CARB revolution Thanks to Professor Tim Noakes, Capetonians are shunning carbohydrates in their droves – but what do local medics think?
He’s set the cat well and truly amongst the dietary pigeons with his claims that a traditional‘healthy’ diet is doing many of us harm, and that just one apple and one banana a day will keep some of us overweight for life.
With his controversial Real Meal Revolution science-cum-recipe book that blames carbs for many ills and claims we’ll get thin by eating the fat on our chops, UCT’s Prof Noakes has stuck his neck high above the nutritional parapet.
But he’s got a large and growing number of followers, both in Cape Town and abroad, and it’s the best-selling South African book ever. The Australian cricket team’s doctor, Peter Brukner, calls him ‘my hero’ and hundreds of people are saying Tim Noakes has transformed their health and their bodies. His team is now working on a budget version of the diet that could spread it to millions in South Africa and beyond.
But is this maverick on to something huge that helps explain global obesity or is this just another fad that will fade − or, worse still, do us harm? thislife asked some respected local medics what they think…
Dr Philip Mills, non-interventional preventative cardiologist, Constantiaberg Hospital ‘I’ve been prescribing a low-carbohydrate, high-fat (LCHF) diet to some of my patients for several years now, and there’s no doubt that for many it’s a great tool for inducing weight loss and improving heart health. Professor Tim Noakes is 100% spot on with his ‘anti-carb’ and ‘anti-diabesity’ (diabetes and obesity) campaign. All carbohydrates, whether simple, processed or refined, are particularly addictive and trigger brain receptors in a very similar way to cocaine and nicotine: highly addictively!
The idea that fat-free and low-fat is better for you is an ill-conceived dietary path we’ve been led down for the past 50 years. A Woman’s Health Initiative trial1 set up by the American government followed 48 835 women between the ages of 50 and 79 years for an average of 8.1 years and discovered that reducing total fat intake and increasing intake of vegetables, fruits and grains did not significantly reduce the risk of heart disease in postmenopausal women, and produced only modest effects on the heart disease risk factors. This suggests that other dietary and lifestyle interventions may be needed to improve risk factors and reduce heart risk.
Heart disease is the number one killer worldwide, and in Sub-Saharan Africa it’s no different2. You can’t always tell by looking at someone how high their risk for heart disease is. Of 2,000 ‘healthy’ 50-year-old men and women you see walking down the street, less than five actually have truly healthy hearts!
Typically in my practice, I see an average 8kg weight loss at three months and 12 to 15kg after six months of a supervised LCHF lifestyle, with significant improvement in heart health parameters. In addition, on LCHF, a spectrum of ‘auto-immune’ diseases like psoriasis, arthritis, thyroiditis and leaky-gut syndromes are often markedly improved because of the elimination of gluten and other ‘grass-seed proteins’ from the diet. I’ve had patients whose psoriasis totally disappeared on this diet.
The principle of reducing carbs has been known for hundreds of years. William Banting, on whose diet Prof Noakes has based The Real Meal Revolution, wrote about it in 1864, observing ‘obesity seems to me very little understood’.3 Little has changed since then!
Atkins, Paleolithic, Dukan and Eco-Atkins are all variations of the LCHF lifestyle. The science behind reducing carbs to less than 10% of daily calories and increasing fat to about 60% of calories is well established in many clinical trials,4-5 and they come up trumps for weight loss comparing head-to-head with traditional high-carb, low-fat trials6. In my experience, people usually look and feel far better on LCHF lifestyles compared to traditional low-fat or low-calorie diets because they lose body fat, not muscle. If they add daily exercise to the programme, people tend to look really great.
However, this way of eating is not a panacea or a ‘one-size-fits-all’ way of eating. The type of people who respond well to it are those with ‘middle-age-spread’, type II (lifestyle-induced) diabetics, and people with insulin resistance or ‘metabolic syndrome’ (visceral obesity and abnormalities of glucose, blood pressure and lipoprotein). These people generally respond well to LCHF diets and will improve virtually all metabolic parameters of heart health as they lose weight.
A major drawback of the LCHF diet is that a third of people on it will not improve their lipoprotein parameters but go in completely the opposite direction! This is why this diet must be medically supervised by someone who can interpret all the data and check you’re moving in the right direction, with improvement in all metabolic parameters. (As a general rule, I monitor people’s atherogenic and anti-atherogenic lipoproteins; their inflammatory markers such as us-CRP; glucose levels and, if they are diabetic, HbA1c levels).
Other drawbacks of LCHF include gout and fruity ‘ketone-breath’. As the body adapts from burning carbs to body fat, a process that lasts one to two weeks, you can feel shaky, fatigued and experience ‘brain fog’ until fat-burning (ketosis) is in full swing. Gentle exercise, plenty of water and brightly coloured vegetables with higher potassium and magnesium during this transition help remedy this.
The key lies in practising a LCHF lifestyle correctly, as there’s a lot of misunderstanding. People think it’s a high protein diet, which it’s not – in fact, it’s critically important to keep protein intake at normal levels, otherwise the physiology of the diet breaks down. The carbohydrate restriction should be tailored to the individual’s physiology and may be minimal (about 150g carb per day) to severe (less than 60g a day).
Some people are concerned about the red meat on the diet, but the different styles of LCHF available (Paleolithic/Atkins/Eco- Atkins) tend to address this within a person’s taste. I’m personally not too concerned about red meat intake (though I limit it to about once or twice a week), but have a preference for a ‘Spanish Mediterranean ketogenic LCHF diet’7 with a high proportion of vegan and fish ‘good’ oils, olives, olive oil, nuts and seeds and oily fish such as mackerel, sardines, pilchards and salmon.
I’m also not concerned about LCHF diets cutting down on fruit as vegetables, nuts, seeds and salads can supply all the minerals, fibre, trace elements, electrolytes, oils, fats and vitamins the body requires. As a cardiologist, I disagree, however, with Professor Noakes’s views that lipoproteins have no relation to heart disease and that statins aren’t generally useful for those with high cholesterol (abnormal lipoproteins). Evidence-based data shows irrefutable benefit for those with the conventional risk profile for heart disease.
People think you have to be careful once you hit 50, but in fact it’s the first five decades of life that make the difference to heart health. One of the principles of healthy longevity is to be lean, as this slows our cellular degradation and promotes ‘longevity’ hormones and chemicals. There’s considerable evidence that people who restrict their carbs ‘age’ their brains better, and that diets high in simple sugars and processed carbs add to cognitive decline (dementia) with age. It’s important to understand that LCHF lifestyles are only part of the solution to health. I see many healthy eaters who are not healthy because of other risk factors such as smoking, stress, too much alcohol and lack of weight-bearing exercise.’
References: 1. Low-Fat Dietary Pattern and Risk of Cardiovascular Disease. Website: www.ncbi.nlm.nih.gov/ pubmed/16467234 2. Risk Factors Associated with Myocardial Infarction in Africa. The INTERHEART Africa study. Website: http://circ.ahajournals.org/content/112/23/3554 3. Letter on Corpulence, by William Banting. Website: www.proteinpower.com/banting/ 4. Effects of a Low–Glycemic Load vs Low-Fat Diet in Obese Young Adults. A Randomised Trial. Ebbeling C et al. JAMA. 2007;297:2092-2102 5. Carbohydrate-restricted diet in conjunction with metformin and liraglutide is an effective treatment in patients with deteriorated type 2 diabetes mellitus: proof-of-concept study. Website: http://www.nutritionandmetabolism. com/content/8/1/92 6. Comparison of the Atkins, Zone, Ornish and LEARN Diets for Change in Weight and Related Risk Factors among Overweight Premenopausal Women. The A TO Z Weight Loss Study: A Randomised Trial. Gardener C et.al. JAMA. 2007;297:969-977 7. Spanish Ketogenic Mediterranean diet: a healthy cardiovascular diet for weight loss. Website:http://www.nutritionj.com/content/7/1/30
Dr Adie Horak, cardiologist, Vincent Pallotti Hospital, Pinelands
‘A low-carb, high-fat diet really does work for weight loss, even though I think people who follow it look terrible! It’s particularly effective for weight-loss in people who are diabetic or carbohydrate intolerant. However, there’s very little evidence to show what it does to your health in the long run. What will we be saying about it in five years’ time?
Yes, there’s a lot to be said for avoiding refined carbs, but you need to be balanced in life and do things in moderation. This way of eating includes lots of saturated fat, but there’s not one shred of evidence that it’s good for you. In fact, there’s very little evidence when it comes to diets. They’re hard to stick to longterm or prove in studies.
Professor Noakes’s Real Meal Revolution claims statins aren’t actually helping the majority of people who take them to control their cholesterol. This is completely contradictory to all the evidence I have seen. This diet is elitist as it can work out quite expensive, whereas most diets work for weightloss if you stick to them. I’m doing the 5:2 diet, when you eat normally for five days and semifast for two. I’ve lost 3.5kg in two weeks!’
Dr Neville Wellington, GP, Kenilworth Medicross
‘Much has been said and written about lowcarbohydrate lifestyles and diets over the past few years in Cape Town. Some exuberant conversations have occurred around Prof Tim Noakes’s apparent change of heart and current advocacy of the so-called low-carbohydrate, high-fat lifestyle. While some view it as just another fad, the question stands: is there any merit in cutting down on carbs in one’s diet?
For the past three years, via a Cardiff University postgraduate diploma in diabetes, I have delved quite deeply into the subject of diabetes. This has led me to understand the biological mechanisms by which high glucose levels cause cell damage in everyone (not just diabetics), and why it’s so important to control these levels.
What has become apparent over the past 15 years is that high glucose levels (or hyperglycaemia) in body cells cause a destructive process called oxidative stress. While normal levels of glucose are used to produce energy in cells, hyperglycaemia, by contrast, can actually prevent the breakdown of glucose and cause build-up of some damaging byproducts. The final outcome is that these cells become inflamed.
With repeated spikes of hyperglycaemia, the body’s defences become overwhelmed. Eventually, people may develop heart disease, obesity, diabetes, kidney failure, eye damage (cataracts and blindness), nerve and brain damage (Alzheimer’s), and many other problems.
So where do carbs come in? And what about weight issues? We’ve known for a long time that the greatest source of glucose comes from the food we eat, viz carbohydrates. Carbs are broken down in our intestines to glucose and other simple sugars, then absorbed into the blood stream where the body tries hard to keep them at specific levels to prevent them from causing damage. Some of the glucose is converted to glycogen for shortterm energy use, but the rest is converted into triglycerides which are eventually stored as fat. The result – weight that’s hard to shift! Over time, if glucose levels remain high in the blood stream, the body keeps insulin levels high, and ultimately this leads to insulin resistance and the prevention of fat breakdown in the body.
Thus, high-carb intake is associated with multiple changes in the body which some call metabolic syndrome (overweight, raised glucose levels, hypertension and changes to the cholesterol profile), and others call carbohydrate intolerance.
In addition, there’s the problem of processed sugar and high fructose corn syrup (HFCS), part of almost all processed foods since the 1970s. As sugar and HFCS consumption has increased, so have obesity, diabetes, heart disease and gout. Studies have now confirmed a direct correlation.
The good news is that these problems can be reversed by reducing carbohydrate intake, and a number of studies show these improvements. Reducing carbs to levels of under 50g a day or less for those who are overweight or have diabetes has been shown by some researchers to achieve significant improvements. Anecdotally, I’ve seen the same remarkable improvements in my patients. In practice, this would include cutting out all sugars, sweetened drinks, fruit juices and confectionary, and keeping treats like sweets for the odd occasion. For those with medical problems like obesity, hypertension and diabetes, this also means cutting out cereals, breads, pastas and starchy veg − and limiting fruit. This may sound hard but it’s been shown that when people swap carbohydrates for fat, they feel more satiated and their overall calorie consumption actually reduces, helping to reduce weight! People without specific problems can still benefit their health by eating no more than 130g of carbs daily.
Recent large studies have confirmed that increasing the intake of saturated fat doesn’t increase heart disease, and this has again been highlighted recently by correspondence in the British Medical Journal. Many patients do find an increase in their overall cholesterol figures in the first few months, but I have found that many of them return to relatively normal levels within six months to a year. Significantly, they find a reduction in their triglycerides and an increase in their HDL cholesterol levels which are beneficial.
So, while a low-carbohydrate diet may seem to be going against traditional dietary recommendations, the science behind it is actually quite strong. The biological mechanisms by which hyperglycaemic spikes cause damage is now well understood. I believe there is plenty of evidence for a low-carb, high-fat diet improving health and have seen this in my patients.’
Dietician Jean Mills, Claremont private practice
‘It’s a good thing that Tim Noakes has stirred things up and made people aware they’re eating too much sugar. I’m also delighted that it highlights the undesirability of eating processed and junk food. If you’re very overweight and want to lose weight quickly, I’ve no problem if you follow a LCHF (lowcarb, high-fat) diet under medical supervision. Short-term, your weight-loss is faster, though studies suggest that after one year, weightloss is the same as on a conventional weight reduction diet.
However, this way of eating is unsustainable for most people long-term, and there’s no evidence yet that it’s healthy on a long-term basis. It’s concerning to reduce fruit significantly, and red meat increases the risk of inflammation which can lead to cancer and arthritis.
One main negative: carbohydrates are important for production of serotonin. Low serotonin levels can lead to depression and a low glucose level can affect your mood, concentration and energy levels.
Another con is that it’s expensive and doesn’t really work for vegetarians. I also wouldn’t recommend it for cancer patients. There are too few studies of following a LCHF diet for over a year to really know how it will affect people long-term. Those who follow this diet may find their cholesterol coming down because they’ve adapted their diet to healthier eating, not necessarily because of this specific diet.
However, there is a place for this diet. If it works for you and you do it under medical supervision, regularly checking that your blood results are normal, then stick to it. It’s better for some people than others.’
What does Prof Noakes himself say? ‘People who stay lean on a high-carb diet may not benefit in any way from this eating plan: it might even be detrimental. This diet is for others, including those who’ve tried other options and found they don’t work for them. The beauty of it is, you don’t have to listen to what I’m saying, you can just try it and you’ll see if it works for you within a week.’ For more from Tim Noakes, go to his new website, www.originaleating.org
What does thislife think? It’s definitely worth considering this way of eating for a short period if you suspect you’re carbohydrate intolerant or can’t lose weight on other diets. But for some this diet may pose a real health risk, so if you don’t do it under medical supervision, you’re crazy!