A quick update on Influenza
How does it spread?
The influenza virus spreads from person-to-person. The main form of transmission is through the coughs or sneezes of an infected person. Infected droplets are released into the air and breathed in by others. However, these droplets do not remain in the air long and generally only affect people within two metres.
It is also possible to get influenza by touching contaminated surfaces, and then touching your nose, mouth or eyes.
How infectious is it?
Because this virus is new, people have no immunity to it so it will spread more quickly and widely than the seasonal flu. The pandemic situation could mean lots of people become sick at the same time and this could have a big impact on our day-to-day lives, and place considerable pressure on the health services.
Experts aren’t yet sure how long people who have the new Influenza A (H1N1) virus are infectious and able to pass the virus to others. It appears they could be infectious from a day before they experience symptoms until about seven days after they first experience them.
Children, especially younger children, may be infectious for longer periods. However early use of antiviral medicines, such as Tamiflu, can reduce this infectious period.
If you’ve got flu symptoms, stay at home until essentially well, that is not sneezing and coughing as this is how the virus spreads. This is usually around three to four days after symptoms start, but may be up to a week.
Stop the spread of flu germs by:
- Covering coughs and sneezes
- Regularly washing your hands and drying them thoroughly
- Avoiding contact with sick people and reducing time spent in crowded settings.
If your condition worsens, seek medical advice by phoning Healthline 0800 611 116 or your healthcare provider (Mapua Health Centre – 540 2211).
Get medical advice if you have a serious condition including respiratory disease, heart disease, liver disease, blood disorders and neurological conditions or have a suppressed immune system (including the effects of certain medications such as steroids or known to have HIV).
Natural Approaches to Hypertension
High blood pressure (BP) is linked to an increased risk of heart attack and stroke. A high BP has generally been defined as any number larger than 140 to 160 /90 to 100 mmHg and, despite some recent research suggesting a protective effect of lower BP of <1301, the latest Cochrane review recommends that aiming for blood pressure targets lower than 140/90 mmHg is not beneficial2.
There are some basic lifestyle recommendations that continue to underpin blood pressure control including weight loss, reduced sodium intake, avoidance or moderation in alcohol consumption, and increased physical activity3.
From a dietary perspective, keeping to a diet rich in vegetables, fruits, and low-fat dairy products (DASH diet) for a period of 3 months has been found to be more effective than routine outpatient hospital-based nutrition in reducing systolic blood pressure4. And in a study involving 2245 subjects 55 years of age or older, free of hypertension at baseline, the risk of hypertension was found to be inversely associated with dairy product intake so that, at 6 years, a 20% reduction in risk of hypertension was found for both total dairy and low-fat dairy intake5. Nuts also seem protective in a dose-dependent way so that eating nuts 7 or more times/week gave a hazard ratio of 0.82 for developing HT, down to 0.98 for once/week6.
Vitamin D could be important as a study7 involving 1,484 women between the ages of 32 and 52 years who were not hypertensive at baseline, found that the plasma 25(OH)D levels were “inversely and independently associated with the risk of developing hypertension.” Another large epidemiological study showed that dietary linoleic acid intake may contribute to prevention and control of adverse blood pressure8, while a cross-sectional study of 242 healthy young women 18-21 years, who were followed for 10 years, found that plasma levels of ascorbic acid to be inversely associated with systolic and diastolic blood pressure9.
Thankfully chocolate10 and cocoa11 look enjoyably promising in helping to bring down BP, although coffee doesn’t stack up as well with a long-term longitudinal study12 suggesting that coffee abstinence is associated with a lower hypertension risk than is low coffee consumption, with an inverse U-shaped relation between coffee intake and risk of hypertension (in women). Whereas, on the positive side, a RCT on green tea found that healthy adult volunteers had lowered systolic and diastolic blood pressures by 5 and 4 mmHg after 3 weeks13.
In terms of complementary medicine (CM) use, a USA study found that CM has a high use (69.5%) among older adults with hypertension (HT), but the vast majority of CM is actually used for treating or preventing other conditions and only 7.8% reported using CM to treat HT14.
Numerous herbal remedies, non-herbal remedies and other approaches have been investigated and some seem to have antihypertensive effects. According to a review in 2005 by Ernst15, the effect size is usually modest, and independent replications are frequently missing with the most encouraging data relating to garlic, relaxation, biofeedback and yoga. However, more recent trials have indicated a broader application for CM in the treatment of HT.
In a review of clinical trials looking at coenzyme Q10 in the treatment of hypertension16, a meta-analysis of 12 clinical trials involving 362 patients found reductions in BP which ranged from 11-17 mm Hg for systolic BP and 8 to 10 mm Hg for diastolic BP. No serious adverse effects were reported and doses of coenzyme Q10 used in the studies ranged from 34 mg/day to 225 mg/day, with the duration of the studies ranging from 2 months to 13 months. In terms of the mechanism of action, the authors note that oxidative stress, which ultimately leads to vasoconstriction, is known to be present in hypertensive states and coenzyme Q10 is a potent antioxidant which may decrease BP through its vasodilating effects.
A meta-analysis of 10 RCT’s looking at the effect of garlic on blood pressure17 showed an average reduction of systolic BP of 16.3 mmHg and diastolic BP of 9.3 mmHg. Smaller studies have looked at various other nutrients, including olive leaf extract in 20 sets of identical twins with “borderline” hypertension which showed mild improvement18; a 3% decrease in systolic BP with the use of olive oil in a non-Mediterranean diet19; omega-3 oils with the latest study giving a mean decrease of 2.7 mmHg systolic BP after 1 year of 2g/day intake20; quercetin (150mg/day) in a RCT gave a reduction of 2.9 mmHg21; and a 6-month treatment with ascorbic acid (600mg)was found to be beneficial for controlling refractory blood pressure among elderly patients22.
There are also a number of medicinal herbs that have been shown, in mostly small studies, to possibly have useful effects on HT including various Chinese herbs23 24, Ayurvedic herbs25 and European herbs such as hawthorn26.
Several minerals have been used in HT and, although some studies appear to support the use of magnesium27, calcium (where an earlier meta-analysis suggested a small reductionin systolic but not diastolic blood pressure)28, and potassium29, there have been 2 recent Cochrane reviews which did not find any definite benefit30, 31.
As far as relaxation goes, a Cochrane review32 of 25 RCT’s stated that “overall, relaxation reduced blood pressure by a small amount: the average reduction systolic/diastolic was 5/3 mmHg, but might be anywhere between 8/5 mmHg and 3/2 mmHg”. They found no evidence that autogenic training was effective, while progressive muscle relaxation, cognitive/behavioural therapies and biofeedback seemed to be more likely to reduce blood pressure.
A recent meta-analysis of acupuncture33 reported 4 studies of acupuncture compared to antihypertensive medication which showed that acupuncture was equivalent at lowering BP, although their quality was considered poor, and they concluded that “the notion that acupuncture may lower high BP is inconclusive”. There is some suggestion that osteopathy could be beneficial although more rigorous trials are needed34,35.
In conclusion, it looks like the best options for preventing or treating hypertension in addition to basic lifestyle changes are a mix of diet (rich in vegetables, fruits, nuts, and garlic); extra linoleic acid, olive oil, fish oil, green tea, dark chocolate and cocoa; supplements such as Co Q10, quercetin, vitamin C and various herbs; and relaxation and yoga (preferably in the sunshine for that extra vitamin D)!
- Verdecchia P, Staessen J, et al. Usual versus tight control of systolic blood pressure in non-diabetic patients with hypertension (Cardio-Sis). The Lancet 2009;374(9689):525 – 533.
- Arguedas J, Perez M, Wright J. Treatment blood pressure targets for hypertension. Cochrane Database Syst.Rev. 2009;3.
- Whelton P. Epidemiology and the Prevention of Hypertension. J Clin Hypertens 2004;6(11):636-642.
- Couch S, Saelens B, et al. The efficacy of a clinic-based behavioral nutrition intervention emphasizing a DASH-type diet for adolescents with elevated blood pressure. J Pediatr 2008;152(4):494-501.
- Engberink M, Hendriksen M, et al. Inverse association between dairy intake and hypertension: the Rotterdam Study. Am J Clin Nutr 2009;89(6):1877-83.
- Djousse L, Rudich T, Gaziano J. Nut consumption and risk of hypertension in US male physicians. Clin Nutr 2008;28(1):10-14.
- Forman J, Curhan G, Taylor E. Plasma 25-hydroxyvitamin D levels and risk of incident hypertension among young women. Hypertension 2008;52(5):828-32.
- Miura K, Stamler J, et al. Relationship of Dietary Linoleic Acid to Blood Pressure. Hypertension 2008;52:408-414.
- Block G, Jensen C, et al. Vitamin C in plasma is inversely related to blood pressure and change in blood pressure during the previous year in young Black and White women. Nutr J 2008;7(1):35.
- Faridi Z, Njike V, et al. Acute dark chocolate and cocoa ingestion and endothelial function: a randomized controlled crossover trial. Am J Clin Nutr 2008;88(1):58-63.
- Davison K, Berry N, et al. Dose-related effects of flavanol-rich cocoa on blood pressure. J Hum Hypertens 2010:Jan 21.
- Uiterwaal C, Verschuren W, al. e. Coffee intake and incidence of hypertension. Am J Clin Nutr 2007;85(3):718-23.
- Nantz M, Rowe C, Bukowski J, Percival S. Standardized capsule of Camellia sinensis lowers cardiovascular risk factors in a randomized, double-blind, placebo-controlled study. Nutrition 2008;25,(2):147-154.
- Ronny A, Bell CK, et al. CAM Use Among Older Adults Age 65 or Older with Hypertension in the United States. The Journal of Alternative and Complementary Medicine 2006;12(9):903-909.
- Ernst E. Complementary/alternative medicine for hypertension: a mini-review. . Wein Med Wochenschr 2005;155:386–91.
- Rosenfeldt F, Haas S, et al. Coenzyme Q10 in the treatment of hypertension: a meta-analysis of the clinical trials. Journal of Human Hypertension 2007;21(4):297-306.
- Reinhart K, Coleman C, et al. Effects of Garlic on Blood Pressure in Patients With and Without Systolic Hypertension: A Meta-Analysis. BMC Cardiovascular Disorders 2008;8(13).
- Perrinjaquet-Moccetti T, Busjahn A, et al. Food Supplementation with and Olive (Olea europea L.) leaf extract reduces blood pressure in borderline hypertensive monozygotic twins. Phytotherapy Research 2008;22:1239–1242.
- Bondia-Pons I, Schroder H, et al. Moderate consumption of olive oil by healthy European men reduces systolic blood pressure in non-Mediterranean participants. J Nutr 2007;137(1):84-7.
- Cicero A, Borghi C, et al. Omega 3 polyunsaturated fatty acids supplementation and blood pressure levels in hypertriglyceridemic patients with untreated normal-high blood pressure and with or without metabolic syndrome: a retrospective study. Clin Exp Hypertens 2010;32(2):137-44.
- Egert S, Bosy-Westphal A, et al. Quercetin reduces systolic blood pressure and plasma oxidised low-density lipoprotein concentrations in overweight subjects with a high-cardiovascular disease risk phenotype: a double-blinded, placebo-controlled cross-over study. Br J Nutr 2009:1-10.
- Sato K, Dohi Y, et al. Effects of ascorbic acid on ambulatory blood pressure in elderly patients with refractory hypertension. Arzneimittelforschung 2006;56(7):535-40.
- Zhou C, Yu Z, al. e. The principle and technique of using Chinese drugs in the treatment of hypertension. Journal of Traditional Chinese Medicine 2001;21(1):7-11.
- Kang DG, Oh H, al. e. Inhibition of angiotensin converting enzyme by lithospermic acid B isolated from Radix Salviae miltiorrhiza Bunge. Phytotherapy Research 2003; 17(8):917-20.
- Srividya N, Periwal S. Diuretic, hypotensive and hypoglycaemic effect of Phyllanthus amarus. Indian Journal of Experimental Biology 1995; 33(11):861-4.
- Walker A, Marakis G, al. e. Promising hypotensive effect of hawthorn extract: a randomized double-blind pilot study of mild, essential hypertension. Phytotherapy Research 2002;16(1):48-54.
- Hatzistavri L, Sarafidis P. Oral magnesium supplementation reduces ambulatory blood pressure in patients with mild hypertension. Am J Hypertens 2009;10:1070-5.
- Bucher HC, Cook RJ. Effects of Dietary Calcium Supplementation on Blood Pressure: A Meta-analysis of Randomized Controlled Trials. JAMA 1996;275(13):1016-1022.
- Patki PS, Singh SV. Efficacy of potassium and magnesium in essential hypertension: a double-blind, placebo controlled, crossover study. BMJ 1990;301(6751):521-523.
- Dickinson H, Nicolson D, al e. Calcium supplementation for the management of primary hypertension in adults. Cochrane Database of Systematic Reviews 2010(5).
- Beyer F, Dickinson H, Nicolson D, Ford G, Mason J. Combined calcium, magnesium and potassium supplementation for the management of primary hypertension in adults. The Cochrane Database of Systematic Reviews 2010(5).
- Dickinson H, Beyer F, et al. Relaxation therapies for the management of primary hypertension in adults. Cochrane Database of Systematic Reviews 2010(5).
- Lee H, Kim S, Park J, Kim Y, Lee H, Park H. Acupuncture for lowering blood pressure: systematic review and meta-analysis. Am J Hypertens 2009;22(1):122-8.
- Morgan JP, Dickey JL, Hunt HH, Hudgins PM. A controlled trial of spinal manipulation in the management of hypertension. Journal of the American Osteopathic Association 1985;85(5):308-13.
- Spiegel AJ, Capobianco JD, Kruger A, Spinner WD. Osteopathic manipulative medicine in the treatment of hypertension: an alternative, conventional approach. Heart Disease 2003;5(4):272-8.