Seed oils have found themselves at the center of a nutritional storm.
From political figures like Robert F. Kennedy Jr. to countless wellness influencers, there’s a rising tide of criticism against common cooking oils such as canola, soybean, and sunflower oil. Kennedy’s “Make America Healthy Again” campaign even hawks merchandise stamped with slogans like “Make Frying Oil Tallow Again”, echoing the nostalgic days of beef fat sizzling in cast-iron pans.
But is this backlash backed by science—or are we oversimplifying a complex dietary issue?
What Are Seed Oils, Really?
Often grouped under the misleading label of “vegetable oils,” seed oils are extracted from the seeds of various plants. These include what some call the “hateful eight”:
Canola, corn, soybean, cottonseed, grapeseed, sunflower, safflower, and rice bran oil.
Their rise in popularity was largely enabled by the invention of the screw press in 1888, which allowed oil to be extracted from seeds in mass quantities. This industrial advancement transformed the American pantry, pushing consumption of oils like soybean up by 1,000 times between 1909 and 1999. As a result, the levels of omega-6 fatty acids in our body fat have risen dramatically—by roughly 136% over the past 50 years.
Omega-6 vs. Omega-3: The Inflammatory Tug-of-War
At the heart of the seed oil controversy lies a biochemical balancing act. Omega-6 and omega-3 fatty acids are both essential fats our bodies need—but in balance. Omega-6s tend to ramp up inflammation, a natural immune response, while omega-3s help calm it down.
Historically, humans consumed these fats in roughly equal amounts. Today, that ratio has ballooned to 15:1 in favor of omega-6, mostly due to our reliance on seed oils. That imbalance has been linked to a slew of health issues: mood disorders, chronic pain, menstrual discomfort, preterm birth—and possibly even colon cancer.
But not all seed oils are created equal. Their omega-6 to omega-3 ratios vary widely:
- Safflower oil: 125:1
- Sunflower oil: 91:1
- Corn oil: 50:1
- Soybean oil: 8:1
- Canola oil: 2:1
So while some oils skew heavily toward inflammation-promoting fats, others—like canola and soybean—are far more balanced.
Do Seed Oils Actually Cause Inflammation?
The science is murky. Meta-analyses of studies examining inflammatory markers in people consuming seed oils have found inconsistent results. Only one key inflammatory marker was elevated in those with the highest omega-6 intake, while most others remained unaffected.
What’s more, genetics appear to play a role. People of African, Indigenous, and Latino descent may metabolize omega-6 fatty acids faster, potentially making them more sensitive to the inflammatory effects of seed oils. This adds another layer of complexity—and helps explain why the same oil may impact people differently.
Heart Health: The Good, the Bad, and the Context
Seed oils are often touted as heart-healthy alternatives to saturated fats like butter or tallow. And to some extent, this claim holds water. Clinical trials show that replacing saturated fats with oils like soybean or canola, which have more favorable omega-6:omega-3 ratios, can lower both cholesterol and heart disease risk.
However, the reverse may be true for oils with high omega-6 levels. A long-lost study from the 1970s—recently rediscovered on dusty audio tapes—showed that replacing saturated fats with high omega-6 oils like corn oil actually increased the risk of death from heart disease, despite lowering cholesterol levels.
So, it’s not about whether seed oils are bad, but rather which ones—and in what context—they’re consumed.
Seed Oils and Migraine Relief: A Surprising Twist
Beyond heart health, seed oils may also play a role in neurological conditions—particularly migraines. A landmark randomized controlled trial found that increasing omega-3 intake (via foods like salmon) reduced migraine frequency by two days per month. Even better, combining increased omega-3s with a reduction in omega-6s led to four fewer migraines per month.
That’s a notable improvement—especially when you consider that most modern migraine medications offer only a two-day monthly reduction.
For the estimated 1 in 6 Americans affected by migraines, a dietary shift away from seed oils and toward fatty fish and olive oil may be more effective than a prescription.
What Should You Do?
The debate around seed oils is clearly more nuanced than the viral social media posts suggest. Rather than demonizing all seed oils, the focus should be on moderation, quality, and balance:
- Prioritize low omega-6 options like canola and soybean oil over higher-ratio oils like corn or safflower.
- Limit ultra-processed foods, which often contain the worst offenders in seed oil form.
- Boost your omega-3 intake with fatty fish (like salmon, mackerel, or sardines) or high-quality fish oil supplements.
- Choose extra virgin olive oil, avocado oil, or coconut oil when cooking at home for more stable fat profiles.
- Avoid fear-based food narratives. Nutrition is never black and white—and your health choices should reflect science, not slogans.
The Verdict: It’s Complicated
Seed oils have undoubtedly transformed the modern diet, and their effects on human health are still being understood. While it’s unlikely that simply switching back to beef tallow will solve our dietary woes, it’s equally unhelpful to ignore the real biochemical shifts brought on by excessive omega-6 consumption.
So rather than rallying behind blanket statements, perhaps the real message should be one of balance, awareness, and informed choices.
As with so many things in health, the devil—and the healing—is in the details.
Mary J. Scourboutakos is a physician and nutrition scientist devoted to translating research into real-life dietary solutions. This article originally appeared in The Conversation and was republished by Spirit of Change Magazine.