Does a vegan diet lower cholesterol, and what about statins?

The objection

“Your liver makes its own cholesterol, so cutting out meat and eggs can only shift it a little. Plenty of vegans still have high cholesterol. If mine goes up, my GP will put me on a statin, and a pill will do far more for it than a plate of lentils ever could.”

The answer

The body does make its own cholesterol, and statins work by cutting how much it makes, the NHS says [2]. What you eat still changes how much of it ends up in your blood, and randomised trials, in which people are assigned a diet by chance, show that a vegan or vegetarian diet brings it down. A 2023 meta-analysis in the European Heart Journal (Koch et al.) pooled 30 such trials with 2,372 adults, published between 1982 and 2022, each comparing a vegetarian or vegan diet with an omnivorous one [1]. In the 27 trials that reported it, LDL cholesterol, which genetic studies and trials have shown to be a cause of atherosclerotic cardiovascular disease, fell by 0.30 mmol/L more on the plant-based diets (95% CI 0.19 to 0.40), about 10% from where people started [1]. Total cholesterol fell by 0.34 mmol/L, or 7%, and apolipoprotein B, a measure of the particles that build up in artery walls, fell by 12.92 mg/dL, or 14%, though only six trials measured it; triglycerides didn’t change [1]. The objection is right that a statin does more, as the authors themselves say, but they add that one doesn’t exclude the other and that a plant-based diet could postpone or even reduce the need for a statin [1].

How much does a vegan diet lower cholesterol?

On average a vegan or vegetarian diet lowers LDL cholesterol by about a tenth, and the trials found no significant difference between vegan and vegetarian diets. Koch’s team saw similar effects whatever people’s age, continent or state of health and however long the trial ran [1]. The trials have weaknesses, which the authors list: most were small and lasted under a year, none kept participants unaware of which diet they were on, and a test for publication bias suggested that small studies with large effects were overrepresented, which can make a pooled figure look bigger than it is [1]. Trials with more than 80 people, and those published after 2005, found significantly smaller falls than the small, older trials, which the authors put down partly to small studies following their participants more closely [1]. Earlier studies had seen the effect on LDL halve after a few months, though in this analysis trials lasting more than three months showed no such fading [1]. The authors doubt that weight loss explains the result, because losing weight tends to lower triglycerides, and these didn’t fall [1].

The authors put the effect down to what plant-based diets usually contain: more polyunsaturated fat, and less saturated fat, less cholesterol and less fat overall [1]. Linoleic acid, an omega-6 fat, lowers LDL by increasing the number of LDL receptors in the liver, while omega-3 fats have no significant effect on it [1].

People who have eaten this way for years show the same pattern. In a 2014 study of 1,694 British adults from the EPIC-Oxford cohort, matched for age and sex, with 422 vegans among them, the vegans had the lowest total cholesterol, non-HDL cholesterol and apolipoprotein B of any diet group (Bradbury et al.) [3]. Vegan men’s total cholesterol was 0.87 mmol/L lower than meat-eating men’s, and vegan women’s 0.60 mmol/L lower than meat-eating women’s; allowing for body weight narrowed the gaps only to 0.76 and 0.55 mmol/L, and the authors concluded that a large share of the difference was most likely due to diet [3]. A cross-sectional snapshot like this can’t prove cause, but it fits what the trials found. Whether a diet can reverse heart disease that is already there is a separate question.

Why do some vegans still have high cholesterol?

Genes can keep cholesterol high even on a good diet, and a vegan diet can still be heavy in saturated fat. The NHS’s list of foods to cut down on to lower cholesterol includes fatty meat, butter and cheese, but also cakes, biscuits and foods containing coconut or palm oil, while the foods it suggests eating more of include oily fish, olive and rapeseed oils, wholegrains, nuts, seeds, fruit and vegetables [4]. A vegan diet that leans on cakes, biscuits and other vegan junk food made with those oils can work against your cholesterol. Coconut oil raised LDL cholesterol by 10.47 mg/dL (95% CI 3.01 to 17.94) compared with non-tropical vegetable oils in a 2020 meta-analysis of 16 trials (Neelakantan et al.) [5]. It raised HDL too, by 4.00 mg/dL, but the authors concluded that its effect on LDL should inform choices about eating it [5]. Body weight matters as well: in Koch’s trials, total cholesterol fell less in people with obesity, which the authors link to the body making more of its own cholesterol in obesity [1].

The NHS says high cholesterol is more likely if you’re over 50, a man, past the menopause, or of South Asian or sub-Saharan African origin, and that it can run in families [6]. In familial hypercholesterolaemia, an inherited condition, LDL cholesterol is raised from birth. Around 2020, NHS England’s London clinical network put it at about 1 in 250 people in the UK, of whom fewer than 8% had been identified, and said that people with it need a statin alongside changes to diet and lifestyle, with children starting one where necessary [7].

Lipoprotein(a), another particle that carries cholesterol, is a second inherited risk. A 2022 consensus statement from the European Atherosclerosis Society (Kronenberg et al.) says more than 90% of a person’s level is set by their genes, that lifestyle changes have minimal impact on it, and that raised levels affect about 1.4 billion people worldwide [8]. Its cholesterol can’t be separated from LDL in the lab, so it is counted in the ordinary LDL result [8]. On limited data, the statement lists replacing saturated fat with carbohydrate or unsaturated fat, which a plant-based diet usually does, as raising lipoprotein(a) by about 10 to 15% [8]. It recommends that every adult has their lipoprotein(a) measured at least once [8].

Can diet replace a statin?

For some people diet and exercise are enough, but a diet lowers LDL by less than a statin does, so people at high risk may need both, and nobody should stop a statin without speaking to their doctor first. The NHS says you can lower cholesterol by eating healthily and getting more exercise, and that some people also need medicine [6], for example if their cholesterol hasn’t come down after changing their diet and lifestyle or if they are at high risk of a heart attack or stroke [9]. Statins are usually taken long term, and the NHS says to talk to a doctor or pharmacist before stopping them [2].

A meta-analysis of 164 placebo-controlled trials (Law et al., 2003) found that atorvastatin 10 mg, simvastatin 40 mg and similar doses lowered LDL by 40% on average, and atorvastatin 80 mg by 55%, in people starting from 4.8 mmol/L [10]. Statin trials also show what a lower LDL is worth. Pooling 26 trials with about 170,000 people, the Cholesterol Treatment Trialists’ Collaboration (2010) found that each 1 mmol/L fall in LDL cut the yearly rate of heart attacks, procedures to reopen arteries and ischaemic strokes by just over a fifth [11].

The Portfolio diet, a plant-based pattern that combines nuts, plant protein such as soy, viscous fibre and plant sterols, has been tested head to head against a statin [12][14]. In a one-month trial in Canada (Jenkins et al., 2003), 46 adults with high cholesterol were randomly assigned a diet very low in saturated fat, the same diet with 20 mg of lovastatin a day, or the Portfolio diet [12]. LDL fell by 8.0%, 30.9% and 28.6% respectively, and the difference between the statin and the Portfolio diet was not significant, though with 14 and 16 people in those two groups the trial was too small to show that the two were equal [12]. That dose of lovastatin is half the 40 mg that lowered LDL by 40% in Law’s pooled trials [10]. The effect was smaller when people chose their own food. A trial that randomly assigned 351 people with high cholesterol in four Canadian cities to six months of advice on either the Portfolio diet, at two levels of intensity, or a low-saturated-fat diet found that LDL fell by 13.8% with seven clinic visits and 13.1% with two, against 3.0% on the control advice, and the closer people kept to the Portfolio diet the more it fell (Jenkins et al., 2011) [13]. Between 18% and 26% of each group dropped out [13]. A 2018 meta-analysis of seven trial comparisons with 439 people found that adding the Portfolio diet to the US National Cholesterol Education Program’s Step II diet lowered LDL by about 17%, or 0.73 mmol/L, more than the Step II diet alone, and rated the certainty of that evidence high (Chiavaroli et al.) [14]. Jenkins was first author of both trials and is an author of the meta-analysis [12][13][14].

Diet and a statin can work together. In Koch’s analysis, trials that included people already on cholesterol-lowering drugs showed a smaller extra fall in LDL from the plant-based diet, but still a significant one, and the authors expect combining the two to give a larger effect than either alone [1]. If you take a statin, keep taking it while you change what you eat, talk to your GP or pharmacist before stopping or changing any medicine, and ask about a repeat blood test, because high cholesterol doesn’t usually cause symptoms and only a blood test shows it [2][6].

Can cholesterol go too low on a vegan diet?

Statin trials suggest not, because statins take LDL much lower than a diet does and lowering it below 2 mmol/L still brought benefit without raising cancer rates, though one large British cohort study found more haemorrhagic strokes in vegetarians [10][11][15]. In the 26 trials pooled by the Cholesterol Treatment Trialists’ Collaboration (2010), strokes overall fell by 16% for each 1 mmol/L fall in LDL, while haemorrhagic strokes showed a non-significant excess of 12%, which became a significant 21% only when the authors added the results of two further trials [11]. For patients at high risk of heart attacks and strokes, the authors put the absolute size of that possible hazard at about 50 times smaller than the benefit, with perhaps a few extra haemorrhagic strokes a year for every 10,000 people treated against a few hundred fewer heart attacks and other events caused by blocked arteries [11].

The British study is EPIC-Oxford, which followed 48,188 adults for 18 years (Tong et al., 2019) [15]. Its vegetarians, vegans among them, had about 0.5 mmol/L less total and non-HDL cholesterol than its meat-eaters, and after allowing for lifestyle differences they had a 22% lower rate of ischaemic heart disease and a 20% higher rate of stroke, mostly haemorrhagic, which works out at 10 fewer cases of heart disease and three more strokes per 1,000 people over ten years [15]. The reason isn’t known, though the researchers suggested that vegetarians’ relatively low LDL could help explain their higher rate of haemorrhagic stroke, and that their lower blood levels of vitamin B12, vitamin D, essential amino acids and long-chain omega-3 fats could also play a part [15]. When a 2023 meta-analysis (Dybvik et al.) pooled 12 cohort studies, EPIC-Oxford among them, it found no clear difference between vegetarians’ risk of stroke and non-vegetarians’ (relative risk 0.90, 95% CI 0.77 to 1.05), and for vegans the estimate from five studies was too uncertain to point either way (1.17, 0.69 to 1.99) [16]. The health record of plant-based diets covers stroke alongside the other outcomes. Anyone on a statin who is worried by any of this should talk to their doctor or pharmacist before stopping it, as the NHS advises [2].