Going nuts
by Pieta Cedaro APD (Consult Dietician)
Over the past two decades nut consumption has decreased in Australia. Research indicates that this is in part due to public awareness that they are a high fat food. However, recent studies have consistently shown that many types of nuts can protect against heart disease and, possibly, diabetes. Furthermore if eaten in small amounts as part of a healthy diet, they do not seem to increase the risk of weight gain.
What makes nuts so nutritious and good for me?
Although different nuts contain unique combination of nutrients, generally
most contain the following:
- Low levels of saturated or bad fats.
- High levels of mono-unsaturated and polyunsaturated fats.
- No cholesterol.
- Phytochemicals, such as phytoestrogens (isoflavones) and phenolic compounds, ellagic acid and flavonoids.
- Dietary fibre.
- Plant protein, which makes them a good alternative to meat; nuts are also high in the amino acid arginine.
- Vitamins E, B6, niacin and folic acid.
- Minerals such as magnesium, zinc, iron, calcium, copper, selenium and potassium.
Nuts and heart disease
Eating nuts seems to help lower LDL(bad) cholesterol levels -the type
responsible for blocking arteries. Thus nuts appear to help to maintain
healthy blood vessels. This may have something to do with their high
content of mono-unsaturated and polyunsaturated fats, antioxidants,
vitamins and minerals, the vitamin folate and the amino acid arginine. In
one study, eating a handful of nuts five times per week was found to halve
the risk of heart disease.
Exceptions to the rule
Most nuts - including almonds, walnuts, pecans, cashews, brazil nuts,
chestnuts, hazelnuts, peanuts and pistachios - contain mainly
mono-unsaturated fats. However, coconut and palm nuts (and their oils and
milks/creams) contain high levels of saturated fats; so consumption of
these should be limited.
Nuts, obesity and diabetes
Dietary fats are energy dense, with twice the amount of kilojoules per gram (37kJ) than either protein (17kJ) or carbohydrate (16kJ). People who are overweight and obese can still benefit from the protective properties of nuts, without associated weight gain, if they swap them for existing food intake (in moderate amounts) instead of eating high fat processed snack foods. Some nuts contain more fat than others, but varieties such as chestnuts have comparatively low amounts of fat.
Nuts and allergy
Peanuts - and to a lesser extent brazil nuts, almonds and hazelnuts - can cause acute allergy in some people, particularly young children. This can be life threatening. Young children with a predisposition to allergies should avoid peanuts and other types of nuts as, once developed, this allergy will probably persist into adulthood.
Recommendations for nut intake
Research studies have highlighted the role of nuts in protecting us against heart disease and diabetes. As a result, recommendations regarding nuts have recently changed. Probably the best advice is to have a handful (nine to 15 nuts) of a variety of nuts daily, especially walnuts and almonds.
How should I include nuts in my diet
Instead of eating a biscuit or piece of cake as a snack, try having a handful of plain unroasted nuts. Combining nuts with low energy-dense foods (such as vegetables) in meals is a good way to eat them -reduce the amount of meat and add a few nuts.For example try a few nuts in Asian style dishes as stir fries and curries, added to a salad or sprinkled on some low fat yoghurt atop fresh fruit.
Furthermore people who avoid red meat (such as vegans, vegetarians) can benefit from eating nuts daily because nuts provide similar nutrients found in meat (they contain protein, fat, iron, zinc and niacin), although in significantly lower concentrations.