[2017] Lore of Nutrition: Challenging Conventional Dietary Beliefs
Page 25
So the diet that the HSFSA promotes adversely affects what it labels ‘good’ cholesterol. Surely that cannot be ‘good’? Or, as Steven Hamley concludes: ‘Available evidence from adequately controlled randomised controlled trials suggest replacing SFA [saturated fatty acids] with mostly n-6 PUFA [polyunsaturated fatty acids] is unlikely to reduce CHD events, CHD mortality or total mortality. The suggestion of benefits reported in earlier meta-analyses is due to the inclusion of inadequately controlled trials. These findings have implications for current dietary recommendations.’59 All this evidence should be the final nail in the coffin for the diet-heart hypothesis.60 Anyone who claims otherwise is simply not telling the truth. In fact, there is clear evidence that cooking in ‘vegetable’ oils is likely to be very bad for our health.
Professor Martin Grootveld and colleagues from the De Montfort University Leicester conducted an experiment in which participants were given vegetable oil, sunflower oil, corn oil, olive oil, cold-pressed rapeseed oil, goose fat, lard and butter to use for their daily cooking. Participants collected the leftovers and returned them to the scientists, who then analysed the returned fats and oils for their content of aldehydes, chemicals that have been linked to heart disease, cancer and dementia. The researchers found that sunflower and corn oil produced aldehydes at levels 20 times higher than recommended by the World Health Organization (WHO), and that the longer these oils were heated, the greater the production of toxic aldehydes. Olive oil, rapeseed oil, butter and goose fat, however, produced far fewer aldehydes.
As a result of this analysis, Grootveld recommended that, to reduce aldehyde production, people should cook with ‘an oil or fat that is high in monounsaturated or saturated fats (preferably greater than 60% for one or the other, and more than 80% for the two combined), and low in polyunsaturates (less than 20%)’. He further suggested that we use ‘olive oil for frying and cooking – even butter and lard are better than vegetable oil when used at high temperatures’.61
Mungal-Singh does not acknowledge the science that disproves the stated position of the HSFSA. In fact, by encouraging the public to replace dietary saturated fats with polyunsaturated fats, the HSFSA has likely not prevented a single case of heart disease. Rather, it may have increased heart-attack rates in the elderly, and perhaps even cancer rates. The latter possibility is suggested by an original 1970s study and by what has become known as the Israeli paradox.
In a study published in 1971, M.L Pearce and S. Dayton described ‘an eight-year controlled clinical trial of a diet high in polyunsaturated vegetable oils and low in saturated fat and cholesterol in preventing complications of atherosclerosis’. They found that while there were fewer deaths from heart attack in the vegetable-oil (experimental) group, overall mortality was the same in both groups. This was because of an almost twofold greater (31 versus 17) incidence of fatal cancers in the experimental group.62
Then there is the Israeli paradox, described by D. Yam, A. Eliraz and E.M. Berry in 1996 as follows:
Israel has one of the highest dietary polyunsaturated/saturated fat ratios in the world; the consumption of omega-6 polyunsaturated fatty acids (PUFA) is about 8% higher than in the USA, and 10–12% higher than in most European countries. In fact, Israeli Jews may be regarded as a population-based dietary experiment of the effect of a high omega-6 PUFA diet, a diet that until recently was widely recommended. Despite such national habits, there is paradoxically a high prevalence of cardiovascular diseases, hypertension, non-insulin-dependent diabetes mellitus and obesity – all diseases that are associated with hyperinsulinemia (HI) and insulin resistance (IR), and grouped together as the insulin resistance syndrome or syndrome X. There is also an increased cancer incidence and mortality rate, especially in women, compared with western countries. Studies suggest that high omega-6 linoleic acid consumption might aggravate HI and IR, in addition to being a substrate for lipid peroxidation and free radical formation. Thus, rather than being beneficial, high omega-6 PUFA diets may have some long-term side effects, within the cluster of hyperinsulinemia, atherosclerosis and tumorigenesis.63
Perhaps the reason why the HSFSA does not ever address the dangers of polyunsaturated fats is because it receives life-sustaining funding from Unilever.
In the ultimate irony, Mungal-Singh writes in her open letter on behalf of the HSFSA: ‘We trust that Prof Noakes is not recommending that people increase their trans fat intake (this is a fat too!). We know that trans fats significantly increase the risk for cardiovascular disease and so should be avoided.’ Until very recently, every heart foundation in the world was guilty of ignoring the evidence about the dangers of trans fats, which were first flagged in 1978.
Under the heading ‘Not all carbohydrates are bad’, Mungal-Singh suggests that: ‘There is no doubt that unrefined or wholegrain carbohydrates are healthy and protective against certain diseases including cancer.’ Once again, there is absolutely no direct evidence from appropriate RCTs that wholegrain carbohydrates do anything for our health.
Mungal-Singh then makes this important admission:
In reality, when people cut back on fat, they fill up on foods full of refined carbohydrates (e.g. white bread, sugary drinks) or use fat-free products without the healthy fats and which contain hidden sugars. The result is an increased risk for obesity, CVD and diabetes, which is why we recommend replacing foods high in bad fats with foods high in good fats – not with refined carbohydrates.
Hang on, was it not the HSFSA that advised us to cut the fat, to eat ‘fat-free products’ and to replace the missing calories with carbohydrates, including even refined carbohydrates and sugar? Is the CEO of the HSFSA now admitting that this substitution is the cause of the diabetes/obesity epidemic? And what is her solution? To replace bad fats with good fats – which is precisely what we promote in The Real Meal Revolution. The only difference is that we suggest also replacing the bad carbohydrates and wholegrain carbohydrates (that are without proven health benefits and which may be harmful to the majority) with good fats.
Next, Mungal-Singh turns her attention to the ‘matter of over-simplifying the causes of heart disease’. ‘It is common knowledge,’ she writes, ‘that the causes of heart disease are multi-factorial, and are not exclusive to only blood cholesterol and a high fat diet as claimed. In fact, overweight and obesity are one of the risk factors. Maintaining a healthy weight requires much more than a diet. It means having to balance your energy intake with energy used through exercise.’ She says that, as a result of my advocacy of the LCHF eating plan, ‘the exercise message gets lost in the debate – which is a danger’.
Clearly, Mungal-Singh has not read my Lore of Running, which emphasises the crucial importance of exercise for all-round health, but not for weight control. Perhaps the lean Mungal-Singh has yet to learn that she is not lean because she exercises, any more than I and the likes of Bruce Fordyce and Oscar Chalupsky progressively gained weight in our middle years because we are lazy. It is difficult to accuse Bruce of laziness: in his athletic life he completed more than 200 standard marathons and perhaps another 50 ultra-marathons. Similarly, Oscar, who won the Molokai Challenge surf-ski race a remarkable 12 times, between the ages of 20 and 49.64 Yet so much exercise could not prevent weight gain in these athletes’ middle ages, as both became progressively more insulin resistant. (I address this issue further in Chapter 17, where I discuss the evidence that one cannot outrun a bad diet.)
The truth is that if you have to exercise to control your weight, then your diet is wrong. Those of us who have lost weight on the LCHF eating plan have learnt that you cannot outrun a bad diet, and that Mungal-Singh is absolutely correct: it is the carbohydrates in the diet that are driving the obesity epidemic, not the fats.
Mungal-Singh completes her letter with the following statement:
Perhaps the recent debate will feed your need to believe that you can indulge in butter, bacon, biltong and boerewors. Unfortunately, this cannot be without moderation, nor can it be in isolation of ot
her factors … To ignore other contributing factors, behaviours and living context that lead to heart disease would be erroneous and dangerous.
Again, nothing in The Real Meal Revolution disagrees with this statement.
The letter received 14 comments within the first 48 hours of its publication on Health24. The vast majority of commentators challenged the statements of the HSFSA and preferred my position. Perhaps if the HSFSA listened to public opinion it would be able to reduce the tsunami of arterial disease caused by T2DM and their advice to eat LFHC diets.
As the Banting movement continued to gain traction across the length and breadth of South Africa, perhaps predictably in 2016 the HSFSA felt it necessary to once again warn South Africans of the dangers and stupidity of adopting the LCHF eating plan. This time they put up an article on their website titled ‘The highs and lows of a low-carb-high-fat (LCHF) diet’.65
The article* begins with a backhanded compliment: ‘We have heard many accounts of people who lost weight using a LCHF approach by making radical changes to their eating habits.’ However: ‘To follow a LCHF-diet long-term is possible but requires extreme dedication, restriction of a wide range of foods, and may in fact be more expensive.’ They go on to say that while some people may be able to adhere to this approach long term, many are unable to sustain it, as it is ‘such an extreme intervention’. But, they say, the HSFSA does acknowledge that short-term weight-loss strategies are sometimes ‘necessary’, but in the long term, they recommend ‘a more balanced approach’.
Clearly the HSFSA has not yet heard that South Africa is the third most obese nation in the world and that this could be the result of their and ADSA’s promotion of the low-fat diet.
The article continues with a false statement: that the Banting diet is an LCHF diet that is based on ‘predominantly saturated fat sources and animal protein sources’, and that it is usually – and according to them, often inadvertently – ‘moderate to high in protein’. It then goes on to list some of the possible consequences of an LCHF diet:
People with genetically elevated LDL cholesterol or with existing heart disease may increase their risk of atherosclerosis substantially by increasing their saturated fat intake. (Genetic defects leading to raised cholesterol are more common in some South African communities than anywhere else in the world!) [This is not true: Arterial disease is caused by high-carbohydrate diets in those with IR, causing NAFLD and the serious form of atherogenic dyslipidaemia, as fully described in Chapter 17. The diet promoted by the HSFSA is the one that causes arterial disease.]
Individuals with a genetically elevated iron level may incur liver damage when they increase their red meat intake significantly. [Where is the evidence for this statement? The LCHF diet is not a diet high in meat. People with genetically elevated iron levels are aware of their condition and know what they should and should not be eating. They do not need a heart foundation to tell them.]
People with asymptomatic undiagnosed kidney disease (a common condition often present in people with diabetes), may accelerate their kidney disease by an even modest increase in protein intake. [This statement has no basis in fact. People with undiagnosed kidney disease are most likely to have T2DM, as described earlier in this chapter. Eating a high-fat diet that better controls their diabetes will reduce the probability that they will develop kidney failure. In contrast, continuing to eat the high-carbohydrate diet promoted by the HSFSA will worsen their diabetes.]
Decreasing intake of dietary fibre may increase the risk of bowel conditions such as constipation, diverticular disease and bowel cancer. [As Dr Caryn Zinn clearly showed during her expert testimony in the HPSCA hearing, the LCHF diet provides more dietary fibre than the diet the HSFSA promotes. The LCHF diet promotes the intake of fibre-rich, low-carbohydrate vegetables and fruits like avocados.]
Liver is often recommended as an affordable LCHF food choice but is also a very rich source of vitamin A. Consuming liver during early pregnancy may cause birth defects. As little as 20–100g liver exceeds the World Health Organization recommended maximum daily intake of vitamin A during pregnancy. [Most South Africans eating the traditional maize-based diet are vitamin-A deficient and would benefit from vitamin-A supplementation. I am unaware of anyone in South Africa eating more than 20 grams liver daily. Who and where is that person?]
Very restrictive high fat diets may be low in various vitamins and minerals, depending on which foods are being eliminated. [This is another bogus statement. The evidence is that high-fat diets provide more vitamins and minerals because they are more nutrient dense than the diet that the HSFSA promotes. In addition, as Weston Price argues (see Chapter 16), without sufficient fat in the diet it is not possible to absorb effectively the (lower) vitamin and mineral contents of the nutrient-poor, low-fat diet promoted by the HSFSA.]
Diets high in animal protein, sodium and/or low in calcium may increase the risk for osteoporosis. [This is another bogus statement for which there is no scientific evidence. 66 Osteoporosis is a modern disease of nutrition that did not exist before humans began eating ‘healthy’ wholegrains at the start of the Agricultural Revolution 12 000 years ago. Indeed, the introduction of cereal and grains into the human diet was associated with a dramatic reduction in human height and the first appearance of bone diseases and dental caries. It is diets high in cereals and grains and low in fat-soluble vitamins, especially Vitamin D, which cause osteoporosis (See Chapter 16.]
The HSFSA then says that, as even the best diets can be ‘badly executed’, they recommend that anyone who attempts to follow ‘an extreme diet such as a[n] LCHF diet does so under medical supervision’. And anyone with diabetes, high cholesterol or high blood pressure is advised to monitor their kidney function, blood pressure and LDL cholesterol.
Indeed. And they will notice that their kidney function, blood pressure and LDL cholesterol all improve on the LCHF diet.67 These improvements will soon convince them that following the Banting diet is far more healthy than following the diet the HSFSA recommends.
The anti-Banting propaganda continues with another backhanded compliment. They say that although a low-carb diet can assist type-2 diabetics with weight loss, and may aid in blood sugar control, this can also be achieved with a diet consisting of moderate, good-quality carbohydrates. The latter statement is again simply not true, as the evidence presented earlier in this chapter makes clear: adequate control of T2DM, including the potential to put the disease into remission, can only be achieved with diets that limit carbohydrate intake to about 25 grams per day.
The HSFSA goes on to say that they have no evidence that an LCHF diet prevents the development of heart disease, and that it may even accelerate this process in some individuals. They recommend a more moderate approach, which includes ‘a reduction in energy intake from excess carbohydrates AND/OR fat, and choosing good quality carbohydrates and fats’. As I show in Chapter 17, there is no evidence that the diet currently promoted by the HSFSA ‘prevents the development of heart disease’. Instead, all the evidence suggests that their diet promotes T2DM and, hence, heart disease. So one might legitimately ask on what scientific basis the HSFSA promotes its allegedly ‘heart-healthy’ diet.
The article concludes by saying that although the Banting diet has promoted awareness around nutrition and health in South Africa, the HSFSA does not agree with all the elements that make up this diet. They then list the foods they believe South Africans should eat, and recommend a reduced intake of sugar and processed foods. Their aim, they say, is to beat obesity, heart disease and diabetes in South Africans by recommending that they eat healthier foods like ‘unrefined grains’, healthy oils, fruit and vegetables, and limit the intake of salt, sugars and saturated fats. One wonders if the HSFSA has ever considered why their own message has failed to achieve the requisite results.
In a recent rant on the South African Heart Association (SAHA) website, ‘the sole organization representing the professional interests of all cardiologists and cardio-thoracic
surgeons in the country’, the association repeated much of the same misinformation, while including the interesting statement that the Banting diet’s ‘rationale is based on a world-wide epidemic of obesity and type 2 diabetes, which is multi-factorial in its development, but to an extent is due to widespread consumption of sugar-sweetened beverages’.68
This is an interesting admission, given that the HSFSA, a non-governmental organisation linked to SAHA, allows its ‘healthy’ Heart Mark to be used on no fewer than 14 sugar-sweetened beverages,69 as well as 23 breakfast cereals, the taste of the majority of which may be ‘enhanced’ with added sugar.
The article continues: ‘There are two problems with the Banting diet: Firstly it is an untested hypothesis, and secondly it comes at considerable cost as it is accompanied by a deterioration in adherents’ lipid profiles, which is certain to increase the likelihood of cardiovascular disease. The SA Heart Association cannot condone the Banting diet until conclusive proof of the long-term beneficial effects of increasing dietary saturated fat have been demonstrated.’
Which raises the question: If SAHA is really so concerned that its pronouncements be based on hard scientific evidence, why does it continue to promote a diet for which, despite 50 years of research, there is still no ‘conclusive proof of the long-term beneficial effects’ (Chapter 13)? And how can it claim that the Banting diet is an ‘untested hypothesis’? Or that Banting exclusively promotes a diet high in saturated fat? Is SAHA not aware that any diet that promotes an increased fat intake must promote an increased consumption of all three types of fat: mono- and polyunsaturated fats, as well as saturated fats (see Table 8.2)? Is SAHA simply ignorant of all this information, or is it wilfully misleading the South African public?