Four Foods to Avoid if You Have High Blood Pressure
Did you know that one in five Kiwis have high blood pressure? Like cholesterol and BMI, blood pressure is one of those medical terms we’re all aware of and something we know we need to keep in check for our health and longevity. In this article, we'll take you through four foods to cut down on to reduce your risk of increasing your blood pressure. You might find number four surprising!
It refers to the pressure in our arteries - the vessels that carry blood away from the heart and around the body. While we do need some pressure in these tubes to keep blood flowing, too much raises the risk of suffering a life-threatening heart attack or stroke. Health surveys over the last couple of decades have persistently shown around one in three adults in England (and one in five in NZ) have high blood pressure. Smoking, being overweight or obese and a lack of exercise are among the biggest risk factors but diet also plays a major role, says Dr Frankie Phillips, a registered dietitian and spokesperson for the British Dietetic Association. Here, she shares the foods to cut down on to limit your risk.
Salty foods
It’s not necessary to eliminate salt completely, says Phillips. For our bodies to work efficiently, we do need some in our diet. Around a quarter of a teaspoon daily is all that’s needed to keep our muscles, nerves and fluid balance in check. However, we’re eating much more than this. As a population, we’re told to consume a maximum of six grams per day (one teaspoon), but we’re actually eating around nine grams. “We’ve known for quite a long time that there seems to be a link between salt and high blood pressure,” Phillips says. A high salt intake draws water into our bloodstream, which means there’s a higher volume of blood being pumped throughout our bodies, forcing our heart to work harder, she explains. Ditching the table salt may not be the most effective move. “Around three-quarters of the salt in our diet comes from food which already contains salt, rather than the salt we add,” Phillips notes. The likes of ready meals, salty snacks, pies, pasties, bacon, salami, sausages, ham, tinned soup, ketchup and brown sauce are some of the biggest culprits, she says.
Sugary and fatty foods
Enjoying foods high in sugar and fat won’t directly lead to high blood pressure. The problem kicks in if you eat too much and gain weight. “Being overweight or obese is linked with high blood pressure,” Phillips says. When your weight increases, you increase the amount of blood volume that’s travelling through your body, so the heart has to work harder to push that around, she explains. While eating too much of any food will lead to weight gain, sugary and fatty foods like doughnuts, cakes and biscuits are all too easy to overeat. “It’s those kinds of foods that you need to watch out for, as they contain empty calories and don’t offer any extra nutrition, rather than those high in healthy fats, like nuts and avocados,” she says. “If you’re going to have a treat, then try to look for something that is higher in fibre and has got some fruit or vegetables in it.” Examples include nutty flapjacks, yoghurt and berries or vegetables and hummus, she adds.
Alcohol
Unfortunately, there is no safe limit regarding the amount of alcohol we can consume without risking our blood pressure increasing, according to Phillips. “That’s because it affects three hormones [renin, angiotensin and aldosterone] that regulate blood pressure,” she explains. For example, alcohol increases levels of renin, which causes blood vessels to constrict and become smaller, meaning blood pressure has to increase to push the blood through a narrower space, Phillips says. Research suggests one alcoholic drink per day raises both systolic blood pressure (the pressure when your heart pushes blood out) and diastolic blood pressure (the pressure when the heart is at rest) by one point, while four drinks per day raises them by around five points. For comparison, there’s a 15 to 40 point difference between a healthy and high blood pressure reading. Alcohol is also a high-calorie drink, meaning it is very easy to consume a lot of excess calories. “Alcohol is a two-pronged attack on blood pressure - one on the effects it has on hormonal systems but also the risk of increasing body weight,” Phillips adds.
Caffeine
As well as the obvious coffee and energy drinks, tea and chocolate are also sources of caffeine, though they contain smaller doses. “One of the ways that caffeine affects blood pressure is that it causes your adrenal glands to secrete more adrenaline, which causes your blood pressure to go up,” Phillips explains. It’s the same mechanism for how stress raises blood pressure, she notes. If you’re used to drinking coffee every day, then you don’t necessarily see such a major impact as the body adapts to the stimulant, she says. “It’s all a balance, because we know that a small amount of caffeine can help increase our alertness and our ability to work efficiently. So it’s one of those things when a little can be good but too much is not good.” In general, up to 400mg of caffeine per day is fine even if you have high blood pressure, she says. That’s around four standard cups of coffee, or one or two cups if you’re buying from a cafe, as these tend to be stronger, Phillips notes.