Are fats and cholesterol really as demonic as we thought?
New research suggests that doctors may needlessly vilify cholesterol and demonise fatbrunch Updated: Jul 22, 2017 23:02 IST
Each time I come across an interesting bit of news about food and health, I write about it. If you’ve been following my health articles, you will know that they follow two basic trajectories. One: foods that may not necessarily be very good for you, such as milk or gluten. And two: the links between heart disease and the food we eat.
It’s the second strand that intrigues me this week. Ever since the turn of the century when The New York Times Magazine ran a now famous cover story, we have all been grappling with the idea that decades of medical orthodoxy may be founded on a misconception – that fat is a villain and the enemy of good health.
The survey that The Times quoted in that influential article suggested that fats may not cause heart disease or even be bad for you. Such was the impact of the story that protein and fat-rich diets such as Atkins began to soar in popularity. A second finding of the research – that carbohydrates caused obesity – became nearly as influential. In much of the West, people gave up on bread and rice, preferring such newly-rediscovered grains as quinoa. (Actually quinoa is not really a grain in the traditional sense, it is a protein that people use as a rice substitute.)
In much of the West, people gave up on bread and rice, preferring newly- rediscovered grains such as quinoa
Over the years, both of those conclusions have been reinforced by more and more research. In America, they now trace the epidemic of obesity back to a notorious government recommendation that urged people to eat less meat and more grain. You don’t need to be a scientist to work out that the fattest Americans tend to be those at the bottom of the socio-economic ladder who eat lots of wheat-rich (hamburgers, pizza, sandwiches, etc.) foods. (It always intrigues me that, in body-size terms, America is the opposite of the Third World. Here, if somebody is very thin, it often means they are poor and can’t afford enough food. In America, the rich stay thin while the poor get fat.)
Another US government recommendation kicked off the global craze for olive oil. Americans were told that saturated fats (basically, any fat that turns solid when cool) like butter were the enemy and that olive oil was good for you. Till that point, olive oil had been preferred for its taste. Now, people spend three or four times the amount they would spend on normal oil to buy olive oil in the belief that it would keep their hearts healthy.
Doctors even used olive oil to explain the so-called French paradox. If meat was so bad for you, people wondered, then why did the French – who eat lots of red meat – have relatively low rates of heart disease? Ah, easy to explain, said the nutritionists. They cook in olive oil and olive oil contains substances that sweep through the arteries clearing plaque and widening them.
This sounded miraculous till you realised that the parts of France with low rates of heart disease were located in the North where they prefer to cook in lard and butter and not in olive oil. (In any case, the evidence for the French paradox itself, now seems to be fading.)
Over the last decade, studies suggest that the basis for the medical establishment’s hatred of fats (and especially animal fats like butter) is fundamentally flawed. Last year, the US government conceded that there was no direct link between dietary cholesterol and cholesterol levels in the blood. Till then, doctors had believed that if we ate cholesterol-rich foods, this cholesterol would show up in our blood. Now, they accept that our bodies do not work in such a simplistic way.
The fat-is-poison orthodoxy suffered another blow two months ago when researchers from the US National Institutes of Health, the Mayo Clinic and the University of North Carolina published a paper suggesting that even in the 1970s, doctors should have known that the anti-fat orthodoxy was flawed. (There is an excellent article about this by Katherine Ellen Foley in Quartz, from where I’ve gleaned much of this information.)
Researchers looked at the raw data of a study that ran from 1968 to 1973, which followed the diets of 9,750 men and women. Some of those who were part of the study ate meals made with animal fats (butter, for instance) while others ate food cooked with olive oil or vegetable fats.
The research showed that those who used plant fats had 14 per cent lower cholesterol overall. But, surprisingly, the people with lower cholesterol had higher risks of death than those who ate animal fats! For every 30 points that cholesterol went down, the risk of death actually increased by 22 per cent. (This is a statistical study so it only tells you what happened, not why it happened.)
So does that mean that the received wisdom about cholesterol and the risk of death is wrong?
Well, may be.
Most of us have been brought up on a plumbing model of heart disease. According to this model, your heart is a big pump and the arteries are the pipes that lead out of it. If these pipes are clogged, it leads to heart disease. The problem with cholesterol or any fat in the blood, we are told, is that it functions like grease and clogs up the pipes, narrowing the flow of blood. And when the flow is restricted, you get a heart attack.
This model is not necessarily wrong. It is just over-simplistic. And the bit about grease blocking the pipe is particularly misleading. In April, researchers from the UK and the US reviewed all the existing studies about cholesterol and heart disease. Their conclusion was that these studies proved that “the conceptual model of dietary saturated fat clogging a pipe is just wrong”.
Heart disease is caused by inflammation. And various factors could cause that inflammation. Blood cholesterol is not entirely blameless. There can be tiny cholesterol bubbles inside the arteries and they could cause heart attacks when they burst. But what makes them burst is still not clear.
What we do know, however, is that another spoon of ghee will not cause the cholesterol bubbles to burst. The researchers found that in every study they looked at, the lowering of fat levels in diets did not reduce the incidence of heart attacks, strokes or coronary disease itself.
Giving up red meat might make sense in America, but in India, chicken often has more fat than goats
So, what should we, as Indians, take away from all this research? I am no doctor. But speaking as a layman who likes reading up on this stuff, here are some tentative conclusions:
Don’t waste money on expensive oils unless you actually like the taste. Olive oil is the subject of huge scams (which I wrote about here a few years ago) revolving around its origin and virginity. It is not clear that it helps greatly in reducing heart disease. And in any case, there are many cheaper oils with many of the same properties as olive oil.
Don’t get too bothered if doctors start telling you to give up red meat. This may make sense in America where beef has a high fat content but in India, chicken often has more fat than our goats. And you are better off eating goat meat (which is usually free range) than nasty industrial broiler chicken.
Statins are a controversial medical subject, so you should probably listen to your doctor and not to me. But here’s what I do know: the obsession with blood cholesterol levels is falling out of favour in modern medicine. The market for statins used to be $20 billion till recently. But after the American Heart Association put out guidelines suggesting to doctors that they prescribe them less, the market has dropped to $12.5 billion.
None of this is to suggest that you should give up eating rice or rotis and gorge on butter. If there is one thing I have learnt after years of seeing scientists change their minds, it is this: ignore the fads. The basic Indian diet was always okay with the possible exception of sugar (we may eat too much of it).
So pay no attention to the same people who once told us to use vanaspati (which is really bad for you) instead of ghee (which is fine), who try and control our red meat consumption and who shove too many expensive medicines down our throats.
Minimise your fast food intake and eat simply and eat well. That, and a little exercise, should be enough to keep you going.
From HT Brunch, July 23, 2017
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First Published: Jul 22, 2017 23:02 IST