For a food that’s got plenty to offer on the nutrition front, fruit gets a bad rap. It’s often perceived as having too many carbs, too much sugar and/or too many calories.
If you’ve ditched fruit because you think it’s a dietary no-no, or if it’s something you just don’t think to reach for, consider including two servings in your daily diet.
Doing so, say Australian researchers, can help ward off type 2 diabetes. The new research findings add to growing evidence that fruit plays a role in controlling blood sugar and mitigating diabetes risk.
The latest findings
The study included 7,675 men and women, average age of 54, who had been recruited to the ongoing Australian Diabetes, Obesity and Lifestyle Study.
Researchers assessed participants’ intakes of total fruit, individual fruits and fruit juice and administered blood tests to measure insulin resistance. Participants were followed for up to 12 years to see if they had developed type 2 diabetes.
Insulin resistance occurs when cells in the body don’t respond properly to the blood-sugar-lowering hormone insulin. As a result, the pancreas has to make more insulin to allow glucose to enter cells.
People who ate at least two servings of whole fruit a day (versus less than one-half) had significantly better measures of insulin sensitivity, suggesting that they produced less insulin to lower their blood glucose.
Having high levels of insulin circulating in the bloodstream can damage blood vessels and is tied to a greater risk of diabetes, obesity and heart disease.
Compared to those who ate little or no fruit, participants with a higher fruit intake were 36 per cent less likely to develop type 2 diabetes during five years of follow-up. Researchers accounted for risk factors such as body mass index, physical activity, family history of diabetes and dietary factors.
Individual fruits and fruit juice were not associated with measures of insulin resistance or diabetes risk.
This study was observational in nature, so it can’t prove that eating whole fruit lowers diabetes risk. Still, its findings are consistent with previous large studies that investigated fruit intake and diabetes risk.
Fruit’s protective properties
Fruit may guard against insulin resistance and type 2 diabetes in a number of ways. Most whole fruits have a low glycemic load, meaning they lead to lower and slower rises in blood glucose.
Certain types of fibre in fruit feed and fuel the growth of gut microbes which, in turn, have been shown to play a role in glucose metabolism.
Vitamins, minerals and phytochemicals may also contribute. Many types of fruit, for example, are good sources of flavonoids, phytochemicals that have been shown to improve insulin sensitivity.
The health benefits of eating whole fruit extend beyond type 2 diabetes. Eating more fruit has also been linked to a lower risk of high blood pressure, heart attack, stroke and certain cancers.
What about the sugar?
Yes, fruit contains sugar but it’s naturally-occurring sugar that comes packaged with fibre, which helps to slows the release of natural sugars into the bloodstream. It’s not the same as free sugars (e.g., added sugars, fruit juice), which cause rapid spikes in blood sugar levels.
The health risks of consuming too much sugar come from free sugars, not natural sugars in whole fruit.
That said, not everyone should eat lots of fruit each day.
If you’re trying to lose weight, the calories from natural sugars add up if you eat too much. If you have prediabetes or diabetes, you’ll need to limit (but not avoid) fruit intake to help control blood sugar.
Many of us, though, could stand to eat more fruit.
Add fruit to your summer menu
Now’s the time to enjoy the flavour and nutrition of in-season locally grown fruit. While all summer fruit is good for you, I have a few favourites.
Strawberries, in season now, are an excellent source of vitamin C (98 mg per one cup, a full day’s worth) and brain-friendly anthocyanins. Raspberries are also packed with anthocyanins, not to mention fibre (8 g per one cup).
Cantaloupe is my go-to summer melon. It’s an outstanding source of potassium (427 mg per one cup), vitamin C (60 mg) and beta-carotene (3.2 mg). And next month, I’ll be replacing my snack of dried apricots with fresh ones.
Leslie Beck, a Toronto-based private practice dietitian, is director of food and nutrition at Medcan. Follow her on Twitter @LeslieBeckRD
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