What Free Radicals Actually Do in a Modern Body

By Dr. Raj Dhadwal

You have probably felt the vague version of this worry. The city air is not clean. You spent the afternoon in the sun. Dinner was fried and quick because the day ran long, you slept badly, and somewhere in the background is a low hum of the idea that modern life is quietly oxidizing you, and that you should be eating something with antioxidants in it. It is one of the most searched ideas in nutrition, and it is also one of the most misused words. So let us do the honest version: what a free radical actually is, what it does inside a body, what an antioxidant actually is as a piece of chemistry, and what the published research on foods, sea buckthorn among them, has and has not shown.

This is education about chemistry and normal biology, not medical advice, and nothing here describes treating, curing or preventing any condition. Be sceptical of anyone, in a shop or online, who tells you a single food defends you from disease. That is not how any of this works, and the real story is more interesting anyway.

What is a free radical, really?

Electrons in a molecule like to travel in pairs. A free radical is simply a molecule or atom that has an unpaired electron, and that makes it reactive, because it will try to grab an electron from a neighbour to complete the pair. When it does, the neighbour is now short an electron, so it becomes a radical in turn, and you get a chain reaction rippling from one molecule to the next.

The commonest examples in a body are reactive oxygen species, radicals built around oxygen. They are not villains from nowhere. Your cells make them on purpose as a normal by-product of turning food and oxygen into energy in the mitochondria, and your immune cells make them deliberately as a tool against microbes. Radicals are a normal part of running a body. The concept that matters is balance: when the production of radicals outruns the body's capacity to neutralise them, chemists call that state oxidative stress, and the targets of that excess are the molecules radicals react with most easily, the fats in cell membranes, proteins, and DNA. We go deeper into that balance in what oxidative stress means.

The modern-life inputs you were worrying about, air pollution, ultraviolet light, cigarette smoke, some cooking methods, and the metabolic load of poor sleep and stress, are studied as things that can push radical production up. That is a statement about chemistry and physiology. It is not a diagnosis, and none of it names a disease.

What is an antioxidant, as a piece of chemistry?

Here is the definition to hold onto, because it is the honest one. An antioxidant is a molecule that can donate an electron to a radical, satisfying that unpaired electron and quenching the chain reaction, without itself becoming destructively reactive in the process. That is the whole job description. It is a chemical property, measurable in a test tube, and nothing more grand than that. When you read that a food is high in antioxidants, what has usually been measured is its capacity to donate electrons to radicals in a laboratory assay. We unpack the label itself in what antioxidant actually means.

Your body does not wait for food to do this. It runs its own antioxidant enzymes, superoxide dismutase, catalase and the glutathione system, which are its first line for handling radicals, covered in the body's own antioxidant enzymes. On top of those, the diet supplies molecules that also act as electron donors, the best known being vitamin C and vitamin E, which we compare in vitamin C versus vitamin E. Plant foods add a large family of phenolic compounds, the pigments and bitter compounds in fruit, that show antioxidant activity in the lab.

The crucial discipline, and the place most marketing goes wrong, is this: antioxidant activity in a test tube is a measurement of chemistry, and it does not automatically translate into a health outcome in a living person. A molecule that quenches a radical in a beaker has to be absorbed, has to reach the right place, and has to matter to a process that affects health, before any of that becomes a claim you can make about a body. Most of the time that whole chain has not been demonstrated. So "high in antioxidants" is a fact about chemistry, and it is where the honest statement ends.

What has research examined for sea buckthorn?

Sea buckthorn is one of the antioxidant-dense berries that has been studied, and two references are worth reporting precisely as literature, including what they did not find.

Study	Design	What it used	What it reported
Eccleston and colleagues, Journal of Nutritional Biochemistry, 2002 (PMID 12088800)	Controlled human study, 20 healthy men	Sea buckthorn juice daily for eight weeks	Reported a moderate decrease in the susceptibility of LDL particles to oxidation in a laboratory test, with no significant change in total cholesterol. It measured a chemistry endpoint, not a health event.
Ciesarova and colleagues, Frontiers in Pharmacology, 2018 (PMID 29662448)	Review of berry phenolic antioxidants	Surveys the published composition and antioxidant-assay literature	Documents antioxidant-related composition and assay findings for sea buckthorn and related berry compounds. Those assay findings should not be treated as demonstrated health outcomes in people.

Read the Eccleston line exactly as it stands. It reported a laboratory measure, how readily LDL particles could be oxidized in a test, moving in one direction after eight weeks of juice, in twenty men, with no significant change in their total cholesterol. That is a real, reported result about a chemistry endpoint. It is not a statement that the juice does anything to heart disease or to your risk of anything, and I am not making that bridge, because the study did not measure it and the compliance line and the science both forbid it. The review documents that berries, sea buckthorn included, carry phenolic antioxidants, and the same discipline applies here: the antioxidant number is a chemistry number that should not be read as a health promise.

So what should a reasonable person actually do?

The measured, unexciting answer is the defensible one. The things that most reliably lower excess radical production are not a jar of anything: not smoking, sensible sun habits, decent sleep, and regular movement. Beyond that, a varied diet with plenty of whole plant foods supplies many compounds that can show antioxidant activity in laboratory and nutritional contexts, arriving in a food matrix rather than as an isolated high dose, which we discuss in whole food versus isolated nutrients. That is a food-and-lifestyle statement, and it is about as far as the honest science reaches.

Sea buckthorn enters here only as one of the antioxidant-dense whole foods that researchers have measured. Its interest is compositional: it is a berry that carries a dense and varied set of phenolic compounds along with vitamin C and vitamin E. Stating that is describing chemistry and content. It is not telling you the berry defends your cells, because that would be a claim the research does not support, and the whole point of this article is that the word antioxidant has been stretched past what it can honestly carry.

Where does this sit in a whole berry?

Human Renaissance is the only sea buckthorn puree in the world sold in a single-serve pouch. 190+ naturally occurring compounds, omega 3, 6, 7 and 9, 201 mg of vitamin C per pouch, 0 g sugar, 5,640 hand-picked berries per box.

Many of those compounds are the phenolic and vitamin antioxidants described above, present because the berry is pressed whole. That is a fact about composition, stated once and left there. It is not a health claim, and this article has deliberately avoided turning the chemistry into one.

The short version

A free radical is a molecule with an unpaired electron, which makes it reactive enough to pull an electron from a neighbour and start a chain reaction that damages fats, proteins and DNA. Your body makes radicals normally, in the mitochondria and in immune cells, and the state where their production outruns your capacity to neutralise them is called oxidative stress. Modern inputs like pollution, ultraviolet light, smoke, poor sleep and stress are studied as things that push radical production up. An antioxidant is simply a molecule that donates an electron and quenches a radical, a chemical property measured in a test tube, and the body already runs its own antioxidant enzymes alongside dietary ones like vitamin C and E. The one discipline that matters most is that antioxidant activity in a beaker is not a health outcome in a person. Sea buckthorn is one of the antioxidant-dense berries studied; a controlled human study reported a decrease in LDL oxidation susceptibility with no significant cholesterol change, and a review documents the phenolic content while warning that the chemistry is not a health promise. This is education about chemistry, not medical advice, and nothing here treats, cures or prevents any condition.