Stevia And High Blood Pressure

stevia

Sugar, high fructose corn syrup and artificial sweeteners have all been linked with high blood pressure and an increased risk of stroke. The solution is to slowly wean yourself off sweetness, but while doing so the natural sweetener, Stevia, is your best option. Here’s why.

Sugar and high blood pressure

Sugar is undoubtedly bad for blood pressure as it stimulates the release of insulin. As well as being the main fat-storing hormone in the body, insulin is now known to act on the kidneys to increase sodium reabsorption and fluid retention. As a result, following a high sugar diet increases the risk of hypertension.

At least 12 studies, involving over 409,700 people, have now shown a positive relationship between increased intakes of sugar, and especially sugar-sweetened drinks, and a rise in blood pressure. Those with the highest sugar intake have, on average, a blood pressure that is  6.9/5.6 mmHg greater than those with the lowest dietary sugar intakes.

Insulin and blood pressure

A large study has confirmed the link between fasting blood insulin level and hypertension in 25,062 healthy men who were initially free of hypertension (and diabetes). The men were followed for five years, and almost a quarter (23.2%) of those with the highest fasting insulin levels went on to develop hypertension, compared with 13.3% of those with the lowest insulin levels. After taking all other known risk factors into account, the men with the highest insulin levels were 75% more likely to develop hypertension than those with the lowest insulin levels. This suggests that fasting insulin levels are an early predictor of hypertension, as they are a sign of metabolic abnormalities associated with metabolic syndrome. Cutting back on your intake of sugar, and carbohydrates in general, can help to reduce the risks.

Unfortunately, most other sweeteners also have negative effects on blood pressure and increase your risk of heart disease and stroke, as well as causing you to pile on weight

High fructose corn syrup and blood pressure

Fructose is a sugar that is naturally found in fruit. When eaten in fruit, it comes with lots of other nutritional ‘goodies’ such as antioxidants, vitamins, minerals and fibre which slows its digestion and absorption to avoid sudden surges in blood sugar levels. When eaten in the form of high fructose corn syrup, however, which provides a combination of fructose and glucose, it can be harmful when used in large amounts. If you check labels you will find high fructose corn syrup added to many different foods and drinks. If you have high blood pressure (and/or diabetes) these products are best avoided.

Fructose is metabolised by the liver and, while some is converted to glucose, much of it is converted into triglyceride fat, which increases your risk of heart disease. Researchers at the University of Colorado have also found that people who consumed more than 74g of fructose per day (the equivalent of 2.5 sugary soft drinks) were more likely to develop high blood pressure – probably through effects on the liver that mimic those of metabolic syndrome.

Among 4,528 adults who had not previously been diagnosed with hypertension, those with an intake of more than 74g fructose were 26% more likely to have a blood pressure of 135/85 mmHg or greater, 30% more likely to have a blood pressure of 140/90 mmHg or higher, and 77% more likely to have a blood pressure of at least 160/100 mmHg.

These results took other known risk factors for hypertension into account, including age; gender, smoking, diabetes, physical activity, waist circumference, body mass index, glucose and cholesterol levels, triglycerides, kidney function (estimated GFR) and dietary intakes of  carbohydrate, sodium, potassium, alcohol and vitamin C. All that was left was the effect of added fructose, making the results quite robust.

Avoid products whose labels include added fructose or high fructose corn syrup!

Artificial sweeteners and high blood pressure

You may think that artificial sweeteners, such as aspartame and sucralose, are the answer, as they contain negligible calories. Surprisingly, high intakes of artificial sweeteners are also associated with long-term increased risks of obesity, diabetes, high blood pressure and heart disease, according to a new study published in the Canadian Medical Association Journal.

The researchers analysed 37 studies, involving over 405,000 people who were for an average of 10 years. These long term observations showed a link between consumption of artificial sweeteners and higher risks of weight gain, high blood pressure, diabetes and heart disease.

Five of the studies, involving 232,630 people, looked at effects on blood pressure, and found that people with the highest intake of artificial sweeteners were 12% more likely to have hypertension than those with the lowest intakes.

These unexpected findings are believed to result from the effects of artificial sweeteners on your metabolism, liver, gut bacteria and appetite. They may cause you to continue wanting sweet foods so you end up making unhealthy choices.

Avoid using artificial sweeteners!

Artificial sweeteners and stroke

Drinking sweetened beverages such as soft drinks has been found to increase the risk of stroke. A study that followed 32,575 healthy women and 35,884 men without high blood pressure for over ten years, found that drinking any sweetened beverages, including sugar-sweetened and artificially sweetened soft drinks and juice drinks, significantly increased the risk of developing a stroke. Compared to those who had no sweetened drinks, having two or more sweetened drinks per day (200 ml each) increased the total risk of all type of stroke by 19% and the risk of an ischaemic stroke (due to a blood clot) by 22%, but not the risk of haemorrhagic stroke (due to a bleed).

Another study, involving 2,888 adults aged 45 years and over, found that after adjusting for age, sex, calorie intake, diet quality, physical activity, and smoking, those who drank the most artificially sweetened soft drinks were almost three-fold (2.89) more likely to experience a stroke, and 18% more likely to develop Alzheimer’s disease.

Avoid drinking any form of sweetened drinks. If you currently have sugar or sweeteners in your tea or coffee, for example, either wean yourself off, or switch to using stevia.

Stevia and high blood pressure

Stevia (Stevia rebaudiana) is a shrubby plant found in the rainforests of Paraguay and Southern Brazil. Its leaves contain sweet substances (stevioside, rebaudiosides and dulcoside) that make them at least 30 times sweeter than cane sugar. Because the body does not metabolise these sweet chemicals, they pass through the body and are excreted unchanged. These naturally sweet leaves therefore have negligible calories and do not leave an unpleasant aftertaste like some artificial sweeteners.

A study assessed the effects of stevia extracts on blood pressure in 100 people with normal blood pressures, who consumed either 1000mg/day rebaudioside or placebo for 4 weeks. in 100 individuals with normal and low-normal systolic blood pressure (SBP) and diastolic blood pressure (DBP). At the end of the month, there were no significant changes to the blood pressure of those using stevia compared with placebo. This suggests that even a very high intake of stevia does not have a clinically important effect in blood pressure in healthy adults.

Similarly, a study involving 86 people with type 1 diabetes, type 2 diabetes and a group with normal or low blood pressure tested the effects of taking stevioside (250mg three times a day) or placebo for 3 months. Blood pressures and glucose control were not significantly different in those taking the stevia.

And in a 2-year study, 174 men and women with hypertension took capsules containing 500 mg stevioside powder, or placebo, three times a day for 2 years. Blood pressure was measured every month in a clinic and after 2 years, those using stevioside had significant improvements in their blood pressure, from an average of 150/95 mmHg down to 140/89 mmHg. These effects were noted in patient diaries beginning approximately 1 week after the start of treatment and persisted throughout the study.

A similar study involved 106 people with hypertension who took stevioside (250 mg) or placebo three times a day. Blood pressures were checked every month for 1 year and within 3 months, there was a significant fall from 166.0/104.7 mmHg down to152.6/90.3 mmHg, which persisted for the whole year.

These studies suggest that the stevia extract, stevioside, is not only a safe and well tolerated sweetener for people with hypertension, but may even have a beneficial effect on your blood pressure readings.

The best ansewr of course, is it wean yourself off needing any sweetener in your drinks, but for cooking and the occasiona dessert, Stevia is king!


About DrSarahBrewer

Dr Sarah Brewer MSc (Nutr Med), MA (Cantab), MB, BChir, RNutr, MBANT, CNHC qualified from Cambridge University with degrees in Natural Sciences, Medicine and Surgery. After working in general practice, she gained a master's degree in nutritional medicine from the University of Surrey. Sarah is a registered Medical Doctor, a registered Nutritionist and a registered Nutritional Therapist. She is an award winning author of over 60 popular self-help books and a columnist for Prima magazine.

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