The Lies That Shaped Three Decades of Bad Advice

It's 1988. I'm sitting in a physiology lecture at university. This is serious education — a science degree, respected professors, peer-reviewed data on overhead projectors. My lecturer is presenting findings from the Framingham Heart Study: one of the largest, longest-running human cardiovascular studies ever conducted. Thousands of participants. Decades of data. He points at the graphs and says: "Fat and cholesterol. That's what's killing people."

I believed him completely. Why wouldn't I? The data looked clear. The conclusions seemed obvious. And it aligned perfectly with everything I'd been hearing my entire life: fat makes you fat, cholesterol clogs your arteries, saturated fat causes heart disease, eat low-fat and high-carb. The media had been saying it since my childhood. Academia was now confirming it. Every dietary guideline, every fitness magazine, every health authority reinforced the same message.

So I did what any dedicated athlete and aspiring health professional would do: I avoided fat and cholesterol religiously. For the better part of a decade. Chicken breast and pasta. Egg whites only — the yolks thrown away. Skim milk. Fat-free everything. High-carb fuelling because I was training twice a day — boxing, making weight, PT sessions. I needed energy, so I loaded up on carbs.

And I was hungry all the time. Brain fog. Energy crashes. Irritable. But I chalked it up to hard training and stress. I thought I just needed more discipline. After all, I had a science degree. I understood biochemistry. If I was struggling, it must have been because I wasn't following the guidelines strictly enough.

It took me almost ten years — until around 1998 — to come to believe that the low-fat consensus had been built on weaker evidence than it was presented with. The low-fat diet advice had serious holes, and they were papered over for decades.

I'm not telling you this story because cholesterol is what we're here to talk about. I'm telling you this story because of what it reveals about how health advice actually works. Good lies don't need to be completely false. They just need to be half-truths, presented with authority, repeated endlessly, until questioning them feels foolish. That's how the low-fat myth survived for forty years despite accumulating contradictory evidence. And it's the same mechanism that keeps other deeply unhelpful pieces of health advice alive today.

Cholesterol — What the Biochemistry Actually Says

Let me take you through the actual biochemistry of cholesterol, because understanding this doesn't just correct a single misconception — it teaches you how to question authoritative health claims in general.

"Good" and "bad" cholesterol are shorthand: HDL and LDL are lipoproteins, the particles that carry cholesterol, not two kinds of cholesterol. LDL carries cholesterol out to cells that need it for membrane repair, hormone synthesis, vitamin D production, and bile acid formation. HDL carries it back to the liver for recycling. They're taxis, not moral categories.

LDL is a transport particle, and cholesterol itself is essential. In short: cholesterol travels in lipoproteins; LDL is the vehicle. Too many of those vehicles, for too many years, drives plaque, so LDL is a cause, not a bystander. But one number isn’t your heart risk. The pattern is: ApoB or non-HDL, blood pressure, blood sugar, smoking, family history and age. That’s how risk is assessed properly, and it’s how any decision about a statin should be made.

The evidence that a high LDL over many years causes heart disease is strong: genetic, population and drug-trial studies all point the same way (Ference 2017). Across 26 statin trials, each 1 mmol/L (about 39 mg/dL) lower LDL cut major vascular events (heart attacks, strokes and procedures to reopen arteries) by about a fifth, and deaths from any cause by about a tenth (CTT 2010). In people without heart disease, statins also lowered deaths from any cause (Cochrane, Taylor 2013). A high LDL is a reason to see your GP, not something to ignore.

Your body makes most of the cholesterol it needs itself. Cholesterol is essential for:

• Cell membrane integrity — every cell in your body requires cholesterol to maintain its structure
• Hormone production — cholesterol is the precursor to all sex hormones (testosterone, oestrogen, progesterone), all stress hormones (cortisol, DHEA, aldosterone), and vitamin D
• Brain function — the brain is one of the most cholesterol-rich organs in the body; cholesterol is essential for neurotransmitter function, synapse formation, and myelin production
• Digestion — cholesterol is needed to produce bile acids, which allow you to absorb fats and fat-soluble vitamins A, D, E, and K

When I was avoiding cholesterol and saturated fat while simultaneously over-training, under-sleeping, and managing a young family and a growing practice, my body was starving for the building blocks it needed to make hormones, maintain brain function, and repair the damage from relentless physical stress. I was denying it the very materials it was desperately trying to obtain.

My Father's Heart Attack — What It Taught Me

My father had a heart attack at 54, followed by a triple bypass. His cholesterol had always been low, and he wasn't prescribed a statin until many years later. I was in the middle of my own low-fat phase at the time and had no reason to question the advice of the day.

I don't know whether hydration played any part in my father's heart disease. What it taught me was to ask about the basics, including how much someone drinks, before anything else. I ask about fluid intake early, because it's easy to fix.

Normal Is Not the Same as Optimal

If you leave this module understanding only one thing, let it be this: "normal" on a lab report doesn't always mean what you think. Many lab ranges are population ranges (the middle 95% of a reference group); some — HbA1c, glucose, lipids, vitamin D — are set from outcome data. Where I use a tighter target I label it as mine and give its source.

Your GP tells you your results are "normal." That statement means your results fall within the population reference range. It does not mean your thyroid is converting hormones efficiently. It does not mean your iron stores are adequate for the energy demands you're placing on your system. It does not mean your blood sugar regulation is stable throughout the day. It does not mean you're healthy. It means you're not yet sick enough for the pathological threshold to have been crossed.

Consider what this means in practice. A ferritin of 18 µg/L (18 ng/mL) is "within the normal range" on many lab reports. In anaemic patients, a ferritin of 30 µg/L (30 ng/mL) or less identified iron deficiency far more reliably than the old cut-off of 12 µg/L (12 ng/mL) (Mast 1998). Even with a normal blood count, a ferritin below 30 µg/L (30 ng/mL) means low iron stores, with iron deficiency likely (BSG 2021; in people seeing a doctor, sensitivity 79%, specificity 98%, low-certainty evidence, Garcia-Casal 2021). And in non-anaemic women with unexplained fatigue, iron helped only when ferritin was 50 µg/L (50 ng/mL) or below (Verdon 2003). Their GP may tell them their iron is fine. Both can be said of the same number — and that's the problem.

The same logic applies to some other markers, though not all. TSH is the cautionary case: in people followed from age 85, a higher TSH went with lower mortality (Gussekloo 2004), so I don't read a TSH of 3.5 mU/L as a problem on its own. In trials, treating subclinical hypothyroidism (raised TSH, normal free T4) did not improve quality of life or symptoms (Feller 2018). I read it with free T4, free T3, antibodies and symptoms. Vitamin D at 52 nmol/L (21 ng/mL) passes the UK deficiency cut-off of 25 nmol/L (10 ng/mL); whether more helps beyond bone health is not settled.

I don't just look at individual markers. I look at patterns, relationships between markers, and trends over time. Your standard blood panel might show nothing flagged. A functional interpretation of the same panel — looking at the same numbers through different lenses, against different benchmarks, and in relation to each other — sometimes tells a different story, and sometimes confirms that nothing needs doing.

Why Guessing Always Fails

Most health interventions — whether from a GP, a nutritionist, or a wellness influencer — are guesses. Educated guesses, often well-intentioned guesses, sometimes guesses backed by population-level research. But guesses nonetheless, because they are not based on what is actually happening inside your body specifically.

There are two fundamental reasons guessing fails. The first is that symptoms overlap so completely that the same presentation can have a dozen different causes. The second is that bodies are not generic, and a protocol built for average people cannot be optimised for any individual person.

The Symptom Overlap Problem

Consider fatigue. It's the most common complaint I see, week after week, year after year. And it can be caused by:

You cannot guess which one is driving your fatigue from symptoms alone. A stress-support protocol will do nothing if the primary driver is iron deficiency. An iron protocol will fail to move the needle if the real issue is a gut problem affecting absorption.

Without testing, you're treating the average of all possibilities. Which means you're probably not treating your actual situation at all.

Bodies Are Not Generic

Generic health advice is built on population averages. The research says "Mediterranean diet reduces cardiovascular risk." That's true — in population studies, averaged across thousands of participants. It tells you nothing about whether Mediterranean dietary patterns are optimal for your specific Metabolic Nature, your current hormonal status, your gut microbiome composition, or your detoxification capacity.

Your biochemistry is not my biochemistry. Your stress load is not my stress load. Your gut microbiome — shaped by your birth, your childhood antibiotic history, your diet, your geography, your stress history — is entirely unique. What heals one person can genuinely harm another. Not because the research is wrong, but because the research describes populations, not individuals.

This is not a fringe view. It's the fundamental premise of precision medicine, nutrigenomics, and pharmacogenetics — fields that are now well-established in conventional science. The NHS is investing in genomic medicine precisely because it's becoming impossible to ignore that individual variation matters enormously in treatment outcomes. Functional medicine has been applying this logic for decades.

The Five-Test Foundation — Why These Tests, Together

After years of working with clients — testing myself and many clients, observing what actually moves the needle — I developed what I call the Five-Test Foundation. The tests were chosen because, together, they give a comprehensive picture of the body systems that, when dysfunctional, are responsible for the vast majority of chronic symptoms people present with.

The critical word is together. Individual tests, viewed in isolation, often mislead more than they illuminate. A normal cortisol level tells you almost nothing without knowing what's happening with DHEA. Elevated inflammation markers tell you there's a fire but not where the smoke is coming from. Blood sugar that looks acceptable on a fasting test might be wildly unstable after meals. It's the cross-referencing of findings across all five tests that produces the clinical picture impossible to achieve with any single test or conventional panel.

These five tests, run simultaneously, produce over 500 data points. The clinical analysis cross-references findings across all five — identifying patterns that no single test could reveal and that conventional testing would miss entirely. This is the difference between looking at a building from one window versus walking through every room with the lights on.

The Economics of Testing vs Guessing

One of the most common objections I hear when discussing functional testing is the cost. And I understand it — the five-test programme represents a meaningful financial investment. But I want you to think carefully about what you've already spent on not knowing.

Add up the supplements you've bought over the past five years that haven't produced consistent results. The elimination diets you've followed without resolution. The consultations with practitioners who gave you protocols built on incomplete information. The time you've spent feeling unwell and operating below your capacity. The productivity you've lost, the things you've said no to, the compromises you've made to accommodate symptoms that should have been identified and addressed years ago.

Most of the clients I see have spent several thousand pounds before they reach me — on products and approaches that were guesses. Good guesses, often. But guesses. And the cumulative cost of those guesses, measured in money, time, and diminished quality of life, almost always exceeds the cost of the investigation that would have provided the actual answers.

Testing is not an expense. It is the elimination of all the expenses you would otherwise incur by not knowing what you're actually dealing with.

There's also a more immediate commercial reality to understand: the healthcare and supplement industry does not profit from you getting well quickly. It profits from you staying ill slowly and expensively. Products that require ongoing purchase, conditions that require chronic management rather than root cause resolution, advice generic enough to sell to everyone — these are commercially valuable. A targeted protocol based on your specific test results, executed correctly, that resolves the underlying dysfunction — that's not a repeating revenue stream for anyone. Which is partly why it isn't the default approach.

The Intervention Hierarchy — Why Supplements Are Layer 7

One of the most damaging habits in modern health culture is reaching for a supplement as the first response to a symptom. I understand why it happens — supplements are accessible, they feel like action, they don't require significant behaviour change, and they carry no immediate downside in the way that drugs do. But supplements are the seventh layer of the intervention hierarchy, not the first.

The hierarchy matters because each layer either enables or undermines every layer above it. You cannot supplement your way out of a layer 1 or 2 problem. Targeted supplementation based on confirmed deficiencies can be genuinely transformative — but only when the layers beneath it are stable.

I've worked with clients who arrive with shopping bags of supplements — twelve, fifteen, twenty different products. Some will be genuinely useful. Most will be unnecessary. Some will be contraindicated for their specific situation. All of them were purchased without the test results that would have made clear which, if any, were actually needed.

Testing tells you which layer of the hierarchy needs attention. It tells you whether your fatigue is a layer 1 problem (pathogen, cause to remove), a layer 2 problem (chronic stress lowering sex hormone output), or a layer 7 problem (confirmed B12 deficiency requiring supplementation). You cannot make that determination from symptoms alone. And the cost of getting it wrong — financially, in terms of time, and in terms of the ongoing burden of unresolved symptoms — is always higher than the cost of finding out.