More Sugar-Sweetened Drinks, Less Fruit Both
Increase Diabetes Risk; Low-Fat Diet a Wash
‘Our number one goal for the reduction of new cases
of type 2 diabetes mellitus should be to reduce the intake of
high-energy, low-benefit foods’
Distribution of
Age at Diagnosis of Diabetes among Adult Incident Cases Aged
18–79 Years, United States, 2005
In 2005, about one half (47%) of
the adult incident cases (i.e., cases diagnosed within past
year) of diabetes were diagnosed between the age of 45 and 59
years. About 10% were diagnosed before the age of 35 and about
18% were diagnosed at age 65 or older. Click graphic for
larger view.
July 29, 2008 - Senior citizens are increasingly
alert to the risk of diabetes as they see it attack more and more of
their peers. Three new studies offer interesting insight into eating
habits and their association with the disease. Drinking more
sugar-sweetened sodas or eating fewer fruits and vegetables
may
both be associated with an increased risk of type 2 diabetes. On
the other hand, eating a low-fat diet does not appear to be associated
with any change in diabetes risk.
Diabetes rates continue to increase, particularly
in developed countries, according to the reports in the July 28 issue of
Archives of Internal Medicine, one of the JAMA/Archives journals.
By the year 2030, 11.2 percent of U.S. adults are
expected to have the condition and obesity is the strongest modifiable
risk factor for the development of type 2 diabetes.
Consumpiton of sugar-sweetened soft drinks
In one study, Julie R. Palmer, Sc.D., of the Slone
Epidemiology Center, Boston University, and colleagues examined the
association between type 2 diabetes, weight gain and the consumption of
sugar-sweetened soft drinks and fruit drinks in 43,960 African American
women. In 1995 and again in 2001, the women completed a questionnaire
about the types of foods and beverages they typically consumed. A total
of 17 percent reported drinking one sugar-sweetened soft drink each day,
32 percent drank one sweetened fruit drink each day and 22 percent had
at least one glass of orange juice or grapefruit juice.
Over 10 years of follow-up, 2,713 of the women
developed type 2 diabetes. Those who drank more regular soft drinks and
fruit drinks - including regular soda, other fruit juices, fortified
fruit drinks and Kool-Aid but not diet soda, orange juice or grapefruit
juice - were more likely to develop diabetes than those who drank less
of those beverages.
Diagnosed
Diabetes by Age, United States, 1980–2005
From 1980
through 2005, the prevalence of diagnosed diabetes increased in
all age groups. In general, throughout the time period, people
aged 65-74 years had the highest prevalence, followed by people
aged 75 or older, people aged 45-64 years, and people less than
45 years of age. In 2005, the prevalence of diagnosed diabetes
among people aged 65-74 (18.5%) was about 12 times that of
people less than 45 years of age (1.4%). Click chart for
larger view
Women who drank two or more soft drinks per day had
a 24 percent increase in diabetes risk compared with women who drank
less than one soft drink per month, and those who drank two or more
fruit drinks per day had a 31 percent increased risk compared with women
who drank less than one per month. Diet soft drinks, grapefruit juice
and orange juice were not associated with diabetes risk.
When the researchers adjusted for body mass index
(BMI), the association between soft drinks and diabetes risk decreased.
However, the association between fruit drinks and diabetes risk did not
appear dependent on BMI.
“Our study suggests that the mechanism for the
increase in diabetes risk associated with soft drink consumption is
primarily through increased weight. Reducing consumption of soft drinks
or switching from sugar-sweetened soft drinks to diet soft drinks is a
concrete step that women may find easier to achieve than other
approaches to weight loss,” the authors write.
“Finally, it should be noted that consumption of
fruit drinks conveyed as high an increase in risk as did consumption of
soft drinks. Fruit drinks typically contain as many or more calories
compared with soft drinks and, like soft drinks, may not decrease
satiety to the same extent as solid food,” they conclude. “The public
should be made aware that these drinks are not a healthy alternative to
soft drinks with regard to risk of type 2 diabetes.”
Fruit and vegetable consumption
In another study, Anne-Helen Harding, Ph.D., of
Addenbrooke’s Hospital, Cambridge, England, and colleagues analyzed
blood vitamin C levels and fruit and vegetable intake in 21,831
individuals (average age 58) who did not have diabetes at the beginning
of the study (1993 to 1997). Vitamin C level is a good indicator of
fruit and vegetable consumption, the authors note, because these foods
are the main source of vitamin C in the Western diet.
Participants provided blood samples and reported
how often they ate fruits and vegetables on a food frequency
questionnaire.
Over 12 years of follow-up, 735 participants
developed diabetes. Those with higher blood levels of vitamin C were
substantially less likely to develop diabetes.
“Compared with men and women in the bottom quintile
[one-fifth] of plasma vitamin C, the odds of developing diabetes was 62
percent lower for those in the top quintile of plasma vitamin C,” the
authors write. “A weaker inverse association between fruit and vegetable
consumption and diabetes risk was observed.”
Fruits and vegetables may reduce diabetes risk by
preventing obesity or by providing nutrients that protect against
diabetes, including antioxidants, the authors note.
“Because fruits and vegetables are the main sources
of vitamin C, the findings suggest that eating even a small quantity of
fruits and vegetables may be beneficial and that the protection against
diabetes increases progressively with the quantity of fruit and
vegetables consumed,” they conclude.
Effects of eating a low-fat diet on diabetes
risk
In a third article, Lesley F. Tinker, Ph.D., of the
Women’s Health Initiative, Fred Hutchison Cancer Research Center,
Seattle, and colleagues studied the effects of eating a low-fat diet on
diabetes risk in 48,835 post-menopausal women. From 1993 to 2005, 29,294
of the women were randomly assigned to continue eating their usual diet
while 19,541 were given a low-fat (20 percent of calories from fat) diet
with increased levels of fruits, vegetables and whole grains. The diet
was not intended to help participants lose weight.
A
total of 1,303 of the women eating the low-fat diet (7.1 percent) and
2,039 women eating their usual diet (7.4 percent) developed diabetes
over the 8.1 years of the study. There was no significant reduction in
the risk of developing diabetes among women on the low-fat diet.
However, “trends toward reduced incidence were greater with greater
decreases in total fat intake and weight loss,” the authors write.
Women in the low-fat diet group lost about 1.9
kilograms or 4.2 pounds more weight over the course of the study than
women in the regular diet group. “Weight loss, rather than macronutrient
composition, may be the dominant predictor of reduced risk of diabetes,”
the authors conclude.
(Arch Intern Med. 2008;168[14]:
1487-1492,
1493-1499,
1500-1511. Available to the media pre-embargo at
www.jamamedia.org).
Editorial: Calories may count the most in
reducing diabetes risk
“The relationship between food and the development
of type 2 diabetes mellitus has been debated for many years,” write Mark
N. Feinglos, M.D., C.M., and Susan E. Totten, R.D., of Duke University
Medical Center, Durham, N.C., in an accompanying editorial.
“So, what do we now know about the impact of diet
on the development of type 2 diabetes mellitus, and what remains
unknown?” they write.
“We know that, as a population, we eat too much for
our level of activity, and we are growing fatter as a result. In
association with this increasing weight, we are in the midst of a
dramatic increase in the number of cases of type 2 diabetes mellitus,
not only in the United States, but in countries like India and China,
where the caloric intake has also increased.”
“We do not know whether specific macronutrients put
genetically predisposed people at increased risk of developing diabetes
mellitus, or whether adding lots of fat or refined carbohydrate to the
diet just makes it easier to take in excess calories,” Drs. Feinglos and
Totten conclude.
“Studies to isolate these effects will be difficult
to perform, but, until we have more information, we have to assume that
calories trump everything else, and that our number one goal for the
reduction of new cases of type 2 diabetes mellitus should be to reduce
the intake of high-energy, low-benefit foods, particularly in young
members of the most vulnerable populations.”
Keep up with the latest news for senior citizens, baby
boomers
A
total of 1,303 of the women eating the low-fat diet (7.1 percent) and
2,039 women eating their usual diet (7.4 percent) developed diabetes
over the 8.1 years of the study. There was no significant reduction in
the risk of developing diabetes among women on the low-fat diet.
However, “trends toward reduced incidence were greater with greater
decreases in total fat intake and weight loss,” the authors write.