What causes inflammation? The 7 real culprits

Why it matters

Ultra-processed foods, refined sugar, and industrial seed oils are the loudest inflammation drivers in most diets. They flood your body with oxidized fats and rapid blood sugar spikes, both of which trigger immune responses 3-4 times a day, every day.

How to tell if it's you

Look at last week. How many ultra-processed items did you eat? (Anything with more than 5 ingredients on the label, half of them unrecognizable.) If it's most of your meals, this is your starting point.

What to do

Two weeks. Cut sugary drinks, swap seed oils for olive oil, eat one less packaged thing per day. That's it. Don't try to overhaul everything.

Why it matters

Sleeping fewer than 6 hours raises IL-6 (a major inflammation marker) independently of any other factor. One night doesn't matter. Months of it changes everything. Your body uses deep sleep to clear cellular debris, and you're skipping that.

How to tell if it's you

Track for a week. If you're under 7 hours regularly and you don't bounce out of bed, this is bigger than your diet.

What to do

Stop drinking coffee after noon, no screens for 30 minutes before bed, room cold and dark. Add magnesium glycinate at night if it's chronic. Sleep first, supplements second.

Why it matters

Acute stress is fine. Chronic stress desensitizes your immune cells to cortisol, the hormone that's supposed to dial down inflammation. So cortisol stops working, and inflammation runs unchecked. The PNAS study on this is one of the clearest links in the research.

How to tell if it's you

Stress that you've adapted to doesn't feel like stress anymore. Look for: tight shoulders, jaw clenching, can't actually relax on weekends, racing thoughts at night.

What to do

Walks outside, breathing exercises before bed, real boundaries with work. Therapy works. Meditation apps work if you actually use them. Pretending you're not stressed doesn't work.

Why it matters

Sedentary muscle is metabolically active in a bad way. It releases pro-inflammatory cytokines just sitting there. Active muscle releases anti-inflammatory ones (myokines). The difference is huge.

How to tell if it's you

If you sit for 6+ hours a day and don't exercise, you're in the high-risk zone regardless of weight. Office workers, drivers, anyone WFH.

What to do

Walking 30 minutes a day, daily. Strength training twice a week is the highest-leverage move. You don't need a gym. Bodyweight or cheap dumbbells at home work fine.

Why it matters

Subcutaneous fat (the soft stuff under skin) is mostly storage. Visceral fat (the firm belly fat around organs) is a hormone factory. It actively produces inflammatory cytokines, including IL-6 and TNF-alpha. This is why central obesity correlates so strongly with chronic disease, even at normal BMIs.

How to tell if it's you

Waist circumference is more useful than weight. Over 40 inches for men, over 35 for women, you've got too much visceral fat regardless of what the scale says.

What to do

Strength training, protein at every meal, cut liquid sugar. Visceral fat responds to consistent food and movement changes faster than subcutaneous fat does, ironically.

Why it matters

Your gut bacteria train your immune system. When the microbiome is healthy (diverse, well-fed by fiber), it produces short-chain fatty acids that calm inflammation. When it's not (low diversity, fed by sugar), it produces compounds that leak through the gut lining and trigger immune flares throughout the body.

How to tell if it's you

Most people with chronic gut issues (IBS, frequent bloating, irregular bowels) have microbiome imbalances. So do people on multiple rounds of antibiotics, heavy NSAID users, and anyone who ate primarily ultra-processed foods for years.

What to do

Eat 30 different plant foods per week (vegetables, fruits, beans, nuts, grains all count). One daily fermented food (yogurt, kefir, sauerkraut, kimchi). Cut artificial sweeteners. Skip the expensive probiotics until you've done the food version for a month.

Why it matters

Smoking, heavy drinking, air pollution, and chronic exposure to certain chemicals are all proven inflammation drivers. They contribute differently. Smoking is the worst single input you can give yourself. Alcohol matters more than people admit. Air pollution is mostly out of your control but is real.

How to tell if it's you

Smoker, heavy drinker (more than 7 drinks/week consistently), or living in a high-pollution area. You probably already know.

What to do

Stop smoking. Cap alcohol at 5-7 drinks per week max, with at least 2 zero-drink days. For pollution, indoor air filters help. Outside is mostly bigger than any one of us.