Sleep - (or, the lack of it, termed as insomnia) - and sleeplessness - the 'father' of all medicine, Hippocrates, prescribed lettuce for its sedative qualities. Wild lettuce (Laduca virosa) is a mild narcotic and is often used in herbal preparations. Since sleeplessness is often caused by worry and anxiety, it is wise to relax before going to bed. the recommendations to limit worry and anxiety apply equally well here. Herbal preparations that offer more refreshing sleep, include ingredients such as valerian root, hops and pulsatilla are often recommended.

Sleep problems, including snoring, sleep apnea, insomnia, sleep deprivation, and restless legs syndrome, are common. Good sleep is necessary for optimal health and can affect hormone levels, mood and weight.

Between 1971 and 1978 Dr Ernest Hartman of Boston State Hospital carried out a series of experiments on the amino acid tryptophan under double-blind conditions. These showed that it enabled the subjects to go to sleep more quickly and that the sleep was deeper. This amino acid is converted into the neurotransmitter serotonin which is concerned with sleep. Most protein foods contain tryptophan, including milk, cottage cheese, almonds, peanuts, sesame, sunflower and pumpkin seeds, poultry, pheasant, tuna and beef. However, it needs the presence of vitamin B6 and a small amount of carbohydrate to work. Therefore the ideal bedtime snack consists of, say, a slice of wholemeal sunflower-seed bread with peanut butter and a cup of warm skimmed milk with a little honey. Buy your peanut butter without salt as the sodium acts as a stimulant on the adrenal glands. Otherwise a handful of pumpkin seeds mixed with sultanas and almonds, together with lettuce or camumile tea, is suitable for vegans. Do not drink ordinary tea or coffee after 5pm, if at all.

How much sleep does a person need?  Individuals vary greatly in their need for sleep; there are no established criteria to determine exactly how much sleep a person needs. Eight hours or more may be necessary for some people, while others may consider this to be too much sleep.

The National Institute of Health (NIH) suggests that most average adults need about 7 to 9 hours of sleep each night. Newborn babies, by contrast, sleep from 16 to 18 hours a day. Preschool-aged children typically sleep between 10 and 12 hours a day. Older, school-aged children and teens need at least 9 hours of sleep a night. Women in the first trimester of pregnancy have been observed to need a few more hours' sleep than is usual for them.

Does the amount of sleep we need change as we age?  Changes in the sleep cycle do occur with aging. Deep or slow wave sleep (Stage N3) sleep declines as we age, while light sleep (Stage N1) increases with age, so that older adults may spend less time in the more restorative stages of sleep and more time in lighter sleep. Older people are also more easily aroused from sleep. While some people believe that older adults need less sleep as they get older, there is no scientific evidence that older people need less sleep than younger adults. Health-advertising@UKandSpain.com