Refined seed oils

Why it matters

Not all fat is equal, and seed oils are where the nuance gets lost. Whole-food fats from fish, nuts and olives support hormones; the problem is the industrially refined liquid oils — soybean, corn, sunflower, safflower, canola — extracted with heat and solvents, stripped of antioxidants, and now poured into almost everything. Two issues stack up. First, they're overwhelmingly omega-6, and a diet drowning in omega-6 while short on omega-3 tilts the body toward a pro-inflammatory state — and chronic inflammation is one of the quiet disruptors of clean hormone signalling. Second, these fragile fats oxidise when heated, generating compounds that add to that oxidative load right where your hormones are made.

What's inside

The defining feature is linoleic acid, an omega-6 fat that is essential in small amounts but harmful in the flood most people now get. Refined seed oils carry it in bulk with almost no balancing omega-3, skewing the ratio that governs whether your fat intake calms or fuels inflammation. Refining also strips away the natural antioxidants that protect fats in whole foods, leaving them prone to oxidation — especially under the high heat of frying, where they form aldehydes and other reactive by-products. There is nothing nutritionally redeeming being added here; the entry is about subtraction.

For men

The clearest concern for men is indirect but real: a diet built on fried food and seed oils tends to be pro-inflammatory and is repeatedly associated with poorer metabolic health — the soil in which low testosterone grows. Some animal and observational work links high intakes of oxidised, omega-6-heavy oils to testicular oxidative stress and lower testosterone, though human evidence is still debated and shouldn't be overstated. The practical point stands regardless: less fried and processed food, cooked in better fats, is one of the simpler wins for a man's hormonal environment.

For women

For women the issue is the same inflammatory tilt. A chronically high omega-6 load works against the anti-inflammatory balance that supports comfortable cycles, mood and metabolic health — the opposite of what omega-3-rich foods like oily fish and flax provide. Because seed oils are hidden in so many packaged and takeaway foods, cutting back tends to improve the overall quality of the diet at the same time, which matters more than any single oil.

How to eat it

You don't need to fear a salad dressed with a little sunflower oil. The real exposure comes from fried food, takeaways and ultra-processed products, where these oils dominate — so reducing those cuts most of it automatically. At home, swap to extra-virgin olive oil for dressing and gentle cooking, avocado oil or butter/ghee for higher heat, and check labels on the packaged foods you buy most. Think of it as upgrading your fats, not declaring war on a food group.

Worth knowing

This is a genuinely debated area, and honesty matters: refined seed oils are not in the same clear-cut category as artificial trans fats, and the strongest case against them is the company they keep (fried and ultra-processed food) plus oxidation and omega-6 excess — not a proven, direct hormone toxin. Whole-food omega-6 from nuts and seeds is fine and even beneficial. The sensible position is moderation and better swaps, not panic.

Bottom line

The problem isn't a drizzle of oil — it's a diet built on fried and packaged food carrying a flood of fragile omega-6. Cook in olive, avocado or butter instead, and most of the issue takes care of itself.