Brimming with benefits
'Gardeners who grow their own fruit and vegetables could be the healthiest people'; so claims Dr Laurence J Trueman, a molecular biologist and biochemist currently working as a consultant to the horticulture industry specialising in the effect of eating fruit and vegetables on human health.
Dr Trueman describes the health benefits of fruit & veg:
- Eating 400g (14oz) of fruit and vegetables a day provides protection against cancer and cardiovascular disease.
- Vegetables may provide more benefits than fruit - up to twice as much.
- Variety is the key to life: it is important to eat a wide variety of fruit and vegetables in as wide a range of colours as possible.
- Selenium, beneficial to the human body, is a co-factor in helping the effectiveness of fruit and vegetables fight these diseases. Selenium is rare in British soils, but is common in manure and manure-based fertilisers, and so is present in soils fed with these substances.
- Stress is a major contributor to cardiovascular disease and gardening is known to reduce stress.
The power of fruit and vegetables
Campaigns such as the Government-backed five-a-day encourage people to increase their consumption of fruit and vegetables.
There is found to be a significant link between a diet lacking fruit and vegetables and an increased risk of contracting cancer or cardiovascular disease (CVD).
The best strategy for reducing the risk of contracting CVDs and extending our life is to fill our bodies with antioxidants from diet; the best sources of this are fruit and vegetables.
Protective compounds
Science is now discovering that fruit and vegetables have protective compounds and indeed other unexpected properties. An example is glucosinolates, a class of compounds found in cruciferous vegetables (e.g. brassicas). There is increasing evidence that some of these compounds may not only protect against cancer, but actively slow the growth and in some cases kill cancer cells.
Home-grown fruit and vegetables may also hold an advantage in terms of conferred health benefits. Commercial growers are skilled at maximising yields and quality by reducing the stress load on their crops. Gardeners however, tend to refrain from using pesticides and artificial fertilisers with the aim of producing a more ‘natural’ product.
This has the effect of forcing the plant to cope with the stresses it encounters using its natural biochemical defences. Many gardeners know that to maximise the odour of many plants, which often have therapeutic properties, you ‘grow them hard’.
The spice of life
A major tenet of the five-a-day campaign is variety - every crop may confer slightly different health benefits. This can be taken a step further in that different varieties can confer different health benefits; coloured carrots being a prime example.
Finally, many government recommendations are concerned with removing the causes of cancer and CVD. These include giving up smoking, increased exercise and a reduction in your level of stress - a major cause of high blood pressure and consequently CVD. Many gardeners find their plot a welcome break from the pressures of the outside world, making gardening a major health benefit.
To summarise, cancer and cardiovascular disease are natural consequences of ageing due to damage by reactive oxygen species. By eating a diet rich in fruit and vegetables we can bolster our natural defences against ageing and reduce our risk of contracting these diseases.