PLANT FOR LIFE
Briefing Report 12: June 2006
Ross Cameron and Sarah Swan
University of Reading
Gardening better than other activities in offsetting Osteoporosis?
Two website reports highlight the use of gardening activities in fighting osteoporosis
in the elderly (Krischer, 2006, see
http://home.ivillage.com/gardening/0,,mp14,00.html and (Welch, 2001, see
http://aggiehorticulture.tamu.edu/extension/newsletters/hortupdate/nov01/art10nov.html). These
quote research carried out by Dr Lori Turner at Arkansas University, although it has
been difficult to track down the original scientific publication. Nevertheless, the data
quoted suggests women over 50 who garden at least once a week, have a higher bone
density reading (the reading that is used to diagnose osteoporosis) than women who
take part in almost any other form of exercise. In a study of 3,300 woman it was
found that ‘yard-work’ and gardening was more beneficial than other weight-bearing
exercise such as jogging, swimming, walking and aerobics. Gardening was
comparable to moderate weight training in terms of aiding bone strength. The authors
claim that gardening is not only beneficial in providing opportunities to build muscle
and bone, but that because it is a popular and enjoyable past-time participants are
more likely to be active more frequently. Also the report states that being in sunshine
not only feels good, it increases vitamin D production which helps the body absorb
calcium. (presumably there are also risks for the elderly associated with overexposure of sunlight, e.g. melanoma, when precautions are not taken.)
The second report covers an oral paper given by Lori Turner to the American Nursery
& Landscape Association. Here, Dr. Turner offered some ongoing advice for those
interested in gardening as a healthy habit and as a way to help avoid osteoporosis.
“Getting started
If you’ve taken a winter break from yard work or haven’t been an avid gardener, start
slowly and work your way up. If weather forces you indoors for several months, do
callisthenics or weight training to keep in shape for gardening season. It’s also a
good idea to have a physical exam before starting strenuous exercise. It is
recommended that women have bone density tests around age 50, or at menopause.
Take a few minutes to stretch or warm up before you begin digging, weeding or
pushing the wheelbarrow. Don’t risk dehydration. Keep water close at hand while
working outdoors. People aged 65 and over must make an aggressive effort to stay
hydrated. Use sunscreen and/or wear a hat and pause for shade breaks.
Work smarter
Several simple methods keep gardening from becoming a backbreaking chore. Raised
beds require less bending and stooping. A portable stool makes weeding or planting
easier on the body. Foam pads are gentler on the knees than hard ground. Next trip to
the garden centre, look for long-handled tools with good grip surfaces. Having
several sitting areas throughout the yard encourages gardeners to stop, rest, and
appreciate their efforts. Keep in mind the time-honoured adage, “Take time to smell
the flowers.”
Consider alternatives to lugging heavy bags of soil. You might have aged compost
delivered by the truckload, directly to your garden. If small scale gardening is your
ticket, most garden centres and nurseries are willing to load bags of dirt for you.
What do you do once you’ve gotten the heavies home? Garden author Marianne
Binetti suggest laying a tarp on the ground behind your car. Roll the bags of soil out
of the car and onto the tarp. Drag the tarp to your intended garden site. Split the bags
with a sharp knife and encourage the contents to spill out. This minimizes heavy
lifting and allows you to garden independently.” (http://aggiehorticulture.tamu.edu/extension/newsletters/hortupdate/nov01/art10nov.html).
Gardening for exercise
Another web- based article (Gilliam 2006,
http://www.active.com/story.cfm?story_id=13057&sidebar=574&category=wellness)
describes other benefits of gardening. Research has shown that gardening is
physically and mentally healthy. Aside from getting a great workout, people who
garden regularly experience a greater sense of calmness and relaxation, resulting in a
better mood that lasts for hours.
One study at the University of California found that gardening reduces stress more
effectively than many other more standard methods of relaxation, and gardening has
been shown to be very beneficial to those with depression and other health problems.
Physically, it improves strength, muscular endurance and helps to control weight.
Again the report provides some practical pointers to the un-initiated !
•
How can you help turn gardening into a good workout? Doing your gardening
nonstop instead of continually stopping and starting will give you the most
calorie burn for the time spent and keep your metabolism boosted.
•
At approximately three calories per pound of body weight for each hour, a
150-pound person can burn as many as 450 calories. Time seems to fly by
with outdoor activities. By spending more time active, you burn more calories.
•
Gardening can be challenging, so if you'
re overweight, unaccustomed to
exertion or if you have a medical condition, be careful not to do too much too
soon. It'
s best to spend shorter amounts of time initially and pace yourself.
•
Most people don'
t think of gardening as a strenuous activity, but it involves
bending, stooping, squatting down, lifting and digging. It'
s a major worker for
nearly all of muscles, including the back, legs, glutes, arms and abs.
•
To lessen the risk of injury, it'
s important to prepare for a gardening workout.
It'
s estimated that nearly a quarter million people require hospital treatment
every year for injuries they sustained while gardening. Just as with any
activity, spend a few minutes beforehand warming up and loosening the body
with gentle stretching, and take time during the activity to stretch.
•
Alternating between different tasks is also helpful. For example, after 10 to 15
minutes of weeding, stop and do some raking or pruning, and so on.
•
Keep in mind that staying hunched over or doing any activity with a rounded
back for long periods of time is hard on the lower back, creating stiffness and
soreness that can last for days. Remember to protect your back as much as
possible when gardening. Try to maintain proper posture and when lifting, get
as close to the object as possible, squat down and lift with the legs and not the
back and take time to stretch periodically.
Motivation for gardening
Other reports have looked at the motivating factors that encourage people to get
involved in gardening. One study focussed on the motivations to grow vegetables,
(Anderson, 2006, (http://www.ru.ac.za/community/ISER/gardening.htm). Perceived
benefits range from savings on household expenditure, to better household nutrition,
to health and wellbeing. The gardeners remain fit and experience a real sense of
achievement when they see their gardens grow. The study found that in spite of the
many advantages, home gardening enjoys a poor image in the community. It is
associated with a survival strategy for the elderly and the poor and with rural
backwardness rather than with youthfulness, initiative, health, vigour, and selfreliance. The authors conclude that there is a need for an image makeover if urban
agriculture is to play a role in contemporary community development.
Work done in New Zealand (Kidd and Brascamp, 2004) aimed to determine the
essential personal characteristics, if any, and the necessary conditions that enable
adult New Zealand gardeners to reap the non-physical benefits of the gardening
experience that may contribute to enhanced well-being. Specific focus was on factors
that influence people to become involved with gardening, their reasons for gardening,
and levels of satisfaction with various gardening activities. Gardeners’ personal
characteristics and self-perceived gardening qualities were correlated with intangible
(i.e. psychological) benefits. Overall psychological well-being was assessed using the
six scales of the Psychological Well-being Index (PWI). Data was derived from 361
responses to a countrywide mail-out survey sent to self-selected “keen” gardeners
who responded to media advertising and publicity. Results reinforce findings of an
earlier investigation of New Zealand mid-aged women gardeners that gardening
serves a wide range of needs and benefits on many levels, including psychological,
emotional, social, and spiritual. The data also provide an understanding of the type of
persons who engage in gardening and give an overall picture of their motivations for
gardening. Finally, the study identifies which factors are apparent indicators for
someone to find satisfaction and a sense of well-being from gardening.
Other work illustrated peoples responses to different gardening activities (Catanzaro
and Ekanem, 2004). A written survey was developed in 2001 to collect information
from home gardeners on the types of plants they grew, their purchasing habits, the
types of gardening activities in which they participated and enjoyed, and their
perceptions of how important various aspects of gardening were to them. The survey
was conducted at two events: the Tennessee Green Industries Field Day
(McMinnville), and the Tennessee State Fair (Nashville). Eighty nine percent of
respondents grew annuals in their home gardens, while 69-74% reported growing
herbaceous perennials, shrubs, trees, and edible crop plants. Among those who
reported purchases during the previous year, average expenditures were highest for
trees ($95), with approximately half that amount spent for each of the following:
annuals, perennials, and shrubs. With regard to specific activities undertaken, 86% or
more of home gardeners engaged in planting, watering, weed control, pruning,
mulching/composting, and mowing. Less than one-half of respondents participated in
water gardening or hard landscaping.
Gardeners reported weed control and planting as the most time consuming activities.
Planting was chosen most frequently as the most enjoyable activity. Respondents
rated the statements “Home gardens provide a reduction in feelings of stress” and
“Home gardens provide interaction with nature” as very important. Respondents rated
as important that home gardens provide an opportunity for self-expression, physical
and physiological benefits, and restorative experiences. Less important to home
gardeners surveyed were aspects of cultural or ethnic representation, symbolism, and
economic benefits. Results suggest that although gardeners select from a wide range
of plant materials and activities in an individualistic manner, the interaction with
nature in a nurturing environment provides a number of benefits important to them,
including mental well-being.
Lawn mowing may keep you fit, but may not be as ‘green’ as you think.
One study looked at the variability of energy expended doing a range of ‘everyday’
tasks (Gunn et. al, 2002). The purpose was to investigate variations between
individuals, but the data also provides some insight to which activities involve most
energy use. Comparisons were made between moderate paced walking, self-paced
sweeping, window cleaning, vacuuming and lawn mowing. Twelve men and 12
women were measured for metabolic rate and oxygen use during the five activities on
two separate days. Mean values derived from oxygen use divided by measured
metabolic rate were significantly (P < 0.001) above 3.0 for moderate paced walking
(range = 3.3-8.7), sweeping (2.9-6.7), window cleaning (3.0-6.0), vacuuming (2.64.4), and lawn mowing (4.9-7.5). Although values varied markedly for individuals,
the data suggested lawn mowing involved highest energy expenditure, as it was the
only activity where all subjects scored above 3.0.
A number of web-sites are reporting negative qualities associated with lawn mowing
and other garden activities in terms of ‘The Environment’. These may be relaying
outdated information, as some of the statistics appear rather elderly. Again it is
difficult to source the original references in some cases. One article dating back to
1996, highlights the problem of petrol mowers (Lamarre, 1996). In the USA, state and
federal air quality regulations are cracking down on the gasoline-powered lawn
mower, limiting air pollutants emitted by this previously unregulated machine. A
study sponsored by Electric Power Research Institute (EPRI), the Environmental
Protection Agency, the Edison Electric Institute, and 18 electric utilities undertook the
first-ever national sampling of emissions from gasoline mowers in use and found that
the mowers are even dirtier than previously believed. The results showed that the
emissions associated with cordless electric mowers (i.e., emissions from plants
generating the power to charge them) are dramatically lower than those from gasoline
mowers in some cases, thousands of times lower. What`s more, consumers who
swapped their gasoline mowers for cordless electric mowers through the study were
very pleased with the change, finding the electrics comparable in performance and
superior in convenience. Manufacturers are gearing up for what many anticipate will
be a thriving market for cordless electric mowers, and electric utilities are stepping up
their support for the technology. The fact that this research was jointly sponsored by
companies promoting electrical goods (rather than petrol driven), however, does not
necessarily help aid the impartiality of the research!
Similar findings, however, are supported on other web-sites. According to Statistics
Canada the use of gasoline-powered lawn equipment releases about 80 000 tonnes of
greenhouse gas (GHG) emissions in Canada every year (Van Caeseele, 2002 http://www.climatechangeconnection.org/pages/yardcare.html). Small combustion
engines in lawnmowers, leaf blowers and chainsaws have a big impact on air quality.
They emit harmful nitrogen oxides, carbon dioxide, hydrocarbons and particulate
matter, just like a large automobile engine. The report states what is shocking is the
rate at which they spew out climate-changing emissions. In one hour, a conventional
lawn mower produces as much pollution as 40 late model cars driving for the same
amount of time! In addition a typical lawnmower spends forty hours per year (the
equivalent of a one-week vacation) mowing the lawn. The age and type of machine
can be important - Post-1997 lawnmowers have overhead valve engines that produce
one-third less emissions than older models. Overhead valve engines combust fuels
more quickly, burning them more uniformly.
The report goes on to suggest that electrical machines are more energy efficient, but
better still is to use solar powered mowers, manual mowers that help keep you fit, or
even to reduce the area of ‘high maintenance’ lawn present.
Other areas of concern were highlighted in the report with respect to environmental
damage associated with gardening. These were:
•
“Nitrogen-based fertilizers produce nitrous oxide (N2O). Nitrous oxide is over
300 times more effective than CO2 in greenhouse warming. Such fertilizers are
overused regularly by homeowners on their lawns and gardens.
•
In addition to GHG emissions, residential abuse of fertilizers and pesticides
are responsible for surface and groundwater contamination.
•
The average suburban lawn is deluged with 10 times as much chemical
fertilizers and pesticides per acre as farmland.
•
Approximately 50 million kilograms of chemicals are dumped on Canadian
lawns and gardens every year. Such excess use has far-reducing impacts on
human health, as well as climate and the environment.
•
The Ontario College of Family Physicians have concluded that Canadian
children at serious risk from lawn and garden chemicals. Because they play
outdoors, they are more likely to come into contact with such substances.
Research suggests that exposure to these chemicals during prenatal and early
childhood development result in permanent loss of brain function.
•
Children regularly exposed to pesticides are six times more likely to develop
childhood leukemia and brain cancer.
•
Adults aren'
t safe either. Some chemicals used on urban lawns have the
potential to disrupt human hormone and endocrine systems. Endocrine
disruption can lead to:
decreased immune system function,
impaired reproductive abilities,
behavioural changes such as attention deficit and hyperactivity
disorder
and increased susceptibility to breast and testicular cancer.”
In contrast to this report, another one highlights that gardens may be important
refuges for wildlife as climate change impacts on their natural habitats (Alter, 2006 http://www.treehugger.com/files/2006/06/good_gardening.php). As the world’s
temperatures change, many species of birds, bees, butterflies, and mice will lose their
feeding and breeding grounds and wildlife gardening is being encouraged as an aspect
of the solution. Many gardeners already know the importance of growing plants
which are native to their local area instead of exotic flowers which require intensive
care (and watering).
The report highlights advice from English Nature
“Among the tips suggested by English Nature are planting colourful flowers,
honeysuckle and lavender to attract butterflies. Bumblebees like pollen-rich flowers
such as foxglove, thyme and campanula. Do not use slug pellets or pesticides. Ponds
provide a habitat for frogs and amphibians—one third of which are under threat. For
the birds: planting flowers with seed heads and shrubs with berries provides food in
the autumn. Evergreen trees offer protection for nests. Using less water is equally
important. This means collecting rainwater in barrels for re-use, using compost and
mulches to prevent weeds and growing plants that need less water. Since nearly two
thirds of British adults are gardeners—amazingly that’s twice as many as those who
watch football—these steps can make a difference”
References
Alter, B. (2006). Good gardening can slow climate change.
http://www.treehugger.com/files/2006/06/good_gardening.php.
Anderson, I. (2006). Gardening for Well-being. Rhodes University- Community
engagement. (http://www.ru.ac.za/community/ISER/gardening.htm).
Catanzaro, C. and Ekanem, E. (2004). Home gardeners value stress reduction and
interaction with nature. ISHS International Horticultural Congress XXVI: Expanding
Roles for Horticulture in Improving Human Well-Being and Life Quality. Acta
Horticulturae 639: 269-275.
Gilliam, M. (2006). Tending the garden improves mental and physical well-being.
The active network.
http://www.active.com/story.cfm?story_id=13057&sidebar=574&category=wellness)
Gunn, S.M., Brooks, A.G., Withers, R.T., Gore, C.J., Owen, N., Booth, M.L. and
Bauman, A.E.(2002). Determining the energy expenditure during some household and
garden tasks. Medicine & Science in Sports & Exercise. 34: 895-902.
Kidd, J.L. and Brascamp, W. (2004). Benefits of gardening to the well-being of new
zealand gardeners. Acta Horticulturae. (ISHS) 639: 103-112
Krischer, H. (2006). Fight Osteoporosis While Gardening.
http://home.ivillage.com/gardening/0,,mp14,00.html
Lamarre, L. (1996). Mowing down pollution. Electric Power Research Institute
Journal, 21: 16-23.
Van Caeseelehttp. R. (2002). Climate Change and your yard.
http://www.climatechangeconnection.org/pages/yardcare.html .
Welch W. (2001). Gardening: A Great Way to Fight Osteoporosis. Horticulture
Update, produced by Extension Horticulture, Texas Cooperative Extension, The
Texas A&M University System, College Station, Texas.
http://aggiehorticulture.tamu.edu/extension/newsletters/hortupdate/nov01/art10nov.html)
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