What ISN'T the best diet for heart health?
When we see patients in the office, the most important conversation we have is about the best dietary pattern for preventing and even reversing heart disease. Many patients who come to us simply have no idea that their nutrition determines their health. Not just affects it, but determines it.
Other patients come to us feeling that they already know which dietary pattern is the best, because they heard all about it from a friend or from social media/YouTube.
One of the dietary patterns that cycles in and out of popularity is a low-carbohydrate, high-fat diet. In the 1970s, this type of diet was initially popularized as the Atkins diet. It has many iterations; the most recent iterations are the “Paleo” or “Keto” diets. In a 2022 survey, approximately 20% of American adults reported following some form of a low-carbohydrate (LC) dietary pattern, including ketogenic/paleo/atkins type diets.
You might be surprised to know, but despite their popularity there is actually no evidence that these diets lead to better health. In fact, there’s an increasing amount of evidence that suggests that these diets actually worsen health.
An article published this past week added to the ongoing discussion by investigating the association between these “Atkins/Paleo” low carb/high fat dietary patterns with major cardiovascular events: heart attacks, bypass/stent procedures and death from heart disease.
The authors used data from the UK Biobank cohort, which is a huge source of data that we have referred to previously in these blogs. What is the UK Biobank? It is a massive epidemiology study of human health, genomics, and diseases that began recruiting in 2006, and by 2010 had enrolled half a million 40-69 year old participants from across the United Kingdom.
In this recent study, the authors looked at patients eating a low carb/high fat diet, and compared them to matched participants who were eating a “standard” diet (defined as anything other than a low carb/high fat diet). Participants in the low carb/high fat diet group consumed twice as much energy from animal fat, animal proteins and saturated fat compared to the standard diet group. The low carb/high fat diet participants were successful in their goals: they showed higher levels of ketone bodies, which is often the goal of these diets.
Eating a low carb/high fat diet did not, however, translate into better health. The very low carb diet group developed higher levels of LDL-C (“bad cholesterol”) and apolipoprotein B (a more advanced/accurate measurement of “bad” cholesterol). Additionally, 11% of the very low carb diet participants developed EXTREMELY high levels of cholesterol (LDL > 190), which was double the number of people who developed extremely high levels while eating a "standard" diet. The research suggested that these people likely had a genetic susceptibility to developing extreme LDL levels on this diet.
But is it really that bad for “bad” cholesterol to increase? The supporters of low carb/high fat diets say that the health benefits outweigh any downside of cholesterol issues, or that cholesterol simply isn’t important. Which is why it’s so important for scientists to focus on actual life-changing cardiac events when they perform research on these diets.
So was there a difference in outcomes between people eating the two different diets?
Absolutely!
After an average of almost 12 years, people following a low carb/high fat diet were TWICE as likely to have a major cardiac event than those eating a standard diet!
9.8% of low carb/high fat diet followers suffered cardiac events vs. just 4.3% in the “standard” diet group.
Additionally, the 11% of low carb/high fat diet individuals that demonstrated severely high levels of bad cholesterol had the GREATEST risk of a cardiac event, over 6-fold higher risk of an event than the standard diet!
These people ate a diet that drove their cholesterol to dangerous levels, and they paid the price.
In previous studies, researchers have found that low carb/high fat dietary patterns are associated with worse heart health: elevated risk of coronary artery calcium progression and increased heart disease risk in >40,000 Swedish females followed for over 15 years. In another prior research study, ~463,000 people followed for over 16 years found that participants with the lowest carbohydrate intake had the highest risk of overall mortality and CVD death.
To date, there is no evidence that low carb/high fat diets are truly healthy, and the burden of data is building that they are actually harmful. And in this most recent study, the low carb diet participants weren’t even being compared to people eating what we think is the healthiest diet. They were just being compared to an unrestricted “standard” diet.
We can only imagine how much higher their risk was compared to eating a really healthy diet...
At Wisconsin Cardiology Associates, we counsel our patients to aim for a healthy, plant-based diet, emphasizing fruits, vegetables, beans, lentils, whole grains and nuts. Have questions about the best way you can prevent heart disease? Call us and make an appointment for a consultation.
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