What do film stars Gwyneth Paltrow, Alicia Silverstone and Sarah Jessica Parker have in common with their ancestors in the shtetl?
Answer: the macrobiotic diet, which became trendy in the '60s but has plenty in common with Ashkenazi food.
Hippocrates first coined the term which translates as "great life". Rabelais referred to it in the Renaissance, and in 1797 German physician Christopher Hufeland nailed the name in his book Makrobiotik or The Art of Prolonging Life.
But it was barely 50 years ago that Japanese philosopher George Ohsawa set out ground rules for a diet designed to balance the yin and yang energies within the body.
The heroes were wholegrains and vegetables, including pickled ones but excluding tomatoes and other members of the nightshade family. The villains were meat, eggs, dairy and refined sugar, though in theory nothing is absolutely banned. Fish, nuts, seeds, wholegrain bread, baked goods made with natural sweeteners and fruit are considered fine in moderation.
But this limited diet is nothing new to traditional societies. In 19th century Europe, poor Jews subsisted on wholegrains and vegetables which were fresh in summer and pickled in winter. Considering how much the Ashkenazi diet has been criticised, it is startling to be told pickled cucumber and sauerkraut are actually good for you.
"In every part of the world people have taken what's in abundance and preserved it - and to medicinal effect," explains Kenneth Prange, counsellor at the SHA Wellness Centre on Spain's Costa Blanca, the world's only macrobiotic spa.
"In the Mediterranean it's olives, in northern Europe cabbage, in Japan the umeboshi, or pickled plum." The book he favours as a primer for those new to the subject, Macrobiotics for Dummies, suggests it is no accident that pickled cucumbers are served with salt beef - they are alkaline and help neutralise the acid in the meat.
SHA was set up by an Argentinian who credited the rapid disappearance of his stomach tumour to macrobiotics; Kylie Minogue has visited the spa twice following her own cancer diagnosis. While the jury is out on some studies, researchers at New England Medical Centre have demonstrated that macrobiotic women processed oestrogen, associated with breast cancer, better than those following an unrestricted diet, and the benefits of eating vegetables and wholegrains are undisputed.
Pickles, on the other hand, may seem an odd food to foster health, but Prange credits them with helping rid the body of colds and flu, and even preventing them. Their function as an alkalising element is seen as a big deal because of the way modern diets have embraced an excess of acid, throwing, they say, our physiology out of kilter.
"Acids put stress on the body," says Prange, who sings the praises of sea salt, a prime alkalising agent. Tamari - naturally brewed soy sauce - is favoured, as is miso.
Ashkenazi Jews of old apparently did themselves a great favour by tucking into black bread and kasha. Our ancestors also followed macrobiotic principles by eating seasonally and locally and by using sweet vegetables in dishes like tsimmes instead of reaching for the biscuits.
Many stars have flirted with macrobiotics but few follow it religiously. Even Paltrow, its most famous proponent, was recently heard singing the praises of fried chicken. But many of the tenets of macrobiotics are commonsense - exercise, eat naturally and use natural materials for food storage.