Nutritional Solutions to High Blood Pressure
Hypertension or high blood pressure is a key risk factor for cardiovascular disease, the leading cause of death worldwide.
According to the Blood Pressure Association, it affects over 16 million people in the UK; while others put the figure at 10 million.
About half of people over 65, and about 1 in 4 middle aged adults, have high blood pressure. It is less common in younger adults. Most cases are mildly high (between 140/90 and 159/99 mmHg). However, at least 1 in 20 adults have blood pressure of 160/100 mmHg or above.
In the vast majority of people with high blood pressure, there is no single clear-cut cause, and the condition is called essential hypertension.
Since moderately raised pressure or even high pressure doesn’t usually have any symptoms associated with it, most people are unaware of their condition and will only become aware when they have their blood pressure checked or they get sick. It may take many years or decades before it progresses, with the development of various diseases involving the circulatory, renal or neurological systems.
High blood pressure is more common in people from African-Caribbean origin, from the Indian sub-continent, or those with a family history of high blood pressure. Other risk factors are ageing, stress, smoking, obesity, high salt intake, low fruit and vegetables intake, lack of exercise, and high alcohol consumption.
While there is nothing that can be done about some of these risk factors, lifestyle modification would help a huge number of people to either prevent the condition in the first place or reduce mildly high readings back into the normal range.
According to a recent paper “Approximately 50% of subjects with essential hypertension are insulin resistant.” (Nutr Metab Cardiovasc Dis. 2006 Jan;16(1):22-7) A diet that balances blood sugar would be essential for such responders.
The late Dr Atkins who specialised in blood sugar control with a low carbohydrate diet wrote that “the dramatic lowering effect on the blood pressure of the low carbohydrate, anti-insulin diet is seen in over 90% of our patients.”
“I’ve treated more than ten thousand patients who were taking blood pressure medications. Nutritional changes - a new diet and vitanutrients - allowed them to get off their medications.”
“We consistently bring high blood pressure right back down to normal by reducing the carbohydrates in your diet and adding vitanutrients.”
For the 50% who aren’t insulin resistant, cutting back or eliminating sugar and refined carbohydrates will still be important while increasing essential fatty acids and quality protein.
Free radicals and oxidation are higher in those with essential hypertension, so increased consumption of fruits and vegetables is also important.
Since most people drink too little water and ingest too much salt, getting these two in balance is often all that is required. About 60% of hypertensives are thought to be responsive to reduced salt intake.
Essential Fatty Acids
There is good evidence that essential fatty acid metabolism at the vascular level is directly associated with the development of high blood pressure.
Several studies have shown that large doses omega 3 polyunsaturated fatty acids in the form of fish oils are able to lower blood pressure in humans.
They have an anti-inflammatory effect, maintain the flexibility of cells, make vessels more pliable, improve endothelial function, have favourable effects on blood cholesterol levels and enhance the production of nitric oxide to improve blood vessel relaxation.
This can be utilised to make a form of prostacyclin which acts as a vasodilator, relaxing blood vessels, improving blood flow, reducing thickening and preventing blood clots.
Both EPA and DHA are important, but DHA appears to be more effective at lowering blood pressure. One study found that supplementing with 2.04g of EPA and 1.4g DHA lowered both systolic and diastolic by 6mmHg in mildly hypertensive men over 4 months (Thromb Res. 1998 Aug 1;91(3):105-12).
The omega 6 family must also not be forgotten. Experimental studies confirm that a balanced combination of both omega 3 and 6 is essential in lowering blood pressure and reducing atherosclerosis. The optimum proportion of omega 6 to omega 3 is not known but a ratio between 5:1 and 2:1 is thought best. Modern diets have a ratio of 20:1 and worse.
Regular consumption of garlic reduces the risk of heart disease. It lowers cholesterol, prevents blood fats sticking to the walls of the arteries and lowers elevated blood pressure. It also inhibits substances that constricts blood vessels.
An analysis of published and unpublished randomised, controlled trials (415 patients) showed that 600-900mg a day of dried garlic powder may be of clinical value in subjects with mild hypertension (J Hypertens. 1994 Apr;12(4):463-8).
A recent study found 250mg of garlic pearls per day for 2 months had “beneficial effects in reducing blood pressure and counteracting oxidative stress, and thereby, offering cardioprotection in essential hypertensives.” (Mol Cell Biochem. 2005 Jul;275(1-2):85-94).
Another study of 41 moderately hypercholesterolaemic men taking 7.2g aged garlic extract per day for 6 months saw a 5.5% decrease in systolic blood pressure and a modest reduction of diastolic blood pressure (Am J Clin Nutr. 1996 Dec;64(6):866-70).
Coenzyme Q10 enhances the immune system and protects against free radicals. It is particularly valuable in treating heart conditions.
Twenty-six patients with essential arterial hypertension were treated with oral CoQ10, 50mg twice daily for 10 weeks. At the end of the treatment, systolic blood pressure decreased from 164.5 to 146.7 mmHg and diastolic blood pressure decreased from 98.1 to 86.1 mmHg on average (Mol Aspects Med. 1994;15 Suppl:s257-63).
In 109 patients taking 225mg of CoQ10 a day in addition to their medication “a definite and gradual improvement in functional status was observed with the concomitant need to gradually decrease antihypertensive drug therapy within the first one to six months.
Thereafter, clinical status and cardiovascular drug requirements stabilized with a significantly improved systolic and diastolic blood pressure.” (Mol Aspects Med. 1994;15 Suppl:S265-72)
In a study of patients taking 120mg a day “These findings indicate that treatment with coenzyme Q10 decreases blood pressure possibly by decreasing oxidative stress and insulin response”. (J Hum Hypertens. 1999 Mar;13(3):203-8)
In a 3 month trial 83 patients with isolated systolic hypertension taking 120mg a day of CoQ10 saw a reduced systolic pressure of 17.8 mmHg. The authors concluded: “Our results suggest CoQ10 may be safely offered to hypertensive patients as an alternative treatment option.” (South Med J. 2001 Nov; 94(11):1112-7)
Another study states that “The limited data available from studies in animal models and from human intervention studies are generally consistent with a benefit of CoQ10 on vascular function and blood pressure.” Biofactors. 2003;18(1-4):129-36
As an antioxidant, reducer of LDL cholesterol, collagen former and modulator of nitric oxide (vasodilator) activity, vitamin C plays important roles in the cardiovascular system.
Since essential hypertension is associated with an abnormal antioxidant status and reduced levels of nitric oxide, one would expect this vitamin to be able to reduce high blood pressure.
A population based study concluded that “plasma ascorbic acid concentration had a moderate, independent inverse association....with mean resting blood pressure. The marked elevation of blood pressure at the lowest levels of plasma vitamin C concentration supports the hypothesis of the role of antioxidants in the aetiology of hypertension.” (J Hypertens Suppl. 1987 Dec;5(5):S521-4)
In 168 healthy residents, highest and lowest quintiles of plasma vitamin C concentrations differed significantly in mean systolic and diastolic blood pressure. (Am J Clin Nutr. 1993 Feb;57(2):213-7)
Of 69 adults, those with highest blood levels of the vitamin had significantly lower readings. Taking 1000mg a day effectively lowered blood pressure. (NewYork Acad Sci 1992 9 9-12)
Vitamin C at doses of 500mg per day caused significant drops in blood pressure in men and women with hypertension (Lancet. 1999 Dec 11;354(9195):2048-9)
Again because of higher levels of oxidation and lower levels of nitric oxide, vitamin E as well as other antioxidants will be beneficial.
People with hypertension often have low levels of vitamin E and animal studies have shown that vitamin E protects against age-related hypertension.
This non essential amino acid converts to nitric oxide which in turn has profound effects on the endothelium, to allow arteries to relax, keep vessels pliable and elastic, dilate blood vessels, permit better blood flow, lower high blood pressure, prevent platelets and white blood cells from sticking to the vessel wall, regulate oxidative enzymes in the cell to prevent oxidation, reduce growth and multiplication of muscle cells that thicken the vessel wall, and slow plaque growth.
A recent study demonstrated positive effects on the endothelium and reduction in blood pressure taking about 2000mg a day.
Response to L-arginine supplementation is highly individual and much larger dosages, up to 9 grams may be needed.
Although it is a safe supplement to use it should be avoided in those with cancer or a history of cancer, serious infectious diseases, or severe inflammatory conditions.
Calcium Magnesium & Potassium
These nutrients are considered to be important dietary components in the prevention of hypertension.
Several studies have shown that lower calcium intake is associated with higher blood pressures. It is important in smooth muscle contraction of the vasculature.
Magnesium stimulates human endothelial cells to produce prostaglandin I2, a vasodilator.
An analysis of 33 trials to assess the effects of supplementation with oral potassium on blood pressure in humans concluded that potassium supplements do lower blood pressure.
“Increased potassium intake should be considered as a recommendation for prevention and treatment of hypertension, especially in those who are unable to reduce their intake of sodium.” (JAMA. 1997 May 28;277(20):1624-32)
A number of rodent studies have shown that dietary taurine supplementation can alleviate high blood pressure. The beneficial effects of taurine have also been demonstrated in human studies. Taurine supplementation of 6g/day for as little as 7 days resulted in measurable decreases in blood pressure in these patients.
Taurine encourages the excretion of excess fluid and relaxes blood vessels.
This article was first published in Enzyme Digest No. 73, Summer 2006
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