Since the 1950s, people have believed that saturated fat is bad for human health.
This was originally based on observational studies showing that people who consumed a lot of saturated fat had higher rates of death from heart disease.
The diet-heart hypothesis states that saturated fat raises LDL (bad) cholesterol in the blood, which then supposedly lodges in the arteries and causes heart disease.
Even though this hypothesis has never been proven, most official dietary guidelines are based on it (
While the issue is still debated, numerous recent studies have found no link between saturated fat consumption and heart disease.
This article reviews 5 of the large, most comprehensive and most recent studies on this issue.
1. Hooper L, et al.
Reduction in saturated fat intake for cardiovascular disease. Cochrane Database Systematic Review, 2015.
Details: This systematic review and meta-analysis of randomized controlled trials was performed by the Cochrane collaboration — an independent organization of scientists.
This review includes 15 randomized controlled trials with over 59,000 participants.
Each of these studies had a control group, reduced saturated fat or replaced it with other types of fat, lasted for at least 24 months, and looked at hard endpoints, such as heart attacks or death.
Results: The study found no statistically significant effects of reducing saturated fat in regard to heart attacks, strokes, or all-cause deaths.
Although reducing saturated fat had no effects, replacing some of it with polyunsaturated fat led to a 27% lower risk of cardiovascular events (but not death, heart attacks, or strokes).
However, partially replacing saturated fat with polyunsaturated fat may reduce the risk of cardiovascular events (but not death, heart attacks, or strokes).
These results are similar to a previous Cochrane review conducted in 2011 (
2. De Souza RJ, et al.
Intake of saturated and trans unsaturated fatty acids and risk of all-cause mortality, cardiovascular disease, and type 2 diabetes: Systematic review and meta-analysis of observational studies. BMJ, 2015.
Details: This systematic, observational review of studies looked at the association of saturated fat and heart disease, stroke, type 2 diabetes, and death from cardiovascular disease.
The data included 73 studies, with 90,500–339,000 participants for each endpoint.
Results: Saturated fat intake wasn’t linked with heart disease, stroke, type 2 diabetes, or dying of any cause.
Conclusion: People who consumed more saturated fat weren’t more likely to experience heart disease, stroke, type 2 diabetes, or death from any cause, compared with those who ate less saturated fat.
However, the results from the individual studies were very diverse, so it’s hard to draw an exact conclusion from them.
The researchers rated the certainty of the association as “low,” emphasizing the need for more high quality studies on the subject.
3. Siri-Tarino PW, et al.
Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. American Journal of Clinical Nutrition, 2010.
Details: This review looked at evidence from observational studies on the link between dietary saturated fat and risk of heart disease and stroke.
The studies included a total of 347,747 participants, who were followed for 5–23 years.
Results: During follow-up, about 3% of participants (11,006 people) developed heart disease or stroke.
Saturated fat intake wasn’t linked to an increased risk of cardiovascular disease, heart attacks, or strokes, even among those with the highest intake.
Conclusion: This study didn’t find any association between saturated fat intake and cardiovascular disease.
4. Chowdhury R, et al.
Association of dietary, circulating, and supplement fatty acids with coronary risk: A systematic review and meta-analysis. Annals of Internal Medicine Journal, 2014.
Details: This review looked at cohort studies and randomized controlled trials on the link between dietary fatty acids and the risk of heart disease or sudden cardiac death.
The study included 49 observational studies with more than 550,000 participants, as well as 27 randomized controlled trials with more than 100,000 participants.
Results: The study didn’t find any link between saturated fat consumption and the risk of heart disease or death.
Conclusion: People with higher saturated fat intake weren’t at an increased risk of heart disease or sudden death.
Furthermore, the researchers didn’t find any benefit to consuming polyunsaturated fats instead of saturated fats. Long-chain omega-3 fatty acids were an exception, as they had protective effects.
5. Schwab U, et al.
Effect of the amount and type of dietary fat on risk factors for cardiometabolic risk factors, and risk of developing type 2 diabetes, cardiovascular diseases, and cancer: A systematic review. Food and Nutrition Research, 2014.
Details: This systematic review assessed the effects of the amount and type of dietary fat on body weight and the risk of type 2 diabetes, cardiovascular disease, and cancer.
Participants included both people who were healthy and those with risk factors. This review included 607 studies, including randomized controlled trials, prospective cohort studies, and nested case-control studies.
Results: Consuming saturated fat wasn’t linked to an increased risk of heart disease or an increased risk of type 2 diabetes.
The researchers found that partially replacing saturated fat with polyunsaturated or monounsaturated fat may lower LDL (bad) cholesterol concentrations.
It also may decrease the risk of cardiovascular disease, especially in men.
However, substituting refined carbs for saturated fat may increase the risk of cardiovascular disease.
Conclusion: Eating saturated fat doesn’t increase the risk of heart disease or type 2 diabetes. However, partially replacing saturated fat with polyunsaturated fat may help reduce the risk of heart disease, especially in men.
- Reducing saturated fat intake has no effect on your risk of heart disease or death.
- Replacing saturated fat with refined carbs seems to increase your risk of heart disease.
- Replacing saturated fat with polyunsaturated fat may reduce your risk of cardiovascular events, but results for heart attacks, strokes, and death are mixed.
People with certain medical conditions or cholesterol problems may need to watch their saturated fat intake.
However, the study results selected for this article are pretty clear that, for the average individual, saturated fat has no significant association with heart disease.
That said, replacing saturated fat with unsaturated fat may offer slight benefits.
This doesn’t mean that saturated fat is “bad” — just that it’s neutral, while some unsaturated fats are particularly healthy.
By replacing something that’s neutral with something that’s very healthy, you’ll get a net health benefit.
Healthy sources of unsaturated fats include nuts, seeds, fatty fish, extra virgin olive oil, and avocados.
At the end of the day, there doesn’t seem to be any reason for the general population to worry about saturated fat.
There are other issues that are much more worthy of your attention, like avoiding sugary soda and junk food, eating healthy food, and exercising.