Ageing and diet

After people live to (their) 60s or 70s, both their essence and blood are consumed.Even though their life is normal and not (particularly) eventful, they may present heat signs...good wine and fat meat, sodden wheat-flour foods and oil, roasted, stewed, and fired(foods), and acrid, pungent, sweat and greasy (foods) are all included among the prohibited.
Zhu Danxi, 14th century CE

Old people have internal vacuity with a weak spleen and yin depletion with a quick temper...Therefore, it is clear why foods which are hot in nature, are prepared(directly) over a charcoal fire, an fragrant and pungent in qi, or are sweet and oily in flavour are all unfit(for the old) to take.
Zhu dandy, 14th century CE

Young babies are born with weak digestions. They easily develop colic and diarrhoea, and vomit frequently. Yet by the time they are healthy teenagers, they have developed prodigious appetites and cast iron digestions that allow them to wolf down a meal at midnight and reappear at breakfast claiming to be starving.
In a healthy person this ability to eat whatever and whenever we want may last well into adulthood. But as the years pass, perhaps imperceptibly at first, our digestive system begins to weaken. Eating too much, eating late at night, eating excessively rich food-all may start to cause problems. We saw in Chapter 6 that ignoring these signs can slowly lead to digestive disease. But even in the absence of actual disease, if we take no heed and continue as usual, by the time we are old our digestion may have weakened to the extent that we lose our appetite. In both Chinese and modern medicine, this is a worrying sign. A healthy appetite is a key symptom of overall health, while a poor appetite and consequent lack of proper nutrition, will eat away at bodily strength and hasten decline. Involuntary loss of weight in late life is a clear predictor of increased mortality. As two Chinese sayings put it, With Stomach qi there is life, without Stomach qi there is life, without Stomach qi there is death,"and (in defining three basic signs of health), "able to eat, able to sleep, able to defecate."
This understanding of the waxing and waning of digestive vigour through life is at the basis of traditional Chinese dietary principles for the elderly. As always, the advice is simple-do not eat excessively large meals; eat light food; do not eat late at night; avoid overly sweet, spicy, rich or greasy food; avoid too much alcohol and chilled food. All of these put a greater strain on the digestive system.
At the same time, it is important that meals are tasty and nourishing. Since our sense of taste and smell diminish with age, it is not unusual for the elderly to lose interest in food-especially if it is too bland.
It is also important to include liquid foods such as soup and porridge and avoid very dry foods. The Chinese medicine saying that,"the stomach likes moist food", is particularly relevant to the elderly because the innate moistness of the stomach(stomach yin) declines and we are less able to digest what is dry.
These precautions will help maintain a good appetite and protect and prolong the health of the ageing digestive system.
What a shame then that dietary provision for the elderly is often so poor. When people live alone they may lose the incentive to cook well, especially if their appetite is not as robust as it used to be and if they are depressed or lonely. In residential homes, hospitals, and hospices, food may be tasteless, poorly cooked, of poor nutritional quality and inappropriately greasy or sweet. To support life and health it should be exactly the opposite and there is ample research that shows how important a good diet is for healthy ageing.

.In a study of over 3,000 older adults(aged 70 to 79), those who followed a high fat and diary product diet or a high sweets and desserts diet, had a 1.4 times greater risk of dying than those who followed a broadly'healthy diet' (higher intake of low-fat diary products, fruit, whole grains, poultry, fish ,and vegetables.
.The HALE(healthy ageing) study of over three thousand 70 to 90 year old Europeans, found a significantly reduced a risk of mortality in those consuming either a Mediterranean style diet or a diet defined as healthy by the World Health Organisation. The study also found a protective effect for moderate consumption of alcohol. As we saw in Chapter8, small quantities of alcohol-especially spirits-are considered helpful for the elderly, to promote blood circulation and stimulate appetite.
.A study into diets of older Dutch women(60-69 years) found a reduction in mortality risk of 30 percent among those who ate a 'healthy traditional Dutch diet'(higher intake of vegetables, fruit and non-alcoholic drinks) compared to those who ate a 'non-healthy traditional Dutch diet'(higher intake of meat, potatoes and alcohol).