Issue 64
Do vegetarians live longer?
Meat products represent a major source of protein in
the Western diet and so findings on whether meat intake significantly contributes
to the burden of fatal disease have important clinical and public health implications.
Literature promoting the health benefits of a vegetarian diet often cites historical
accounts of longevity among populations with a low consumption of meat.
It has been shown that the life expectancy of adults
in Japan and certain Mediterranean countries is up to two years longer than
that of their Western peers, who tend to have a significantly higher level of
meat consumption.
A recent review examined whether a very low meat intake
was associated with an increased life expectancy. The data from six prospective
cohort studies were reviewed and the authors reported new findings on the life
expectancy of long-term vegetarians.
After a review of the six studies, the following trends
were reported:
-
A very low meat intake was associated with a significant
decrease in risk of death in four out of six studies.
-
Two of the studies in which a low meat intake significantly
decreased mortality risk also indicated that adherence to this diet for
at least 20 years contributed to a significant decrease in mortality risk
and an increase of more than three years in life expectancy.
-
The protective effect of a very low meat intake
seems to decrease after the age of 90 years.
It was concluded that current prospective cohort data
from adults in North America and Europe raises the possibility that a lifestyle
pattern that includes a very low meat intake is associated with a longer life.
Am J Clin Nutr. 2003 Sep;78(3 Suppl):526S-532S
Cod liver oil and rheumatoid arthritis A recent pilot
study investigated the effects of supplementation with cod liver oil on the
symptoms of rheumatoid arthritis.
43 patients with rheumatoid arthritis were supplemented
with cod liver oil (in a capsule form) at a dosage of 1000mg per day over a
period of three months.
The results showed significant decreases in morning stiffness
(52.4%), joint pain (42.7%), joint swelling (40%) and intensity of pain (67.5%).
The patients reported their experiences of supplementation with cod liver oil
with regard to efficacy and tolerability. Ratings of ‘good’ or ‘very
good’ were awarded by 68% of patients for efficacy and by 95% for tolerability.
It was concluded that cod liver oil can be recommended
for the treatment of arthritis.
Adv Ther. 2002 Mar-Apr;19(2):101-7.
Folic acid supplementation for coffee drinkers? Elevated
levels of plasma homocysteine (tHcy) are identified as independent risk factors
for coronary heart disease and foetal neural tube defects. tHcy levels are negatively
associated with folic acid intakes but increase as a result of coffee consumption.
The ability of folic acid supplementation to eliminate
the tHcy-elevating effect of coffee was investigated in a recent randomised,
blinded study. A total of 121 healthy non-smoking subjects (male and female,
aged 29-65 years) participated in the trial.
The effects of consuming 600ml coffee per day in combination
with placebo were compared with the effects of consuming 600 ml per day in combination
with a folic acid supplement (200ug per day).
It was concluded that supplementation with 200ug of folic
acid eliminates the tHcy increasing effect of 600ml of filtered coffee.
Eur J Clin Nutr. 2003 Nov;57 (11):1411-7.
Can a multivitamin reduce the risk of myorcardial infarction?
The association between the self-selected use of multivitamin
supplements and the risk of myocardial infarction was examined in a recent epidemiology
program.
The study included 1296 cases with a history of a first
non-fatal myocardial infarction and 1685 matched healthy controls. The use of
nutritional supplements among the study population was investigated and it was
found that use of multivitamin supplements was significantly higher in the control
group (women = 57%; men = 35%) than in the myocardial infarction group (women
= 42%, men = 27%).
The results of the study showed that the use of a multivitamin
supplement was associated with a reduction in the occurrence of myocardial infarction.
It was concluded that the use of multivitamin supplements may aid in the prevention
of myocardial infarction.
J Nutr. 2003 Aug;133(8):2650-4.
Antioxidant complex for UV protection Ultra-violet (UV)
light is involved in the initiation of almost all types of skin cancer via damage
to the cells’ DNA. 25 human subjects were used in this study to assess
the capacity of an antioxidant complex (AOC) composed of lycopene, beta-carotene,
alpha-tocopherol and selenium to reduce UV induced damage.
The results showed that many parameters of the epidermal
defence against UV-induced damages improved significantly, following the oral
intake of an antioxidant complex.
It was concluded that the oral intake of an antioxidant
complex could provide a safe, daylong and efficient complement to photo-protective
measures provided by topical and physical agents and may contribute to reduce
the DNA damages leading to skin ageing and skin cancers during exposure to UV
light.
Photodermatol Photoimmunol Photomed. 2003 Aug;19(4):182-9.
Tomatoes and cardiovascular health Diet is a major influence
on the development of cardiovascular disease, the commonest cause of death in
most industrialised countries. Tomatoes are widely produced and consumed, they
are also a rich source of lycopene, beta carotene, folate, potassium, vitamin
C, flavonoids and vitamin E. A recent review examined the role of tomatoes in
protecting against heart disease.
It was reported that many of the nutrients present in
tomatoes may function individually or in concert to protect lipoproteins and
vascular cells from oxidative damage, a major step in the development of atherosclerosis.
Other reported benefits included the reduction of LDL cholesterol, homocysteine,
platelet aggregation and blood pressure.
Crit Rev Food Sci Nutr. 2003;43(1):1-18.
Can CLA reduce appetite?
The effects of conjugated linoleic acid (CLA) supplementation
after weight loss were investigated in a recent placebo-controlled randomised
trial.
Subsequent to weight loss a total of 26 men and 28 women
(age 37.8 years +/- 7.7 years) participated in the trial, which was undertaken
over a period of 13 weeks.
Each subject was assigned to either CLA (1.8g/day), CLA
(3.6g/day) or placebo.
The results showed that feelings of hunger were decreased
after 13 weeks intervention with CLA compared to placebo.
It was concluded that appetite (hunger, satiety and
fullness) was favourably affected by consumption of 1.8g or 3.6g of CLA per
day.
Eur J Clin Nutr. 2003 Oct;57(10):1268-74.
Homocysteine and cognitive function Elevated plasma homocysteine
has been reported to be inversely related to cognitive function in patients
with Alzheimer,s disease and community-dwelling older adults.
The cross-sectional relationship between total plasma
homocysteine levels and cognitive functions among an elderly study population
(aged at least 60 years) was recently investigated.
Global cognitive function and specific cognitive functions
were assessed and then the associations between the cognitive function scores
and homocysteine levels were measured by multiple-regression analysis.
It was concluded that homocysteine might be a predictor
of cognitive function in the elderly and that reducing homocysteine levels through
supplementation with B vitamins might protect against cognitive decline in elderly
populations.
Am J Clin nutr 2003;78:441 – 7.
Vitamin D
Vitamin D is a fat-soluble vitamin. The vitamin is made
in the skin by the action of sunlight on cholesterol. Vitamin D is also present
in certain foods and is stable to normal cooking procedures.
What does it do?
Vitamin D is converted in the body into a calcium-controlling
hormone (1,25-dihydroxycholecalciferol) and its functions are all related to
the effects of this hormone. Its principle function is to regulate the level
of calcium in the blood. It does this by controlling the amount of calcium and
phosphorous absorbed by the intestine or released from bones. To maintain the
correct ratio of Calcium to Phosphorus it can regulate the amount of Phosphorous
excreted by the kidney.
What are the deficiency signs?
Rickets: Developed during childhood, rickets can begin
to show at just 2 months when craniotabes (areas of softening on the skull)
are noted. Production of first teeth can be delayed and posture affected. Enlargement
at the end of long bones can cause the child to develop a characteristic bowing
of legs when beginning to walk.
Osteomalacia: Develops in adults, similar to rickets
but different in that the bones are no longer developing. There is thinning
and weakening of bone and spontaneous fractures may occur. Osteoporosis and
Hip Fracture: Incidence of brittle bones and hip fracture may be increased in
post-menopausal women with an inadequate vitamin D supply.
Is it Toxic?
There are some reports f hypercalcaemia (high blood calcium
levels) in infants at an intake of 50μg. Signs of toxicity appear in adults
at a daily intake of 625μg.
Who should supplement?
There are certain categories of people who are more
susceptible to a Vitamin D deficiency, and who may thus need to supplement their
diets. These groups include: vegetarians and vegans, Asian women (who may not
consume adequate vitamin D, or choose to cover their skin), lactating women
(whose breast-milk may be low in vitamin D especially during the winter), and
the housebound or elderly (who tend to eat poorly).
Intake Levels: micrograms (μg) RDA = 5 Upper Safe
Level = 10 (Long Term) 50 (Short Term)
Which Foods? Micrograms (μg) / 100g
Cod Liver
Oil 212.5
Herring and Kipper 22.4
Salmon, canned 12.5
Milk, evaporated 4.0
Eggs 1.6
Butter 0.8
Liver 0.8
Cheese, cheddar 0.3
Milk, whole 0.03
Milk, skimmed 0
1. Vitamin and mineral safety council for responsible
nutrition: 1997
2. Handbook of dietary supplements: 1995
3. Med Hypotheses, 1995, 44;6:490-492
4. Health Essentials vitamin guide: 1994
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