November 8, 2004
November 14th is World Diabetes Day, and the
theme for this year’s campaign is ‘Fight Obesity, Prevent Diabetes’. Read on
for a summary of current expert thinking on how and why its so important to
halt the rising rates of overweight and obesity around the world…
Diabetes, especially Type 2
diabetes, is on the increase worldwide. At least 177 million people worldwide
are thought to have some form of diabetes and this figure is expected to
double by 2030. This is especially true in Asia: the number of cases of
diabetes in India, China, Indonesia, Japan and Pakistan are some of the
highest in the world. The rapid rate of increase in the number of cases, which
is strongly associated with escalating cases of overweight and obesity has
been described as a ‘diabesity’ pandemic by some observers. The key question
is, “is there anything that can be done to slow or reverse this trend”. The
answer from experts is a resounding “ yes!” The evidence is very strong that
diet and lifestyle changes can have a huge impact for both whole populations
and individuals in preventing onset and/or delaying progression of Type 2
diabetes. The changes required are not radical or complicated but will take
some concerted effort. Read on for some highlights of what is known about how
we can prevent and limit the serious health complications of Type 2 diabetes…
What is Type 2 diabetes?
Type 2
diabetes, which makes up 90% of diabetes cases, is characterized by high
levels of glucose in the blood. Glucose is the main energy source used by the
body to fuel almost every action it performs, from breathing and blinking, to
exercising and keeping warm. Insulin is produced by the body to control the
amount of glucose circulating in the blood by controlling the uptake of
glucose into body cells. In Type 2 diabetes, the body cells become rather
insensitive to the insulin, so the body has to produce very large amounts of
insulin in order for the body cells to react and absorb the insulin required
for them to function. The high levels of circulating blood glucose, and the
large amounts of insulin that are being produced both put serious strains on
the body. Without effective intervention to limit these strains on the body, a
whole range of serious health complications can develop, such as loss of
eyesight, kidney damage, and ulcers. Abnormally high glucose and insulin
levels in the blood also result in a much higher risk of cardiovascular
disease and stroke. Clearly, avoiding the onset of Type 2 diabetes, or for
those who have it - managing it effectively to lessen the damage to the body,
is a high priority.
What are the causes of Type 2 diabetes?
Type 2 diabetes is more common
in some families, but it is avoidable. However, although those with a family
history of diabetes have an increased susceptibility to developing diabetes,
taking active steps to address other risk factors may prevent its onset.
Being overweight or obese is
the most important risk factor, and the risk increases over time.
Susceptibility also appears to increase with age, so it’s important to sustain
efforts throughout life. Type 2 diabetes is also strongly associated with
sedentary, inactive lifestyles. For example, a recent study published in the
Journal of the American Medical Association found a direct link between number
of hours of TV watching and Type 2 diabetes in middle-aged women.
Some experts believe that a
metabolic make-up which has evolved to help humans survive periods of famine,
may, in modern times of plentiful food supply, be working against current
generations who live longer and rarely experience hunger. The hypothesis,
known as the "thrifty gene” theory, is that insulin resistance is beneficial
when food supplies are unreliable because it encourages conservation of fat
deposits. However, in the absence of periodic food shortages, the fat deposits
are never used up, and as we live longer than our ancestors, the long-term
cumulative effects of both insulin resistance and accumulation of body fat are
transformed from a health advantage to a health risk. This has particular
relevance to many Asian populations who are now experiencing very rapid
transition from food insecurity to a food supply abundant of readily
available, cheap, high energy food.
Many experts also believe that
the greater tendency for Asian nationalities to develop Type 2 diabetes is
related to the Asian tendency to accumulate excess fat around the abdomen. On
a weight-for-weight basis, fat deposited around tummy increases the risk of
developing Type 2 diabetes, far more than fat deposited in other parts of the
body such as buttocks and limbs.
Can any special diet help
to prevent diabetes?
A lot of research has been
devoted to this topic. There is strong agreement that regardless of the makeup
of the diet, eating just enough energy (calories) to maintain a healthy body
weight is the most effective dietary strategy to prevent the onset of Type 2
diabetes. In 2001, a study in Finland found that the risk of developing Type 2
diabetes was 58% lower in the group that lost weight with a diet and exercise
program, than the comparison group who were given no intervention.
The World Health Organisation
(WHO) has concluded that the scientific evidence that a diet high in dietary
fibre is protective against diabetes is very strong. This provides yet another
reason to consume a diet which includes plenty of wholegrain cereals, fruit
and vegetables. Related to this, a low glycaemic load diet, that is one which
does not create rapid peaks and troughs in blood glucose levels, seems to have
some protective role. The relative importance of this in the long term is not
yet fully understood, but adds further weight to the advice to substitute
refined carbohydrates with high fibre foods (because high fibre foods tend to
lower glycaemic load of a meal or snack ) whenever possible.
Research also indicates that
exclusive breast feeding in early life reduces the chances of developing Type
2 (and indeed Type 1) diabetes, although, more work still needs to be done to
fully understand how and why this is the case.
What is the latest research
news on diet and diabetes ?
There have been some very
exciting study results, which indicate that diets rich in some micronutrients
might offer some protection but there is still a great deal of additional
research to be done in this area before those with, or at risk of developing
diabetes, should consider making changes to their diet. Research into
potentially protective roles for magnesium (found in legumes, nuts, seeds and
green leafy vegetables); chromium (found in liver, brewers yeast, wholegrains,
nuts and cheeses); and vitamin E (found in many foods but especially rich
sources include fortified margarine, vegetable oils, soybeans and some nuts)
is still ongoing.
A recent US study reported
that individuals who drank more coffee and other caffeinated beverages were
less likely to develop Type 2 diabetes, than those who drank few or no
caffeinated beverages. However, authors of the study cautioned that people
should not increase their coffee drinking in order to prevent Type 2 diabetes
until further studies are completed and analysed.
What about children and young people ?
Type 2 diabetes used to be a disease that only
affected older people, so much so, it was sometimes called “adult-onset
diabetes”. During the last decade, however, cases of Type 2 diabetes amongst
the younger generation have begun to emerge. Developing Type 2 diabetes in
childhood is serious because the earlier the onset, the greater the exposure
to abnormal insulin and glucose and fat concentrations in the blood, and the
greater the cumulative damage to the eyes, kidneys, heart, etc.. All the cases
of Type 2 diabetes in childhood and adolescence are associated with obesity
and inactive lifestyles, and medical intervention in these cases nearly always
includes efforts to encourage better weight management and an increase in
daily physical activity levels.
Top priorities for those who wish to avoid
becoming one of the ‘diabesity’ statistics, especially those who suspect they
may be at risk, are to get more active, and to lose weight.
What should I do next to avoid Type 2 diabetes
?
-
Increasing physical activity levels will diminish any existing insulin
resistance and will also discourage the deposition of fat around the
abdomen. Researchers have found that increased physical activity levels,
even without reduction in body weight will reduce the risk of Type 2
diabetes. Any increase in physical activity levels will help, but an ideal
target to aim for is at least 30 minutes per day of brisk walking, moderate
swimming or any other similar exercise.
-
For those who are overweight, any reduction in body weight will help.
Prevention of diabetes has to be approached as a lifelong goal, and so
gradual weight loss which can be sustained is the most effective and
appropriate strategy. Adjusting your diet to include more dietary fibre,
from wholegrains, legumes, beans, fruit and vegetables will have a double
benefit as multiple studies endorsed by WHO have demonstrated that high
fibre diets not only reduce the risk of developing Type 2 diabetes, but are
also extremely effective in weight loss diets.
-
The diagnostic tests for Type 2 diabetes are very simple and therefore
regular screening should become part of your personal health strategy.
Doctors report that many people who are insulin resistant or are Type 2
diabetic are not aware of this, sometimes for many years. During this time,
the uncontrolled blood glucose and insulin levels will be having a
deleterious effect on the body’s internal organs and nerves.
What if I already have Type 2 diabetes?
The actions recommended for prevention are also
very beneficial for those with diabetes, as increased exercise, loss of weight
and a high fibre diet will all help to lessen the effect of high glucose
levels in the blood. In addition, more detailed dietary advice, and regular
medical checks are of paramount importance to monitor and improve the
management of the condition. For some drug treatment will be necessary, in
addition to these diet and lifestyle changes.
Further Reading
Diabetes Atlas (Second Edition), International Diabetes Federation 2003.
www.idf.org/e-atlas
