If your morning routine consists of drinking coffee, followed by a glass of orange juice with a piece of toast, you may need to break this unhealthy habit. Your morning glass of fruit juice is a source of high sugar content and low fiber. According to a recent study published in the journal Appetite, frequent consumption of fruit juice may contribute to excessive sugar intake, which can exacerbate the prevalence of high blood pressure (BP) and cardiovascular disease.

“Although juices may have essential vitamins, they commonly contain high amounts of sugar with negligible fiber,” Dr. Matthew Pase, from the SwinburneUniversity of Technology in Hawthorn, Victoria, in Australia told the Daily Express. Although fruit juice has commonly been seen as a healthy option, it has come under scrutiny after some juices have comparable sugar levels to soft drinks like Coca-Cola. Phrases like "100% pure" and "pure squeezed" have actually been used by big commercial orange juice manufacturers to make a processed, sugar-laden product.

Pase and his colleagues sought to challenge the dietary guidelines — no more than one serving (4 ounces) of 100 percent fruit juice as part of the daily fruit intake — by analyzing the fruit juice intake and BP of a small cohort. A total of 160 community dwelling adults completed a 12-month dietary recall questionnaire that measured their habitual fruit juice consumption. On the same day, brachial and central (aortic) BP was estimated through radial artery applanation — a tonometry technology for the continuous noninvasive monitoring of blood pressure. The frequency of fruit juice consumption was classified as rare, occasional, or daily.

The findings revealed those who consumed fruit juice daily compared to those who rarely or occasionally did, had a significantly higher central BP. This refers to the pressure in the aorta, which is the largest artery into which the heart pumps. High central BP has been associated with an increased risk of problems, such as a heart attack or angina.

"The findings suggest the daily use of fruit juice may increase central blood pressures, which are known to be associated with cardiovascular disease risk and cognitive impairment — problems with mental functioning,” Pase said. Even orange, apple, cherry, and grape juice without sugar added can contain the same amount of sugar as a soft drink. This is because apples, oranges, and grapes are fruits that are naturally full of sugar. For example, 12 ounces of Coca-Cola contains 40 grams (g) of carbs from sugar with 10 teaspoons (tsp) of sugar while orange juice contains 33g of carbs from sugar and 8tsp.

These findings are also important because of the common misconception that fruit juice is healthy. Fruit juices are not adequate substitutes for fruit because they typically lack fiber. When we eat a whole apple, the sugar is “nicely balanced” by the fiber, giving “the liver a chance to fully metabolise what's coming in,” said Robert Lustig, an American obesity expert and author of Fat Chance: The Bitter Truth about Sugar, The Telegraph reported. However, when we choose to drink half a pint of apple juice, this actually brings a huge dose of energy directly to the liver. Fruit smoothies are also comparable to fruit juices because the insoluble fiber is actually “torn to smithereens.”

The study highlights the possibility frequent fruit juice consumption could be contributing to excessive sugar intake, which can lead to heart disease. A recent study published in the journal Nutrition found, on average, fruit juice has a fructose concentration of about 45.5g per liter, which is only a bit less than the average of 50g per liter for sodas. Minute Maid was found to have 100 percent apple juice with about 66g of fructose per liter. This is more than the 62.5 g per liter in Coca-Cola and 61g per liter in Dr Pepper.

Soda and fruit juice aren’t the only food culprits of high BP; these four unsuspecting foods below can lead to dangerously high levels:

1. Alcohol

Small to moderate amounts of alcohol can actually lower your BP, but drinking in excess could increase your blood pressure, even for those who are occasional drinkers. Consuming more than three drinks in one sitting can lead to a temporary increase in BP, says the Mayo Clinic. Continuous drinking can lead to permanent BP complications.

2. Coffee

You may need to kick your morning cup of coffee to the curb, along with your glass of orange juice. Drinking coffee can lead to a temporary increase in BP. Those who drink coffee on a regular basis may be susceptible to hypertension.

3. Pickles

Vegetables that sit in cans preserving liquids typically contain high levels of salt. This means these foods are sodium-laden and can take a toll on your BP. A spear has 385 milligrams of sodium.

4. Tomatoes

Tomato sauces, pasta sauces, and tomato juices are all high in sodium, which can spike BP levels. The American Heart Association suggests looking for low-sodium versions of these tomato-based products. Potassium found in tomatoes has been associated with improved BP, but only in products with low-sodium content.

Sources: Cockerell R, Grima N, Pase MP, Pipingas A. Habitual intake of fruit juice predicts central blood pressure. Appetite. 2014.

Dumke KA, Goran MI, Walker RW. Fructose content in popular beverages made with and without high-fructose corn syrup. Nutrition. 2014.