IT'S PERFECT timing. In the month that may well produce the biggest demand on party nibbles of all time, the American Peanut Information Office has the perfect PR story: peanuts are good for your heart.

A study conducted at Penn State University and published this month in the American Journal of Clinical Nutrition shows that foods that are high in monounsaturated fat - such as peanuts - can actively help heart health, more even than low-fat diets.

The nutrition science community has spent the last couple of decades qualifying its earlier breakthroughs. Fat is bad! Fibre is good! Cholesterol is bad! Now, increasingly, all these arguments are being seen as over- simplifications.

Good cholesterol is an important defence against the more recently discovered risk factors for cardiovascular disease. For example, our triclyceride level (the amount of circulating fat in the blood) is now recognised as an important predictor of the risk of heart disease.

A diet that is low in fat lowers the total cholesterol, which means that the good HDL cholesterol is lowered as well as the bad, which in turn upsets the balance and raises triglyceride (bad) levels in the blood.

Monounsaturated fat, however, like the majority of fat in peanuts and that other party nibble goodie, olives, lowers the bad cholesterol (known as LDL) level, while maintaining good cholesterol (known as HDL) levels.

"Most people, when trying to cut fat out of their diets, put more carbohydrates and sugars in," says Pat Kearney, chief nutritionist for the Peanut Institute in Georgia (not too hard to see on which side her bread is peanut buttered). "They are not satisfied after cutting out the fat. Dr Penny Kris-Etherton at Penn State University has now challenged the traditional weight-loss diet. Low fat foods by themselves are not the answer to a healthier heart."

The good thing about peanuts, of course, is that people actually want to eat them - always an important factor in nutrition. On 15 and 16 January scientists will be gathering in London for a conference partly organised by the Royal College of Physicians to discuss how nations obsessed with fast food can be won over to the charms of foods such as slow-olive-oil cooked ratatouille. It seems that peanut butter might be a good compromise.

"It is certainly true," says Sara Stanner, nutrition scientist at the British Nutrition Foundation, "that when it comes to parties you are better off eating olives and peanuts than crisps and pastry. But you can still have too many."

The best advice for getting the balance right at the temptation-laden Christmas party nibble trays, says Stanner, "is to eat at home first. That way you will be less likely to succumb when you get to the party. The worst thing you can do is arrive hungry and then start trying to soak up the alcohol with snacks. You can easily eat a whole day's calories without realising it. A gram of fat contains far more calories than a gram of carbohydrate, yet it will not fill up your stomach. If you do nibble, put the food on a plate, so that you see how much you are really eating."

The calorific value of favourite nibbles

Handful of peanuts 73

Mushroom vol-au-vent 158

Party pizza slice 117

Onion bhajee 109

Small mince pie 233

Carrot and taramasalata 227

Chicken drumstick 152

Small bag of crisps 74

Meat samosa 297

Vegetable samosa 236