Tony Blair munches through a daily supply of pistachios and Dame Kelly Holmes claims that cashews were crucial in her securing her Olympic double gold. Nuts, it seems, are becoming Britain's nibble of choice, while sales of crisps, crackers and poppadums are declining, as people react to fears of obesity.
Not only are nuts healthier and more natural than processed, deep-fried snacks, nutritionists also say they are natural wonder drugs that can help reduce the risk of breast cancer, heart disease and male infertility, as well as delay signs of ageing.
After winning the 800m and 1,500m events in Athens, Dame Kelly confided: "Cashew nuts are my little secret." She claimed that they helped to accelerate her powers of recovery so that her body was well prepared for its next test of speed and endurance. But it is not just Olympic athletes and prime ministers who benefit from the proteins, vitamins and minerals abundant in nuts.
Ursula Arens, a dietitian and spokesperson for the Dietetic Association, says: "Nuts are high in fat, but it is healthy fat because it is unsaturated. They should not be condemned as a snack food due to their high fat content. For the majority of people who are not overweight or on a diet, they are as useful as cheese in maintaining a balanced diet, because they contain high levels of protein. They are also rich in vitamin E.
"Brazil nuts are uniquely high in selenium, a nutrient needed by a potent antioxidant enzyme in the body. The antioxidant properties reduce the risk of heart disease and cancer, according to population data."
Selenium is a trace mineral found in the soil. It is absolutely essential for a healthy immune system, fertility and thyroid metabolism, but levels in British soil have become so low over the past few decades, due to intensive farming methods, that the amounts getting into the food chain have been adversely affected.
In Finland, where a national selenium fortification programme was introduced by the government in 1985, white muscle disease of the heart - a major risk factor for heart disease - has been eradicated.
In this country, the governmental Food Standards Agency has reported that there is an inverse relationship between selenium intake and mortality from cancer.
Brazil nuts were linked last year with a reduced risk of breast cancer in some women by scientists at the University of Illinois. They claim that selenium interacts with a natural body chemical to offer protection against the disease.
Many more studies have pointed to the long-term health benefits of eating nuts. One showed that regular consumption could cut the risk of bladder cancer in half because of their high vitamin E content. Professor John Radcliffe, a nutrition researcher at Texas Woman's University, surveyed 10,000 people and found that those who consumed the highest amount of vitamin E had a 50 per cent lower incidence of bladder cancer.
A study published in The Journal of Nutrition found that people who replaced half the fat in their daily diets with almonds experienced a drop in harmful LDL cholesterol of six per cent over six weeks.
Despite the high fat and calorie content of nuts, which is similar to the levels in crisps, there is evidence to suggest that they can actually help with weight loss. The reason is their high protein content, which creates a feeling of satiety.
Sue Baic, a registered dietitian and lecturer in nutrition at Bristol University, says: "Eating massive amounts of nuts will build up calories. But if they are eaten as a snack in small quantities, they can help people who are watching their weight, because they are more satisfying to the appetite than chocolate or crisps.
"The fat content in nuts is high, but it is monounsaturated so in fact protects against heart disease. They can reduce cholesterol and prevent damage to arteries. This includes all types of nuts, including peanuts, which are technically legumes."
Eating nuts may also help to delay the ageing process. Monica Grenfell, a nutritionist and author of Fabulous in a Fortnight, says: "Nuts are good for your looks. Almonds, particularly, are high in vitamin E, which prevents wrinkles and influences how you age. They should be eaten as part of a balanced diet, incorporated with five fruit and vegetables a day.
"Almonds and pistachios are high in calcium, which is particularly important for vegans or people who cannot eat dairy products. And Brazil nuts are good for men's fertility due to their high zinc content. I eat three Brazil nuts a day and six whole almonds, to boost my immune system and protect my skin from rapid ageing."
The £201m nuts market grew by 11.6 per cent last year, as health-conscious shoppers bought 0.4 per cent fewer crisps and 4.4 per cent fewer crackers than in 2003, according to research analysts TNS. A report in the trade magazine The Grocer also revealed that raisins and sultanas are growing in popularity.
Consumers are eight times more likely to eat nuts for health reasons than other bagged snacks, according to a TNS survey of 11,000 people. Arens says: "The only drawback to the nut craze is that processed nuts often have a lot of salt added, which is not healthy and leads to high blood pressure. People should choose unsalted varieties.
"Also, a small percentage of the population is severely allergic to nuts, and has a dramatic sensitivity, particularly to peanuts."
Need to know
Britons consume more than 18,000 tonnes of peanuts a year. They are a source of vitamins B and E, and also contain magnesium, phosphorus, copper, iron and zinc, which are difficult to absorb from everyday diets. Swedish scientists have discovered that peanuts contain arginine, too, which boosts the body's defence system.
Brazil nuts are high in selenium, a nutrient needed by a potent antioxidant enzyme in the body. The antioxidant properties reduce the risk of heart disease and cancer, according to population data. Two brazils contain more than half the recommended daily amount of selenium.
Eating two or three 1oz servings of pistachios a day can help to lower cholesterol levels by up to 10 per cent, according to scientists in Virginia, USA. They are also a good source of potassium, which can help to regulate blood pressure.
Cashew nuts are rich in iron, which is vital for energy. One and a half ounces of cashews provides one-fifth of a woman's daily iron requirement, and 20 nuts provides more than one-tenth of a man's daily zinc needs.
Almonds can reduce cholesterol levels and the risk of heart disease, according to the Almond Board of California. They are high in protein, fibre, calcium, riboflavin, copper, iron, potassium and zinc.
Walnuts may help to prevent diabetes, being rich in vitamin E and alpha-tocopherol, according to research in Diabetes Care. They also contain unsaturated fats that are converted into a blood-thinning agent, making them effective at reducing cholesterol. They are also high in omega-3 fatty acids.Reuse content