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21 Sep 2012 04:28
Professor Tim Noakes at the Sports Science Institute in Newlands, Cape Town. (David Harrison, M&G)
Tim Noakes is busy. In addition to his usual duties as a professor at the Sports Science Institute of South Africa in Cape Town where he conducts research and lectures students, he has been fielding up to 200 queries a week about his diet from individuals and the media.
On the morning of our interview his name appears in the papers again.
A group of six doctors, comprising cardiologists and University of Cape Town academics, have written to the Cape Times suggesting that Noakes has gone too far in claiming his low-carb, high-fat diet is suitable for all patients, and that his statements about statins, a class of cholesterol- lowering drug, are at best unwise and may be harmful.
"Having survived Aids denialism we do not need to be exposed to cholesterol denialism," the letter reads.
Noakes is a genial, animated man, given to drumming his hands on the desk as he speaks.
"It's great," he said, referring to the letter.
"The key is you must not be irrelevant. The fact that I can stir up this controversy is because I'm relevant."
The charismatic rebel professor first gained popular acclaim in 1985 as a 27-year-old wunderkind when he published Lore of Running, a tome of biblical proportions, which is now in its fourth edition and for years most serious runners have considered it gospel. Following Noakes's advice on nutrition, athletes began carbo-loading religiously to improve their performance. Bruce Fordyce and Paula Newby-Fraser, both exceptional ultra-endurance athletes, became but two of his many high-profile followers.
Noakes' academic career took off. He published a paper in a prestigious American scientific publication describing, for the first time, the uncommon, but occasionally life-threatening condition of exercise-associated hyponatraemia (low blood sodium). The paper was initially met with mixed responses and some scepticism, but his continued research in the field of fluid balance, in which he challenged powerful sports drink companies, came to the sensible and scientifically sound – conclusion that athletes should drink when they are thirsty and stick to water.
In 2005 the original article was republished in Wilderness Medicine along with an editorial that read: "Tim Noakes was right in 1985 and the passage of two decades has done nothing to reduce the accuracy of his conclusions." This research would win the International Cannes Grand Prix award for research in medicine and water, and would form the basis of his book Waterlogged. In it, Noakes proposed a central governor hypothesis explaining the brain's role in exercise and fatigue. It was a novel theory that was published in five articles in British Sports Medicine. These "became instant classics", according to his memoir Challenging Beliefs, but Noakes felt more scientists should have embraced his ideas, a failure he attributes to research funding bias.
Noakes has his name on more than 450 publications, sits on multiple international editorial boards of scientific journals, is an A-rated scientist and has been the recipient of several lifetime awards for his contribution to science including the Order of Mapungubwe, Silver, in 2008 and the National Research Foundation lifetime achievement award just last week.
But now the former high priest of carbo-loading has perplexed and stunned his followers and colleagues, making an abrupt change in his diet to shun carbohydrates in favour of high-fat, low-carbohydrate eating.
"Tear out the chapter on nutrition in Lore Of Running," he said. "I was wrong."
But how could such a respected scientist have been wrong? Noakes's writing on energy systems and running performance looks so convincing, with diagrams, pie charts, complicated graphs and frequent annotated references to multiple scientific studies. It was science, wasn't it?
All Noakes will say of his initial conclusions about diet and athletic performance is that he "was a bad scientist then. I was only 27, I was young and naive. I'm better at reading articles now."
Actually, a diet changed Noakes's mind. He explains that the change took place about two years ago, at the time he finished writing Waterlogged. For 30 years he had followed a very low-fat, high-carb diet. After the book was published he felt awful, he said. He had been very busy and had not been running enough, so he went for a run, which left him feeling worse. He thought it was age.
Returning home from that run, Noakes chanced upon a spam email promising dramatic weight loss. Looking closer he saw that it was for the new Atkins diet. His first thought, as a medically trained doctor, was that the diet was "bogus", but recognising the names of the researchers, he went out and bought their book. "An hour later I said: 'I've eaten my last carb.'"
As the months passed and he lost weight, Noakes began researching the theories and studies supporting a low-carbohydrate, high-fat diet.
The gold standard of scientific research is the prospective, randomised, double blind control trial, in which huge numbers of subjects are followed closely over decades and neither they nor their researchers know which treatment they are receiving. This eliminates the powerful placebo effect and minimises observer bias. In addition, the starting and end point parameters of a good study should be unambiguous and very tightly defined. Unfortunately, in the field of nutrition there is no such research available.
Most nutritional studies follow very small samples of subjects over weeks or months and use the data to extrapolate findings over the long term, or they have large numbers of people fill in dietary questionnaires as honestly as they want to and their health is followed over decades. Both methods are scientifically problematic.
Besides, the field is inherently murky: vastly different populations live on vastly different diets from blood and milk to sago palm, pap, rice or whale blubber. Populations come in a wide variety of genetic make-ups who exercise differently, smoke or not, have heart disease or not, and suffer a range of micronutrient deficiencies. Many of the research findings are so conflicting that almost any view can be supported.
Noakes reports that he lost weight right away and that his running gradually improved. He started feeling better than ever and has since kept his weight off, run faster and claims to have cured himself of a slew of ailments including exercise-induced asthma, allergic rhinitis, irritable bowel syndrome and sleep apnoea.
Three months into the diet Noakes, who has a family history of diabetes, performed a fasting blood sugar test on himself and found it to be 5.9, which is somewhat raised. He made the assumption that his blood sugar, which he had not tested prior to the diet, must have been even higher before the radical nutritional change, and that he must have been suffering from pre-diabetes, which a change in diet had cured – a bizarre conclusion even for those with a layman's understanding of the scientific process.
Noakes also measured his insulin level and found it to be low, which he interpreted as a sign that his pancreas could be failing as a result of his surmised pre-diabetes.
"Not at all," said Tanya Kinvig, a Cape Town endocrinologist. "Low insulin is a normal response to a low intake of dietary carbohydrates. I would expect it on the diet he isfollowing. "
Noakes's diet could even have caused the raised blood sugar, through cortisol, a stress hormone, which acts on protein to make glucose. In which case he may not have a problem metabolising carbohydrates at all. "There are many causes for an elevated blood sugar," said Kinvig, "but of course all these results are meaningless without a baseline."
Since his embrace of the Palaeolithic diet, tensions have risen between Noakes and members of the medical establishment whom he refers to as "pill pushers". But both sides agree that ingesting a significant load of refined simple carbohydrates, which are rapidly digested and absorbed, causes a spike in insulin that drives glucose into the muscles and liver and converts the excess blood sugar to fat.
Insulin evolved to deal with complex carbohydrates, which are digested at a slower rate than refined sugars, and so have a long half-life. What this all means is that after your sports drink and pastry have been packed away on your hips or in your gut, insulin hangs around long enough to drive your blood sugar down and cause hunger. Eating more refined carbohydrates in response to that hunger results in a vicious cycle that can lead to obesity and – in the genetically susceptible – insulin resistance and type two diabetes. Because protein slows the digestion and absorption of carbohydrates, endocrinologists and dieticians recommend sticking to complex carbohydrates and always combining them with protein.
Noakes, however, claims that carbohydrates are so addictive it is impossible to stick to whole grains without slipping back to sugary drinks and cakes. He prefers to restrict his carbohydrates to one Ryvita a day, which he eats for breakfast with cheese.
On his current diet, which Noakes claims Palaeolithic people ate, he derives 60% of his calories from fat, much of it derived from animals. He concedes that a rise in serum cholesterol is a consequence of eating that much fat but states that total cholesterol is a poor predictor of health. Lipid experts disagree and say his view is inaccurate and simplistic.
Noakes said he experiments on himself and judges the results by how he feels. He encourages lay people to do the same, which doctors say is irresponsible. The problem of being in a study of one, where the subject is also the researcher, is that there is no controlling for placebo effect.
Public interest in Noakes's diet has soared and his internet posts garner hundreds of Facebook likes and comments. Supporters post success stories and refer to his "vast experience in nutrition and exercise" and his "publications in scientific journals". To a dietician who warns of safety issues, the response from a convert is: "You may study for five years, but you don't do research."
Noakes likes to view himself as a rebel, capable of taking on the establishment and winning. In Lore of Running he writes "I learnt not to trust my teachers" and in Challenging Beliefs he recounts conventional myths he has dispelled and the cynicism he was met with. He refers to traditional doctors as "agents of the pharmaceutical companies", who have a financial interest in keeping their patients sick.
Since his talk at UCT in July this year – when Noakes suggested that a high-fat, low-carb diet was suitable for most patients and he questioned the benefit of statins – there have been murmurs among cardiologists that Noakes is the Malema of medicine, a man with a hoarde of followers and considerable media sway, who is capable of producing charismatic, easy to hear and probably irresponsible solutions to very complex problems.
Noakes has postulated that because most people who suffer heart attacks do not have elevated cholesterol levels, cholesterol does not cause heart attacks.
"If cholesterol is not markedly elevated it is not a sole predictor of heart disease, but it is part of the risk calculation," said Dr Dirk Blom, an academic at UCT's lipid clinic who admits that most people who suffer heart attacks do have normal cholesterol.
As for the benefit of cholesterol- lowering statins, a meta-analysis of long-term, double blind, randomised control trials, containing up to 170 000 individuals and taking as its end point the rather unambiguous state of death, showed unequivocally that statins save lives and that the only people who do not benefit from the drugs are low-risk individuals who should not be on them in the first place.
"I feel sorry for Tim," said a cardiologist who preferred not to be named. "He likes to take on a challenge, but when it comes to statins I think he's painted himself into a corner."
Everybody agrees that a low-carb, high-fat diet can cause rapid weight loss, but the regimen is not without acute dangers. Type one diabetics may develop renal failure or go into hypoglycaemic coma, and patients with elevated triglycerides risk contracting potentially fatal pancreatitis. The long-term benefits of the diet remain unclear and, just as short-term athletic performance does not always equate with longevity, weight loss does not always equate to good health. Skinny people have heart attacks too.
Noakes has swung from high carbs to no carbs. The most widely accepted research suggests something in between. Avoid transfats, sugars and refined carbohydrates, eat a calorie-restricted, balanced diet with whole grains, protein and healthy fats, exercise in moderation and, if you are thirsty, drink water.
Martinique Stilwell is a medical doctor, writer and freelance journalist. Her memoir, Thinking Up a Hurricane, was published by Penguin this month
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