GI News - January 2020

GI News is published online every month by the University of Sydney, School of Life and Environmental Sciences and the Charles Perkins Centre, and delivered to the mailboxes of our 97,000 subscribers. Our goal is to help people choose the high-quality carbs that are digested at a rate that our bodies can comfortably accommodate and to share the latest scientific findings on food and diet with a particular focus on carbohydrates, dietary fibres, blood glucose and the glycemic index.

Publisher: Professor Jennie Brand-Miller, AM, PhD, FAIFST, FNSA
Editor: Philippa Sandall
Scientific Editor/Managing Editor: Alan Barclay, PhD, APD, AN
Contact GI News: glycemic.index@gmail.com

Sydney University Glycemic Index Research Service
Manager: Fiona Atkinson, PhD, APD, AN
Contact: sugirs.manager@sydney.edu.au

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FOOD FOR THOUGHT

MEATY MATTERS 
Dietitian Nicole Senior ponders finding health in the happy medium Eating meat kick-started the evolution of modern big-brained humans. But we can actually live long and healthy lives without eating it, and many millions do. However, it’s a highly nutritious food that provides us with essential nutrients more difficult to obtain from plant foods.


Source: Reversing Diabetes (Murdoch Books)

Red meat, for example, is rich in iron necessary for healthy blood, zinc for immunity and vitamin B12 for healthy DNA and cell division. Sure, there are vegetarians who thrive on a meatless diet, but there are also those who don’t and take nutrient supplements to make up the shortfall. In some poor countries, where people cannot afford to eat meat, iron-deficiency anaemia is one of the most common childhood diseases. But meat poses ethical questions around the environment – red meat has the highest environmental footprint – and animal welfare.

While it’s true livestock contribute to environmental problems, the environmental argument against meat has been infused with emotion and ideology as to whether we should eat meat at all. Veganism is rising, with the extremists in the movement taking a militant approach going so far as trespassing on farms and causing damage.

The picture has also been muddied by the rampantly excessive consumption of meat in some rich countries and the environmentally damaging effects of factory farming, the vast scale of commercialised livestock production where animals become a unit in a production line, and the scandals in Australia over the cruel export and slaughter methods of live cattle and sheep, and more recently what happens to race horses that have passed their use-by date (in our book). For many people the way we treat farm animals is no longer acceptable and higher moral standards are being demanded.

In a way, meat offers nutritional insurance for reckless eating and incompetent cooking whereas plant-based eating requires a new diligence both for nutritional balance and enjoyment. The degree of difficulty of a meatless diet is much higher than an omnivorous diet. Maybe rather than blindly following all the vegan marketing hype (not all vegan products are healthy), we just need to be more mindful of our diet generally? For example, reducing the amount of nutrient-poor, highly processed foods we eat, learning to grow and cook our own food, only buying what we can eat, and not throwing food in the bin (which wastes the resources that went in to producing it and produces greenhouse gases in landfill).

The question of how much meat we can get away with eating and still look after our health and the environment is hotly debated and depends on a myriad of factors including: location/region, climate, production method, land and water use, feed type, animal genetics, waste management, supply chain efficiency, transport and wastage.

The EAT-Lancet Commission on Food, Planet, Diet and Health report published in February 2019 took a global approach that aimed to incorporate nutritional needs and environmental limits needs with a Planetary Health Diet. It is a plant-based diet with 14g a day of beef/lamb/pork (98g/week) with a range of 0–28g/day, 29g poultry per day (203g/week), 28g of fish per day (196g/week) and 13g of egg per day (about 2 eggs/week). This report has drawn both congratulations and criticism in equal measure. The harshest criticism has been directed at the very small amounts of meat, which are less than previously proposed for environmental sustainability and less than currently recommended in dietary guidelines. We shall wait to see how the rest of the world takes on their recommendations.

While high intensity factory farming such as feed lot cattle is seen as unacceptable to most on both environmental and ethical grounds, the agricultural story around meat production isn’t all bad. In Australia, for example, most cattle and sheep are grass-fed on marginal land unsuitable for crops. Integrated farming is a better and more sustainable way forward and this approach involves mixing animal and plants on the same farm to allow for maximum output through nutrient cycling and minimal pollution.

It is unrealistic to think we will all stop eating meat to save the environment or to “be kind” to animals, however, we can produce meat in a much more sustainable and ethical way, and we can eat less meat to minimise our environmental impact. There’s no need to banish meat from your dinner plate – just cut back so it’s a tasty side show rather than the main event. We as citizen-eaters can help by eating animals “nose-to-tail” (not just our favourite bits) and not wasting any because throwing animal foods in the bin just adds insult to injury (it wastes the already significant environmental costs in producing it).

Australian ex-food-critic-turned-farmer, TV presenter and author Matthew Evans says we will need to pay more for meat that meets our higher moral expectations, “The simplest way to better impact the animals, the land, the farmer, is to perhaps eat meat less often, but spend more on it.” And remember eating less red meat is easy because there is (sustainably sourced) fish, chicken and pork with smaller environmental footprints as well as good plant sources of protein that we should be eating more of. This dietary strategy when taken on by the population will send a message to producers that they can use less intensive, kinder and more sustainable methods to produce animal foods, and can ramp up sustainable plant food production to meet demand.

My takeout message is this – meat is nutritionally important, but we in rich countries should eat less; and only our fair share. We need to focus on farming animals (and crops) more sustainably and with minimal environmental impact.

Avowed carnivores and vegans are dietary extremes while health is so often found in the happy medium. If we ate according to health guidelines, both our own health and the health of the planet and all the people living on it could be improved!

Read More:

• EAT-Lancet Commission on Food, Planet, Diet and Health 
• Matthew Evans: Going meat free will not prevent animal suffering 
• On Eating Meat, Matthew Evans (Murdoch Books)

WHAT’S NEW?

A RED MEAT ISSUE FLAMES UP 
Five – yes, five – papers in the Annals of Internal Medicine published in October 2019 whipped up a flaming hot controversy about nutrition guidance broadly and red meat specifically reports ConscienHealth’s Ted Kyle. The bottom line from all these papers? Maybe we need to admit that the evidence for harm to health from red meat is not so hard and fast as some people like to think.


Using GRADE criteria, the certainty about the effects of red meat on health is low. Thus, recommendations to eat less red meat for better health are weak. In other words, there are indeed different and valid ways to look at the issue of red meat in the diet.

Harvard’s Frank Hu doesn’t like applying GRADE standards to nutrition advice. “It’s really problematic and inappropriate to use GRADE to evaluate nutrition studies,” he says. One big problem he has with the GRADE system is that it takes randomized, controlled studies to be the gold standard of evidence. Observational data provides weaker evidence. Such thinking is OK for evaluating drugs. But he wrote in 2015 that the standard should be different for nutritional epidemiology: “Some researchers consider RCTs as the be-all and end-all of causal inference. This sentiment may be appropriate in the pharmaceutical industry, but the drug trial paradigm cannot be readily translated for use in the nutritional sciences.”

However, it’s worth saying that standards for scientific rigor were not invented by the pharmaceutical industry. The lead on one of these five papers, Bradley Johnston, explains: “Regarding the reaction among some in the nutrition research community … we are sympathetic to the discomfort of acknowledging the low-quality evidence in one’s field. It seems to us, however, that pretending that the rules of evidence differ across fields because the feasibility of definitive studies is not possible in one’s particular field is a poor solution to the problem. We believe it is important to apply common standards for assessing the certainty of evidence across health-care fields.”

So, what are we to think about red meat? The evidence to say that we’re eating more red meat than we should for our own health is weak. However, we do have other reasons to believe that eating less red meat would be a good thing. Red meat is pretty hard on this planet we share. A little red meat probably won’t kill you. But too much of it might indirectly contribute to killing lots of people through climate change.

Regardless of those facts, opinions and feelings will drive behaviour. Some people are really attached to the red meat in their diets. Others have strong passions for avoiding it.

It’s not easy to be objective about nutrition, but it’s worth a try. Dennis Bier explained this to the New York Times: “The rules of scientific proof are the same for physics as for nutrition.”

Read more:

• ConscienHealth News 
• Click here, here, here, here, and here for these five papers 
• For further reporting, click here, here, here, and here

PRODUCT REVIEW

4 RED MEATS 
Nutritious red meats are valuable for their protein, iron, zinc and vitamin B12. In Product Review, we check out how four of these meats provide the key nutrients per serving so you can compare farmed animals with game. We follow the Australian Dietary Guidelines for servings – a serving of red meat is 65g cooked meat or 100g (3½oz) raw meat.


Fillet steak, lean, raw 
Serving: 100g/3½oz
570kJ/ 136 calories; 22 g protein; 5g fat (includes 2g saturated fat; saturated : unsaturated fat ratio 0.7); 57mg sodium; 380mg potassium; sodium : potassium ratio 0.2; 2.2mg iron; 3.8mg zinc; 1.9ug vitamin B12.

Lamb tenderloin (fillet), lean, raw 
Serving: 100g/3½oz
485kJ/ 116 calories; 20g protein; 4g fat (includes 1.5g saturated fat, saturated : unsaturated fat ratio 0.6); 70mg sodium; 370mg potassium; sodium : potassium ratio 0.2; 2.1mg iron; 2.9mg zinc; 1.3ug vitamin B12.

Venison, lean, raw 
Serving: 100g/3½oz
415kJ/ 100 calories; 22g protein; 1.1g fat (includes 0.5g saturated fat, saturated : unsaturated fat ratio 0.8); 58mg sodium; 380mg potassium; sodium : potassium ratio 0.2; 3.1mg iron; 4.4mg zinc; 1.6ug vitamin B12.

Kangaroo, lean, raw 
Serving: 100g/3½oz
400kJ/ 95 calories; 21g protein; 1g fat (includes 0.3g saturated, saturated : unsaturated fat ratio 0.4); 40mg sodium; 350mg potassium; sodium : potassium ratio 0.1; 3.4mg iron; 2.3mg zinc; 1.9ug vitamin B12.

PERSPECTIVES WITH DR ALAN BARCLAY

Kidneys, kidney disease and protein 
Most people have two bean-shaped kidneys, each about the size of a clenched fist, in the rear left and right sides of their torso, just below their ribs. They have many essential functions (e.g., regulating blood pressure, producing hormones and activating vitamin D), but most importantly they filter our blood and remove excess body fluids and wastes for elimination in the urine. They are able to balance out body fluid, electrolyte (salts) and acid (pH) levels so that all of our organs function optimally, despite our consumption of a variety of fluids from foods and beverages, and fluid losses from physical activity and sweating. Here’s how they do it.


NORMAL KIDNEY FUNCTION
Blood flows from the aorta (the main blood vessel from the heart) into the kidneys via the renal artery. Within the kidney, the parts that filter the blood are called nephrons. Within each nephron is a glomerulus, a bulb-like capsule which contains tiny blood vessels that look a bit like a loosely wound ball of wool.

When the kidney is functioning normally, these tiny blood vessels have a large number of fine holes. They work a bit like sieves, allowing water, some salts (e.g., sodium, potassium, calcium, phosphorus) and waste products to pass through, but they are too small to allow red and white blood cells, and most blood proteins, to leak out. The exact composition of the filtered fluids (filtrate) depends on the body’s requirements for essential minerals like sodium and potassium, the acid-base balance (pH), and concentration of wastes from general metabolism.

Eventually, the filtrate from each nephron flows together and enters collecting ducts within the kidney, where the concentration of the final urine product is determined. The urine then travels through the ureters to the urinary bladder for temporary storage before voluntary urination.

Kidney function is evaluated based on the glomerular filtration rate (the rate at which the kidneys form filtrate) and the amount of the protein albumin lost in the urine. In health, glomerular filtration rates are greater than 90mL/minute, and there is essentially no albumin in the urine.

KIDNEY DISEASES
Nephrotic syndrome occurs when the glomeruli are damaged, increasing the size of the filtration holes, and therefore decreasing their ability to prevent proteins (e.g., albumin, lipoproteins, clotting factors and immunoglobulins) from escaping into the urine. The loss of these proteins can lead to serious health problems including oedema, high cholesterol levels, blood clotting and immune issues. Nephrotic syndrome can be caused by infections, immune disorders, chemical damage (from medications or illicit drugs), or poorly managed diabetes.

Chronic kidney disease is characterised by gradual, irreversible deterioration of the nephrons. Because we have a lot of nephrons, chronic kidney disease develops over many years without causing any symptoms. People are therefore often diagnosed late in the course of the illness, after most kidney function has been lost. Like the nephrotic syndrome, damage to the blood vessels in the nephrons leads to excessive loss of proteins in the urine, which can lead to serious health problems including oedema, high cholesterol, blood clotting and immune issues. Additionally, the nephrons lose their ability to maintain electrolyte (e.g., sodium and potassium) levels, acid-base balance (e.g., uric acid and phosphorus levels) and uraemia (the level of urea – the waste product of protein metabolism – in the blood). The more common causes of chronic kidney disease include diabetes and hypertension (chronically high blood pressure).

PROTEIN AND KIDNEY FUNCTION
The Recommended Dietary Intake (RDI) of protein for women is 0.75 g per kg body weight, and for men it is 0.84g per kg. High protein diets provide more than 1.2g per kg body weight and lower protein diets less than 0.6 g per kg body weight.

Unlike carbohydrate which is stored as glycogen in our muscles and liver, and fat which is stored as triglycerides in our fat cells, we have a limited capacity to store protein. If we eat more protein than our body’s require, some of it can be converted to glucose in the process of gluconeogenesis (see July 2019 edition of GI News). The metabolic process of converting proteins (or more specifically amino acids – the building blocks of proteins) to glucose leads to the production of ammonia, which in turn is converted to urea and excreted in the urine.

HIGH PROTEIN DIETS AND KIDNEY FUNCTION
High protein diets increase glomerular filtration rates, which increases the pressure within the glomerulus and may cause damage in susceptible people. High protein diets also increase urea production. On the other hand, lower protein diets decrease the pressure within the glomerulus and produce less urea.

The highest quality evidence available to date suggests that high protein diets do not have a negative effect on the glomerulus in people with healthy kidneys as the glomerulus is able to cope with the increased pressure and higher urea content.

However, in people with nephropathy/chronic kidney disease, the increased glomerular pressure caused by a high protein diet may lead to increased protein (e.g., albumin) loss in the urine and consequently increase the rate of progression of kidney disease. Therefore, a lower protein diet of 0.6–0.8 per kg body weight is generally recommended to people with existing nephropathy/chronic kidney disease. The problem is, chronic kidney disease develops over many years without causing any symptoms, so some high-risk people (e.g., people with diabetes) may have the condition but not know it.

Finally, for people with nephropathy/chronic kidney disease, approximately half of the proteins should come from plant sources (e.g., beans, lentils, chickpeas, etc...), as there is some evidence that they place less stress on the kidneys than animal sources.

Read more:

• PROTEIN QandA: OUR EXPERTS ANSWER YOUR QUESTIONS 
• Nutrient Reference Values: Protein 
• High-protein diet is bad for kidney health: unleashing the taboo 
• Changes in Kidney Function Do Not Differ between Healthy Adults Consuming Higher- Compared with Lower- or Normal-Protein Diets: A Systematic Review and Meta-Analysis. 
• Efficacy of low-protein diet in diabetic nephropathy: a meta-analysis of randomized controlled trials 
• Effect of whole soy and purified isoflavone daidzein on renal function--a 6-month randomized controlled trial in equol-producing postmenopausal women with prehypertension.

Alan Barclay, PhD is a consultant dietitian and chef (Cert III). He worked for Diabetes Australia (NSW) from 1998–2014 . He is author/co-author of more than 30 scientific publications, and author/co-author of  The good Carbs Cookbook (Murdoch Books), Reversing Diabetes (Murdoch Books), The Low GI Diet: Managing Type 2 Diabetes (Hachette Australia) and The Ultimate Guide to Sugars and Sweeteners (The Experiment, New York).

Contact: You can follow him on Twitter or check out his website.

GOOD CARBS FOOD FACTS

BULGUR 
Making wheat into bulgur (also spelled bulgar, bulghur, burghul and bourghul) has been an integral part of Middle Eastern cuisine for thousands of years. These days, you can still see villagers preparing it the traditional way: boiling the wheat in huge pots, spreading the cooked berries or groats over flat roof tops to dry, then cracking the hardened kernels into coarse pieces and sieving them into different sizes. Don’t confuse it with cracked wheat, which is simply that, and can take up to an hour to cook.


This versatile, nutty-tasting, wholegrain is available in supermarkets, natural/organic health food stores and Middle Eastern produce stores. If you are lucky, you’ll have a choice of grades – fine (#1), medium (#2), coarse (#3), and very coarse (#4). You can make pilafs with medium, coarse, and very coarse bulgur. Tabbouleh and kibbe are best made with fine bulgur. As it’s been parboiled, it needs little cooking and, in most cases, nothing more than a good soak in hot water. Check out the manufacturer’s instructions.


Sources: AusFoods, 2019 and The Good Carbs Cookbook (Murdoch Books)

THE GOOD CARBS KITCHEN

LAMB, FETTA AND BULGUR MEATBALLS 
0:25 Prep • 0:45 Cook • 6 Servings • Family fare


INGREDIENTS 
500g (1lb 2oz) lean minced (ground) beef
1 large onion, finely chopped
⅔ cup (90g/3oz) crumbled fetta
2 tablespoons chopped mint
1 teaspoon ground cinnamon
1 cup (175g/6oz) fine bulgur
2 garlic cloves, crushed salt flakes and freshly ground pepper
¼ cup olive oil
Extra 3 large onions, thinly sliced 400g (14oz) can chopped tomatoes
1 cup water

METHOD 
Put the mince, chopped onion, fetta, mint, cinnamon, bulgur, and half the garlic in a bowl with salt and pepper to taste. Clump the mixture together with your hands to mix well and then cover and set aside for 1 hour. Scoop the mixture and shape into small rounds about the size of golf balls.

Heat the olive oil in a deep non-stick pan and then add the sliced onion and cook for about 7 minutes or until the onions are soft but not coloured. Stir in the remaining garlic and cook for a further 1 minute. Add the tomatoes including the juice, with the water and salt and pepper to taste. Bring the mixture to a gentle simmer and then place the meatballs evenly on top. Pour in enough water to come about two-thirds of the way up the contents of the pan. Cover the pan, reduce the heat and gently simmer for about 35 minutes or until the meatballs are tender and cooked.

NUTRITION 
Per serve 1650kJ/ 395 calories; 26g protein; 21g fat (includes 7g saturated fat; saturated : unsaturated fat ratio 0.5); 23.5g available carbs (includes 5g sugars and 18.5g starch); 6g fibre; 295mg sodium; 610mg potassium; sodium : potassium ratio 0.5

RECIPE  
The Good Carbs Cookbook, Murdoch Books.


ROSEMARY LAMB AND VEGETABLE KEBABS WITH LEMON CRACKED WHEAT
0:30 (+ 2 hours marinating and 15 minutes cooling) Prep • 0:30 Cook • 4 Servings • Family fare • Barbecue


INGREDIENTS
12 rosemary stems
1½ tablespoons olive oil
2 garlic cloves, crushed
2 tablespoons lemon juice
½ teaspoon cracked black pepper
500g (1lb2oz) lean lamb, cut into 3cm (1¼in) cubes
250g (9oz) small button mushrooms
1 large yellow capsicum (pepper), cut into 3cm (1¼in) pieces
1 large red onion, cut into wedges
3 small zucchini (courgettes), thickly sliced
250g (9oz) cherry tomatoes lemon wedges, to serve

Lemon cracked wheat 
1 cup cracked wheat
2 tablespoons lemon juice
2 teaspoons grated lemon zest
2 spring onions (scallions) finely chopped
1 large handful parsley leaves, finely chopped

METHOD
Remove three-quarters of the leaves from the base of each rosemary stem. (If rosemary stems are unavailable, wooden or metal skewers can be used. Soak wooden skewers in water for 30 minutes before use to prevent them from burning during cooking.)

Finely chop one-third of the leaves, discarding the remaining leaves, and set the stems aside. Place the chopped rosemary, oil, garlic, lemon juice and pepper in a glass bowl and mix to combine. Add the lamb and stir to coat, then cover and refrigerate for 2 hours.

Meanwhile, to make the lemon cracked wheat, bring 1¼ cups water to the boil in a saucepan. Add the cracked wheat, reduce the heat and simmer for 15 minutes or until the liquid has been absorbed. Fluff the cracked wheat with a fork, then transfer to a bowl to cool for 15 minutes. Fold in the lemon juice, lemon zest, spring onions and parsley. Cover and refrigerate until needed.

Preheat a chargrill pan or barbecue plate to medium. Thread the lamb, mushrooms, capsicum, onion, zucchini and tomatoes onto the rosemary stems. Cook the kebabs, turning occasionally, for 8-10 minutes or until done to your liking. Serve the kebabs with the lemon cracked wheat and lemon wedges.

NUTRITION 
Per serve 2070kJ/ 395 calories; 37g protein; 16g fat (includes 4g saturated fat; saturated : unsaturated fat ratio 0.33); 43g available carbs (includes 7g sugars and 36g starch); 13g fibre; 100mg sodium; 1280mg potassium; sodium : potassium ratio 0.08

RECIPE
Reversing Diabetes, Murdoch Books.
 

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Nutritional analysis To analyse Australian foods, beverages, processed products and recipes, we use FoodWorks which contains the AusNut and Nuttab databases. If necessary, this is supplemented with data from www.calorieking.com.au or http://ndb.nal.usda.gov/ndb/search.

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