Prof Jennie Brand-Miller answers your questions.
Can a low GI diet reduce the risk of birth defects?
Moderation is a good thing and that applies to glucose levels in the blood. Very high glucose levels are toxic to cells. That’s why people with diabetes, who are not properly controlled by diet or medications, develop complications such as blindness, kidney failure, nerve damage and cardiovascular disease. High glucose levels are also implicated as one of the causes of a birth defect called a neural tube defect. This is an opening in the spinal cord or brain that should have closed during development. Normally, in the second week of pregnancy, specialised cells begin to fuse and form the neural tube. By week four, the neural tube closes but if it does not close up completely, a neural tube defect develops. In some instances, the brain and/or spinal cord are exposed at birth through a defect in the skull or vertebrae (back bones), a condition known as spina bifida. Unfortunately, neural tube defects are one of the most common birth defects, occurring in approximately one in 1000 live births.
Foremost among the causes of a neural tube defect is a relative deficiency of the vitamin folate. Many women don’t consume the recommended amount of folate as part of a normal diet, and this is the reason why folic acid supplements are routinely recommended for pregnancy.
Diabetes, a condition characterised by high blood glucose levels if not properly managed, is also associated with a having a higher risk of baby with a neural tube defect. For this reason, a woman with type 1 diabetes who is planning to have a baby should do her best so make sure she has optimal glucose control before she conceives.
The concern is well justified because of the known toxic effects of excess glucose in the blood of the mother on the embryo. At this early stage, the embryo has no beta cells and is unable to secrete insulin or regulate their own glucose levels. Studies have confirmed that markedly elevated glucose concentrations contribute to the development of birth defects.
This is an extract from my new book (with Dr Kate Marsh and Prof Robert Moses), The Bump to Baby Low GI Eating Plan for Conception, Pregnancy and Beyond (Hachette Australia). In the book we share the latest science to help women enjoy a healthy pregnancy while safeguarding their baby’s future wellbeing. It’s available from bookshops and online in Australia and NZ and as an eBook from Amazon, iTunes etc. We now have a website too, where you can visit us, learn more about our book (and look inside), find pregnancy friendly recipes, keep up to date with the latest news about the importance of lifestyle for pregnancy and preconception, download information and weight charts, contact us and link to other useful information. Visit us HERE.
New values from GI Labs
Going to the Nth Degree
Specially created for endurance, performance and energy, Nth Degree Low GI Performance Drinks were launched in May 2012. Unlike many sports drinks with high GI values (70–100), this new range with no artificial colours, flavours or preservatives has a low GI thanks to the use of isomaltulose (Palatinose) a slow-release sweetener derived from sugar beets. The drinks are also fortified with B vitamins and a balance of electrolytes such as sodium (sea salt), potassium, magnesium and calcium. Available flavours include Orange, Raspberry, Lemon Citrus & Fruit Punch.
- The actual GI value of these drinks hasn’t been released for publication, but they are certified low GI by GI Labs in Toronto who carried out the clinical testing.
- The 20oz (600ml) bottle delivers 37g carbs. To keep the GL low (under 10), stick to a standard serving of 1 cup (8oz).
During exercise, sports drinks are an ideal way of providing fuel to the working muscle as well as helping with that vital rehydration. In addition, a key benefit of a low GI post-exercise beverage or meal if you are exercising primarily for health, fitness or for weight loss is that it may help your body maintain a higher rate of fat burning (oxidation). For more product information on this new range visit: www.nth4u.com.
GI testing by an accredited laboratory
Dr Alexandra Jenkins
Glycemic Index Laboratories
20 Victoria Street, Suite 300
Toronto, Ontario M5C 298 Canada
Phone +1 416 861 0506
Research Manager, Sydney University Glycemic Index Research Service (SUGiRS)
Human Nutrition Unit, School of Molecular and Microbial Biosciences
NSW 2006 Australia
Phone + 61 2 9351 6018
Fax: + 61 2 9351 6022