Acidity is important in your stomach, but your blood and many other tissues function best in a non-acidic or alkaline environment. Scientific studies suggest that an alkaline diet may result in reduced risk of hypertension, cardiovascular disease and a variety of chronic degenerative conditions, although more research is needed to better understand the effects (Reference 1). Drinking non-acidic juice is helpful in maintaining alkalinity, but some acidic juices are alkalizing also.
Acidity is measured by the 14-point pH scale, which is based on the number of hydrogen ions in solution. Low pH values are acidic, whereas values above 7.0 are alkaline or basic. Your stomach functions best when the pH of the gastric juice is close to 3.0, whereas your blood is carefully maintained at about 7.35. When considering the acidity or alkalinity of fruit and vegetable juices there are two ways of looking at them. One way is measuring the pH of the fruit and vegetable juices directly, whereas another is to determine the general effect a juice has on pH levels in your body. Some sour-tasting acidic juices, such as those made from lemon, grapefruit and sour cherry, actually have alkalizing effects on body tissues. This may seem contradictory, but natural citrus juices actually reduce the number of hydrogen ions in solution, which increases pH values. On the other hand, non-acidic juices obviously help maintain alkalinity.
Wheatgrass juice is one of the most alkaline natural liquids and also one of the moist nutritious, which is why it’s often called a “superfood” by nutritionists. The pH levels of all fruit and vegetable juices depend on harvesting time and freshness, as well as their vitamin and mineral content, which is directly related to soil quality and growing conditions. Consequently, pH levels of juice can vary a great deal, but fresh wheatgrass juice usually matches the pH of healthy human blood or is slightly more alkaline. Making wheatgrass juice requires a special juicing device.
Cucumber juice may not be very common, but it’s quite alkaline and may have a taste that’s more agreeable to your palate compared to wheatgrass juice. The high alkalinity in cucumbers comes from minerals such as calcium, phosphorus, potassium, molybdenum, manganese, sulfur and silica. Minerals from natural foods are organic, which means they are “alive” and better assimilated by your body compared to inorganic forms found in supplements and added to food.
Fresh carrot juice is usually alkaline, but many types of fresh juice can become more acidic as they sit, depending on sugar content. Drink carrot juice and other natural juices within 30 minutes of juicing in order to get the most nutrients and freshest taste. Carrot juice is also a rich source of vitamins and minerals and it goes well with many other vegetable and fruit juices such as celery, beet, tomato and orange.
Of all of the leafy greens, spinach juice is probably the most alkaline and usually hovers around the pH of healthy human blood. Spinach juice is high in minerals, especially calcium, although much of it may not be absorbed by your body due to the presence of oxalic acid. Oxalic acid binds to calcium and makes it unavailable to your body. Like wheatgrass, spinach is rich in chlorophyll, which is very similar to human blood in pH level.
- Journal of Environmental and Public Health: The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health?
- Contemporary Nutrition: Functional Approach; Gordon M. Wardlaw, et al.
- Superfoods: The Healthiest Foods on the Planet; Tonia Reinhard
- Advanced Nutrition and Human Metabolism; James L. Groff, et al.
Sirah Dubois is currently a PhD student in food science after having completed her master's degree in nutrition at the University of Alberta. She has worked in private practice as a dietitian in Edmonton, Canada and her nutrition-related articles have appeared in The Edmonton Journal newspaper.