In a Nutshell

By Joanna McMillan-Price, extracted from Life Etc Magazine

Magnesium, potassium, calcium, iron, zinc, B group vitamins, vitamin E, vitamin A, copper, manganese and selenium: no, it's not the ingredients list of the latest nutritional supplement, just a selection of the nutrients we get from nuts. Yet so many of us are reluctant to eat them regularly and think of them as an indulgence.

Nuts have been on the nutritional merry-go-round for a while. While they've always been a favourite of the healthfood consumer, most of us bought into warnings to limit the use of nuts or avoid them altogether because of their high fat and calorie content.

That information wasn't wrong. Nuts do have a high fat content and are indeed energy dense. But what seemed a commonsense assumption - that nuts would therefore be detrimental to weight control and heart disease - has been proved unequivocally to be wrong. In fact, just the opposite seems to be true.

Nuts and weight control

Four large-scale studies found that people who eat nuts tend to have a lower body mass index (BMI); a fifth found no association. In short, contrary to expectations, these studies found that, on the whole, nut eaters tended to weigh less. Plus, a host of clinical studies have shown people can successfully lose weight while eating up to 100g of nuts a day as part of a restricted-calorie diet.

Even where nuts have been added to a person's usual diet to push up the calorie intake, the amount of weight the subjects gained was far less than predicted from the known calorie content of nuts. So what's going on? There are two likely explanations.

Nuts are very satiating and successfully curb our desire to over-eat other foods. Secondly, nuts are an intact food containing lots of fibre: the body has to work hard to break down the individual cell walls to absorb and make use of the energy and nutrients. This in turn may mean we're not 100 per cent successful in completing the task and therefore fail to absorb all of the energy, particularly from fat, contained in the nut.

In other words, we may be getting fewer calories and fat from nuts than the nutrient composition data seems to predict.

Nuts and heart disease

Can you really halve your risk of heart disease by regularly consuming a high-fat food? Well, yes, you can, according to research on nut consumption - by eating a small handful (30g) of nuts five or more days a week.

Even more amazing is that even those who eat nuts once a week have been found to have less heart disease than those who don't eat nuts at all!

It appears that it's the type of fat that makes nuts so heart-healthy. Saturated fat is the type that's been shown to increase our risk of heart disease, primarily by raising blood LDL (bad) cholesterol levels. Almost all nuts are low in saturated fat. The fat they contain is largely the healthy unsaturated kind. The exception is coconut which is extremely high in saturated fats, but even coconut may not be as bad for your heart as that might suggest.

Not all saturated fats raise blood cholesterol levels to the same extent. Coconut differs from other high saturated fat foods such as butter in that it contains predominantly short- and medium-chain saturated fats. These appear to have a neutral effect, neither raising nor lowering blood cholesterol levels. So coconuts may not be bad for us, but there are certainly many better choices from the nut world.

Pecans, pistachios, cashews, almonds, hazelnuts, peanuts and macadamias are all rich in monounsaturated fat (like olive oil) while brazil nuts, pine nuts and walnuts are rich in polyunsaturated fat. These fats have been shown to help lower bad cholesterol levels in the blood, while raising good cholesterol. There are even some super-healthy omega-3 fats in good quantities in pecans, walnuts and hazelnuts.

But it's not just the fat. Nuts provide a host of essential nutrients that benefit the heart. Nuts are fibre-rich and this undoubtedly contributes to their cholesterol-lowering effects. They also provide protein and, in particular, the amino acid arginine, known to be important in maintaining healthy blood flow through the arteries.

Antioxidants are a major part of our defence against damaged and clogged arteries, and nuts are full of them. These include vitamin E - almonds are a fabulous source of this vitamin, a small handful providing 80 per cent of the daily needs of men and 100 per cent of women.
Selenium plays a vital antioxidant role in preventing cellular damage, but is also crucial for healthy immune and thyroid function. Two or three brazil nuts are all you need to meet your daily demand.

Nuts and overall health

Nuts provide many other essential nutrients for overall health. They're good for bones, providing magnesium and small amounts of calcium, particularly almonds. They provide iron and zinc, two minerals often low in our diet, particularly if you don't eat meat. Cashews are the clear winners here with 30g, providing women with 8 per cent of daily iron and 21 per cent of daily zinc needs (19 per cent and 12 per cent respectively for men).

Nuts also provide a whole battery of B group vitamins necessary to convert the food we eat into energy for the body, for healthy skin, hair and nails, and to maintain healthy blood cells.

So how to eat them?

Steer clear of the salted roasted varieties and the nut butters with added sugar, salt, additives and preservatives. Buy your nuts raw and unsalted - you can roast them yourself for a few minutes in a hot oven - and as natural, unadulterated butters. You'll find these in the health food section of your supermarket; they're delicious on toast instead of butter.

It's time to break your low-fat mantra and indulge happily in nature's own nutrient-packed pill. Go nuts.