Question

I am 70 this year, have no arthritis or joint pain of any sort and am also free of heart disease, diabetes or any other limiting ailments, thank God. In order to try and keep it this way I used to take glucosamine, but this upset my gastrointestinal tract (glucosamine has also allegedly been proved to be ineffective). Therefore I moved on to cod-liver oil capsules, but the same thing happened to my genito-urinary tract. Can you suggest anything else that will not have the same result? I am also following a Pilates DVD.
Sue Jennings

· If you have a health question for our experts, email health@observer.co.uk

The healthcare expert

Cameron Swift

Unless you have a significant vitamin deficiency (which usually presents itself medically), then there is no evidence that dosing yourself with vitamins and antioxidants on a daily basis delays the effects of ageing. Still, most safe supplements are inexpensive, so if you want to try them, feel free - talk to a registered dietitian about your best options. Many doctors believe that no more than 30 to 40 per cent of life longevity is solely attributable to genes, so an early detection of any medical problems, along with lifestyle changes (more exercise, less fat in the diet, no smoking, moderate drinking) are your best protections against illness.

Have regular checks at your GP for blood pressure and blood cholesterol (for heart attacks and stroke risk), a blood count (for anaemia) and a fasting blood glucose test (for diabetes). Pilates is a fun and perfectly reasonable way to keep yourself healthy.

· Cameron Swift is Emeritus Professor of Health Care of the Elderly, King's College London School of Medicine

The nutritionist

Dr John Briffa

Several well-conducted studies have found glucosamine to be effective in the treatment of osteoarthritis ('wear and tear' arthritis). I have also found it in practice to be helpful in maintaining joint health, and think that your idea to try it was a good one. Very rarely do I find that it causes gastrointestinal symptoms.

Cod-liver oil is also usually well tolerated. You could try other brands of glucosamine and/or cod-liver oil, as it might be something in the formulations you have tried (rather than the active substances themselves) that you are sensitive to. However, your reaction might mean your gut is unduly sensitive. This is common in the elderly as our gut lining can degenerate. I can therefore recommend one remedy to regenerate your gut lining. This is L-glutamine (not to be confused with glucosamine). I suggest a dose of 1g, two or three times a day for two months.

· Dr John Briffa is a holistic doctor specialising in nutritional medicine. His website is www.drbriffa.com

The gastroenterologist
Dr John Hunter

I see no reason why you need to take 'preventative' medications such as glucosamine and cod-liver oil, as you are in perfectly good health. It sounds very boring, I know, but the best way to protect yourself against arthritis, heart disease and diabetes is to follow a well-balanced diet with some meat and plenty of fish, lots of fruit and vegetables and plenty of chewy foods, such as wholemeal breads. I'd also recommend as much exercise as you feel comfortable doing. Your reaction isn't necessarily an age issue. People from all age groups can get upset by certain foods, such as fats, milk and wheat. If you decide to continue taking supplements, you could try taking a pro-biotic (available in most supermarkets) to help settle your bowel, although pro-biotics are a lottery - you have to hope that the particular bacterium you're missing in your gut is present in the pro-biotic.

· Dr John Hunter is consultant gastroenterologist at Addenbrooke's Hospital, Cambridge