Atherosclerosis

Plaque accumulates for decades before it announces itself. Subclinical atherosclerosis is present in more than half of adults over 40, and the disease is typically silent until a lesion either narrows a vessel enough to limit flow under demand, producing angina or claudication, or ruptures and provokes a thrombus, producing an infarct or a stroke. The distinction matters for interpreting evidence, because the plaques that cause events are not necessarily the largest ones but the most unstable.

The process begins with retention of apolipoprotein B-containing lipoproteins in the arterial intima, followed by their oxidative modification, the recruitment of monocytes that ingest them and become foam cells, and the formation of a fibrous cap over a lipid-rich core. Each step supplies a plausible target, and this is precisely why the supplement literature on atherosclerosis is broad in ambition and thin in confirmation.

Eight ingredients are graded here across 34 studies and 51,310 participants, and the grade distribution is the inverse of the one seen for blood pressure: one Grade B, two Grade C, and five at Grade D, the tier reserved for very early research. Nattokinase holds the sole Grade B rating on 4 studies and 300 participants, an evidence base narrow enough that the grade reflects consistency rather than weight.

Vitamin E carries Grade C with a mixed direction, and its 50,000 participants account for almost the entire participant total on this page. That single figure summarises a chapter of cardiovascular research: the antioxidant hypothesis was tested at scale in the 1990s and 2000s precisely because oxidised LDL is central to the mechanism, and the large randomised trials did not confirm the benefit the mechanism predicted. A mixed direction attached to 50,000 participants is a stronger statement than a positive direction attached to 300.

Resveratrol is the second Grade C entry, on 5 studies and 400 participants, and it retains attention because its proposed mechanisms are numerous and specific. Preclinical work has described effects on TGF and ERK signalling in atherosclerotic models ^[1], and reviews have catalogued its biochemical actions in cardiovascular tissue more broadly ^[2]. The compound's popular profile derives largely from its presence in grapes and wine, a connection examined critically in the cardiovascular literature ^[3]. The gap between mechanistic breadth and clinical evidence remains wide.

The five Grade D entries, lycopene, olive leaf extract, flaxseed oil, quercetin and omega-7, rest on one to three studies each, with participant totals between 60 and 200. All are polyphenols or lipids with documented antioxidant or anti-inflammatory activity in vitro, and dietary polyphenol intake has been examined in relation to stroke risk in observational work ^[4]. A Grade D rating records that a hypothesis exists and has not been tested at a scale that could confirm it.

The established risk factors, dyslipidaemia, hypertension, smoking, diabetes, family history, obesity and inactivity, remain the determinants against which any ingredient here would have to be measured.