EXTREME CUISINE: Haydn Shaughnessy tells us what to eat in order to live to a healthy old age
There is both a diet detective out there and a diet doctor, writers who claim to have elevated their trade above the ordinary.
The diet detective, aka Charles Stuart Platkin, is syndicated in more than 160 American newspapers.
The diet doctor, aka Ian Marber, hails from London.
This month's Extreme Cuisine is also stepping up its game.
Welcome to Dottori Culinari, godfather of culinary approaches to healthy ageing.
In this column: How to grow to a ripe old age without getting (too) poorly.
Anti-ageing diets are growing in volume and arguably in popularity. Recently Time magazine ran a four-page special on how to combat the ageing process, written by well-known medical writer Dr Andrew Weil.
Weil's recommendations don't differ dramatically from the ones you can find in books like The Okinawa Diet, based on the super-longevity of inhabitants living on the Okinawa Islands in Japan.
Meditation, or some other form of spirituality, exercise and diet are the three areas Weil focuses on, as do the Wilcox brothers, authors of The Okinawa Program, a leading anti-ageing resource.
Diet-wise their recommendations add up to a food pharmacy.
Eat less wheat products, more whole grains, that would be barley, oats and rye; replace full fat products like butter with healthier fat choices like coconut oil; eat plenty of fibre, and oily fish; take in plenty of phytonutrients by consuming a wide range of fruit and vegetables; supplement with folic acid and calcium; and eat the healthful spices like ginger and turmeric.
I would argue, and have argued in this column, that typically scientists and researchers urge upon us fresh food without pause for thought and overlook the value of naturally preserved foods.
Preserved foods provide micro-flora balance in the gut, countering the evil world of the bacterial, viral and parasitical that we consume, with the good world of probiotic bacteria.
A dawning reality is that our guts do much more than digest food.
Good gut balance is related to the production of histamine and serotonin, neurotransmitters that regulate important aspects of our health.
Ninety-five per cent of the serotonin in the body is manufactured in the gut rather than the brain, and we identify serotonin with happiness.
That's why the best way to a man's heart used to be his stomach.
Histamine irregularities are responsible for disease like asthma yet it begins its life not in the lung but in our digestive system. Histamine irregularities also contribute to chronic inflammation in the body, a source of degenerative disease.
But putting these differences to one side, why do ageing experts make what are becoming familiar recommendations?
Partly, it's because nutritional science is offering better insights into what works at different stages in our lives.
Whereas for two generations doctors have focused on cholesterol as a cause of heart disease, the spotlight is now slowly shifting to a compound called homocysteine.
Folic acid, vitamin B6 and vitamin B12 help keep levels of homocysteine low in the blood and the assumption, for now, is that if they are present in large enough quantities and doing their job, then the heart should be doing okay.
The B vitamins are abundant in whole grains, hence the preference of many doctors to recommend them.
Digesting whole grains, however, can also be inflammatory. Traditional ways of preparing grains have included soaking, mashing and fermenting to aid their digestion.
Weil's word of caution, to avoid wheat-based products, is salutary. We just get too much of it and many are adulterated with other ingredients, bread for example with soy flour and trans-fats.
Vitamin D is an essential vitamin that we become less efficient at producing as we age. Exposing our skin to sunlight produces vitamin D, but by around retirement age our bodies produce about half of what they did as teenagers.
Fish, particularly cod liver oil, is a great dietary source though sunlight remains the best.
Free radical damage to our cells is a well-known byproduct of metabolism so anti-oxidants that scavenge them are important in negating their cumulative effects. Those anti-oxidants are full-on in the phytonutrients found in plants and green vegetables.
And finally inflammation. Chronic inflammation is increasingly associated with disease.
Traditional medicine, however, has known for years that certain foods have an anti-inflammatory effect - turmeric is thought to be the most potent, oats, rose petals as well as the herb rosemary, cherries, resveratrol in wine, blueberries, and carrots are all good anti-inflammatories.
But if all this attention to detail sounds a little dull, take a look at a diet recommended by Dutch and Australian doctors just in time for Christmas last year.
They produced what they called the polymeal, a nutritional karate kick to the ills associated with ageing.
The polymeal, they claim, can reduce cardiovascular disease by 76 per cent.
For men, again a claim, taking the polymeal daily potentially leads to an increase in total life expectancy of 6.6 years.
The recommended daily "dosage" in the polymeal is 150ml of wine, 100g of dark chocolate, 400g of fruits and vegetables, 2.7g of fresh or frozen garlic, 68g of almonds and 114g of fish four times a week.
Chocolate and garlic can also work as aphrodisiacs which could make those extra 6.6 years a good deal happier than they might otherwise be.
A dawning reality is that our guts do much more than digest food