Fruit and vegetables

People who eat about five portions of fruit and vegetables a day die less often of heart disease, cancer and lung disease than people who eat two, and most of that gain is reached by five. The evidence is observational, the one clear trial result is a modest drop in blood pressure, and the pills that tried to bottle the benefit made things worse.

Eat at least five portions a day, about 400 g, roughly two of fruit and three of vegetables, and make most of them whole foods rather than juice or potatoes. Fresh, frozen and canned all count. Variety matters more than any single "superfood".

Most of the benefit arrives by five a day

The two largest analyses agree on the direction and differ on where the curve flattens. Pooling 95 cohort studies, each extra 200 g of fruit and vegetables a day went with about 10% lower death rates from any cause, 8% less cardiovascular disease and 16% less stroke, with the risk still falling, more gently, up to about 800 g a day; for cancer the link was much weaker, about 3% per 200 g, and levelled off around 600 g.^[1]

A Harvard analysis of two US cohorts of nurses and other health professionals, plus 24 other cohorts covering almost 1.9 million people, found a clearer plateau. Compared with two servings a day, five went with about 13% lower mortality from any cause, 12% less cardiovascular death, 10% less cancer death and 35% less death from respiratory disease. Above five servings, roughly two of fruit and three of vegetables, there was no further gain.^[2]

The two fit together. The Harvard meta-analysis counted a serving as 80 g, so five servings is 400 g a day, which is where both curves have delivered most of their benefit; eating more is harmless and may add a little for the heart, but it is not where the big difference lies. This is also the "5+ servings a day" of the Mediterranean pattern.

All of this is observational. People who eat a lot of produce also smoke less, exercise more and are wealthier, and adjustment for that can never be complete. Treat the numbers as an upper estimate of what changing your own plate would do.

What counts as a portion, and what doesn't

A portion is about 80 g: a medium apple, banana or orange, two plums or kiwis, a handful of berries, a cereal bowl of salad, or three heaped tablespoons of cooked vegetables. Under UK guidance, 30 g of dried fruit counts as one portion, and juice or smoothies count as one portion at most, capped at 150 mL a day. Beans and lentils count once however much you eat, and potatoes don't count at all.^[3]

The mortality data back those exclusions. In the Harvard analysis, fruit juice and potatoes showed no link with mortality, and starchy vegetables such as peas and corn were the one group not associated with lower risk.^[4] Potatoes are better thought of as a starch, like bread or rice. In three US cohorts, seven or more servings of potatoes a week went with about 33% more type 2 diabetes than less than one serving, driven mostly by chips (French fries); swapping three weekly servings for whole grains tracked with about 12% lower risk.^[5] A smaller study of 4,440 North American adults found fried potatoes two or more times a week went with roughly double the death rate over eight years, while boiled, baked or mashed potatoes did not.^[6] Juice belongs with the sugary drinks; the evidence is on Foods to avoid.

Which kinds stand out, honestly

Most groups of fruit and vegetables track with lower risk, and the differences between them are small next to the difference between eating a lot and eating little. The pooled cohorts found the clearest links to lower cardiovascular disease and mortality for apples and pears, citrus fruit, green leafy vegetables, cruciferous vegetables (broccoli, cabbage, cauliflower, kale) and salads, and to lower cancer risk for cruciferous and green-yellow vegetables such as carrots and peppers.^[7] In the Harvard analysis, green leafy and cruciferous vegetables, citrus fruit, and produce rich in vitamin C or beta-carotene all tracked with lower mortality.^[8] These are associations within already noisy data, not a ranking, and "superfood" claims about single fruits go well beyond them.

Two groups have a specific case. Leafy greens are the MIND diet's emphasis, together with berries; see MIND diet. They also supply lutein for the eye (Lutein, Vision) and vitamin K1, so if you take warfarin, keep your intake of greens steady rather than avoiding them; see Vitamin K. Leafy greens and beetroot are rich in inorganic nitrate, which the body turns into nitric oxide, a blood-vessel relaxant. Across 16 small crossover trials in 254 people, nitrate or beetroot juice lowered systolic (top-number) blood pressure by about 4 mmHg, but the trials lasted from two hours to two weeks, so whether the effect holds over years is unknown.^[9]

What the trials show

The firmest randomised result is on blood pressure. In the DASH (Dietary Approaches to Stop Hypertension) feeding trial, 459 adults were given all their food for eight weeks with salt and weight held steady. A diet rich in fruit and vegetables lowered systolic pressure by about 2.8 mmHg more than a typical American diet, and the full DASH diet, which also added low-fat dairy and cut fat, by 5.5 mmHg.^[10] More on DASH diet and Blood pressure.

No trial has shown that eating more produce lowers deaths. The large diet trials that raised fruit and vegetables as part of a low-fat, higher-fibre diet changed intake only modestly and found no clear effect on cardiovascular disease or bowel polyps; they are covered on Fiber.

The trials that tried to put produce in a pill did worse than nothing. In Finland, 29,133 male smokers given 20 mg of beta-carotene a day, the orange pigment of carrots, had 18% more lung cancer and 8% higher overall mortality than those on placebo.^[11] In a US trial of 18,314 smokers and asbestos-exposed workers, beta-carotene plus vitamin A raised lung cancer by 28% and deaths by 17%, and the trial was stopped early.^[12] A Cochrane review of all such trials found that beta-carotene and vitamin E supplements, and possibly high-dose vitamin A, slightly increase mortality.^[13] Whatever produce does, it is not reproduced by isolating its antioxidants.

Fruit sugar is not the problem

Whole fruit does not behave like added sugar. In a Chinese study of about half a million adults followed for seven years, people who ate fresh fruit daily had about 12% lower risk of developing diabetes than people who rarely ate it, and among those who already had diabetes, each extra 100 g of fruit a day went with about 17% lower mortality.^[14] In three US cohorts, whole fruit overall went with slightly lower diabetes risk, with blueberries, grapes and apples standing out, while fruit juice went with higher risk.^[15] The fibre and the need to chew slow the sugar down; juice removes both.

Dried fruit is whole fruit with the water taken out, so it is easy to eat several portions' worth of sugar in a minute. A small handful, about 30 g, with a meal is a reasonable portion.

Fresh, frozen, canned, cooked or raw

Frozen produce is picked ripe and frozen within hours, and in a comparison of eight fruits and vegetables, its vitamin content was comparable to and sometimes higher than fresh produce stored in the fridge for a few days; beta-carotene was the exception, falling in some frozen vegetables. The work was done in partnership with the frozen-food industry's research foundation.^[16] Canned vegetables and fruit count too; choose them without added salt and fruit in juice or water rather than syrup.

Raw versus cooked is a trade, not a rule. Cooking softens cell walls and releases more carotenoids, such as the lycopene in tomatoes and the beta-carotene in carrots, while boiling leaches vitamin C into the water. Eat both, and steam or roast rather than boil for long.

Pesticides and organic

Conventional produce more often carries detectable pesticide residues than organic, but a systematic review found no clear evidence that organic food is more nutritious or that it improves health, and the gap in produce exceeding legal residue limits was small.^[17] Rinsing removes some surface residues, and the evidence on glyphosate, the most-used weedkiller, is on Glyphosate. The health gap between eating produce and not eating it is far larger than any gap between organic and conventional, so buy whichever lets you eat more.

What to actually do

Count to five portions of about 80 g a day, roughly two fruit and three vegetables. More is fine; fewer than five is where the gains are.
Put a vegetable in every meal: berries or a banana with breakfast, a salad or soup at lunch, two vegetables at dinner. The sample weekly menu shows how this fits a whole week.
Favour leafy greens, cruciferous vegetables, berries and citrus when you choose, but variety beats chasing one food.
Eat fruit whole. Keep juice and smoothies occasional, and don't count potatoes or chips as vegetables.
Use frozen and canned produce to make it cheap and easy; it is nutritionally close to fresh.
Skip beta-carotene and antioxidant pills, especially if you smoke or used to.