Dear Dietitian,
Some of the fruit juices in supermarkets claim that they have no sugar
added. Does that mean that these juices will not affect my blood sugar
levels and weight since they have no sugar?
Dear Reader,
For packaged fruit juice drinks, nutrient claims such as “no added
sugar” often refers to no added glucose or sucrose or other sugars to
the product during processing. All fruit juices however, still contain
fructose, which is a sugar that occurs naturally in all fruits.
Fructose, glucose and sucrose are just different types of sugar and will
all affect your blood sugar levels. Your body cannot distinguish between
natural fruit sugar and added sugar; it uses both in similar ways.
Rather than the type of sugar, what mainly affects blood sugar levels is
the total amount of sugar (or total amount of carbohydrate), in a
serving of juice. The overall energy and carbohydrate content per 100ml
of original and “no added sugar” varieties of fruit juice at the
supermarkets are almost similar, with the original varieties usually
slightly higher. These small differences may become significant though
if your juice intake is high. Be careful not to drink excessive amounts
of juices even if they are the “no added sugar” variety.
The Health Promotion Board has recommended two servings of fruit to be
consumed daily with no more than one serving coming from fruit juice
(one serving is equivalent to one cup (250ml) of pure fruit juice). If
you have diabetes, you may want to further limit this to only half a cup
per day. Much of the valuable fibre in fruit is removed in the process
of making juices; therefore it is best to eat fresh fruit instead of
drinking juice2. If you are watching your weight, do also bear in mind t
at one cup of fruit juice may require two or more servings of fruit to
produce and will provide you with more calories than just having one
serving of fruit.
Dear Dietitian,
How are packaged fruit juices from the supermarket different from
homemade (squeezed/juiced) juices? Are they a better choice since they
are fortified with vitamins and minerals?
Dear Reader,
To be marketed as a “fruit juice” the product must contain at least 90%
natural juice. A quick survey of major supermarkets revealed that the
majority of packaged juices sold are reconstituted “fruit juice drinks”,
which have been concentrated and then diluted prior to sale and may have
sugars or sweeteners added.
True fresh squeezed juice such as those from home is harder to market commercially due to issues of shelf life. By reading the ingredients list found on the packaged drink, you will sometimes be able to tell if a juice is reconstituted, as “juice concentrates” will be listed there. Concentration of juices is achieved by heating the juice to evaporate water, and the concentrate is eventually refrigerated until it is ready to be reconstituted. This process is useful by extending the shelf life of the juice and making storage and shipping more economical. An apple and cranberry juice drink may be made by blending apple, cranberry and other concentrates together with water to achieve the desired sugar to acid ratio, colour and flavour, before the juice is packaged for sale.
Additives such as permitted flavouring, preservatives and antioxidants
are also added to improve shelf life. Fortification of juices with
Vitamins A & E, beta-carotene and calcium is increasingly common but
does not make packaged juices a better choice, as the extent of
stability and absorption of these added vitamins and minerals is
uncertain.
Freshly juiced or squeezed juice at home is free of additives and also
high in vitamins and minerals if consumed soon after juicing. Remember
to consume the pulp together with the juice for valuable fibre!
Dear Dietitian,
I am currently drinking bittergourd juice every morning. Does this help
lower my blood sugar levels?
Dear Reader,
Studies on bittergourd’s blood sugar lowering effects in humans are
still inconclusive currently. Two published scientific reviews2-3
concluded that although bittergourd may have blood sugar lowering
effects, better-designed human studies are necessary to properly assess
its safety and efficacy before a dietary recommendation can be given.
Some adverse effects such as hypoglycaemia coma, convulsions and
headaches after intake of bittergourd tea and seeds have also been
reported3.
It is therefore important to inform your healthcare professional caring
for your diabetes that you are having bittergourd juice and monitor for
any adverse effects. Do not forget, however, that bittergourd is a
highly nutritious vegetable and can be considered as one of your options
when having at least two servings of vegetables a day!
1 Health Promotion Board (HPB) 2006, ABCs of Healthy Eating, Health
Promotion Board, Singapore
2 Basch E., Gabardi S. & Ulbricht C. 2003, ‘Bitter melon (Momordica
charantia): A review of efficacy and safety’, Am J Health-Syst Pharm,
Vol.60, pp.356-359.
3 Krawinkel MB & Gudrun BK. 2006, ‘Bitter Gourd (Momordica charantia): A
Dietary Approach to Hyperglycemia’, Nutrition Reviews, Vol.64 (7),
pp.331-337.
This issue’s resident dietitian is Ms. Ong Fangyi, Dietitian at National Healthcare Group Polyclinics (NHGP).
Email your questions for Dear Dietitian to editor@diabetes.org.sg or fax the questions addressed to the
Editor, Diabetes Singapore,
Diabetic Society of Singapore.
Fax: 6553 1801
