A review commissioned by World Health Organisation reports that fibre in good carbohydrates has a positive and protective effect on health.
Fiber is something the body needs but doesn’t digest, and in fact it stays more or less the same from eating through to digestion and exiting the body. There are two types of fiber, soluble and insoluble, and most plant-based foods contain a mixture of both. Soluble fiber turns to gel in the stomach and slows down digestion, helping to lower cholesterol and blood glucose. Insoluble fiber, remains unchanged all the way to the colon, making waste heavier and softer, enabling it to pass through the intestines more easily. Despite the differences, neither type of fiber is absorbed into the body.
Fiber is found in many good carbohydrates such as oatmeal, wholegrain bread, cereals and pasta.
Eating more fibre, found in wholegrain cereals, pasta and bread as well as nuts and pulses, will cut people’s chances of suffering from non-communicable diseases, such as heart disease, type-2 diabetes and Alzheimer's disease, according to the review commissioned by the WHO.
The WHO says that roughly 10% of people in the developed world eat sufficient amounts for fiber, while the Institute of Medicine has recommended that men under 50 should eat a minimum of 38 grams of fiber each day and women should consume no less than 25 grams. Adults over 50 require less fiber, (30 grams for men and 21 grams for women), due to their decreased food consumption. To put that into perspective, a young man is supposed to eat the same amount of fiber equivalent to about 15 slices of whole-wheat bread per day.
The authors of the review, led by Prof Jim Mann at the University of Otago in New Zealand, also have reported the need for reducing sugar from the diet. Sugar is a carbohydrate but a bad one, and fiber is found in good carbohydrates such as oatmeal, however the huge backlash against sugar has led to diets rejecting carbohydrates and with it many which contain high amounts of fiber.
How does fiber help so much with health?
A main type of immune cell in the brain, Microglia tends to become inflamed and with age. This inflammation of the microglia is one of the main causes of memory and cognitive decline in old age. Previous research has pointed to butyrate, which is a short-chain fatty acid and is produced in the colon when bacteria ferment fiber in the gut, which can reduce inflammation of Microglia in the brain. It is suspected that this was achieved by diminishing the production of a pro-inflammatory chemical known as interleukin-1β, which some studies have linked with Alzheimer's.
It is known that diet has a major influence on the composition and function of microbes in the gut, and that diets high in fiber benefit good microbes, while diets high in fat and protein can have a negative influence on microbial composition and function.
What you eat matters. Older adults consume 40 percent less dietary fiber than is recommended. Not getting enough fiber could have negative consequences for things you don't even think about, such as connections to brain health and inflammation in general.
How to get at least 30g of fibre in your daily diet:
- Wholegrain cereals are a good choice for breakfast. Oat-based muesli is good as long as it doesn’t have too much added sugar. Bran flakes contain about 10g of fibre in a 50g portion.
- There is about 3g of fibre in a medium banana.
- A small apple weighing around 80g has roughly 3g of fiber.
- An average sized pear has about 3g of fiber.
- Thirty grams of nuts contains about 2g of fibre.
- Has about 2g of fibre per slice.
- A medium-sized potato with the skin on contains about 4g of fibre.
- 75g of wholewheat spaghetti contains about 8g of fibre.
- Beans, peas and lentils are good sources of fibre, with 6.8g of fibre in 150g of baked beans; 100g of boiled lentils contains 8g.