In recent years, seed oils have been caught in a swirl of controversy. Critics claim they contribute to chronic disease and inflammation. However, new research is shedding light on a different narrative—one that suggests linoleic acid, a major component of seed oils, may actually help reduce the risk of heart disease, type 2 diabetes, and systemic inflammation.

This insight challenges the widespread perception that seed oils are harmful, especially when used in moderation and sourced from whole food ingredients.

Rethinking the Reputation of Seed Oils

Seed oils like sunflower, soybean, and canola have become dietary staples around the world, especially in cooking and food manufacturing. Yet their popularity has also attracted criticism, especially on social media and in alternative health circles. Some claim that omega-6 fatty acids found in these oils break down into harmful byproducts when heated, triggering inflammation and chronic disease.

But according to a growing body of research, these concerns may be overblown. In fact, when consumed from healthy sources, seed oils might actually improve several important health markers.

What Is Linoleic Acid?

Linoleic acid is a type of polyunsaturated fatty acid (PUFA), specifically an omega-6 fatty acid. It’s considered an essential nutrient, meaning your body cannot produce it on its own and must obtain it through food.

Common sources include:

  • Seed oils (sunflower, safflower, soybean, canola)

  • Nuts and seeds

  • Eggs

  • Poultry and some meats

PUFAs like linoleic acid are known to:

  • Lower LDL (“bad”) cholesterol

  • Improve insulin sensitivity

  • Support immune system function

Despite these benefits, linoleic acid has become controversial due to its rise in the American diet over the past few decades, largely due to its presence in processed foods.

Where Did the Concern About Seed Oils Come From?

The suspicion surrounding seed oils dates back to the late 1960s and early 1970s, a period that saw the increased use of soybean oil in packaged foods. During the same time, rates of obesity and type 2 diabetes began rising in the United States.

Some critics, including public figures like Robert F. Kennedy Jr., argue there’s a causal link. Their theory is that heating seed oils leads to the breakdown of omega-6 fatty acids into toxic compounds that cause inflammation, oxidative stress, and metabolic dysfunction.

However, scientists caution against jumping to conclusions. Health outcomes are influenced by a wide range of factors—including sedentary behavior, smoking, alcohol consumption, and overall diet quality.

New Research Finds Linoleic Acid May Lower Disease Risk

Recent findings presented at the American Society for Nutrition’s annual meeting provide a strong counterpoint to the anti-seed oil narrative.

Researchers analyzed data from 1,894 adults and evaluated levels of linoleic acid in their blood. They compared these levels to biomarkers of insulin resistance, inflammation, and metabolic health. The results showed that individuals with higher levels of linoleic acid had:

  • Lower blood glucose

  • Lower insulin concentrations

  • Reduced HOMA-IR scores (a marker for insulin resistance)

  • Lower levels of inflammatory biomarkers

In other words, higher linoleic acid intake was associated with better metabolic and cardiovascular health.

What This Means for Chronic Disease Risk

These findings support earlier studies linking linoleic acid to a reduced risk of heart disease, stroke, and type 2 diabetes. According to Dr. Kevin Maki, one of the researchers involved in the study, the results are consistent with evidence suggesting linoleic acid may have anti-inflammatory rather than pro-inflammatory effects.

So why the confusion? Experts say much of the alarm over seed oils is driven by how they are used in processed foods. When seed oils are used in deep-fried snacks or overly refined packaged goods, they are often consumed alongside added sugars, refined carbs, and trans fats—which are known contributors to chronic illness.

Why Unsaturated Fats Like Linoleic Acid May Be Beneficial

Replacing saturated fats (like butter, lard, and coconut oil) with unsaturated fats, including PUFAs, is a well-supported heart-healthy strategy. Unsaturated fats help:

  • Maintain cell membrane integrity

  • Regulate hormones and enzyme activity

  • Support brain and nervous system health

Furthermore, some research suggests that linoleic acid and other unsaturated fats may influence gene expression and play a role in reducing oxidative stress—factors that may protect against insulin resistance and metabolic syndrome.

Understanding the Real Problem: Processed Foods, Not the Oils

One of the most important takeaways from the new research is that context matters. Linoleic acid in itself is not harmful—but the source of it is critical.

Nyree Dardarian, a registered dietitian and director of the Center for Nutrition and Performance at Drexel University, explains that seed oils in their natural form—as found in nuts, seeds, and whole plant oils—are beneficial. However, ultra-processed foods fried in these oils can lead to excess calorie intake, inflammation, and poor metabolic outcomes.

“Roasting vegetables in a small amount of seed oil is not the same as eating ultra-processed chips or fast food,” Dardarian notes.

Smart Ways to Use Seed Oils in a Healthy Diet

Experts recommend the following guidelines for incorporating seed oils safely and effectively:

  • Choose unrefined or cold-pressed oils when available.

  • Use seed oils like canola, sunflower, or soybean in moderation when cooking at home.

  • Avoid deep frying or reusing oils multiple times at high temperatures.

  • Balance fat intake by also including monounsaturated fats (olive oil, avocado) and omega-3 sources (flaxseeds, chia seeds, fatty fish).

  • Prioritize whole food sources of linoleic acid like nuts, seeds, and legumes.

This balanced approach allows you to benefit from linoleic acid without the health risks linked to ultra-processed foods.

What Do Doctors Who Cook Say?

Dr. Nate Wood, a physician who specializes in culinary medicine, isn’t just a medical expert—he’s also a home cook. He personally uses canola oil in his kitchen.

“If I believed seed oils were harmful, I wouldn’t be cooking with them,” he said. His practical experience mirrors what science is increasingly showing: that seed oils, when used appropriately, are safe and even beneficial.

Conclusion: Don’t Fear Seed Oils—Use Them Wisely

Despite internet rumors and popular myths, current research indicates that seed oils are not inherently harmful. In fact, linoleic acid—a key component of seed oils—may offer protective effects against major chronic diseases, including heart disease and diabetes.

The key is to focus on quality and moderation. Avoid seed oils that have been used to fry processed foods, and instead use them as part of a diverse, nutrient-rich diet.

Rather than cutting out seed oils entirely, embrace a smart and informed approach to cooking. Used correctly, they can be a valuable tool for supporting long-term health.