* Altered mitochondrial function due to oxidative stress. Mitochondria are the energy powerhouses of the cell, where nutrients are broken down to release energy for cell repair, defence mechanisms, neuromuscular function, and other processes that maintain the body and help resist ageing. Mitochondrial disorders such as fibromyalgia, heart problems, immune deficiencies, and central and peripheral nervous system problems such as Alzheimer’s and dementia are associated with accelerated ageing (N Engl J Med, 1995; 333: 638-44).

* Increased protein glycation. In this process, blood sugar (glucose) is turned into glycated proteins, including glycohaemoglobin, which is involved in the control of blood sugar in diabetics - but too many of these proteins can lead to poor glucose control. Other proteins in the body become glycated when there is poor control of insulin and glucose metabolism. This can lead to periodontal disease and tooth loss (J Periodontal Res, 1996; 31: 508-15), skin ageing and wrinkling (J Clin Invest, 1993; 91: 2463-9), and an increased risk of heart disease (J Clin Invest, 1995; 96: 1395-402).

* Chronic inflammation. This begins in the gut, triggered by allergens or parasites, and can give rise to local and systemic immune reactions with gut-associated lymphoid tissue (GALT). Among genetically susceptible individuals, chronic inflammation is associated not only with gastrointestinal and liver-related disorders, but with the risk of Alzheimer’s and heart diseases as well (Neurology, 1997; 48: 626-32; N Engl J Med, 1997; 336: 973-9).

* Poor metabolism of homocysteine (an amino acid) increases the risk of heart disease (JAMA, 1997; 277: 1775-81), stroke and dementia among certain individuals.

* Compromised detoxification means that toxins accumulate in the body, including drugs as well as environmental pollutants that may be toxic in themselves, and also contribute to free-radical production.

* Altered immunity may result from all of the above. As immunity declines, susceptibility increases to infectious agents as well as to allergens.

These problems can all be modified through diet and exercise (see boxes on page 2 and above).

If your doctor doesn’t tell you - or, more likely, doesn’t know - you also need to find out which drugs are not appropriate for seniors (see box, page 3). It’s now known that one in four and one in seven older patients are receiving at least one inappropriate medication (Ann Pharmacother, 2000; 34: 338-46). The most often prescribed risky drugs are long-acting benzodiazepines (tranquillisers and sleeping pills), the antiplatelet drug dipyridamole (Persantine), the pain reliever propoxyphene (Darvon) and the tricyclic antidepressant amitriptyline (Elavil).

Staying alert for gradual changes that may signal a harmful side-effect is essential. Important ‘red-flag’ symptoms include changes in mood, energy, attitude or memory. Too often, these alterations are overlooked, ignored or just chalked off to ‘old age’ or senility. But virtually every heart drug, blood pressure drug, sleeping pill and tranquilliser can trigger these symptoms. So, when a psychological symptom appears - in yourself, a senior patient or a loved one - look to the medications first.

Cutting down on drug use By asking a few simple questions, you can avoid the prescribing cascade. If you don’t feel confident enough to challenge your physician, take a supportive family member with you.