A Handful of Nuts Every Day: What Studies Show

Key points

A handful of nuts is a simple and pleasant habit for the heart. In observations of hundreds of thousands of people, those who eat about 28 g of nuts a day are less likely to die of any cause and of heart disease. In trials they slightly lower “bad” cholesterol, and weight does not rise. And you do not need much for the benefit: in observations the main benefit is already visible at 15–20 g a day.

What a handful is and how much you need

The handful the studies talk about is roughly 28 g, about as much as fits in your palm. In the large analysis of cohort observations, dose-response was calculated per 28 g a day, and the main benefit appeared already at 15–20 g: beyond that the curve flattened (Aune D BMC Med 2016. PMID 27916000^[1]). This means even a small handful a day makes sense, and there is no need to chase larger portions.

Which nuts to choose

The large analysis of observations looked at nuts as a whole, and in the PREDIMED trial participants received a mix of walnuts, hazelnuts and almonds. So there is no need to hunt for the one right nut: you can alternate kinds so the diet does not get boring. Walnuts are good in salads and with cottage cheese, almonds with vegetables and kefir, and hazelnuts are mild in taste and go well with berries. The main rule is simple: nuts should be unsalted and without sugar glaze, otherwise extra salt and sugar come into the diet along with the nuts. Salted snack nuts, sweet bars and nut spreads with sugar are not part of this habit.

Heart and longevity: an association in large observations

A meta-analysis of prospective cohort studies compared how people live with different amounts of nuts in the diet. At 28 g of nuts a day, all-cause mortality was 22 % lower (relative risk 0.78; 16 studies, 819,448 people), coronary heart disease 29 % lower (0.71; 11 studies, 315,397 people) and cardiovascular disease overall 21 % lower (0.79; 12 studies, 376,228 people) (Aune D BMC Med 2016. PMID 27916000^[1]). These are observations, not trials: they show a link with lower risk and do not prove a cause.

Cholesterol: a small shift

A pooled analysis of 38 randomised trials showed that 28 g of nuts a day lower LDL (“bad”) cholesterol by 0.11 mmol/L (4.2 mg/dL) (Del Gobbo LC Am J Clin Nutr 2015. PMID 26561616^[2]). The shift is modest, but it was shown in randomised trials. Blood pressure, “good” cholesterol (HDL) and C-reactive protein, a marker of inflammation, did not change in those trials.

Weight: nuts are high in calories, but weight does not rise

Many people are put off by the fear of gaining weight. A review of randomised trials (105 comparisons, 9,655 people) showed that with regular nuts body weight does not rise: the difference was +0.09 kg and not significant (Nishi SK Obes Rev 2021. PMID 34494363^[3]). So a handful of nuts can comfortably take the place of biscuits or sweets.

The whole diet: what PREDIMED showed

In the 2018 republication, the PREDIMED trial compared a Mediterranean diet supplemented with 30 g of nuts a day against advice to cut fat. Among 7,447 people aged 55–80 at high cardiovascular risk, there were fewer major cardiovascular events over 4.8 years: HR 0.72 (95 % CI 0.54–0.95), that is 28 % lower. The result held after excluding 1,588 people whose randomisation had been disrupted. But the whole diet was tested, not nuts alone, so the result cannot be attributed to nuts by themselves (Estruch R N Engl J Med 2018. PMID 29897866^[4]).

How to eat nuts

• A handful of nuts between meals instead of biscuits or sweets.
• Unsalted and unsweetened: raw or lightly dried.
• At breakfast: cottage cheese or kefir with walnuts and berries.
• At lunch: a salad of vegetables and greens, sprinkled with chopped almonds or hazelnuts, with olive oil.
• At dinner: baked fish or chicken with a crust of chopped nuts and herbs.
• Store in a tightly closed jar in a cool place so they do not turn bitter.

So that a handful does not turn into half a bag, measure a portion once on kitchen scales and remember how it looks in your palm or in a small bowl. After that you do not need scales: the bowl becomes the measure. Nuts are nicer eaten calmly with tea or water, chewing each one, rather than on the go from a big pack. If you used to snack on biscuits at the same time each day, put a handful of nuts in that slot: this way the new habit takes the place of the old one. For trips and work, small closed jars with one portion are handy.

An example day for steady blood sugar without grains or bread: for breakfast an omelette with herbs and a few walnut kernels, at midday a salad with avocado, cucumber and almonds, for dinner fish with vegetables. A simple habit is easy to keep: put a jar of nuts in a visible place and take a handful at the same time each day.

How the habit looks over a week: on Monday a handful of walnuts with cottage cheese, on Tuesday almonds with salad, on Wednesday hazelnuts with kefir, on Thursday walnuts again with fish, on Friday a mix as a snack instead of sweets. At the weekend you can repeat your favourite option. If you skip a day, it is not a problem: the studies looked at habitual eating, not at a single day. For convenience, measure out a handful for the next day into a small container the evening before and take it to work.

Who should see a doctor first

With a nut allergy, nuts are excluded completely. Small children are not given whole nuts because of the risk of choking. In diseases of the digestive tract, kidney stones and special diets, discuss the portion with a doctor. Prescribed treatment should not be changed on your own.

Bottom line

A handful of nuts a day is a simple habit linked to a lower risk of death and heart disease, slightly lowers “bad” cholesterol and does not add weight. 15–30 g a day is enough. Choose unsalted nuts, combine them with vegetables, fish and olive oil.