Functional foods to combat age-related disease

Functional foods of the future might seek to address the underlying causes of age-related chronic diseases such as Alzheimer’s, arthritis and certain cancers, scientists have predicted.

Research suggested that many chronic diseases associated with ageing stemmed from inflammation and oxidative stress, which started attacking cells from birth, said experts gathered at the British Nutrition Foundation’s (BNF’s) healthy ageing conference in London last week.

While many functional foods and supplements were currently very specifically targeted (eg. plant sterols for cholesterol reduction; lutein for eye health), a more holistic approach that tried to address the progressive damage caused to cell machinery (rather than a systems approach looking at reducing the risk of, say, dementia, through diet), might develop in future, they predicted.

However, antioxidant supplementation, which was the best example of a nutritional intervention designed to tackle the everyday damage caused to cells through oxidation, had not delivered encouraging results in human intervention studies, admitted Dr Robert Clarke, reader in epidemiology and public health medicine at the University of Oxford.

“Randomised trials of antioxidant vitamins and B vitamins have not shown any protective effects on the risk of coronary heart disease and stroke, for example.”

Nevertheless, epidemiological data clearly suggested that a diet rich in foods containing antioxidants, such as fruits and vegetables, was protective against a raft of diseases, he explained.

As a rule, nutritional interventions designed to help people improve their quality of life in old age should begin as early as possible, delegates were told.

In other words, while far more energy was finally being devoted to addressing the dietary needs of older people, prevention was still better than cure, said professor John Mathers from Newcastle University’s human nutrition research centre. “Ageing is something that applies across the whole of the life course; it’s not something that just kicks in at the end.”

The biggest problem facing healthcare professionals and food manufacturers was that many people did not change their diet until they had had a shock, such as a cholesterol test, or discovered they had high blood pressure, said professor Paul Dieppe from the University of Oxford. “It often takes a crisis to change behaviour. I’m afraid just telling people what is good for them simply doesn’t work.”

There was a tendency for people to worry a lot about what they were feeding their babies and children but to ignore their own health until things started going wrong, agreed David Cherry, vice president at omega-3 fatty acid giant Croda Healthcare. He added: “There is a massive, underexploited opportunity [for food manufacturers and supplement suppliers] to target people in the prime of life rather than just at the start and the end. We are very assiduous about giving our babies and children the best start in life, which is why there has been such growth in maternal and infant nutrition for omega-3s. But we don’t typically start taking action again until we are in our 50s or 60s.

“It’s at this point that the omega-3 market picks up again as cognitive function, joint health and cardiovascular health are suddenly top of mind. There is still a huge amount of work to be done to educate people about the benefits of getting omega-3s across every life stage.”

While life expectancy was rising by about two years every decade, greater longevity was not necessarily accompanied by good health, with many older people suffering from chronic pain, dementia, poor dentition, impaired gastric function and eyesight, muscle wastage and brittle bones, said professor Judy Buttriss, director general of the British Nutrition Foundation. “The amount of time spent in good health is not increasing in correlation with actual life expectancy. We’re living to an old age, but not necessarily to a healthy old age.”

The conference was produced to mark the launch of a new book called ‘‘Health Ageing: The Role of Nutrition and Lifestyle’’, published by Wiley-Blackwell for the BNF.