Category: Longevity & Health

Research at the Institute for Transfusion Medicine in Pittsburgh, USA has examined whether supplements can benefit levels of iron and haemoglobin in blood donors. Donors in the US are allowed to give one pint of blood every 8 weeks (12-16 weeks in the UK), but about 25-35% of regular donors develop iron deficiency, and nearly 7% have to delay their donation due to low haemoglobin levels.

The researchers followed 215 blood donors, aged 18 to 79, at four blood centres. Participants had previously donated blood, but not within the last four months. Their levels of ferritin (a protein that stores iron and can be used as an indirect measure of iron levels) were measured, then they donated blood. Based on their original ferritin levels, participants were placed in one of two groups: higher and lower ferritin. Half of each group took an iron supplement daily for the next 168 days.

Those taking supplements more quickly returned to 80% of pre-donation haemoglobin levels in both the lower ferritin (32 days versus 23 weeks) and higher ferritin groups (31 days versus 11 weeks). Similarly, donors taking supplements recovered iron more rapidly. Overall, the median time for iron to reach pre-donation levels was 11 weeks among those taking supplements and 24 weeks in the no-supplement group.

“This study highlights the importance of maintaining iron levels after blood donation and shows that supplemental iron effectively restores hemoglobin, even in donors with higher iron levels,” say the study authors.

(Oral Iron Supplementation After Blood Donation: A Randomized Clinical Trial. Journal of the American Medical Association, 10 February 2015. http://jama.jamanetwork.com/article.aspx?articleid=2108889).

For current advice on blood donation in the UK, visit NHS Blood & Transplant.

Researchers at Florida State University in the US have found that daily consumption of blueberries for only eight weeks, resulted in significant reductions of blood pressure in post-menopausal women. Although hypertension is associated with aging in both sexes, the increased incidence particularly of raised systolic blood pressure in women after menopause, exceeds that in men.

Forty-eight women were recruited to participate in an eight-week, randomized, double-blind, placebo-controlled trial. Investigators found that daily incorporation of 22g of freeze-dried blueberry powder, equating to one cup of fresh blueberries, into the diet of postmenopausal women with hypertension, improved blood pressure and arterial stiffness potentially through enhanced nitric oxide-mediated vasodilation. At the conclusion of the study, mean systolic blood pressure was lower by 5.1% and mean diastolic blood pressure was lower by 6.3% in the subjects in the blueberry group, with no corresponding lowering in the placebo group.

Among all fruit, blueberries are one of the richest sources of phenolic compounds, including flavonoids, phenolic acids, and stilbenes, which are known to have biological activity and high antioxidant capacity. They are a promising food with respect to vascular health.

(Daily Blueberry Consumption Improves Blood Pressure and Arterial Stiffness in Postmenopausal Women with Pre- and Stage 1-Hypertension: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial. Journal of the Academy of Nutrition & Dietetics, published on-line 7 January 2015.)

Research from Brigham And Women’s Hospital in Boston, USA, suggests that servings of two or more fish per week are associated with a lower risk of hearing loss in women. Data on over 65 000 women followed over the period 1991 to 2009, showed that compared to women who rarely consumed fish, those women who had two or more servings per week, were 20% less likely to experience hearing loss. Higher intake of long-chain omega-3 polyunsaturated fatty acids (PUFA) showed a similar association.

Dr Sharon Curhan, who led the study, said,“Although a decline in hearing is often considered an inevitable aspect of aging, the identification of several potentially modifiable risk factors has provided new insight into possibilities for prevention or delay of acquired hearing loss. Consumption of any type of fish (tuna, dark fish, light fish, or shellfish) tended to be associated with lower risk. These findings suggest that diet may be important in the prevention of acquired hearing loss.”

(Fish and fatty acid consumption and the risk of hearing loss in women. American Journal of Clinical Nutrition. Online 10 September 2014.)

Research from the University of Warwick has found that higher fruit and vegetable consumption is associated with better mental wellbeing. In a survey of 13 983 adults in England, looking at factors such as health, obesity, smoking and alcohol consumption, 33% of participants with high mental wellbeing, were found to be eating five or more portions of fruit and vegetables daily. Across the study as a whole, high fruit and vegetable consumption was associated with both high likelihood of good mental wellbeing and reduced likelihood of poor mental wellbeing.

The researchers believe that their findings add to the mounting evidence that fruit and vegetable intake could be a way of enhancing mental wellbeing whilst at the same time preventing heart disease and cancer.

(Major health-related behaviours and mental well-being in the general population: the Health Survey for England. BMJ Open, 19 September 2014. http://bmjopen.bmj.com/content/4/9/e005878.full)

Researchers at the London School of Hygiene and Tropical Medicine have found that commuters who travel to work by walking, cycling or public transport, have a significantly lower body mass index (BMI) and percentage body fat, compared with those who use private transport (predominantly the car, but also taxi, moped and motorbike).

A total of 15 777 people were included in the study. Factors such as age, disability, diet quality, participation in sport, and physical activity in the workplace, were all allowed for in anticipation that they might affect any association between commuting mode and obesity. Men who commuted via public or active transport modes were found to have BMI scores respectively 1.10 and 0.97 lower than those using private transport. For women, the corresponding figures were 0.7 and 0.87.

A key finding was that the effects observed for public transport were very similar in size to those for walking or cycling, probably due to walking between transport hubs and making journey connections. The observed effect size for men of around 1 BMI point suggests that, for the average man in the sample (43 years old, 176 cm tall, weight 86 kg, and BMI 27.8), this would equate to a difference in weight of 3 kg (almost half a stone). For the average woman in the sample (43 years old, 163 cm tall, weight 72.8 kg, BMI 27.4), an effect size of around 0.7 BMI points would correspond to a difference in weight of approximately 2.5 kg (5.5 lb).

(Associations between active commuting, body fat, and body mass index: population based, cross sectional study in the United Kingdom. British Medical Journal, online 19 August 2014.)