Margarine May Raise Diabetes, Heart Disease Risk

The long-running debate over margarine or butter or other fats has been around for years, and rightfully so. Experts generally agree that trans fats, often found in older forms of margarine, should be avoided due to their link to heart disease. But saturated fats, commonly found in butter and other dairy products, remain controversial. While they’ve traditionally been associated with heart risks, some studies have suggested that dairy fats might actually offer certain health benefits.  Butter, however, has been noted in some research to increase “bad” LDL cholesterol, though not all studies agree.

Margarine and spreads similar to margarine are made from vegetable oils, which means they typically have less saturated fat than butter. Initially, margarine was believed to be a healthier alternative to butter for heart health and reducing the risk of cardiovascular disease (CVD). But further research revealed that the trans fats in margarine could negatively impact health. While regulations in the U.S. have significantly reduced and eventually eliminated industrial trans fats in these products, the levels of trans fats in foods in some other countries remain a concern. Additionally, oils vary in their mix of unsaturated and saturated fats, and some margarines contain trans fats if they are partially hydrogenated. 

Researchers are still trying to fully understand how long-term consumption of butter, margarine and non-hydrogenated oils (like olive oil) impacts heart disease and diabetes. Current dietary advice suggests limiting saturated fats, but some recent studies indicate that dairy fat might have certain health benefits. To learn more, a recent study was conducted to bridge this knowledge gap, and the results were published in the European Journal of Clinical Nutrition.

How Was This Study Conducted?

To conduct this study, researchers used data from the Framingham Offspring cohort, involving over 5,000 participants. The Framingham Offspring cohort concluded in 2014 after more than 40 years of data collection. After excluding participants who had certain traits, like having low or high body weights or drinking excessive alcohol intake, the researchers evaluated data from 2,459 subjects. 

To gather information about what participants ate, researchers asked them to record everything they consumed over two sets of three days, covering two weekdays and one weekend day. 

The analysis looked at three main types of fats people use in cooking and eating:

• Butter, which can come in tub or stick form 
• Margarine, which can be full-fat or lower-fat
• Non-hydrogenated oils, such as olive oil, safflower oil, coconut oil, palm oil, soy oil and blends of these. 

The researchers investigated potential links between consumption of these foods and cardiovascular disease and type 2 diabetes risk.

Four years after the final dietary assessment, researchers measured body fat, cholesterol and blood sugar levels to better understand participants’ health. Since data from this later exam wasn’t fully available, some information, like insulin resistance, was taken from the previous exam. Blood samples, taken after participants fasted overnight, were tested for “good” cholesterol (HDL), “bad” cholesterol (LDL), triglycerides and blood sugar levels using reliable methods. Body mass index (BMI) was also calculated. All of this data was used to track and evaluate various health outcomes over time.

What Did The Study Find?

Eating more margarine (around 7 grams or more per day compared to 2 grams or less) was linked to a higher risk of developing heart disease and type 2 diabetes. Specifically, people who consumed more margarine had about a 29% higher chance of heart health problems and a 41% greater chance of developing type 2 diabetes. Oils didn’t appear to affect the risk of developing type 2 diabetes.

The findings also indicated that people who consumed the most butter had a 31% lower risk of developing type 2 diabetes compared to those who consumed less. Interestingly, both butter and oil seemed to be linked with a lower risk of cardiovascular disease, but the relationship wasn’t straightforward, and it varied depending on the amount consumed. 

Eating non-hydrogenated oils was linked to slightly higher levels of body fat, but neither butter nor margarine showed any clear connection to body fat levels. However, when factors like age, sex, body weight, carbohydrate intake and diet quality were considered, people who consumed more butter and non-hydrogenated oils had lower levels of insulin resistance. 

When it came to blood cholesterol levels, butter stood out as the only fat that showed a positive connection with “good” HDL cholesterol, lower triglycerides (a type of fat found in the blood) and a healthier balance between triglycerides and HDL cholesterol. On the other hand, eating more than 7 grams of non-hydrogenated oil per day, compared to 2 grams or less, was linked to higher levels of “bad” LDL cholesterol. For margarine, however, there didn’t seem to be any significant effects on cholesterol or blood fat levels in these analyses.

An important limitation is that the study participants were mostly white and European, which means the findings may not apply to people from other backgrounds. Additionally, while efforts were made to consider other possible influencing factors, it’s still possible that not all of them were accounted for.  Another limitation of the study is the reliance on self-reported dietary data, which can be prone to inaccuracies and biases, such as underreporting or overestimating food intake. 

Furthermore, as the study is based on observational data, it cannot establish a cause-and-effect relationship between the variables, only correlations. Finally, margarine, particularly at the time of the dietary data collection in this study, was more likely to contain industrial trans fats, which may not reflect the effects of margarines available at many retail stores that are free from those fats. 

How Does This Apply to Real Life?

If you are focused on making dietary choices to support your health, understanding these findings can help. For instance, if you’re someone who enjoys using butter, this research suggests that moderate consumption might not be as harmful as once feared. Butter’s potential association with improved HDL cholesterol and lower triglycerides may provide some reassurance, especially when balanced with an otherwise healthy diet.

However, it’s essential to keep portion sizes and overall saturated fat intake in mind, as excess consumption may still have negative health implications. For those looking to reduce risks of heart disease and type 2 diabetes, using non-hydrogenated oils like olive or safflower oil for cooking might be a better option when prioritizing healthy fats.

For margarine consumers, this study highlights the importance of being mindful about the products you choose. Opting for newer formulations that don’t contain trans fats is crucial, as older or partially hydrogenated margarines are linked to higher risks of heart disease and type 2 diabetes. 

The Bottom Line

A new study published in the European Journal of Clinical Nutrition sheds valuable light on how various fats may impact health. In particular, it found that regular margarine use may raise the risk of diabetes and heart disease. Choosing newer margarine products that are free of trans fats may help you avoid some of those health effects. This study also observed that butter, once widely criticized for its saturated fat content, shows potential benefits when consumed in moderation, particularly its association with improved HDL cholesterol and lower triglyceride levels. Non-hydrogenated oils also appear to be a solid choice for heart health, offering healthier fat profiles, though they do require mindful consumption due to their potential link to higher LDL cholesterol levels.

Ultimately, the key takeaway is that balance and informed choices are essential. Rather than demonizing or overly glorifying a single type of fat, focusing on variety and high-quality options may lead to better health outcomes.