MAKE EVERY FOOD A SUPERFOOD

Ethnobotanist James Wong reveals how simple tweaks can nutritionally boost everyday fruit and vegetables

Simple tweaks to nutritionally boost fruit and vegetables

LESS IS MORE

A University of Glasgow study found that simply picking cherry tomatoes instead of larger varieties could give you twice as many flavonols – anti-inflammatory compounds that can reduce cholesterol and blood pressure and may even prevent against certain types of cancer. Similar results have been found in a number of studies for the heart-healthy red pigment lycopene, too, with cherry types consistently having on average about twice the amount of others.

KEEP BROCCOLI UNDER WRAPS

One study in the journal Food Chemistry found that broccoli can lose up to 70 per cent of its vitamin C and betacarotene and 50 per cent of its antioxidant activity in just six days after picking. The research also showed that always keeping broccoli refrigerated and stored in sealed bags (as opposed to unwrapped in the fridge) could reduce these declines almost entirely.

TURN CABBAGE INTO COLESLAW

Slicing and dicing raw cruciferous vegetables such as cabbage triggers complex chemical reactions, which can make it measurably better for you. Even once harvested, vegetables are still living plants, and they react to this simulated pest damage by attempting to defend themselves. Once their cells are broken

A simple olive oil and lemon juice dressing enhances the absorption of phytonutrients in salad leaves

open, an enzyme called myrosinase reacts with glucosinolates to produce compounds called isothiocyanates. It is these protective elements that are believed to be what’s behind many of the crucifers’ health benefits, such as their potentially cancer-fighting properties. By finely chopping and leaving cabbage for an hour or two before eating (or cooking) means there is a greater amount of time for this reaction to take place.

SWAP ICEBERG FOR LOOSE-LEAF

Protected within a ball-like head, the inner leaves of lettuce such as iceberg are not exposed to the harsh UV light, battering winds and predation from insects and therefore don’t produce the defence chemicals they usually would need. Yet these are the exact same chemicals that provide salads with many of their nutritional benefits.

A study in the Journal of Food Biochemistry found that on the same lettuce plant, the external leaves could contain twice the antioxidant activity, three times the heart-healthy polyphenols and a whopping five times the carotenes of those in the centre. Loose-leafed varieties of greens, whose leaves grow exposed to the sun, will contain far more phytonutrients than tightly closed ones.

USE OLD GARLIC

When you slice into a garlic bulb, you spark chemical reactions that churn out pungent sulphur-based compounds. A growing body of research demonstrates that these compounds act as natural blood thinners. Old bulbs, especially those that have started to sprout, have been shown to manufacture far more of the sulphur-based chemicals, sending their antioxidant content soaring. And use a garlic press – the finer you chop garlic and the more damage you inflict, the more anti-clotting sulphur compounds you’ll generate.

OPT FOR NEW POTATOES

Up to 50 per cent of the polyphenols in potatoes come from their fibre-rich skin. The smaller the spud, the more they have, which means that by simply picking new potatoes over larger types, you will get more phytonutrients. The indigestible fibre in the skin also slows the absorption of the carbohydrate,

lowering their glycaemic index (how a food affects blood sugar levels). Being cooked whole also means that they tend to lose less of their phytonutrients to the cooking water.

GO FOR LONG AND LANKY ASPARAGUS

Researchers in Japan found that the heart-healthy rutin content of asparagus increased exponentially as the stems grew, meaning 24cm-long stems had twice that of the stubby 8cm ones that were just a week or two younger. As the stalks lengthen, they also tend to become skinnier, greatly increasing the surface area of each spear where rutin is concentrated. Pick the cheaper stems sold at pencil thickness instead of the ‘premium’ ones the width of your finger and you can get double the rutin, according to a trial at Canada’s University of Guelph, and at a lower cost.

SOLAR-POWERED MUSHROOMS

Popped on a sunny windowsill for an hour or two, mushrooms (which commercially are grown in near total darkness) will react to the UV light, churning out loads more of the antioxidant vitamin D to defend themselves from solar-radiation damage. A team at Penn State University found that a serving of white button mushrooms exposed to UV lamps for just one second could go from containing essentially zero vitamin D to an astonishing 824 per cent of your daily recommended intake. As the gill tissue (the brown underside of the mushroom caps) is more sensitive to light, placing them with the gills facing up will trigger the strongest spike.