Diabetes
Prevention
Diabetes
is about to become a concern for millions of middle-aged people
who never gave it much thought before. The American Diabetes
Association, backed by federal health authorities, recently
called for routine
screening using a simple, inexpensive
test, in order to detect more cases of Type 2 diabetes earlier.
This form of diabetes, previously called non-insulin
dependent or adult-onset diabetes, accounts for 90 to 95% of
cases of diabetes. Until now, the disease has generally been
diagnosed when people develop symptoms, such as unusual thirst
or frequent urination, or when people at high risk for the disease
(such as those with a family history of it) are tested for it.
Now blood sugar testing may become as routine as blood pressure
screening.
The
Association issued recent guidelines that lower the cutoff points
between normal, borderline, and high (diabetic) levels of blood
sugar. That, combined with widespread screening, is expected
to identify an additional 2 million Americans as diabetics.
It's estimated that 14 to 16 million have diabetes, but half
have not been diagnosed. And the half that have been diagnosed
typically have the disease for seven years before it is diagnosed.
Experts hope that early detection will identify cases when they
are still mild. It's hoped that this way, before symptoms develop,
people can take steps to minimize the subtle damage to organs
and blood vessels caused by years of high blood sugar levels,
and avoid later complications of diabetes, such as heart disease,
hypertension, stroke, and diseases of the eyes, nerves, and
kidneys, which often lead to premature death.
Diabetes
is a breakdown in the body's ability to utilize glucose (blood
sugar) efficiently. Glucose, the main sugar into which foods
are digested, can be used by our cells only in the presence
of the hormone insulin. With Type 2 diabetes, the cells become
resistant to the effects of insulin, and thus blood levels of
glucose rise. (With Type 1, which is usually diagnosed in young
people, the body virtually stops producing insulin.) The incidence
of Type 2 diabetes is on the rise, largely because populations
in developed countries are aging and getting heavier.
The
new guidelines
•
If you are 45 or over, you should be tested every three
years.
•
You should be tested earlier and more frequently if you:
—
are obese (more than 20% above healthy body weight). The obesity
rate has risen dramatically during the past two decades and
now includes one-third of Americans.
—
have a parent or sibling with diabetes.
—
are black, Hispanic, or Native American, or belong to another
high-risk ethnic group.
—
gave birth to a baby weighing more than nine pounds, or developed
gestational diabetes during pregnancy.
—
have high blood pressure (140/90 or higher).
—
have an HDL ("good") cholesterol level of 35 or
below and/or a blood triglyceride level of 250 or higher.
•
The ADA recommends the fasting plasma glucose test (no
food for eight hours before) because it is simplest, cheapest
(about $10), and most likely to be utilized on a regular basis.
The same vial of blood drawn for the test can also be used to
measure cholesterol and for other standard blood work, if needed.
•
A result of 126 mg/dl (milligrams of glucose in one-tenth
liter of blood) or more, confirmed on a second day, means you
have diabetes. The former guidelines set the cutoff at 140.
Researchers now believe that serious problems linked to diabetes
begin with test results in the mid-120s.
 |
| BLOOD
SUGAR (mg/dl) |
|
DIAGNOSIS
|
|
| Less
than 110 |
|
Normal |
 |
|
| 110-125
|
Impaired
fasting glucose |
|
|
| 126
and above (twice) |
Diabetes |
•
If you are diagnosed with diabetes in its early stages,
you'll be advised to lose weight if you're overweight, exercise
more, improve your diet (choose the same low-fat, semi-vegetarian
diet that is known to lower the risk of heart disease and cancer),
and quit smoking if you smoke. The goal of early detection is
to avoid diabetes medications, or at least postpone or minimize
their use, not merely to start drug therapy earlier.
•
If your result is between 110 and 125, you fall into
a new category called "impaired fasting glucose,"
a danger zone or borderline area. This means that you should
take the same steps as outlined above, since blood sugar levels
tend to rise with age. Here is where it may truly be possible
to prevent diabetes. (For more about a diabetes-prevention diet,
see the article below).
Last
words: Unfortunately, there's no clear evidence that
earlier treatment with drugs will reduce the long-term complications
of Type 2 diabetes (though it does for Type 1). Next year the
results of a major ongoing British study may provide this evidence.
In any case, if screening for diabetes serves as an additional
incentive for people to make life-style changes (such as losing
weight and exercising), that can only be beneficial.
Diabetes
Prevention: Exercise
(see
diet and exercise reduce diabetes)
Diabetes
Prevention: The Diet
Many
people still believe that eating too much sugar causes diabetes.
This misconception arises because diabetes is diagnosed by measuring
blood sugar (glucose). But dietary sugar is only part of the
picture. According to two recent Harvard studies, a diet rich
in certain high-carbohydrate foods—those low in fiber and
with a high glycemic index (see below)—increases the risk
of Type 2 diabetes, at least in those
predisposed to it.
One
study tracked 65,000 female nurses (age 40 to 65); the other
followed 43,000 male health professionals. Over the course of
six years, a total of 1,438 developed diabetes. Men and women
whose diet had a high glycemic index and low fiber content more
than doubled their chance of developing diabetes. Foods that
seemed to pose the greatest risk were white bread, white rice,
potatoes, and sugary soft drinks. In contrast, whole-grain breads
and cereals (rich in fiber and with a lower glycemic index)
appeared to reduce the risk of diabetes. Fruits and vegetables
didn't seem to have an effect, good or bad.
The
researchers suggested that excessive amounts of carbohydrate-rich
foods with a high glycemic index put pressure on the pancreas
to produce more of the hormone insulin, which stimulates the
body's cells to take in and store glucose. Over time, the body
may become resistant to insulin. In such insulin-resistant people,
the cells become less and less sensitive to insulin. This is
characteristic of Type 2 diabetes. Of course, not everyone on
such a low-fiber, high-starch diet develops diabetes. There
seems to be a genetic predisposition to diabetes, which may
be exacerbated by this kind of diet. Without these dietary factors,
the men and women in these two studies might have developed
diabetes later in life, or perhaps not at all.
Obesity
is probably the leading risk factor for Type 2 diabetes. Family
history of the disease, advancing age, and lack of exercise
are other important factors.
Magnesium
helps, too
The
study also found that the mineral magnesium has a protective
effect against diabetes. A few studies have suggested that this
mineral improves insulin sensitivity. But since whole grains
are rich in magnesium, it's hard to say whether the proposed
benefit is due to something else in the grain (notably its fiber)
or the mineral.
Bottom line: A diabetes-prevention diet, if there is one, is
the same low-fat, high-fiber, semi-vegetarian diet that is known
to lower the risk of heart disease and cancer. The Harvard studies
simply underline the importance of choosing whole-grain products,
as opposed to highly refined, low-fiber grain products such
as white bread, in order to help control blood sugar. Such a
diet helps in weight control. It also provides the vitamins,
minerals, and other nutrients you need to help prevent chronic
diseases, including, perhaps, diabetes.
The
Glycemic Index
The glycemic index indicates how fast a high-carbohydrate
food is digested into glucose and how much it causes blood
glucose to rise. The index doesn't depend merely on whether
the carbohydrates are simple (sugars) or complex (starches).
Many factors come into play, including the amount of fiber
and fat in the food, how refined the food is, how fast the
food is digested, whether it was cooked, and what else is
eaten with it. Table sugar and honey have a high glycemic
index (meaning they have a strong effect on blood sugar).
But so do raisins, corn, potatoes, carrots, white bread,
instant rice, and most refined cereals. Though sweet, apples
and peaches, as well as beans, grapefruit, and peanuts,
have a low glycemic index. Pasta gets a middle rating, as
does oatmeal. There is no reason
to avoid foods with a high glycemic index—many are
very nutritious. Even people predisposed to diabetes, or
with the disease, can eat these foods in moderation.
More
info on glycemic index |
Additional
articles
on Diabetes Prevention
Reference
Source 89, 98
