You need to count calories (not grams of fat), lay off sugary drinks and increase your consumption of fruits and vegetables if you want to ward off Type 2 diabetes. That's the take-home message from three studies published in the latest issue of Archives of Internal Medicine.
It's estimated that more than two million Canadians have diabetes, a number that's expected to rise to three million by the end of the decade. The vast majority - 90 per cent - have Type 2 diabetes, a condition in which the body's pancreas does not secrete enough insulin, the hormone that removes sugar from the bloodstream, or body cells do not use insulin properly.
Risk factors for Type 2 diabetes include obesity (especially abdominal obesity), inactivity, family history and increasing age.
In one study, which included 21,813 healthy adults aged 40 to 75, researchers sought to determine whether fruit and vegetable intake and blood vitamin C levels were linked with the risk of developing Type 2 diabetes. After 12 years of follow up, the diagnosis of Type 2 diabetes was 62 per cent less likely in people with the highest blood levels of vitamin C and 22 per cent less likely in those who ate the most fruit and
The level of vitamin C in your bloodstream is a strong marker of fruit and vegetable intake. People with the highest vitamin C levels ate five to six servings of fruit and vegetables each day.
Findings from a second study involving 59,000 African-American women revealed that drinking two or more soft drinks a day - compared with less than one a month - boosted the risk of Type 2 diabetes 24 per cent.
The researchers noted that women who increased their intake of soft drinks had considerably higher weight gain over a six-year period than their peers who reduced their consumption.
The third study set out to determine whether reducing fat intake could lower the risk of Type 2 diabetes in 48,835 healthy postmenopausal women. One group was advised to cut their fat intake to 20 per cent of calories. Women in the other group followed their usual diet. None of the women were told to lose weight or exercise.
Over the next eight years, women in both groups were equally likely to develop diabetes. However, there was a trend toward a lower risk of diabetes among women who reduced their fat intake the most and lost weight, suggesting that weight loss - rather than reducing fat intake - guards against Type 2 diabetes.
Previous studies have clearly shown the benefit of weight loss on the risk of Type 2 diabetes. Two landmark studies published in the New England Journal of Medicine demonstrated that moderate weight loss (5 to 7 per cent of body weight), coupled with 150 minutes of exercise a week, substantially reduced the risk of developing diabetes in people with impaired fasting glucose. (Impaired fasting glucose, or prediabetes, is a level of fasting blood sugar higher than normal, but not high enough to be diagnosed as diabetes.)
In both trials, progression to full-blown diabetes was prevented in 58 per cent of the participants assigned to the lifestyle intervention group.
It's clear we eat too many calories for our activity level as demonstrated by the growing number of obese adults and children in Canada. And as we're getting fatter, we're witnessing an epidemic of Type 2 diabetes, a condition that is largely preventable by making healthy lifestyle choices.
The following strategies can help you manage your weight and, ultimately, reduce the risk of Type 2 diabetes:
ADD FRUITS AND VEGETABLES
These foods supply antioxidants, such as vitamin C, that may offer protection from diabetes. Getting seven to 10 daily servings can also help you manage your weight. Thanks to their high water and fibre content, fruits and vegetables help you feel full on fewer calories.
A recent study that followed 71,346 healthy women for 18 years found that green leafy vegetables, such as spinach, kale, Swiss chard and rapini, as well as fruit protected from diabetes, while fruit juice increased the risk.
AVOID SUGARY DRINKS
Soft drinks, fruit drinks and even fruit juice supply extra calories that can promote weight gain. Research suggests we don't register the calories we drink as well as the calories we eat. Liquid calories don't fill us up, so we don't compensate for them by eating less food.
But there's also concern that high-fructose corn syrup in soft drinks may be especially effective at promoting weight gain by affecting certain hormones in the body.
CHOOSE LOW GLYCEMIC FOODS
Foods that break down slowly during digestion - such as many whole grains - release glucose gradually into the blood. On the other hand, quickly digested foods release glucose rapidly, which causes the pancreas to produce excess insulin. A steady intake of such foods can cause the pancreas to wear out over time, leading to Type 2 diabetes.
Examples of low glycemic foods include grainy breads with seeds, steel-cut oats, bran cereals, brown rice, sweet potatoes, pasta, apples, citrus fruit, grapes, pears, legumes, nuts, milk, yogurt and soy milk.
SELECT WHOLE GRAINS
Eating at least three daily servings of whole grains has been linked in a number of studies with protection from Type 2 diabetes. Foods such as whole wheat, whole rye, oats, brown rice and quinoa contain fibre which produces a greater feeling of fullness, aiding weight control.
Whole grains also supply magnesium, a mineral that helps regulate blood sugar by influencing the release and activity of insulin.
There's strong evidence that 30 minutes of moderate to vigorous aerobic exercise, five days a week, guards against Type 2 diabetes. However, longer workouts - up to an hour - may be needed for the long-term maintenance of weight loss.
Leslie Beck, a Toronto-based dietitian at the Medcan Clinic, is on CTV's Canada AM every Wednesday. Her website is lesliebeck.com.