Eat nuts, prunes... and REAL butter

LOW-FAT BUTTERS

Until relatively recently, margarines contained trans fats (liquid fats which have been industrially hardened). These are now banned because they significantly raise cholesterol and risk of heart disease, so margarine and other vegetable oils are now made using sophisticated chemical processes using heat, chemicals and enzymes then blended with salty water using emulsifiers, starch and often milk powder. The question remains, though, whether this kind of tinkering with fats will turn out to be harmful in the way that trans fats are. Enjoy real butter or polyphenol rich extra virgin olive oil instead.

STEER CLEAR OF ‘HEALTHY’ CRISPS

The quest for the healthy high-fibre crisp has led to all sorts of processed crunchy products made with peas, lentils, chickpeas and mixed legumes. But despite lower salt and sugar contents, many of these snacks are still ultraprocessed, often with more than 14 ingredients, emulsifiers and flavourings. The humble potato crisp with only two or three ingredients and preferably the skin still on is a better option eaten occasionally.

SWITCH ICEBERG LETTUCE FOR COLOURFUL LEAVES

The least nutritious vegetable in the fridge is the iceberg lettuce which was introduced for commercial production in the US in the 1940s as the only variety which could survive cross-country transportation (on ice). It might be transportable but it has no taste and few nutrients. If you depend on iceberg for one of your ‘five a day’ you would need 500 a day. Italian lollo rosso curly loose-leaf varieties are packed with beneficial plant compounds and have 300 times more antioxidant potential than iceberg.

NUTS ARE GOOD FOR YOUR WAISTLINE

Numerous studies have concluded that nuts do not make you fat. In fact, we could have overestimated (by a quarter) the calorie content, which has given them a bad name. Studies show nuts can reduce your risk of obesity by 20 per cent if you eat five portions a week. Our trials showed that daily nut consumption slightly reduce weight gain and waist size by about a centimetre, over five years. This effect could be caused by the high protein and viscous fibre content making you feel fuller faster; or it could be direct effects of the fats and chemicals in the nuts, altering and speeding up energy expenditure. It could also be due to a general antiinflammatory effect of the polyphenols and prebiotic fibre, thanks to our gut microbes, or if they’re not ground or turned to a butter the energy in the fat isn’t absorbed in our small intestine thanks to their hard-to-break-down food matrix. Whatever mechanism is at play, this could mean we have missed out on the wonderful benefits of nuts in our diet, due to their bad name and our obsession with calorie counting.

PUT PRUNES BACK ON THE MENU

Although prunes have long been lauded as a constipation cure, they drifted out of fashion until ten years ago when the Californian prune board officially renamed them ‘dried plums’ and sales have soared since. Not only are they one of the only dried fruit which preserve their beneficial plant compounds without the addition of sulphur preservatives but they really do have a laxative effect, helping increase regular bowel movements in some people.

The fibre works to soften stools by retaining water and bulking them up, but more recently a key chemical called sorbitol has been identified in prunes. Although we can’t digest sorbitol, it is happily fermented by our gut microbes, creating a laxative effect in those who have the specific microbes that can ferment sorbitol. If you know, you know.

© Tim Spector, 2022 l Food For Life, by Tim Spector, is published by Jonathan Cape on October 27 at £20. To pre-order a copy for £18, go to mailshop.co.uk/books or call 020 3176 2937 before October 22. Free UK delivery on orders over £20.