"Let food by thy medicine and medicine be thy food" so said Hippocrates. If you search this phrase on the Internet you will find thousands of claims of how foods can cure you of everything. It reminds me of the days when men would travel around with magic potions that could cure whatever ails you. Literature and theatre abound with tales and songs of miracle elixirs. And there is an even longer history of the health-promoting aspects of certain foods.
For thousands of years fermented foods have been eaten throughout the world. Abraham's long life is attributed to eating sour milk. The Romans treated gastroenteritis with fermented milk products. But I am still a sceptic as I look at all the claims on the Internet. I decided to review the medical literature where there are more and more articles looking at food, and this topic specifically, and what it can do for health. I will try and summarize the many studies that I reviewed to make some sense out of all that's out there so that you can decide what, if anything, you what to spend your money on.
So today's blog will be an overview on what is a functional food and how scientists define prebiotics, probiotics and synbiotics. The next blogs will go into specifics about them and what the studies have shown and haven't shown about their effects on health. If there are a lot of comments and/or questions I will address them further.
FUNCTIONAL FOODS
When you look at the label on packaged food it gives you the nutritional value of the food (calories, vitamins, proteins, etc.) but it won't tell you its wellness-maintaining properties. It doesn't address issues of its potential medicinal benefits. But for a food to make the claim of being "functional" it should have some enhancement of health beyond its nutritional value.
I plan to focus this discussion on foods that have their effect on the gut. In a normal gut, you would want the organisms that promote good health to predominate over the organisms that are potentially harmful. Basically, the whole point of functional food is that after you eat this stuff, you will promote an increase number of healthy bacteria. Therefore the food has a function "beyond nutrition".
PREBIOTIC
A prebiotic was first defined in 1995 and then further refined over the years. Presently the accepted definition from the International Scientific Scientific Association for Probiotics and Prebiotics (ISAPP) meeting in 2008 is "A dietary prebiotic is a selectively fermented ingredient that results in specific changes, in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefit(s) upon host well being and health." This means that certain functional foods are not digested by the person but will actually be fermented by selective intestinal bacteria and promote their growth. These bacteria are beneficial to the person's health.
PROBIOTIC
Although there are some variations in the definitions on what makes up a probiotic, they all agree that the probiotic microorganisms must be living and that scientifically there needs to be proven health effects. Probiotics are defined as actual microorganisms which get to the intestines in an active form and in a large enough quantity so that the can exert a positive effect on health. Although many people will use the term probiotics interchangeably with probiotic foods they are not the same thing. Probiotic foods are foods that also contain organisms (probiotics) that will give an additional health benefit beyond that of the nutritional content of the food.
SYNBIOTICS
Symbiotics are a mixture of probiotics and prebiotics which when added together are supposed to act "synergistically" by promoting the implantation of the live organism (probiotic) and improve its survival (prebiotic). For a food to be classified as a prebiotic or a probiotic, it has to be in certain quantities or concentrations. Food companies have been launching more and more products and want to promote the health benefits of their foods, but they cannot classify them in either category because they do not meet criteria. So what they are doing is putting both pre and pro biotics in their foods and labeling them as "synbiotics". Often these foods do not have enough pre and pro biotics in them to act in the synergistic way the companies state to have the claimed health benefits.
In the next blogs I will address the myriad of potential health benefits and look at what has been proved, disproved, shown in animals only and thought to be possible from food.
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