Low carb diets

Aoife Hanna Registered Dietitian

Aoife Hanna runs her own dietetic practice, EatRight Ireland. She sees clients for diabetes, weight management and IBS and is a member of the Irish Nutrition and Dietetic Institute. Aoife also sits on the Weight Management Interest Group Committee for the INDI.

For full article references please email info@ networkhealth group.co.uk

LOW CARB DIETS AND TYPE 1 DIABETES: SHOULD WE BE WARNING OUR PATIENTS?

Low carbohydrate diets are everywhere these days. You just can’t escape them, unless you switch off from all social media, TV, radio and never have a discussion about diet with anyone. Ever! So, it’s understandable that those with Type 1 diabetes are asking, “What about me? Am I ok to reduce my carbohydrate intake too?”

Prior to the development of injectable insulin, low carbohydrate diets were the cornerstone for the treatment of diabetes. Since its discovery and with more flexible insulin regimes, people are encouraged to adopt a more ‘regular’ diet. For many, this means eating regular meals throughout the day, with each meal containing roughly the same amount of carbohydrate.

Over the last number of years, carbohydrate counting, and adjusting insulin dosage accordingly, has become the gold standard dietary management for Type 1 diabetes. In fact, NICE guidelines recommend carbohydrate counting should be offered to all adults six to 12 months after diagnosis.¹ This approach allows people with diabetes much greater flexibility and control over their diet, thus improving their diabetic control. However, this approach, for some, still yields suboptimal control.

We know that some patients have ended up restricting the amount of carbohydrates they eat, since large carbohydrate intake and a subsequent large insulin dose, led to increased unpredictability in their blood glucose levels. Additionally, many patients also report that they found themselves stuck in a carbohydrate ‘rut’. They knew the amount of carbohydrates in certain foods, and the amount of insulin they needed for it, and as a result they adopted the “I’ll stick to what I know” principle. We also now know that, even if the person with diabetes estimated their carbohydrate intake correctly, insulin absorption rates can vary by up to as much as 30% in some.

In 2013, while working in New Zealand, a patient of mine asked me, “Am I ok to follow a low carbohydrate diet, even though I have Type 1 diabetes?” I was a practising Diabetes Dietitian within the hospital at the time, and I was at a loss. But then we thought, if we’re recommending insulin dose adjustments for carbohydrates that are consumed, surely we can dose adjust for carbohydrates that aren’t being consumed? And further still, with less carbohydrate coming in, the unpredictability in blood glucose levels would be less. Therefore, restricting carbohydrates may have the potential to further improve glucose control when one is carbohydrate counting.

WHO IS FOLOWING A LOW CARB DIET? I can say with certainty that any dietitian who has worked in the area of Type 1 diabetes has come across Dr Richard Bernstein, an 82-year-old American physician, who was diagnosed with Type 1 diabetes at the age of 12. He is probably the most famous advocate of low carbohydrate diets for the treatment of patients with both Type 1 and 2 diabetes. The author of six books on diabetes, his two most famous publications are Diabetes Diet and Diabetes Solution. His work is widely

published in numerous magazines and journals and, subsequently, he has received many awards for his contributions to the study of diabetes. Dr Bernstein adheres to a strict low carbohydrate diet, and has done so for years.²

Vinnie Santana, the fastest diabetic ironman athlete of all time, swears by Dr Bernstein’s low carbohydrate approach.³ However, it is worth noting that Vinnie wasn’t following this low carbohydrate diet when he achieved his record breaking time. He has been following Dr Bernstein’s advice (less than 30g carbohydrates per day) since 2012. Although he no longer competes professionally, in the early days of following this diet he found some of his training sessions exhausting. But, since increasing the amount of fat in his diet, Vinnie has been able to sustain a more vigorous and regular training regime. He reports, since reducing his carbohydrates, that his HbA1c has never been greater than 40mmol/mol.

Then there is Lewis Civin, a New Zealander who was diagnosed with diabetes at age 9. At age 38, he too completed an ironman event on a low carbohydrate, high fat diet under the guidance of his coach Stephen Farrell and Dr Bernstein’s book, Diabetes Solution. What’s interesting is Lewis discovered that, despite giving himself enough insulin to cover his carbohydrate intake, a large intake of protein would raise his blood glucose levels (BGL). To control this, he now keeps his protein intake to 30-40g per meal. Prior to beginning his low carbohydrate diet, he had a HbA1c of 53-64mmol/mol, but now reports a HbA1c of <42mmol/mol.4

WHAT ARE SOME OF THE POTENTIAL RISKS? Diabetic ketoacidosis (DKA) occurs when the level of ketones rise in the blood in conjunction with a low level of insulin and is potentially life threatening. Ketones are a by-product of fat breakdown and are used as fuel for the body.

Franziska Spritzler, a registered dietitian from the USA and an advocate for low carbohydrate diets and diabetes, explains that ‘nutritional ketosis’ is normal when following a low carbohydrate diet and can occur when people with Type 1 diabetes follow this diet. She reports that it should not be confused with DKA.4 Professor Grant Schofield of New Zealand, also publically supports the use of low carbohydrate diets in Type 1 diabetes. According to his research, there has been no published report of a Type 1 diabetic developing DKA on a carefully implemented low carbohydrate diet,5 thus suggesting that there is a low risk of people with Type 1 diabetes developing ketoacidosis if following a correctly managed low carbohydrate diet.

Another consideration is the long-term cardiovascular risk that a high fat, low carbohydrate diet might have on people with diabetes. Dr Troy Stapleton is an Australian radiologist, who at 41 years of age, developed Type 1 diabetes. Having received standard diabetes education, he found it frustratingly difficult to manage his BGL. He diligently undertook carbohydrate counting and adjusted his insulin levels accordingly, but suffered from a hypoglycaemic episode, on average, once a week. In an interview with Dr Norman Swan, on Australia’s ABC radio station

Another consideration is the long-term cardiovascular risk that a high fat, low carbohydrate diet might have on people with diabetes.

in August 2013, he discussed how oxidative stress on the endothelium of blood vessels, due to a spike in BGL, causes acceleration of atherosclerosis in people with diabetes. He also explained that every 1% of HbA1c (HbA1c as per DCCT) increase above 29mmol/mol increases the risk of myocardial infarction by 14% and risk of micro-vascular complications by 35-40%. Since following a low carbohydrate, high fat diet, Dr Stapleton’s BGL has gone from an average of 8.4mmol/l to 5.3mmol/l. His HbA1c at the time of the interview was 34mmol/mol. He also reports improved blood pressure, triglycerides, HDL and blood lipid profile since undertaking a low carbohydrate diet. He has gone from having a weekly hypoglycaemic episode, to about one a month. Dr Stapleton admits that the changeover from running off glucose to fat was challenging and he experienced symptoms of lightheadedness, headaches, lethargy and muscle aches, lasting for approximately four to six weeks. He reports now feeling “completely normal”.7

HAVE ANY TRIALS BEEN CONDUCTED? In Sweden in 2005, Nielsen, Jönsson and Ivarsson found that 48 people with Type 1 diabetes, who followed a daily carbohydrate intake of 75g for 12 months, had mean HbA1c reductions from 57mmol/mol to 46mmol/mol, and a subsequent reduction of symptomatic hypoglycaemic from 2.9 to 0.5 per week.8 After two years, 48% of the participants were still following this diet to some degree, suggesting that this diet can be adhered to long term. They have also maintained a HbA1c reduction compared to their original levels, which has lowered the risk of cardiovascular disease by approximately 40% accordingly. Additionally, the improvement seen in the total chol/HDL ratio at the two-year follow-up was estimated to reflect a 20% reduction in the risk of myocardial infarction.9

In New Zealand in 2014, a small pilot randomised control trial compared five people who undertook carbohydrate counting and advised to follow their standard diet, to five other people who also undertook carbohydrate counting, while being asked to follow a low carbohydrate diet. Those on the low carbohydrate diet were asked to restrict their carbohydrate intake to 5075g of carbohydrate daily.10 Unlike Nielsen’s trial, the participants failed to achieve this low level of carbohydrate intake and ate an average of 100g of carbohydrate daily, as they found the diet very difficult to stick to. They reported that they felt like they were “starving”, especially in the initials stages.¹¹ Similarly to that of Lewis Civin, some of the participants in this study found that the amount of insulin taken to cover the carbohydrate in their meals was inadequate, which is possibly caused by protein becoming a significant source of glucose owing to gluconeogenesis. So, if one was to consume larger quantities of protein when following a low carbohydrate diet, there may be a potential need for a carbohydrate and protein to insulin ratio to manage BGL.

This study showed that glycaemic control improved in both groups, but there was no statistical difference between either group. Total daily insulin dose reduced significantly in the low carbohydrate group, but, unlike in Sweden, glycaemic control, as measured by continuous glucose monitoring and HbA1c, did not improve.10

FINAL THOUGHTS This area of research is desperately lacking at present. As healthcare professionals, it is of paramount importance that we are equipped with scientifically sound, evidence-based guidelines to advise our patients on how to follow a low carbohydrate diet correctly and safely. The experiences of those involved in the trials discussed, Dr Bernstein, Dr Stapleton, Lewis Civin and Vinnie Santana, are only the tip of the iceberg, and I have no doubt that this topic will continue to be debated and explored over the next number of years.

UNIQUE PRODUCT

Per 200 ml

Kcal Protein

200

5.2g

AA/ DHA Fibre 0g

supporting infants with tolerance issues

POOR TOLERANCE CAN BE AN ISSUE IN INFANTS AND MAY LEAD TO DISCOMFORT AND FALTERING GROWTH.1-3 Infatrini Peptisorb – the first ready to use formula specially designed to meet the requirements of infants with tolerance issues. • With its unique formulation of 100% extensively hydrolysed whey protein4-6 and optimal balance of fats,7,8

Infatrini Peptisorb is designed to help aid absorption. • Infatrini Peptisorb is a nutritionally complete, high energy feed that optimises nutrient absorption and can support catch-up growth.9

References 1. Daveluy W et al. Clin Nutr 2005; 24: 48-54. 2. Daveluy W et al. J Pediatr Gastroenterol Nutr 2006; 43: 240-244. 3. Weckwerth JA. Nutr Clin Pract 2004 Oct; 19 (5): 496-503. 4. Billeaud C et al. Eur J Clin Nutr 1990; 44: 577-583. 5. Fried MD et al. J Pediatr 1992; 120: 569-572. 6. Brun AC et al. Clin Nutr Sept 2011; doi: 10.1016/j.clnu. 2011.07.009. 7. Bentley D et al. Paediatric Gastroenterology and Clinical Nutrition 2002, London, UK: Remedica Publishing. 8. Goulet O et al. J Pediatr Gastroenterol Nutr 2004; 38: 250-269. 9. Clarke SE et al. J Hum Nutr Diet 2007; 20: 329-339.

Infatrini Peptisorb is a Food for Special Medical Purposes for use under medical supervision, after full consideration of all the feeding options, including breastfeeding. Infatrini is a nutritionally complete, energy dense, ready to use feed for the dietary management of infants (from birth up to 18 months or 9kg in body weight) with faltering growth, or who have increased nutritional requirements and/or require fluid restriction.

Charlotte Stirling-Reed Registered Nutritionist

Charlotte is a Nutrition Consultant with a wealth of experience. She has worked on a variety of projects in many sectors including the NHS, Commercial Companies, Local Authorities and Charities. Her specialist areas are infant and child nutrition, nutrition communications and weight loss. www.srnutrition. co.uk

For full article references please email info@ networkhealth group.co.uk

FITTING A VEGAN DIET INTO THE CONTEXT OF ‘HEALTHY EATING’

In the last couple of years, veganism has become a food trend, hitting the mainstream as something of a new food fad. Whilst celebrities promote it for its health benefits, food ‘experts’ often tout it as a way to cure a seemingly infinite number of diseases.

In recent years, the popularity of vegan, vegetarian and plant-based diets has increased. The Vegan Society reports that there are three and half times as many vegans now as there were in 2006, making it the fastest growing lifestyle movement.1 They also define veganism as: ‘a plant-based diet avoiding all animal foods such as meat (including fish, shellfish and insects), dairy, eggs and honey.’1

The reasons why people take up a plant-based lifestyle include a mix of health, environmental, ethical and cultural factors.1 Food trends for 2015 and 2016 also highlight a growing public interest into where and how food is grown and produced: aside from plant-based eating, trends include sustainable diets, ‘clean eating’ and a desire for ‘natural’ ingredients.2 The actual health benefits of a vegan diet are, however, slightly harder to identify. As many of us working in the field of nutrition know, studying the diet we eat is both challenging and full of controversies.

Our knowledge on veganism is limited by its inconsistent definition by study authors; veganism is often lumped together with vegetarianism and other forms of plant-based eating. Additionally, the meticulousness with which an individual decides to follow a vegan diet and the extent of the period of veganism, may influence findings.3 Additionally, the small vegan population (just ~1% in the UK) makes studies requiring large sample sizes difficult to complete.1

RESEARCH AND GUIDELINES Research into veganism also has problems in the form of multiple confounding factors. The unavoidable fact is that when you’re cutting out all animal products (including poultry, dairy, fish, gelatine, etc.), you’re also likely to be cutting out much in the way of ‘processed’ and discretionary foods too. For example, vegans are more restricted in their intake of accessible food items such as sweets, cakes, chocolates, biscuits and many fast foods. It’s also impossible to disregard the fact that vegans may simply be more astute in terms of what they are putting into their mouths.3 Despite a slight lack in our knowledge around vegan diets, research does point to the fact that vegan, vegetarian and plant-based diets do have many health benefits.

However, for any diet or food trend that grows in popularity, nutritionists and dietitians need to have an understanding of its impact on the long-term health of individuals and, if necessary, what we can do to encourage these diets to fit in with our evidencebased healthy eating messages.

The UK Government’s 2016 healthy eating guidelines5 - the Eatwell Guide - saw a significant shift towards plantbased foods. This comes as a wealth of research points to the benefits of plantbased diets for our health and our environment. Findings from two large epidemiologic studies - The Adventist Health Study-27 and the EPIC-Oxford study8 - show that vegans typically have lower BMIs,9 lower blood cholesterol,10

lower risks of Type 2 diabetes,9 and possibly a lower risk of cancer.3,11,12,13 Another report suggests that a shift from western diets to a plant-based diet could reduce global mortality by 6-10%, while a vegan diet could help avoid 8.1 million global deaths by 2050.4 Supporting this data, large cohort studies have linked increased red and processed meat consumption with higher mortality rates,7 which led last year to the International Agency for Research on Cancer (IARC) labelling red and processed meat as ‘probable’ and ‘definite’ causes of cancer, respectively.6

The Vegan Society certainly agrees with these findings, truly believing in the diet’s disease protective qualities and highlighting research which shows that vegans have a diet higher in fibre, lower in saturated fats and with higher fruit and vegetable consumption.14,15 Set up in 1994, the Vegan Society is reportedly the world’s first vegan organisation and is responsible for promoting and supporting veganism for the general public. Indeed, they first coined the term ‘vegan’, being the start and end of the word ‘VEGetariAN’. The aim of the Vegan Society is to educate the public via the media, as well as helping, advising and supporting new and existing vegans. Interestingly, they also work to support vegans in hospital and prison settings - playing the role of advocacy officers and acting on behalf of vegan individuals to help them gain access to appropriate vegan foods. As well as their supportive roles, the Vegan Society works together with the British Dietetic Association and has recently appointed a dietitian to join their team.

So, how do we go about promoting a balanced, vegan diet? What can’t be ignored is that cutting out whole food groups can ultimately leave you deficient, unless you’re paying careful attention to what you’re eating each day. If you are planning well, it’s perfectly feasible to get all the nutrients your body needs on a vegan diet.16 Meat, for many people, is an important source of multiple nutrients, such as protein, iron, calcium, zinc, B vitamins, healthy fats and vitamin D. Dairy foods are also an important source of calcium, protein, iodine and vitamin B12. Replacing these nutrients is of paramount importance to anyone taking on a vegan diet and, as healthcare professionals, it’s our role to support plant-based eaters in doing this sufficiently.

REPLACING LOST NUTRIENTS Luckily, there are plenty of plant-based alternatives, to many of the nutrients found in meat and dairy; however, the absorption of minerals such as iron is likely to be less efficient and it is undoubtedly harder to get a complete set of amino acids.14 As the Eatwell Guide recommends, it is important to make sure that someone who is vegan is: • consuming five or more portions of fruits and vegetables every day; • basing meals around wholegrain starchy foods; • consuming some beans, pulses and alternatives; • and including some dairy alternative foods each day. There are some specific nutrients that vegans may want to pay particular attention to:

Iron and protein

Iron, especially due to its limited bioavailability, can be of concern for someone following a vegan diet.14 However, there are plenty of iron-rich plantbased foods that you can include in a vegan diet. Baked beans, kidney beans, all types of lentils, chick peas and garden peas all count as pulses and towards iron and protein intakes for vegan individuals. There are many other examples of pulses and beans too, so it’s easy to ensure that there is plenty of variety in the diet. In addition, these foods are often inexpensive and can add to other health benefits such as high fibre intakes.

Eating a healthy, balanced diet for a vegan isn’t as challenging as it may initially seem. . . . Vegans may also benefit from taking a vitamin B12 and vitamin D supplement as a safeguard against deficiency.

Other sources of protein and iron include plant-based alternative foods such as soy, Quorn and tofu. Wholemeal breads, fortified breakfast cereals, nuts and seeds, dark green leafy vegetables, such as broccoli and spring greens, and dried fruits are also a good source of iron for vegans. When consuming iron-rich plant foods, it’s a good idea to try and consume them alongside vitamin C-rich foods, such as fruit, vegetables and potatoes, to help increase the absorption of iron.

Vitamin B12

Vitamin B12 is another nutrient that may be harder to get from a vegan diet.14 Luckily, there are some B12-fortified foods, such as fortified breakfast cereals and fortified milk alternatives and yeast extracts, which can play an important role for vegans. Aside from this, the Vegan Society recommend that vegans, and anyone over the age of 50, take a supplement containing vitamin B12, as a safeguard against deficiency.1

Calcium

Calcium is another nutrient often highlighted as one to watch on a vegan diet. However, there are plenty of plant sources of calcium in the diet, making it easy for vegans to get their daily requirements. For example, fortified soya, almond and oat milks are readily available which contain calcium, vitamin D and added B vitamins. Additionally, foods such as tofu, nuts and seeds, pulses, bread (which is fortified with calcium in the UK), dried fruits and some dark green leafy vegetables such as kale, are all adequate sources of calcium for vegans.

Omega-3

Omega-3 is a very important type of fat and is incorporated into the diet mainly through oily fish. It’s certainly more challenging for vegans to get a good source of quality, long-chain omega-3 fatty acids from a plant-based diet. Flaxseeds, walnuts, rapeseed oil and some soya-based foods do contain a form of α-linolenic acid omega-3, which can be converted in the body to the longer chain eicosapentaenoic (EPA) or docosahexaenoic (DHA) acids; but this is at a fairly low efficiency.14 However, high quality, long chain, omega-3 (DHA) from algae is becoming more readily available as a vegan supplement. This is an option which can be recommended for vegans who are concerned about their omega-3 intakes.14

Vitamin D

Vitamin D is actually one of the most challenging nutrients to acquire in the diet, as it comes mainly from sunlight. Due to high levels of deficiency observed from the National Diet and Nutrition Survey data, suggesting that 40% of the UK population have low vitamin D levels in the winter months,17 there is some consensus that vitamin D supplements, or a fortification strategy, could be beneficial for all members of the public.18 Vitamin D is already fortified in some cereals, breads, milks and spreads in the UK, but as a population group, it may be beneficial for vegans to take a vitamin D supplement daily.

CONCLUSION Eating a healthy, balanced diet for a vegan isn’t as challenging as it may initially seem. Healthcare professionals such as dietitians and registered nutritionists should inform vegans that they can acquire all the nutrients they need by focusing on a diet that is in line with the Government’s Eatwell Guide. That is: based on eating five or more portions of fruits and vegetables every day; including plenty of wholegrain starchy foods and consuming some beans, pulses and alternatives alongside some dairy alternatives each day. Vegans may also benefit from taking a vitamin B12 and vitamin D supplement as a safeguard against deficiency.