Beans are almost universally considered healthy. They feature in every reputable healthy-eating pattern: Mediterranean, DASH, AHEI. And yet they occupy a strangely marginal place in most Western diets.
If your main experience of “eating more beans” involves tipping a tin of something grey and slightly slimy into a saucepan, warming it through and wondering why vegetarians do this to themselves, you’re not alone. There are dozens of varieties to choose from; most of us have tried about three, and the results haven’t always been inspiring.
The consumption figures reflect this. Americans and Canadians average about 21g of legumes a day. Australians manage 26g. Even the UK, the highest consumer in Europe, only reaches 45g. Compare that with New Zealand at 68g, Israel at 75 g, or Afghanistan at 123g. At least some of us know how to eat beans!
(If any New Zealand readers can explain why you eat so many more beans and lentils than your Australian neighbours, I’d genuinely love to know.)
I eat legumes fairly regularly, but I’d still call myself a bean amateur. I’ve also been curious about the fact that while legumes appear in virtually every healthy-eating pattern, when you look closely at the research, the effects aren’t always as dramatic as their reputation might suggest. That prompted this deeper look.
So I dug into the science to find out what legumes actually do for our health.
And I ended up thinking we may have been asking the wrong question.
The science
There are good reasons to expect legumes to be healthy
Legumes are an unusual nutritional package. They deliver meaningful protein alongside fibre and resistant carbohydrate, minerals and polyphenols, while providing very little saturated fat.
That protein-fibre combination is particularly useful. Protein has become something of an obsession lately, and most younger adults eating a mixed diet don’t need to spend much time trying to maximise it. But it becomes more important as we get older, and it deserves more attention in vegetarian and vegan diets.
Legumes can help provide it without giving up the fibre and other components of minimally processed plant foods.
There are plausible reasons why that package might improve metabolic health. Soluble fibre and phytosterols can help lower cholesterol, while resistant carbohydrate reaches the colon and feeds gut bacteria.
That sounds impressive, but the more important test is whether people who eat more legumes actually live longer or develop less disease.
The long-term signal is favourable, but not dramatic
When I’m evaluating a food’s health credentials, I like to start with the ultimate test: is eating more of it associated with a lower risk of dying prematurely?
For legumes, the answer is yes, but modestly.
In a meta-analysis of 32 studies involving 1,141,793 participants, those eating the most legumes had a 6% lower risk of premature death from any cause compared with those eating the least.
A comprehensive 2024 review found a broadly similar figure: roughly 4% lower all-cause mortality among higher consumers. The researchers calculated that for someone aged 30–50, increasing legume consumption to 100g per day long-term might lead to an extra year of life expectancy.
An earlier modelling study took this further. Using the best available data on specific foods and life expectancy, Norwegian researchers estimated that a 20-year-old switching from typical intake (essentially zero) to optimal legume consumption (200g cooked per day) might increase their life expectancy by 2.2–2.5 years. For a 60-year-old making the same change, the figure was 1.6 years.
I love this graph. It shows that predicted gains can be measured in years, not weeks, and that there are potential benefits at whatever age you start eating more. It’s never too late to eat healthier.
It’s important to note that these are statistical models, not guaranteed extra birthdays, and that 200g isn’t a universally accepted optimal dose of legumes. But they illustrate how a modest difference in risk, sustained over decades, could become meaningful.
These aren’t huge effects, but I don’t think that’s a reason to dismiss them. Few individual foods are likely to transform your chances of healthy ageing. But it looks like legumes are one of the foods that nudge the odds in the right direction.
Cardiovascular evidence is less tidy
If legumes really do contribute to lower premature mortality, cardiovascular disease would be an obvious route.
One comprehensive review found that those eating the most legumes had an 8% lower risk of cardiovascular disease and a 10% lower risk of coronary heart disease, though the researchers rated their certainty as low.
A meta-analysis of 26 studies found broadly similar figures: 6% lower cardiovascular disease and 10% lower coronary heart disease among highest consumers.
However, a meta-analysis of 47 studies involving more than 2 million participants found no significant association between legume consumption and cardiovascular disease, coronary heart disease or stroke.
So I don’t think the evidence supports saying that eating more beans has been shown to prevent heart disease. They might, but the jury’s out, and observational studies can’t prove cause and effect.
What is more consistent is the effect on intermediate markers. In that same 47-study analysis, those eating the most legumes had LDL cholesterol roughly 0.15mmol/l (about 5%) lower than those eating the least. Fasting glucose also tends to be modestly lower (by about 0.09–0.19mmol/l).
These effects are plausible: soluble fibre binds bile acids, phytosterols inhibit cholesterol absorption, and both fibre and polyphenols may support a healthier gut microbiome.
So the pattern is a little mixed. Legumes provide excellent nutrition, and there’s a modest reduction in the risk of dying prematurely. But favourable changes in blood lipids aren’t consistently matched by a reliably lower risk of cardiovascular disease. There’s also some interesting evidence that high legume consumption might be linked to a lower risk of colon cancer, but again it’s not consistent enough for me to state it as fact.
So, what if the real advantage of legumes becomes clearer when we stop asking what happens when we add them and ask what happens when they replace something else?
The case becomes more compelling when legumes replace something
Legumes work two ways simultaneously. They bring protein, fibre, resistant carbohydrate and useful plant compounds into the diet, while displacing foods with more saturated fat and less favourable long-term health profiles.
German researchers collated 24 prospective studies and examined substitution effects specifically.
Replacing 50g of unprocessed red meat daily with legumes was associated with a 7% lower risk of premature death from any cause.
Replacing 50g of processed meat: 9% lower mortality, 23% lower cardiovascular disease, 15% lower coronary heart disease, 12% lower type 2 diabetes.
Replacing 1 egg per day: 10% lower mortality, 12% lower cardiovascular disease, 14% lower type 2 diabetes.
Again, these are observational substitution analyses, not proof of causation. But the consistency across endpoints and food types is notable.
A Finnish trial offered experimental support. Over six weeks, 107 men ate either a high red and processed meat diet or one where legume-based foods replaced most of the meat. Both groups consumed similar protein and carbohydrate. But the legume group took in more fibre and polyunsaturated fat, and less saturated fat and cholesterol.
LDL cholesterol fell by 0.19mmol/l (~6%) in the legume group, while it rose by 0.16mmol/l (~5%) in the meat group. The legume group also lost more weight (1kg vs 300g).
A separate meta-analysis of 60 randomised trials calculated that each 1mmol/l fall in LDL lowers the relative risk of a major cardiovascular event by about 22%. A 6% LDL reduction might, therefore, plausibly translate to a 3–4% lower risk over several years, though that extrapolation remains hypothetical.
The evidence, then, suggests that rather than finding room to add a spoonful of beans or lentils to the plate, we’ll reap greater rewards by removing some red or processed meat, or eggs first, and using legumes as a replacement, not a side dish.
But what about the dreaded “anti-nutrients”?
No discussion of legumes survives very long on the internet before someone raises “anti-nutrients”.
I dislike the term because it takes a real piece of biochemistry and turns it into a verdict on the whole food.
Phytates are a good example. Plants use them to store phosphorus, and their chemical structure allows them to bind minerals including iron, zinc and calcium in the gut. That can become important when a diet is already marginal in those minerals and depends heavily on a narrow range of phytate-rich staples. This is principally a problem in poor rural communities in developing countries; it’s much less likely to matter if you’re eating a varied, nutrient-sufficient diet in Seattle or Frankfurt.
For most of us eating a varied, nutrient-sufficient diet, it’s a very different proposition. Gut bacteria can break phytates down, food preparation reduces them, and vitamin C can help offset their effect on iron absorption. Diets rich in whole grains, legumes, nuts and seeds are intrinsically high in phytates, yet are consistently associated with good health. That’s not what you’d expect to see if phytates were harmful.
Phytates also have potentially beneficial properties (antioxidant properties, reduced levels of inflammatory compounds and associations with lower risk of kidney stones and arterial calcification), which makes the blanket “anti-nutrient” label look even less helpful.
Oxalates deserve a little more attention if you’re particularly susceptible to kidney stones or have a condition, like inflammatory bowel disease, that increases oxalate absorption. But soaking and boiling reduce them substantially, while commercial canning removes around 86–93%.
Lectins are the genuine practical exception. Raw or undercooked beans can cause acute gastrointestinal illness. Thorough boiling removes almost all lectins, and canned beans are safe: you’d need to eat roughly a thousand full cans to reach the dose associated with symptoms. Slow cooking or microwaving alone may not reach high enough temperatures, so either boil dried beans first, or use canned.
Which brings me to a confession.
I’m a keen gardener, and this year I have a good crop of runner beans. As they taste delicious, I’d been munching on some while pottering about in the garden. On several occasions I found myself making unexpected and rather urgent trips to the bathroom, completely baffled as to what was upsetting my usually cast-iron stomach. It was only while researching this issue that I learned runner beans should never be eaten raw.
So, while I haven’t changed my mind about “anti-nutrients”, I have acquired a new respect for the much simpler advice to cook beans before eating them. Lesson learned.
And then there’s gas
The other reason people hesitate is gas. Legumes contain lots of fibre and resistant starch, which reach the colon undigested and get fermented by gut bacteria. One product of that fermentation is gas. For many people, the assumption that more beans equals more flatulence is enough to put them off.
The reality is more reassuring than you’d think. In a study where participants ate half a cup of beans daily for 8–12 weeks, about 35% experienced flatulence and 13% bloating in the first week, but for most, it was a single occasion. Symptoms usually resolved within a few weeks as the body adapted.
At this point, I’m left reflecting on what my life has come to that I’m creating graphs about flatulence!
Anyway, the practical answer is simple: if you currently eat very few legumes, build up gradually rather than going from almost none to a heroic bowl of beans every day.
What this means for your health
Legumes deserve their healthy reputation. The nutritional package is excellent, and higher consumption is consistently associated with modestly better long-term health outcomes.
But their direct, independent effects are mostly modest, and cardiovascular findings are genuinely inconsistent. If you’re expecting beans alone to dramatically lower your disease risk, the evidence doesn’t quite support that.
The substitution evidence changes the practical picture. Much of their usefulness seems to come from doing two things at once: bringing fibre-rich plant food into the diet while displacing some red or processed meat or eggs. In practice, that means thinking about where legumes can replace something already on your plate.
“Anti-nutrient” concerns don’t overturn that conclusion for most people eating a varied diet. The one universal safety rule I’ll no longer ignore is to cook beans properly.
I don’t think the evidence identifies a magic dose. My own target is to work towards roughly 100g of cooked legumes per day on average. That’s deliberately ambitious compared with typical Western intakes, but realistic enough to create regular opportunities for substitution.
As always, your responses are anonymous, but they really help me tailor future content to what’s most helpful to you. Please take a moment to click a button.
HEALTH TWEAK OF THE WEEK
Legumes deserve a much bigger place in most of our diets.
Higher legume intake is associated with a 4–6% lower risk of dying prematurely. That may not sound enormous, but healthy ageing is built by stacking exactly these sorts of modest advantages over decades, and legumes also bring a particularly useful combination of protein, fibre, resistant carbohydrate and polyphenols with very little saturated fat.
Better still, you can increase the potential benefit by using them to replace some red or processed meat, or eggs, rather than simply adding them to what you already eat.
1. Work towards ~100g (3.5 oz) cooked legumes per day on average.
That’s roughly half a cup, and well above typical Western intake. If you’re starting from very little, build up over a few weeks. Think weekly average rather than compulsory daily quota: four days at 150g (5 oz) and three at zero gets you there. Increasing gradually also gives your gut time to adapt and minimises any initial discomfort.
2. Get there mainly through substitution.
Rather than adding beans on top of everything else, use them to replace some of the red or processed meat, or an egg-based meal, you’d normally eat. A bean chilli instead of a beef one, lentils in a bolognese, or chickpeas/garbanzos in place of some of the chicken. Three ~100g swaps this week is an easy starting point.
3. Prepare them properly.
Canned legumes are already safely cooked: convenient, affordable and perfectly fine. If cooking dried beans, boil them thoroughly: don’t rely solely on slow cooking, which may not reach high enough temperatures to remove lectins. And whatever you do, don’t eat them raw. Trust me on that one.
Don’t worry about optimising which legumes to choose just yet. Next week, we’ll look at the practical side: which beans give you the best nutritional return, how to make them genuinely enjoyable and how to build them into meals that actually make you want to eat them again.
🎧 Prefer to listen while deciding whether your next chilli really needs quite so much beef?
🎙️ This week’s One Health Tweak a Week podcast takes a closer look at beans, lentils and chickpeas: why they deserve their healthy reputation, where the evidence is less impressive than you might expect, and why their biggest advantage may be what they replace.
You’ll hear:
Why higher legume intake is associated with a 4–6% lower risk of premature death
Why the evidence for preventing cardiovascular disease is more mixed, despite favourable effects on LDL cholesterol
Why replacing some red or processed meat, or eggs, with legumes may be more useful than simply adding beans to what you already eat
Whether you really need to worry about “anti-nutrients”, lectins and gas
Why I now have considerably more respect for the advice not to eat raw runner beans
👉 Good company for your next walk, commute, or while staring at a tin of chickpeas and wondering whether lunch really has to involve hummus again.
(Episodes are free for now. Paid subscribers support the deeper research - and unlock practical tools to help you improve your health without turning it into a second job.)
🧭 Before you go
💬 How often do legumes make it onto your plate at the moment? Are you already eating beans or lentils several times a week, or are they still something you buy with good intentions and rediscover six months later at the back of the cupboard?
📤 Know someone who still thinks beans are mainly vegetarian penance, or who has been frightened off them by warnings about “anti-nutrients”? Forward this to them.
👥 Paid corner - If you’re trying to eat more legumes but aren’t sure where they fit into your existing meals, drop me a message in our private chat and I’ll help you think through some realistic swaps.
Until next Saturday - eat more legumes, preferably in place of something rather than on top of it, and cook the beans before sampling them in the garden.
– Ben
My parents were Italian immigrants. Even though they became fully American in all aspects of their lifestyle, my father built a fixture in the fireplace and all winter long, he would build fires and cook a pot beans in it, because that’s what his parents did “in the old country”.
I'm one of those people who cooks dried chickpeas in her slow cooker, and thus I'm interested in the lectin "controversy." As far as I can tell, it's only kidney beans that should never be cooked this way. I do see many sites misquoting Dr Greger of Nutrition Facts regarding cooking beans in a slow cooker -- he was talking specifically about kidney beans ONLY. Do you have other info to contradict this?