitivity in the Otsuka Long-Evans Tokushima Fatty rat, a model of spontaneous type 2 diabetes. Am J Clin Nutr, 2000 :Vol. 71, No. 1, 54-58,.
15. Nature Genetics 2000;26:163-75).
16.Press Release for Nature Medicine: August 2001.
17 Nature 2001;409:307-12.
18 Fagot-Campagna A.Emergence of type 2diabetes mellitus in children: the epidemiological evidence. J Pediatr Endocrinol Metabol (in press).
19.Ehtisham S,: Prevalence of type 2diabetes in children in Birmingham: BMJ 2001;322:1428
20. BMJ 2001;323:63-64
21. BMJ 2000;321:788

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