Diet, sugar and gestational diabetes

We are all becoming very familiar with diabetes. And we understand it ain’t fun, whether managing the condition with insulin injections; closely monitoring food and lifestyle factors; or simply contending with the associated symptoms such as lethargy and poor circulation.

Type 2 diabetes, the so-called lifestyle induced form, comprises 80-90% of the diabetic population in Australia.

In 2014, over 420 million people worldwide are diagnosed with some form of diabetes according to the World Health Organisation, and the number is rising. Among that is the incidence of gestational diabetes.

Gestational diabetes – an understanding

Gestational diabetes mellitus (GDM) affects 2-14% of women and shares much pathophysiology with type 2 diabetes.

During pregnancy, a hormone is produced by the placenta that can block the activity of insulin. Normally, the pancreas goes into overdrive and simply produces more insulin. The pregnancy continues and insulin production and activity returns to pre-pregnancy levels following birth. Great!⁷

In those that are predisposed, obese, and/or have a poor diet and do not exercise regularly, the ability for the pancreas to call on reserves of insulin to combat the pregnancy hormone is limited. GDM can then develop.

Fortunately, 90% of cases are transient, meaning insulin function returns to normal post pregnancy, regardless of predisposition or not.

Several risk factors have been identified, including family history of diabetes, older age, race and ethnicity, and having polycystic ovarian syndrome. Some are also lifestyle induced, including low physical activity, smoking, pre-pregnancy overweight, and a high glycaemic index and load diet.

Basically it comes down to insulin sensitivity, and each of these factors can affect it.

Importantly, it is the predisposition and lifestyle risk factors that can potentiate not only GDM, but also any subsequent Type 2 diabetes development – not the pregnancy itself.⁷

The good news – there is much that can be done to minimise the risk! And it can start with your next meal.

Dietary influences

Studies have found over recent years strong correlations between high intake of high glycaemic foods, and low intake of high fibre foods, and incidence of GDM. And the influence diet has over developing GDM may begin well before pregnancy.

Mediterranean and DASH do good
As part of the massive Nurses Health Study, 758 of the 13,110 eligible women participating self-reported having GDM. With every 10g of increased fibre intake (from all sources), a 26% reduction in risk was found. Cool!¹¹

Popular diets have been associated with decreased risk, including the Mediterranean and DASH diets.³ This has been supported in later takes on the Nurses Health Study, with reduction in risk seen in the:

• Mediterranean diet (24%)
• DASH diet (34%)
• Healthy Eating Index diet (36%)⁸

What these diets share is a lack of processed, refined or artificial grains, sugar, meats, oils and sweetened beverages.

Low GI and GL is the way to go
On the not so bright side, an Australian study concluded that high intake of high glycemic load foods by women with GDM is associated with decreased intake of monounsaturated fats, potassium and vitamin E. In addition, the majority of the study participants did not meet the recommended intake for nutrients important in pregnancy, including fibre, folate, vitamin D, iodine and iron.⁵

This indicates that nutrient rich, whole foods may be neglected.

However, it’s recently been found that a low-GI diet (though not a low carbohydrate diet – important distinction to make!) in women with GDM had positive effects on insulin use during pregnancy and birth weight of the bub.⁹

Food can be powerful!

Good fats are in
It seems quality of dietary fat is associated with increased risk too. Early investigations are finding relationships between higher intake of anti-inflammatory omega-3 fatty acids and reduced risk.¹

This is all good and well – but why is GDM such a concern?

Why gestational diabetes ain’t ideal

Consequences of GDM aren’t pretty, with increased risk to mum for Type 2 diabetes, increased blood pressure and preeclampsia, perineal tear and caesarean delivery due to increased size of the baby.

And risks to bub include increased birth size and risk for later life obesity,⁴ type 2 diabetes, as well as respiratory and skeletal complications.

Diet can influence the release and action of insulin. Insulin can influence hormones involved in pregnancy. So if we can take action and reduce the risk of GD diagnosis, why wouldn’t we?

The take home – eats and exercise

Here are some considerations for reducing the risk of GDM:

Feed up on fibre
Ensure intake is at least 28 grams per day of a mix of soluble and insoluble fibres.

Keep low to moderate GL, and low GI
Focus on foods with low to moderate glycaemic load, so to avoid blood glucose fluctuations, and increased chance of insulin resistance and excess weight gain.

Foods include:

• non-starchy vegetables
• fruit like berries and citrus
• wholegrains/pseudo grains such as quinoa, amaranth, brown rice and barely/millet
• fats such as olives and avocados, olive oil and coconut oil
• whole food protein from animal, fish, nuts, seeds and legumes.⁶

Boost omega-3 fatty acids
Include whole food sources of these anti-inflammatory superstars, including:

• oily fish like sardines, mackerel, salmon and tuna (wild and sustainably caught);
• algae (as that is where the fish get their omega-3 from!);
• chia and flaxseeds (also sources of our fabulous friend fibre); and
• leafy green vegetables (just wash them thoroughly!).

Eat your breakfast
A great way to moderate blood glucose levels is to start the day right. Include fibre, good fats and whole food protein in your breakfast. The slow release of energy will mitigate blood glucose ups and downs, sugar highs and lows, cravings and poor food choice.

Enjoy exercise
Whilst you will always want to consult with your mid-wife, nurse or obstetrician about the types and intensity of exercise suitable for you. At least 15minutes of exercise 3 times a week is beneficial, but you want to aim for 30minutes daily. Consider resistance exercises, swimming, walking, yoga or gentle stationary cycling to get the body moving, blood flowing, and muscles strong and sensitive to insulin.^2;10 

For more information, our friend Kelly Winder at Belly Belly has written extensively on the subject discussing research, diet, symptoms and management, and more.

By Angela Johnson (BHSc Nut. Med).

References:

1. Barbieiri, P, Nunes, JC, Torres, AG, Nishimura, RY, Zuccolotto, DC, Crivellenti, LC, Franco, LJ, & Sartorelli, DS 2016, ‘Applied nutritional investigation: Indices of dietary fat quality during midpregnancy is associated with gestational diabetes’, Nutrition, vol. 32, pp. 656-661.
2. Brankston, GN, Mitchell, B, Ryan, EA, & Okun, NB 2004, ‘Resistance exercise decreases the need for insulin in overweight women with gestational diabetes mellitus’, American Journal of Obstetrics and Gynecology, vol. 190, pp. 188-193.
3. Izadi, V, Tehrani, H, Haghighatdoost, F, Dehghan, A, Surkan, PJ, & Azadbakht, L 2016, ‘Applied nutritional investigation: Adherence to the DASH and Mediterranean diets is associated with decreased risk for gestational diabetes mellitus’, Nutrition, [Epub ahead of print]
4. Logan, KM, Emsley, RJ, Jeffries, S, Andrzejewska, I, Hyde, MJ, Gale, C, Chappell, K, Mandalia, S, Santhakumaran, S, Parkinson, JC, Mills, L, & Modi, N 2016, ‘Development of Early Adiposity in Infants of Mothers With Gestational Diabetes Mellitus’, Diabetes Care.
5. Louie, JY, Markovic, TP, Ross, GP, Foote, D, & Brand-Miller, JC 2013, ‘Higher glycemic load diet is associated with poorer nutrient intake in women with gestational diabetes mellitus’, Nutrition Research, vol. 33, pp. 259-265.
6. Maki, KC, & Phillips, AK 2015, ‘Dietary substitutions for refined carbohydrate that show promise for reducing risk of type 2 diabetes in men and women’, The Journal Of Nutrition, vol. 145, no. 1, pp. 159S-163S.
7. Poulakos, P, Mintziori, G, Tsirou, E, Taousani, E, Savvaki, D, Harizopoulou, V, & Goulis, DG 2015, ‘Comments on gestational diabetes mellitus: from pathophysiology to clinical practice’, Hormones (Athens, Greece), vol. 14, no. 3, pp. 335-344.
8. Tobias, DK, Zhang, C, Chavarro, J, Bowers, K, Rich-Edwards, J, Rosner, B, Mozaffarian, D, & Hu, FB 2012, ‘Prepregnancy adherence to dietary patterns and lower risk of gestational diabetes mellitus’, The American Journal Of Clinical Nutrition, vol. 96, no. 2, pp. 289-295.
9. Viana, LV, Gross, JL, & Azevedo, MJ 2014, ‘Dietary intervention in patients with gestational diabetes mellitus: a systematic review and meta-analysis of randomized clinical trials on maternal and newborn outcomes’, Diabetes Care, vol. 37, no. 12, pp. 3345-3355 11p.
10. Weissgerber, TL, Wolfe, LA, Davies, GA, & Mottola, MF 2006, ‘Exercise in the prevention and treatment of maternal–fetal disease: a review of the literature’, Applied Physiology, Nutrition & Metabolism, vol. 31, no. 6, pp. 661-674.
11. Zhang, C, Liu, S, Solomon, CG, & Hu, FB 2006, ‘Dietary fiber intake, dietary glycemic load, and the risk for gestational diabetes mellitus’, Diabetes Care, vol. 29, no. 10, pp. 2223-2230.