Fiber is what gives plants their structure, and where many nutrients are bound, to be released in our bodies for our benefit by the bacteria living symbiotically in our intestines and digestive systems. Examining fossilized remains of early human excrement shows that our ancestors consumed over 80-100 grams of fiber daily, eating very plant-rich diets. But today in developed countries, 97% of the population is deficient in this absolutely vital nutrient. The minimum recommended daily allowance is 31.5 grams per day, and most people get only 15 grams per day.
Whole plant-based foods are naturally very rich in fiber; we are meant to have a high level of fiber in our diet to support normal health. There is a whole host of new research indicating there are links between fiber deficiency and modern disease.
A recent observational study about healthy aging and disease found that “of all the factors examined — including a person’s total carbohydrate intake, total fiber intake, glycemic index, glycemic load, and sugar intake — it was, surprisingly, fiber that made the biggest difference to what the researchers termed ‘successful aging.’”
However, it’s important to emphasize that fiber by itself is not what delivers the health benefits; and that such reductionist thinking (hoping for one magic nutrient) has caused no end of confusion and failures. Rather, it’s consuming whole plant foods that are rich in fiber and many other nutrients, that boost our health.
One of the most active areas of nutrition research is investigating how our digestive microbiome affects our health. We have over one trillion bacteria in our digestive system, and most of the healthy bacteria require fiber for optimal function. Fiber deficiency is therefore linked to an imbalance of “good” versus “bad” bacteria in this vitally important bodily system.