Diabetes: The latest research
A staggering 225,840 people are estimated to be living with the disease in Ireland. With World Diabetes Day this Wednesday, our resident dietitian Orla Walsh looks at the most up-to-date advice on managing the condition
Diabetes mellitus (DM) - commonly referred to as diabetes - is now considered an epidemic by the World Health Organisation (WHO). From the very young to the very old, it can affect people from all walks of life. The warning signs can be so mild that you don't notice them and that's especially true of type 2. The prevalence of diabetes is on the rise, so what do we need to know?
■ What is diabetes? Diabetes mellitus is a lifelong condition. The term 'diabetes' means excessive urination and the word 'mellitus' means honey. It occurs, in part, because of issues associated with insulin - a hormone that is produced by beta cells within an organ called the pancreas.
When we eat carbohydrate or simple sugars, they are broken down into sugars called glucose. Insulin's job is to take this glucose into our cells so that our body can produce energy with it. In both types of diabetes - type 1 and type 2 - the glucose can't get into the cells and builds up in the blood.
One of the ways the body deals with excess glucose in the bloodstream is to urinate it out. Therefore, those with uncontrolled diabetes or undiagnosed diabetes urinate a lot. As the person urinates a lot, they are thirstier, as they're losing so much water. Since the body is urinating out the glucose and not using it, this can lead to weight loss. Similarly, as the body isn't using the glucose to create energy, the person will feel very tired.
When the body is subjected to high amounts of glucose in the blood stream for a long time, harm to the body occurs. Most commonly, the person's blood vessels, nerves, kidneys, eyes and heart become damaged.
Back in 1999, it was estimated that 10pc of the national health budget was being consumed treating diabetes. If diabetes is on the rise, so too is this figure. If you were to line-up 15 Irish people - between the ages of 20 and 79 years - one in the 15 would have diabetes.
■ Why are body fat levels so important?
Weighing too much and storing excess body fat, especially belly fat, needs to be discussed when considering diabetes. For one thing, the risk of developing type 2 diabetes increases by 89pc for every 5kg/m2 increase in body mass index (BMI). This is not the case for type 1 diabetes, as it is an auto immune disease.
However, when body fat levels increase above healthy levels, both type 1 and type 2 diabetes are harder to manage. Therefore, being a healthy weight, lean and strong is important.
■ Does exercise reduce insulin?
Although exercise is often encouraged when someone has diabetes for the purpose of weight management, the benefits go far beyond the number on the scales. Type 2 diabetes is insulin-resistant. Exercise makes a person more sensitive to insulin, therefore directly counteracting it. This benefit is seen in type 1 diabetes also, as exercise reduces the amount of insulin a person must take after eating carbohydrate.
Furthermore, in both cases, it supports lean muscle growth. This helps improve a person's storage capacity for carbohydrate and speeds up their metabolism.
Finally, exercise reduces the risk of heart disease, which is a major long-term issue that all diabetics need to be mindful of.
■ What about blood vessel health?
A lot of the damage caused to the body by diabetes is through its negative effect on blood vessels. Not only can a person with diabetes drastically reduce this potential damage by controlling their blood glucose levels, they can also include foods in their diet that actively help improve the health of the blood vessels.
For example, peppers and citrus fruit provide vitamin C, which helps to produce collagen needed in healthy blood vessels. Vitamin C, as well as vitamin A and E, are antioxidant vitamins that protect the body from free radicals which would otherwise age the body. So, tuck into some orange or yellow coloured fruits and vegetables as well as nuts, seeds and avocados.
Other foods that are important for the health of the blood vessels include oily fish for their special omega-3 fats as well as walnuts, which improve the elasticity of the blood vessels.
■ Eat your fruit, don't drink it
The carbohydrate within fruit is released into your blood stream slower than the carbohydrate within fruit juice. This is because the body must break down the fruit before it can be absorbed. The teeth and stomach muscles must mechanically break down the fruit into little bits. This natural processing gives digestive juices greater access to the food so that it can chemically break it down to be absorbed.
When a person drinks juice, no mechanical digestion is needed. The digestive juices can act fast and absorb it quickly, causing a spike in blood glucose levels. This makes achieving steady blood glucose levels harder.
The general rule is - don't drink your fruit.
■ Eat more fibre in your diet
A staggering 80pc of Irish people are fibre deficient - so it's really important to eat 24g-35g of fibre every day. Focusing on healthier sources of carbohydrate, such as choosing wholegrain, higher fibre alternatives is the first step. If looking at the back of a packet, the aim is for more than 6g of fibre per 100g.
However, choosing to eat some naturally higher fibre foods each day will also help to hit the target. For example, mango, pear and berries are fruit that pack a punch. Chia seeds and flaxseeds tend to come out on top when considering nuts and seeds.
Beans, peas and lentils may be the overall winners providing 10g of fibre in a typical serving. Adding more fibre into the diet will help steady blood glucose levels and help achieve a healthy body composition.
Research shows that each extra piece of fruit eaten each day resulted in 0.5 lb lost over four years. None too surprising, berries and pears had an even better impact, resulting in 1.1 lb and 1.2 lb weight lost over four years.
Vegetables had a terrific impact on weight too. Each daily serving of vegetables led to a 0.25 lb weight loss over four years, while a daily serving of cauliflower resulted in a 1.4 lb loss.
■ Balance all meals and snacks for a better glycaemic load (GL)
The glycaemic load considers the amount a meal impacts upon a person's blood glucose levels. To help lower the GL of meals, lean protein, healthy fat, fruit and veg need to be a part of every meal. While any starch, fruit or vegetable eaten at snack times should be combined with a healthy source of protein or fat.
It is this sort of guidance that has found its way into basic diabetes care.
However, finding a cure or coming up with ways to manage the burden of diabetes is at the forefront of research. New studies are being published all the time. So, what's new in the world of diabetes?
■ Should you go vegan?
Will going vegan help prevent diabetes? A new study from researchers in the US investigated whether following a vegan diet for 16 weeks was better for certain health outcomes when compared to the usual diet of a group of people who were overweight. The range of BMIs within this study was between 28 and 40. A BMI of over 30 is obese.
The results suggested that those who followed a vegan diet showed improvements in beta cell function.
Additionally, the results showed that there were lower levels of insulin secreted between meals and a greater level of insulin secreted in response to eating meals. This is a positive result as the beta cells of the pancreas play an important role in regulating blood glucose levels. As a reduction in beta cell function can lead to diabetes, this is a positive result for those who are trying to reduce their risk of diabetes. It may also be a positive result for those that have diabetes, as it might lead to better control of blood sugar levels and reduced short and long-term ill effects.
However, what should be noted when reading reports about this study is that those with diabetes were excluded. Therefore, the presumption that a vegan diet may be beneficial for those with diabetes would really have to be further investigated.
Another positive result that was seen was weight and body fat levels decreased. BMI decreased by two points and didn't change in the group that didn't go vegan. Visceral fat, the fat in and around the organs, decreased in the group following a vegan diet and increased in the group following their normal diet. Again, this will help reduce a person's risk of developing diabetes and will help a person better control their diabetes. It's not surprising that fasting insulin resistance also fell.
As one group were asked to follow a low-fat vegan diet and the other group carried on eating as normal, an instant thought to reading this might be that of course a diet that is rich in fruits and vegetables will be a healthier option for people than the current diet they were eating which lead them to become overweight. However, what makes this study unique is that it is not encouraging a diet that is low in carbohydrates to enable better diabetes control. As a vegan diet is, relatively speaking, higher in carbohydrate, this small study will help change direction of future studies in diabetes.
All in all, these are positive results. It's not surprising that this one study had so many people talking. A big plus for many people wanting to trial this way of eating is that there was no calorie counting or focus on calorie intake. This meant that the diet was straightforward to follow, with a list of foods to eat and a list to avoid.
Nevertheless, this study was not without limitation. The vegan diet is quite restrictive. Cutting out all meat, poultry, dairy, fish, butter and eggs may be too restrictive for some people. It will be important to investigate whether this diet is something that many people could follow in the longer term.
Or would an adapted version of the vegan diet, for example the inclusion of dairy and fish, help with compliance and provide similar results? Additionally, participants prepared their own meals, which meant that dietary changes weren't well controlled. The study also relied on self-reporting, which is not as reliable as scientists would like. The next step would be to conduct this study again, with more people, for a longer duration and with a varied population to see if results are replicated.
Unfortunately, the impact of a vegan diet on 38 people cannot and should not change the dietary guidance for all the people worldwide who are at risk of diabetes.
■ Can fasting help the pancreas to regenerate?
In the last year, headlines suggesting that fasting can help the pancreas regenerate have been circling. This is because of recently conducted research which tested a low-calorie, macronutrient-modified diet on mice.
Interestingly this was perceived to help both type 1 and type 2 diabetes as the mice were modelled to have either type 1 or type 2 diabetes.
To understand this study, it's important to understand some basics of type 1 and type 2 diabetes.
As mentioned, beta cells are cells found in an organ called the pancreas. They store and release insulin in response to blood glucose levels. The body tries to keep blood glucose levels stable. When they go high, after a meal containing carbohydrate is eaten, the beta cells release insulin to bringing these blood levels down. When someone has type 1 diabetes, the person's immune system has destroyed the beta cells.
In type 2 diabetes, which tends to be a result of lifestyle factors, the beta cells are unable to produce enough insulin or the insulin is ineffective. This study aimed to see if a specific fasting protocol was able to promote the generation of new beta cells in mice who had diabetes.
Mice were fed a low-protein, low-carbohydrate but high-fat diet for four days. They were fed 50pc of the calories they required to fuel their body in a day on the first day of the study and then 10pc of their requirements for the following three days.
On the 10-day break from this fasting protocol, the mice were fed what they needed to fuel their bodies and what they needed to regain the weight that they lost. This feeding protocol was then repeated on three more occasions every 10 days.
The researchers then assessed the pancreas of the mice. Mice are often used in research at early stages to help get a better understanding of what might happen in humans.
However, sometimes what happens in rodents cannot be replicated in humans as we're biologically different.
Interestingly, in the mice with type 2 diabetes, insulin secretion was restored and insulin resistance improved. The fasting seemed to result in beta cell regeneration. In the mice with type 1 diabetes, the fasting cycles were able to reduce inflammation. They also noticed that there was an increase in the number of beta cells making insulin.
In the second phase of this trial, human beta cells were collected from people with type 1 diabetes. The researchers also recruited adults without diabetes who were then put through the same fasting protocol as the mice. Interestingly, similar results were seen in the humans as in the mice.
This study shows promise. It's an exciting bit of science. However, further research is needed to see if these results can be replicated in humans with type 1 and type 2 diabetes undergoing this fasting protocol. This is definitely not a protocol to follow at home, as it's much more sophisticated than you might think.
Additionally, it would be unsafe for either type 1 or type 2 diabetics to follow this at home without proper medical supervision and intervention.
* Diabetes Ireland is the only national charity in Ireland dedicated to helping people with diabetes.
They provide support, education and motivation to everyone affected by diabetes.
* Check out diabetes.ie
‘Don’t let diabetes define you — you can live your life to the fullest’
Case study: Aoife Fennell (type 1)
Aoife Fennell has been living with diabetes since she was six years old. Now 23, the Kildare woman says while it doesn't stop her from fulfilling her dreams, it is time-consuming and can take some getting used to.
"When I was in senior infants I began to feel really tired all the time. I was constantly exhausted and couldn't concentrate on anything; I was also very thirsty - sometimes drinking up to four litres of water a day - and needed to use the bathroom a lot. I had all the classic symptoms of diabetes," she says.
"In October 2001, things became really bad and my parents took me to the doctor. They thought it might be diabetes as my half-brother had it (and unfortunately died from complications a couple of years ago). They brought me multiple times to the GP as my symptoms were not improving, but each time I was tested, I had to do a blood sugar fast beforehand and this actually made my bloods return to normal, so my reading always came back fine.
"As the months went on, I began to get very thin and by Christmas I was so tired all the time and couldn't walk very well so my dad had to carry me everywhere. I even remember on Christmas morning that I got my sister to open my presents as I didn't have the energy.
"My parents and the doctors were perplexed and I remember on one hospital visit in February 2002, a consultant said I was probably just constipated and should be encouraged to eat more fibre. However, on this visit, I hadn't fasted and my mother asked him to take a blood test to see if I was diabetic and suddenly everyone was jumping into action.
"My blood sugar reading should have been about seven and it was over 40. I was rushed to ICU where doctors were amazed that I hadn't gone into a diabetic coma as I had been battling with it for so long. I stayed in hospital for a couple of months and when I was discharged, I officially had type 1 diabetes.
"Initially I used to have to have regular injections (up to 10 a day) but these days I have a sensor and pump under the skin, so I am part cyborg, which takes care of everything for me - so it really isn't too difficult. Of course, life is different because I have diabetes, but I would say to others that it's important not to let it define you. Do what needs to be done, talk to others with the condition and live life to the fullest."
TYPE 1 FACTS
* The prevalence of type 1 diabetes is on the rise and is typically diagnosed in childhood.
* People with type 1 diabetes account for approximately 14,000 to 16,000 of the total diabetes population in Ireland.
* Prevention of type 1 diabetes is not possible as it is an auto-immune condition.
* People with type 1 diabetes will need to take medication for life.
Diabetic RetinaScreen – the HSE’s National Diabetic Retinal Screening Programme offers free, annual screening for and treatment of diabetic retinopathy. The HSE is urging anyone living with Type 1 or 2 diabetes in Ireland, aged 12 years and over, to make sure they register for free retinal screening on www.diabeticretinascreen.ie.
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