In a few years it may be the milk jug, rather than the whisky or pill bottle, that people suffering from depression turn to when trying to dull the pain.

At least that's one of the hopes of the many players — from multinational food giants like Danone and Unilever and specialist dairy groups like Valio to a small army of nutrition scientists — searching for the next miracle food.

No one knows yet whether it will be a yogurt that may help slow down the progress of Alzheimer's disease or a milky drink that staves off depression. But it will undoubtedly yield its inventor healthy returns.

Over the past decade the market for cholesterol-lowering spreads, immunity-boosting drinks and other foods that make similar claims has flourished as food manufacturers have latched on to the idea of selling food as an alternative to medicine.

It was a tricky proposition at first — consumers' top criterion when buying food has always been taste — but soon turned out to make a lot of business sense. In developed markets where basic food items have kept getting cheaper, health-focused innovation would help its biggest proponents reinvigorate margins and gain an edge on competitors.

French dairy and water giant Danone is the first multinational to have grasped the potential of health as a motto and marketing tool, selling yogurt in pharmacies in Barcelona as far back as 1919. During the next decades though, it expanded well beyond yogurts. But then in 2007, convinced it would grow faster if it refocused its portfolio on health, it sold its biscuit division to Kraft Foods. It was a return to its roots.

The following year, the title of its annual report read: "Bringing health through food to as many people as possible."

HEALTH OBSESSION

What Danone has latched onto is our growing obsession with treating the body as a temple.

"Like any trend, health first became a focus with the early-adopter group. We're now in the phase where it's in the mainstream, and it's going gangbusters," said Barbara Katz, president of HealthFocus International, a consulting firm specialized in food and nutrition issues.

"Back in the '90s, the focus was on low-fat, low-sugar products. That's how we were defining healthy. Then it became what we were adding rather than what we were taking away: omega-3, calcium, fiber, probiotics," she said.

The reason for the extraordinary success of functional foods and nutraceuticals — a subcategory that further blurs the line between food and medicine and includes products such as special nutrition-heavy yogurts for the elderly — is simple.

In developed markets, where the population is aging, life expectancy is rising and the demands of modern life putting many under strains, the notion that eating foods enriched in components like antioxidants or fatty acids can help prevent diseases has struck a powerful chord with consumers.