Both sugar and fat can negatively impact cholesterol levels if consumed in excess. However, the effect of added sugars versus fats on cholesterol is complex and depends on the specific type and amount of each nutrient. This article examines the latest scientific research to determine whether sugar or fat has a worse impact on cholesterol levels.
How Sugar Affects Cholesterol
Added sugars, particularly from processed foods and beverages, have been linked to lower levels of HDL or “good” cholesterol and higher levels of LDL or “bad” cholesterol and triglycerides. Here’s an overview of the evidence:
Fructose
Fructose is a simple sugar found naturally in fruits but often added to processed foods and drinks. Research indicates that fructose raises LDL and lowers HDL more than other sugars like glucose:
– A review of clinical trials found fructose consistently increased LDL cholesterol compared to glucose [1].
– Another analysis reported fructose-sweetened beverages decreased HDL cholesterol levels [2].
– One proposed mechanism is that fructose increases de novo lipogenesis, or the production of fat, more than other sugars [3].
Added Sugars
Added sugars from processed foods and sugary drinks also appear to negatively impact cholesterol:
– In a study of over 6,000 adults, those who consumed more added sugar had lower HDL and higher triglyceride levels [4].
– Another trial found added sugar intake increased LDL cholesterol and small dense LDL particles linked to heart disease risk [5].
– Replacing added sugars with complex carbohydrates may increase HDL and lower triglycerides [6].
Sucrose
Table sugar or sucrose is made of half fructose and half glucose. Research on sucrose and cholesterol is mixed:
– One study found no significant impact on total or LDL cholesterol compared to starch [7].
– However, another trial reported sucrose increased LDL cholesterol by 6% compared to starch [8].
Overall, added sugars appear more likely to negatively impact cholesterol levels compared to naturally-occurring sugars in fruits and dairy.
How Fat Affects Cholesterol
Dietary fat has complex and varied effects on cholesterol levels. In general, saturated and trans fats tend to increase LDL cholesterol, while unsaturated fats like olive oil have a more beneficial impact. Here’s a summary of how different types of fats affect cholesterol:
Saturated Fat
– Saturated fats, found mainly in animal products like meat and dairy, raise total and LDL cholesterol levels more than unsaturated fats [9].
– Palmitic acid, a saturated fat, boosts LDL cholesterol by decreasing LDL breakdown and clearance [10].
– Replacing just 5% of calories from saturated fat with polyunsaturated fat may reduce LDL cholesterol by 10% [11].
Trans Fat
– Trans fats, found in fried foods, baked goods, and margarine, increase LDL cholesterol, lower HDL, and increase heart disease risk [12].
– Limiting trans fats to under 1% of calories (2 grams per day) significantly decreases total and LDL cholesterol [13].
– The FDA has banned partially hydrogenated oils, the main source of trans fats, as of 2018.
Monounsaturated Fat
– Monounsaturated fats, found in oils like olive oil, avocados, and nuts, tend to lower LDL and raise HDL cholesterol when they replace saturated fat [14].
– Oleic acid, the main monounsaturated fat, may help remove excess cholesterol from tissues [15].
Polyunsaturated Fat
– Polyunsaturated fats like omega-3s and omega-6s lower LDL and triglyceride levels while raising HDL [16].
– Consuming these healthy fats found in fish, nuts, seeds and vegetable oils improves cholesterol levels more than carbohydrates [17].
Dietary Cholesterol
– Dietary cholesterol has a smaller impact on blood cholesterol levels than once believed.
– Saturated fat intake tends to have a greater influence on cholesterol than dietary cholesterol [18].
– However, some sensitive individuals may still need to limit cholesterol from eggs, shellfish and organ meats [19].
Sugar vs Fat: Which is Worse for Cholesterol?
Overall, the preponderance of evidence indicates added sugars have a more direct negative impact on cholesterol levels compared to total and saturated fats:
– While both added sugars and saturated fats can raise LDL and lower HDL cholesterol, sugar appears to have a greater triglyceride-raising effect [20].
– When consumed in equal calories, fructose from added sugars produces worse cholesterol profiles than saturated fat [21].
– However, some types of saturated fats like palmitic acid potently increase LDL cholesterol through specific mechanisms [10].
– Polyunsaturated fats like omega-3s have beneficial effects on cholesterol while added sugars contain no nutrients.
– For optimal heart health, both added sugar and saturated fat should be limited. Focus on anti-inflammatory monounsaturated and polyunsaturated fats instead of pro-inflammatory saturated and trans fats.
Tips to Improve Cholesterol Levels
Here are some evidence-based tips to maintain healthy cholesterol levels:
Limit Added Sugars
– Reduce sources of added sugars including soda, candy, baked goods, and sugary cereals.
– Avoid sweetened beverages and limit fruit juice. Select whole fruits instead for fiber and nutrients.
Reduce Saturated Fats
– Limit red and processed meat, full-fat dairy, butter, cheese, and tropical oils like coconut and palm oil.
– Choose lean proteins including poultry, fish, beans, tofu or nuts.
Increase Unsaturated Fats
– Cook with olive, canola or avocado oil instead of butter or lard.
– Eat fatty fish like salmon or sardines twice a week.
– Snack on nuts, seeds and avocados.
Eat More Fiber
– Choose whole grains like oats, brown rice and quinoa.
– Eat ample vegetables, fruits, beans, lentils and chickpeas daily.
– Add chia, flaxseeds or psyllium husk to boost fiber intake further.
Exercise Regularly
– Get at least 150 minutes of moderate activity or 75 minutes of vigorous activity per week.
– Combine aerobic exercise with strength training for optimal results.
– Exercise helps boost HDL cholesterol and promote weight loss.
Lose Weight If Overweight
– Carrying excess weight negatively impacts cholesterol levels.
– A 5-10% reduction in body weight can help improve cholesterol markers.
– Focus on a sustainable, balanced diet with more vegetables and lean protein.
Conclusion
While both added sugars and saturated fats can negatively impact cholesterol when consumed in excess, the available research suggests added sugars may be more detrimental. Fructose from added sweeteners raises LDL and triglycerides while lowering HDL more than saturated fats. However, palmitic acid in animal foods potently increases LDL cholesterol through specific mechanisms.
For the best cholesterol profile, limit foods high in added sugars, processed carbohydrates, and saturated fats. Focus on anti-inflammatory unsaturated fats from fatty fish, nuts, seeds, avocados and vegetable oils instead. Boosting fiber intake, exercising regularly, maintaining a healthy weight and following an overall balanced diet can all support healthy cholesterol levels. Work with a healthcare provider to determine your optimal cholesterol goals and dietary changes based on your individual heart disease risk.
| Nutrient | Effect on LDL Cholesterol | Effect on HDL Cholesterol | Effect on Triglycerides |
|---|---|---|---|
| Added Sugars | Increase | Decrease | Increase |
| Saturated Fat | Increase | Neutral or decrease | Increase mildly |
| Monounsaturated Fat | Decrease | Increase | Neutral or decrease |
| Polyunsaturated Fat | Decrease | Increase | Decrease |
References
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