AGEING
AGEING OF THE CARDIOVASCULAR SYSTEM DURING 33 YEARS OF
AEROBIC EXERCISE
With increasing age there is loss of aerobic capacity,
which can result in poorer quality of life, reduced chance
of survival in an emergency and greater potential for developing
hypokinetic diseases. Therefore, a study was carried out
to determine the effect of ageing on the circulatory system
in middle-aged men during 33 years of physical training.
The study group consisted of 15 men initially aged 45 years
who took part in an exercise-training programme for 25-33
years. The aerobic training consisted of swimming, jogging,
walking and cycling 3-4 times per week. Sessions were for
61-70 minutes at 77-84% of heart rate reserve.
There was no change in resting heart rate, blood pressure,
percentage fat or body composition. Minimal cardiovascular
losses at maximal work included 5.8-6.8% in minimal oxygen
uptake per decade, 25 beats in maximum heart rate and 26
beats in heart rate reserve. Thus, exercise training has
a favourable effect on ageing of the cardiovascular system
in older men, resulting in minimal loss of oxygen uptake,
no rise in resting blood pressure and no change in body
composition.
KASCH, F.W. et al
AGE & AGEING 1999, 28 (6) 531-6
BRAIN CELLS CAN REGENERATE
Dr. Fred Gage and colleagues at the Salk Institute for
Biological Studies in California, together with doctors
at the Sahlgrenska University Hospital in Sweden have shown
that new neurons do develop after birth.
This flies in the face of conventional wisdom, which suggests
that brain cells, unlike all other cell types, do not reproduce.
Dr. Gage's team took post-mortem brain tissue from 5 patients
who had received an intravenous injection of bromodeoxyuridine
as part of their treatment for squamous cell carcinoma.
This drug is a thymidine analogue and is therefore taken
up into the newly synthesised DNA of dividing cells. Because
of this property, bromodeoxyuridine is sometimes used to
check for tumour cell proliferation. Using immunofluorescence
techniques and a laser microscope, which can optically section
through individual cells, the team was able to detect the
presence of the drug in all 5 postmortem specimens.
In addition to showing that new cells were present in the
brain, the team also confirmed that these cells were neurons
by looking for two other markers which can differentiate
between neuronal cells and glial cells.
The brain tissue studied by Dr. Gage's team comes from
the dentate gyrus, the part of the brain which acts as a
relay station between the cortex and the hippocampus and
is important in memory and learning.
BMJ no.7168 (7th Nov '98) p1272
IMPACT OF TRACE ELEMENTS AND VITAMIN SUPPLEMENTATION ON
IMMUNITY AND INFECTIONS IN INSTITUTIONALISED ELDERLY PATIENTS
It is well known that ageing is often associated with a
poor immune response, particularly the cell-mediated response,
and substantial vulnerability to respiratory tract infections.
Nutritional status has been recognised as a strong factor
in immune impairment, especially in elderly persons in institutions,
but there have been few large trials in elderly people that
have included end points for clinical variables.
Therefore, a study was carried out to determine the effects
of long-term daily supplementation with trace elements (zinc
sulphate and selenium sulfide) or vitamins (beta-carotene,
ascorbic acid, and vitamin E) on immunity and the incidence
of infections in institutionalised elderly people. Patients
received an oral daily supplement of nutritional doses of
trace elements or vitamins or a placebo for 2 years. Correction
of specific nutrient deficiencies was observed after 6 months
of supplementation and was maintained for the first year.
The number of patients without respiratory tract infections
during the study was higher in groups that received trace
elements.
Thus, low-dose supplementation of zinc and selenium provides
significant improvement in elderly patients by increasing
the humoral response after vaccination and could have considerable
public health importance by reducing morbidity from respiratory
tract infections.
Girodon, F. et al
ARCH.INTERN.MED. 1999, 159 (7) 748-54
VITAMIN B6 FOR THE ELDERLY
Researchers measured blood pyridoxine (vitamin B6) levels
in elderly people and found that 48% of subjects living
in the community, and 75% of those living in retirement
homes or hospitals, had plasma levels of pyridoxine well
below those considered to be normal, despite intakes in
excess of reference nutrient intakes for their age group.
BR. J. NUTRIT. 1999, 81, 3, 191-201
HEARING LOSS IN ELDERLY ASSOCIATED WITH VITAMIN B12 AND
FOLATE DEFICIENCY
Scientists tested the hypothesis that age-related hearing
loss may be associated with low blood levels of vitamin
B12 and folic acid. They carried out a clinical trial involving
the screening of 55 elderly women. Results showed consistently
that poor hearing is linked with low blood concentrations
of vitamin B12 and folate.
AM. J. CLIN. NUTRIT. 1999, 69, 3, 564-71
ALCOHOL AND MORTALITY - IS THERE A U-SHAPED RELATION IN
ELDERLY PEOPLE?
In several large population studies abstainers and heavy
drinkers have shown a higher mortality than moderate drinkers.
Therefore, a study was carried out to assess the relation
between alcohol intake and mortality among seven cohorts
of middle-aged and elderly Danes.
It was found that the effect of alcohol intake on mortality
did not differ between middle-aged (50-64 years) and elderly
subjects (>64 years old). There was a U-shaped risk function
in both age groups which persisted also when adjusting for
age, sex, smoking habits, level of education and body mass
index. Abstaining women had a relative risk of 1.29 as compared
with light drinkers (1-6 drinks per week), while the relative
risk for abstaining men was 1.22 as compared with light
drinkers. On the other hand, heavy drinking women (>28
drinks per week) had a relative risk of 1.23 and heavy drinking
men (>69 drinks per week) had a relative risk of 2.11,
both compared with light drinkers. Therefore, among the
middle-aged and elderly, a light alcohol intake is associated
with lower mortality than abstension or heavy drinking.
Gronbaek,M. et al
AGE & AGEING 1998, 27 (6) 739-44
FRUIT AND VEGETABLE CONSUMPTION IN LATER LIFE
Fruit and vegetable consumption may reduce the risk of
several chronic diseases, including cancers, cardiovascular
disease, coronary heart disease, hypertension and stroke.
The World Health Organisation therefore recommends the consumption
of at least 400g, or 5 portions of fruit and vegetables
a day. Most adults’ consumption falls short of this
recommendation, so a study was carried out to assess the
levels of fruit and vegetable consumption in elderly people,
and to examine the socio-economic, physical and psychological
factors which influence this consumption. The subject group
was 445 elderly people (aged 65+) living in the East Midlands.
The recommended target of 5 portions of fruit and vegetables
a day was achieved by less than half the respondents: 37%
of those living in the urban area and 51% of those living
in the rural area. Low fruit and vegetable consumption was
particularly associated with being male, smoking and having
low levels of social engagement. Health programmes promoting
fruit and vegetable consumption may not be successfully
reaching elderly people and need to target those particularly
at risk of low consumption.
Johnson, A.E. et al
AGE & AGEING 1998, 27 (6) 723-8
