Diets low in fat and saturated fat can actually increase your risk of heart disease. But a high fat diet isn't necessarily the solution either. Read the full transcript here: http://bit.ly/1VmIqo0
Diets low in fat and saturated fat can actually increase your risk of heart disease. But a high fat diet isn't necessarily the solution either. Read the full transcript here: http://bit.ly/1VmIqo0
The recently released Dietary Guidelines for Americans continue to stress the importance of limiting saturated fat. The primary charge against saturated fat is that it increases your cholesterol levels, which presumably raises your heart disease risk. But a meta-analysis of 21 studies involving more than a quarter of a million people shows that the amount of saturated fat you consume has no significant influence on your heart disease risk. What's more, three-quarters of the people who end up in the hospital due to heart attacks have normal cholesterol.
Clearly, old assumptions about saturated fat, cholesterol levels, and heart disease risk need to be updated. In fact, new research suggests that saturated fat may actually play a role in reducing your risk of heart disease.
We've all been taught to think of cholesterol as being either "good" or "bad." HDL cholesterol is the "good" kind of cholesterol. The more HDL in your blood, the better. But the blanket categorization of LDL as "bad" cholesterol is an over-simplification. It turns out that LDL cholesterol particles come in different sizes—and the size and shape of your LDL particles may be even more important than how many you have.
If most of your LDL particles are big and fluffy, you may have a lower risk of cardiovascular disease. LDL particles that are small and dense, on the other hand, are associated with a higher risk. So, someone with high LDL cholesterol numbers but lots of big, fluffy particles may be better off than someone who has low LDL cholesterol levels but a lot of small dense particles. And this may explain the paradox of why so many people having heart attacks actually have low or normal cholesterol levels.
This new understanding of cholesterol particle size also changes how we think about the relationship between saturated fat and heart disease risk.
While diets that are very low in fat and saturated fat may reduce LDL cholesterol readings, they can also decrease the number of big fluffy particles and increase the number of small dense particles. That's exactly the opposite of what you want to do. And although eating saturated fats in the form of meats, eggs, full-fat dairy products, and coconut oil may cause your LDL numbers to go up, it may also increase the size of the LDL particles, which is a good thing.
So, did we have the entire thing backward? Is limiting saturated fat actually bad for your heart? That's certainly the position of those who advocate diets that are extremely high in fat, especially saturated fat. But I'm not suggesting such an extreme reversal.
For one thing, this research is still fairly preliminary. We need more data to understand how genetics and other risk factors or health conditions play into this. We need to study the long-term effects of diets that are higher in saturated fat on people with and without other heart disease risk factors such as obesity or Type 2 diabetes.
More importantly, whenever we take our diet to extremes, whether it's extremely low-fat or extremely low-carb or any other extreme, we increase the risk of nutrient deficiencies and imbalances. There is no super-food so super, nor wonder-nutrient so wondrous, that we should eat it to the exclusion of all other foods and nutrients. Our bodies really do thrive on balance and variety.
While I'm convinced that saturated fat doesn't have to be assiduously avoided, why jump to the other extreme? There is a middle ground between complete avoidance and excessive intake—and that goes for total fat as well as saturated fat.
Diets that are extremely low in fat tend to be high in carbohydrates. Now if all of those carbohydrates are in the form of legumes and brightly colored fruits and vegetables, that's usually a pretty good thing. More often, though, a lot of those carbohydrates are in the form of grains and refined carbohydrates, and that's definitely not so great.
Replacing calories from refined carbohydrates with calories from fat is usually a good thing. Practically speaking, I'm suggesting that you might be better off putting a fat pat of butter on your vegetables and skipping the dinner roll, or going with full-fat yogurt and skipping the low-fat blueberry muffin.
But I also think it makes sense to eat both saturated and unsaturated fats. That way you get the benefits of both without the risk of overdoing either. Practically speaking, I'm suggesting that your diet might include moderate amounts of butter and olive oil, cheese and avocado, walnuts and coconut.
See also: What's the Optimal Ratio of Saturated and Unsaturated Fat?