Tuesday, February 9, 2016

Healthy Ageing with Grains and Legumes

By Julie Christy, Accredited Practising Dietitian

As Australia faces an ageing population, addressing health issues associated with ageing is becoming increasingly important. While most older Australians may understand they should be eating more fruit and vegetables for better health, many may not also recognise that higher intakes of core grain foods (mostly whole grain and high fibre) and legumes can be an effective strategy for preventing and managing chronic disease as well as for promoting longevity. With older Australians’ intakes of core grains and legumes falling below recommended intakes, many are missing out on the benefits these foods offer for healthy ageing.

How can grains and legumes benefit older Australians?
With older Australians experiencing the highest incidence of diet related chronic diseases – including heart disease, type 2 diabetes, obesity and cancers, such as bowel cancer – understanding the most powerful dietary strategies to reduce the risk of such diseases can help older Australians to make the best choices for themselves.

While many are aware that plant based foods offer the greatest protection against diet related diseases, it may come as a surprise that a recent comprehensive review, the first of its kind which included a pooled analysis of over 300 meta-analyses and systematic reviews, found that whole grain/high fibre grain foods appear to offer the greatest protection against diet related disease out of all plant based foods.(1) This is not the first study to highlight the potential that whole grain and high fibre foods can play against diet related diseases, as evidence based dietary guidelines from around the world widely recommend a balanced diet, with core grain foods (mostly whole grain and high fibre) and legumes being key components in such recommendations. (2-8)

At the recent Oldways “Finding Common Ground” Conference, a team of leading nutrition experts from a range of dietary research backgrounds reached a consensus on the fundamental principles of healthy eating. According to the OldwaysCommon Ground Consensus Statement, a healthy dietary pattern is one that is high in plant based foods such as whole grains and legumes, along with fruits, vegetables and nuts.(9) As part of this dietary pattern, grains and legumes represent a rich source of nutrients such as fibre, folate, thiamine, iron, magnesium and iodine(10) as well as protective components like phytonutrients that are important for wellbeing over the lifespan.

Not surprisingly, the benefits of incorporating grains and legumes into your diet extend beyond simply reducing the risk of disease but also help to promote longevity. A study from Harvard researchers found that people with the highest whole grain intakes had a 17% lower risk of death from all causes and an 11–48% lower risk of disease-specific mortality compared to people with the lowest intakes of whole grain.(11) Meanwhile, the role of legumes in contributing to a long life has been observed in the diets of long-lived cultures such as the Japanese, who regularly eat soy foods such as tofu, natto, and miso, and people from the Mediterranean, where lentils, chickpeas, and white beans are important components of the traditional diet.(12)

Despite these benefits, older Australians do not appear to be achieving recommendations. The GLNC 2014 Consumption Study found that on average, both men and women aged 51-70 years fell short of the daily core grain serves recommended by the Australian Dietary Guidelines and they also fell short of their 48g whole grain Daily Target Intake. Worryingly, the study also found that only 25% of 51-70 year old Australians overall reported legume consumption on one or both days of the survey. This suggests that older Australians are at risk of missing out on key nutrients important for good health and longevity.

Cultivating good health with grains and legumes
Making just a few small changes can make a big difference to the health of older Australians – eating 2-3 serves of whole grains daily can reduce the risk of developing chronic disease by 20-30%,(13) whilst just a 20g increase in daily legume intake can reduce the risk of death by 7-8%.(14) GLNC recommends that all Australians, including older men and women, enjoy grain foods 3-4 times a day, choosing at least half as whole grain or high fibre, and also aim to enjoy legumes at least 2-3 times each week.

Overall, making healthy choices with core grains and legumes as a priority in your diet is important to leading a long and healthy life. Simple changes older Australians could make to improve their grain and legumes choices toward meeting recommendations include:
  • Choosing whole grain crispbreads, unsalted air-popped popcorn, or wholemeal fruit toast as snacks over discretionary choices such as sweet biscuits, cakes or muffins
  • Adding barley, brown rice or other whole grains to soups, stews and casseroles
  • Swapping pastries and pies for a sandwich, made with whole grain or high fibre bread, at lunch
  •  Looking for breakfast cereals that are high in whole grain or fibre
  • Substituting serves of legumes into your favourite dishes such as kidney beans in casseroles, red lentils in spaghetti bolognaise or chickpeas into any salad.

For more information on the impact of grain and legumes on health and for lots of tasty recipe ideas visit GLNC’s website.

1.            Fardet A, Boirie Y. Associations between food and beverage groups and major diet-related chronic diseases: an exhaustive review of pooled/meta-analyses and systematic reviews. Nutrition Reviews. 2014 Dec;72(12):741-62.
2.            Mellen PB, Walsh TF, Herrington DM. Whole grain intake and cardiovascular disease: a meta-analysis. Nutrition, metabolism, and cardiovascular diseases. NMCD. 2008;18(4):283-90.
3.            NHMRC. Australian Dietary Guidelines - Providing the scientific evidence for healthier Australian diets. 2013. Accessed online January 2014.
4.            Priebe MG, van Binsbergen JJ, de Vos R, Vonk RJ. Whole grain foods for the prevention of type 2 diabetes mellitus. The Cochrane Database of Systematic Reviews.2008(1):Cd006061.
5.            Aune D NT, Romundstad P, Vatten LJ. Whole grain and refined grain consumption and the risk of type 2 diabetes: a systematic review and dose-response meta-analysis of cohort studies. European Journal of Epidemiology. 2013;28(11):845-58.
6.            Kushi LH, Meyer KA, Jacobs DR J. Cereals, legumes, and chronic disease risk reduction: evidence from epidemiologic studies. The American Journal of Clinical Nutrition. 1999;70(3 Suppl):451s-8s.
7.            Afshin A, Micha R, Khatibzadeh S, D M. Consumption of nuts and legumes and risk of incident ischemic heart disease, stroke, and diabetes: a systematic review and meta-analysis. The American Journal of Clinical Nutrition. 2014 Jul;100(1):278-88.
8.            Food and Agriculture Organization of the United Nations. Food-based dietary guidelines [cited 2016 January]. Available from: http://www.fao.org/nutrition/education/food-dietary-guidelines/regions/en/.
9.            Oldways. Oldways Common Ground Consensus Statement on Healthy Eating [cited 2016 January]. Available from: http://oldwayspt.org/common-ground-consensus.
10.          Australian Bureau of Statistics. Australian Health Survey: Nutrition First Results - Food and Nutrients, 2011-12. Canberra: Commonwealth of Australia; 2014.
11.          Tao Huang MX, Albert Lee, Susan Cho, Lu Qiu. Consumption of whole grains and cereal fiber and total and cause-specific mortality: prospective analysis of 367,442 individuals. BMC Med. 2015;13(59).
12.          WHO. Life expectancy: Life expectancy by country [cited 2013 July]. Available from: http://apps.who.int/gho/data/node.main.688?lang=en.
13.          GLNC. The Grains & Legumes Health Report. Grains & Legumes Nutrition Council: 2010.

14.          Darmadi-Blackberry I, Wahlqvist ML, Kouris-Blazos A, Steen B, Lukito W, Horie Y, et al. Legumes: the most important dietary predictor of survival in older people of different ethnicities. Asia Pacific Journal of Clinical Nutrition. 2004;13(2):217-20.

Update On Carbohydrate Recommendations for Type 2 Diabetes

Some people are calling for low-carbohydrate diets to be recommended for people with diabetes but what does the evidence show? Dr Alan Barclay APD, GI Foundation Chief Scientific Officer, looks at the issue.

Type 2 diabetes is increasing rapidly around the globe, due to a large number of factors including our ageing population, decreased physical activity and changes to the foods we eat and drink, amongst many others. While all factors are undoubtedly important, food and nutrition seem to gain a disproportionate amount of attention and generate the most debate. Hardly a week goes by without a new “diet” that self-proclaims it will help people prevent or manage their diabetes better than all preceding diets. Food faddism not only creates confusion and angst for people with diabetes, it also inadvertently affects their families, friends and carers who they share their food with. Low carbohydrate diets are becoming the latest fad, having last been popular in the 1970’s.

To help put healthy eating into perspective, the American Diabetes Association(1) has crafted a number of food and nutrition management goals that summarise all of the main points that need to be considered about healthy eating for diabetes:

1) Achieve and maintain
* Blood glucose levels in the recommended range or as close to recommended as is safely possible
* Blood pressure levels in the recommended range or as close to recommended as is safely possible
* A blood cholesterol and triglyceride profile that reduces the risk of vascular (e.g., heart attack, stroke, retinopathy, kidney and peripheral vascular) diseases

2) Prevent, or at least slow, the rate of development of the chronic complications of diabetes by modifying food and nutrient intakes and lifestyle (e.g., physical activity, drinking, sleep, smoking habits, etc…)

3) Consider individual nutrition needs, taking into account personal and cultural preferences and willingness to make changes

4) Maintain the pleasure of eating by only limiting food choices when indicated by scientific evidence

While points 1 and 2 are self-evident and the focus of most health professionals that work with people with diabetes, points 3 and 4 are arguably just as important, as ultimately they determine how well an individual will be adhere to a dietary regimen in the long-term.

What scientific evidence is there for recommending low carbohydrate diets over other dietary patterns? To answer this, we first need to define what a low carbohydrate diet is. The following definitions have recently been recommended(2):
  • Very low-carbohydrate diets provide 20-50 g/carbohydrate/day or less than 10% of a 8,400 kJ diet.
  •  Low-carbohydrate diets provide less than 130 g/carbohydrate/day or less than 26% of energy from a 8,400 kJ diet.
  • Moderate-carbohydrate diets provide 130-230 g/carbohydrate/day, or 26 - 45% of energy from a 8,400 kJ diet. 
  • High-carbohydrate diets provide greater than 230 g/carbohydrate/day or 45% of energy from a 8,400 kJ diet.
It is also important to consider how much carbohydrate the average Australian, and person with diabetes, is eating at present. The most recent national nutrition survey(3) estimates that the average adult consumed 222 g/carbohydrate/day in 2011/12, and the most recent study of people with diabetes(4) estimates that they consumed 214 g/carbohydrate/day in the 1990’s. In other words, the average Australian consumes a moderate amount of carbohydrate, and it’s likely that people with diabetes consume less.

The American Diabetes Association(1), Canadian Diabetes Association(5) and Diabetes UK(6) have all recently conducted independent systematic reviews of the scientific evidence for the management of diabetes and are all in agreement that there is no evidence for strict macronutrient recommendations for people with diabetes. Instead, there are a variety of healthy eating patterns that may be suitable, based on the individual’s personal and cultural preferences and willingness to change. These may include, but are not limited to Mediterranean style, vegetarian/vegan, low-fat and low-carbohydrate patterns of eating(1).

Systematic reviews and meta-analyses(7) have shown that over the medium-term, all of these different patterns of eating can lead to decreases in HbA1c between 0.12-0.47% points, with low-carbohydrate diets being the least effective (0.12% reduction) and Mediterranean style (0.47% reduction) and vegetarian (0.39% reduction)(8) being the most effective. Unfortunately no long-term (> 2 years) studies have been published to-date.

Since these systematic reviews were conducted, Australia’s CSIRO investigated the effect of a very low-carbohydrate (50 g / day), high fibre (24.7 g / day) and low saturated fat diet versus a moderate carbohydrate (205 g / day), low GI diet in people with diabetes over 12 months(9). Both patterns achieved similar decreases in body weight (~10 kg), BMI (~3.3 kg/m2), waist circumference (~9.5 cm), fasting glucose (-0.7 (low carb) vs -1.5, P=0.1), HbA1c (-1% in both), BP, total and LDL cholesterol. Medication score, glycemic variability, HDL (0.1 vs 0.06 mmol/L) and TG (-0.4 vs -0.01 mmol/L) improved modestly on the very low CHO diet compared to the moderate carbohydrate diet. These results would therefore not materially affect the conclusions of the earlier systematic reviews.

Dietary patterns with widely differing carbohydrate composition may produce similar outcomes due to differences in glycemic index (GI), glycemic load (GL) and insulin responses. It’s important to note that while the amount and type of carbohydrate are the most powerful predictors of the effect of foods on blood glucose(10) and insulin levels(11), protein and fat also have an independent effect(12;13).

Glycemic index values are frequently found on the labels of carbohydrate-containing foods in Australia (e.g. foods with the GI Symbol (see below) and online and total carbohydrate is a mandatory component of the Nutrition Information panel, so people with diabetes can easily calculate the glycemic load (GL = GI Í Carbohydrate per serve ÷ 100) of commonly consumed foods and beverages.

The best way to use the GI is to swap from regular high GI to low GI alternatives within a food group, and this approach also typically identifies the lower GL choices. The insulin response of a food is highly correlated with its glycemic load(14) and for common foods and meals may be used as a surrogate at present. Table 1 lists commonly consumed low GI foods in Australia.

Table 1: Low GI foods
Dense wholegrain bread
Authentic sourdough bread
Pasta and noodles
Pearl cous cous
Doongara rice
Traditional oats
Natural muesli
Most fruits and vegies (except melons and most potatoes)

Reducing the amount of carbohydrate is therefore simply one method of reducing blood glucose and insulin levels, but it is not the only way, nor necessarily the best way – that depends on the individual. Every person with diabetes should see an Accredited Practicing Dietitian for personalised advice.

1.               Evert AB, Boucher JL, Cypress M, Dunbar SA, Franz MJ, Mayer-Davis EJ, et al. Nutrition therapy recommendations for the management of adults with diabetes. Diabetes Care 2014 Jan;37 Suppl 1:S120-43. doi: 10.2337/dc14-S120.:S120-S143.
2.               Feinman RD, Pogozelski WK, Astrup A, Bernstein RK, Fine EJ, Westman EC, et al. Dietary carbohydrate restriction as the first approach in diabetes management: critical review and evidence base. Nutrition 2015 Jan;31(1):1-13.
3.               Australian Bureau of Statistics. Australian Health Survey: Nutrition First Results – Foods and Nutrients, 2011–12 — Australia.  9-5-2014. Canberra, Australia, Australian Bureau of Statistics.
4.               Barclay AW, Brand-Miller JC, Mitchell P. Macronutrient intake, glycaemic index and glycaemic load of older Australian subjects with and without diabetes: baseline data from the Blue Mountains Eye study. Br J Nutr 2006 Jul;96(1):117-23.
5.               Canadian Diabetes Association Clinical Guidelines Expert Committee. Canadian Diabetes Association 2003 clinical practice guidelines for the prevention and management of diabetes in Canada. Canadian Journal of Diabetes 2003;27(Suppl 2):S1-S152.
6.               Diabetes UK. Evidence-Based Nutrition Guidelines for the prevention and management of diabetes. 2011.
7.               Ajala O, English P, Pinkney J. Systematic review and meta-analysis of different dietary approaches to the management of type 2 diabetes. Am J Clin Nutr 2013 Mar;97(3):505-16.
8.               Yokoyama Y, Barnard ND, Levin SM, Watanabe M. Vegetarian diets and glycemic control in diabetes: a systematic review and meta-analysis. Cardiovasc Diagn Ther 2014 Oct;4(5):373-82.
9.               Tay J, Luscombe-Marsh ND, Thompson CH, Noakes M, Buckley JD, Wittert GA, et al. Comparison of low- and high-carbohydrate diets for type 2 diabetes management: a randomized trial. Am J Clin Nutr 2015 Oct;102(4):780-90.
10.           Wolever TM, Bolognesi C. Prediction of glucose and insulin responses of normal subjects after consuming mixed meals varying in energy, protein, fat, carbohydrate and glycemic index. J Nutr 1996 Nov;126(11):2807-12.
11.           Bao J, Atkinson F, Petocz P, Willett WC, Brand-Miller JC. Prediction of postprandial glycemia and insulinemia in lean, young, healthy adults: glycemic load compared with carbohydrate content alone. Am J Clin Nutr 2011 May;93(5):984-96.
12.           Pal S, Ellis V. The acute effects of four protein meals on insulin, glucose, appetite and energy intake in lean men. Br J Nutr 2010 Oct;104(8):1241-8.
13.           Wolpert HA, Atakov-Castillo A, Smith SA, Steil GM. Dietary fat acutely increases glucose concentrations and insulin requirements in patients with type 1 diabetes: implications for carbohydrate-based bolus dose calculation and intensive diabetes management. Diabetes Care 2013 Apr;36(4):810-6.
14.   Bao J, de J, V, Atkinson F, Petocz P, Brand-Miller JC. Food insulin index: physiologic basis for predicting insulin demand evoked by composite meals. Am J Clin Nutr 2009 Oct;90(4):986-92.