Beverages for Better Bones 28568

By David Feder, R.D.
Contributing Editor

Beverages targeting specific health issues comprise a rapidly expanding category. Those that target bone health predominantly include vitamin D and calcium. For years, use of these nutrients was limited to dairy-based products and orange juice to avoid problems with solubility, which in turn can negatively affect sensory characteristics. Now, the drive to widen the variety of available calcium and vitamin D ingredients is increasing.

The importance of calcium in the diet cant be understated, notes Gregory Miller, Ph.D., executive vice president of research, regulatory and scientific affairs, National Dairy Council, Rosemont, IL. When it comes to receiving this key bone nutrient, he notes 9 out of nearly 10 women, and almost two-thirds of men ages 19 and over, fail to meet calcium recommendations. Among people age 51 and older, less than 15% get the daily calcium recommended, he says. Nearly 9 out of 10 teenage girls, and almost 7 out of 10 teenage boys ages 14 to 18, dont meet daily calcium recommendations. About 30% of kids ages 4 to 8 dont get the recommended amount of calcium in their diets.

A study in the July 2009 issue of Journal of Nutrition Education and Behavior (41(4):254-260) revealed a tendency for young people to reduce calcium intake beginning in high school and as they enter their 20s, the age where consumers substitute soft drinks and caffeinated beverages for milk.

While adding calcium to clear juices and carbonated or novelty beverages is one solution, it can result in higher calorie consumption and a combination of pH and phosphoric acid that might contribute to calcium depletion.

The good news is, dairy popularity is growing. Dairy-based beverages that are currently growing in popularity include milk- and/or yogurt-based smoothies, flavored milk, kefir and drinkable yogurt, says Miller.

Ingredients for bone bevs

To maintain bone health, adults need 400 IU, or 10 µg, of vitamin D daily. Calcium needs vary from 1,000 mg for men 19 and up to 1,200 for women 19 and up, adding 100 to 200 mg to those numbers for teenagers. Children ages 4 to 8 need 800 mg calcium daily. Older adults from age 51 need 1,200 mg.

Calcium, however, can pose problems in a drink formulation. Solubility is often the primary issue for manufacturers.

When developing a calcium-fortified food product, the main parameters used to determine the right calcium source are flavor, solubility, bioavailability, mineral content, costs, ease of processing, natural image and stability in application, says Lee Heaton, business development manager for health and wellness, Purac America Inc., Lincolnshire, IL.

Soluble sources vary from extremely bitter, such as calcium chloride, to having a neutral taste, such as calcium lactate or calcium lactate gluconate says Heaton. Insoluble sources are, in general, not bitter, but give a sandy or gritty feel in the mouth.

Nissim Guigui, M.Sc., manager, R&D and quality assurance, Gadot Biochemical Ltd./Pharmline Inc., Buffalo Grove, IL, notes: Solubility is not always a plus, especially in a milk beverage. Free calcium from high solubility in a high-protein beverage will bind with protein, increasing coagulation. This creates problems such as sedimentation, which in turn affects mouthfeel.

Classification of calcium as organic or inorganic depends on the anion it binds with, explains Guigui. You can have calcium from milk that is inorganic if its bound to an inorganic ion, such as phosphate or carbonate, vs. being bound to an organic anion, such as citrate, gluconate or lactate, he says.

Whether organic or inorganic, bioavailability is a big concern. We start by looking at the solubility without giving up bioavailability, Guigui says, noting that some calcium ingredients are most bioavailable in acidic formulations at around 3 to 3.5 pH, such as orange juice.

Moreover, bioavailability should not be confused with the amount of calcium in the compound. Many manufacturers often rely on inorganic calcium, such as calcium phosphate or carbonate, which contain about 36% to 40% calcium and usually are the cheapest forms; the way it binds to the inorganic anion makes it less bioavailable, Guigui says. And, while calcium citrate is only 21% calcium, and calcium gluconate or lactate about 10%, they are much more bioavailable.

In the clear

Calcium-ingredient technology has opened a broader range of choices to manufacturers of clear beverages.

In the case of a clear beverage, good solubility is essential or the calcium source will form an undesirable, visible sediment, explains Heaton. For opaque beverages, such as juices or dairy products, the sediment may not be immediately obvious and can be dispersed on shaking. In this instance, a less-soluble source can be utilized. Dissolution time is very important for beverage processing and is influenced by pH, temperature and the ratio of dry product to water.

Another factor affecting calcium function in beverages is pH. The acidity of a beverage comes into play especially in clear beverage applications. Aciditylow pHequals high solubility, which makes it less so for dairy beverages, says Guigui. But this has no bearing on the bioavailability, only clarity and mouthfeel. Wider applications can use ingredients such as a calcium citrate in combination with carbohydrates such as glucose or fructose. These are good to about 4.3 pH, such as in tomato beverages. If you want to enrich syrups or other liquid bases without a lot of free water and more neutral pH, you need high solubility.

Emerging bone-health ingredients

In addition to calcium and vitamin D, other nutrients, including phosphorous, magnesium, genistein, epigallocatechin gallate (EGCG) and vitamin K₂, are needed to effectively lay down bone.

Some ingredients are designed to align bone-building compounds with their components in nature. For instance, we now have a calcium phosphate ingredient with a ratio identical to that found in bone and teeth suitable for sports beverages and juices. Micronization technology helps to deliver calcium, magnesium and phosphorus in proportions identical to nature.

For more than a decade now, soy isoflavone protein, specifically genistein, has shown promise in increasing bone density in women. One genistein ingredient helps put bone resorption cells (osteoclasts) and bone building cells (osteoblasts) back in balance. This is a critical process in osteoporosis. When a woman enters menopause, her estrogen levels are greatly reduced, if not eliminated, yet it is the estrogen that keeps the osteoclasts in check, allowing them to be in balance with the osteoblasts, explains Robert Berman, Ph.D., senior marketing manager, DSM Nutritional Products, Parsippany, NJ. Without estrogen, osteoclasts become dominant, resorbing more bone than osteoblasts, with the help of calcium and vitamin D, can replace. In fact, a postmenopausal woman can ingest all of the calcium and vitamin D that she can, but will still probably not keep up with potential bone density loss, because of this imbalance.

EGCG, a compound derived from green tea, also might help with bone health by aiding in the mineralization of bone clusters.

A wealth of new research into vitamin K and vascular health reveals possible benefits to bone health in the form of vitamin K2 (menaquinone). The vitamin appears to affect mineralizing proteins needed for calcium uptake into the bones, effectively directing calcium away from the blood vessels and toward the bones. The mounting evidence supporting the benefits of vitamin K2 make it one of the most exciting new ingredients available today, says Rodney L. Benjamin, director of technical development, TandemRain Innovations Inc., Vancouver, WA. I think we will be seeing many companies introducing it into their product lines in the near future.

A number of other nutrientsomega-3s, for exampleare showing promise in research on bone health.

David Feder is director of Chicago-based S/F/B Communications Group, an international cooperative of food, nutrition science and health communications experts and consultants. Contact S/F/B at [email protected].