It’s high in saturated fat and has poor nutritional content.
Jackson isn’t against all fats. He is a fan of the polyunsaturated and monounsaturated varieties. It’s saturated fats he is gunning for because of the overwhelming evidence that they’re bad for your heart. He says the pro-fat lobby often doesn’t mention this distinction, and what’s more, it isn’t talking about one of the good news stories of public health: we are living longer and are far less likely to die of a heart attack.
“Life expectancy in New Zealand is increasing by five hours a day,” says Jackson. “And there has been a 90% decrease in coronary heart disease mortality. When we first started watching this decline, we didn’t believe it. We looked at every possibility – that we’d changed diagnostic criteria, for instance. But there was no doubt it was going down in parallel with a decline in saturated-fat consumption.”
Our big butter-eating years were the early to mid-1960s, when we were getting through 20kg per person each year, says Jackson. “We were leaner than we are now, we ate less processed food, did more exercise and we were dropping dead from heart attacks and strokes at 10 times the rate we are now.”
People were advised to eat less saturated fat and they responded by turning to oils such as olive and canola. By the late 1960s, heart disease rates were starting to decline.
Things changed in the 1980s, says Jackson. “The message was simplified to ‘eat less fat’, because cancer researchers had started to worry about fat as a cause of cancer.”
It had been reasonably easy for food manufacturers to respond to the “less-saturated fat” dictate by simply replacing unhealthy fats with healthier oils. But once they had to produce low-fat products, they looked for another replacement. Since salt already had a bad name, they chose sugar.
“That was a mistake,” says Jackson. “There is reasonable evidence to suggest that replacing fat with sugar led to increased weight.”
However, replacing fat with carbohydrates isn’t the best idea, either. Starchy carbs spike the blood sugar, but there is evidence they lower HDL cholesterol, widely known as the good cholesterol, Jackson says. And low HDL levels are linked to a higher risk of heart disease as well as diabetes.
No protein or calcium
If we had just stayed with that first message, and replaced saturated fats with polyunsaturated and monounsaturated ones rather than sugar and carbs, then we might not be in the grip of an obesity and diabetes epidemic.
Of course, there are other sources of saturated fat besides dairy – fatty cuts of red meat and coconut oil, for instance – so why is Jackson picking on butter? Partly, he says, because all the claims about it being a “natural” food don’t stack up.
“It’s actually very refined. The natural product is milk; butter is the cream on top. It has no protein or calcium, it’s just the fat with a few vitamins you can get in other foods. Cheese and yoghurt are made from whole milk, so they have protein and calcium as well as fat. Butter is made from the bit that is overwhelmingly bad for you.”
We are the world’s leading consumers of butter, he points out. At our lowest point in the late 90s, annual consumption may have got down to about 7kg per person, but by 2011 we were back up to 20kg. In contrast, the French eat less than 8kg and also consume less red meat than we do.
Jackson’s argument is that if we stopped eating just butter, we could radically reduce our saturated fat intake in one fell swoop.
“I’m not a low-fat advocate,” he stresses. “I’m a low-saturated-fat advocate.”
But can we be sure of the link between less bad fat and lower rates of death from heart disease? Haven’t there been other lifestyle and diet changes over the past 40-50 years? We are smoking a lot less, for instance.
Jackson has looked into this and says the pattern with cigarette use is very different. Male smoking rates at the same time as the female rate increased. Meanwhile, heart disease was declining at the same rate in both sexes.
“The first country to reduce smoking was the UK. It had a reduction five to 10 years earlier than us, but its heart disease epidemic didn’t start declining until 10 years after us,” he says.
Although we began eating less salt in the 1950s, when domestic refrigerators meant we didn’t have to rely on it to preserve our food, that may have resulted in a reduction in blood pressure, the major risk factor for stroke, but the number of heart attacks was still rising.
As for statin cholesterol-lowering drugs, Jackson says they only started being prescribed in a big way in the early 2000s. “I think they are the reason we aren’t seeing a rise in heart disease now. People are eating saturated fat, but they’re also taking their statins.”
Fewer processed foods
So, how should we being eating in 2017? Jackson is a fan of the Mediterranean diet, which has plenty of science to back it up.
“We should have a moderate-fat diet that is low in saturated fat, lots of fresh fruit and vegetables, wholefoods and good carbs [not the white, starchy ones]. There’s nothing wrong with lean meat and some dairy, just don’t eat the refined stuff. And we should be eating fewer processed foods because it’s easy to hide lots of calories and refined carbs in them.”
It is not hard to tell whether a fat is saturated. If it’s solid or semi-solid at room temperature, as are coconut oil and butter, then it should be avoided.
Jackson admits he loves the taste of butter. He even eats it once or twice a month, usually at a restaurant.
“It’s a treat food, like ice cream, and people need to start thinking of it that way,” he says. “There is no way they should be eating it on a regular basis.”