Nutrition Myth: Red Meat Causes Heart DiseasePosted by Josh Gape on
The myth that red meat causes heart disease finds it origins in a study carried out by a researcher called Ancel Keys in the early 1950s.
The study looked at the amount of saturated fat, particularly from animal sources, in people’s diets relative to rates of cardiovascular disease.
It showed that there was a correlation between the amount of saturated fat people were consuming and cardiovascular issues.
The conclusion was that red meat, due to it being high in saturated fat, increased cholesterol, which clogged arteries and lead to heart attacks.
This dramatically changed global food policies, leading to a reduction in red meat consumption and an increase in low fat and processed foods entering people lives.
Ironically, it’s these replacements that have contributed to the ever increasing rates of chronic illness we see in society today.
The case against these dietary guidelines is now so strong that even mainstream science is starting to reverse its advice.
A massive meta-analysis and systematic review of both observational and randomised controlled trials involving over 600,000 people concluded that ‘current evidence does not clearly support cardiovascular guidelines that encourage low consumption of saturated fats.’
Also the Academy of Nutrition and Dietetics has come out and said that cholesterol is no longer a nutrient of concern.
So let’s unpack the main issues with this study:
- Correlation is NOT causation - Heart disease takes years to develop, therefore Keys study analysing it took place over a long period of time. This is what’s known as an observational study. By its nature, this type of study does not test a specific intervention against a control group. Instead it observes a sample population to identify trends. Subsequently it can give us some idea if a connection exists between X & Y but can’t say for definite because there are so many other factors at play. For example, it could be observed that people who ate more beef burgers had a higher chance of having a heart attack. However, potentially these people were also eating more chips and drinking greater amounts of sugary drinks and therefore it’s difficult to say exactly what caused the issue. How inaccurate these studies can be was highlighted by Tyler Vigen who identified that between 1999 and 2009 there was a really strong correlation between the films Nicolas Cage appeared in and the number of people who drowned in pools.
- Cherry picking data - Certain populations in Keys data actually showed the opposite of his overall trend. Although they were eating diets containing high amounts of saturated fat from animals, their levels of cardiovascular disease were low. These bucks in the trend led to further research by some of Keys students, who observed that a diet in polyunsaturated fats from vegetable oils, decreased cholesterol levels but not mortality. Whereas people eating a diet high in saturated fat, had higher cholesterol levels but lower mortality rates. These conflicting results were not published until the late 1980’s after the low fat agenda had been implemented and a lot of damage had been done.
- Understanding cholesterol - Cholesterol if often massively over simplified. It’s not uncommon to hear supposed ‘health experts’ state that high cholesterol increases your risk of heart disease. However, when it comes to blood lipids, it is far too simple to just look at total cholesterol or calculated LDL to determine health status. There are three main markers that should be observed and understood here; HDL, LDL and triglycerides. Firstly, if an individuals triglyceride to HDL ratio is less than one, this is promising in terms of cardiovascular health. Secondly, it’s important to understand that LDL, which is often vilified, comes in two forms; small dense LDL and large fluffy LDL. Small dense LDL particles can be problematic, however large fluffy LDL particles are not associated with cardiovascular issues. This is still a simplified way of looking at things because the body works as a holistic system. Therefore this data should be looked at in conjunction with all other health markers to assess someone’s risk of cardiovascular disease. That said, having this greater understanding of cholesterol will give you a much more realistic picture of health status than the basic statement of high cholesterol is bad and raises your risk of heart disease.
Please share this blog post with any one who’s still wary of red meat and the healthy fats within it.