Fibre is an essential part of the human diet, strategic reviews indicate that consuming just 30g of fibre a day is correlated to reduced risk of colon cancer, type-2 diabetes, heart attacks and strokes.
For most of us there is a simple thing we can do to improve our short and long-term health, eat more fibre! The role of fibre in regulating digestion has been understood by humans for hundreds of years. But the full benefits linked to fibre (also known as roughage) are only just starting to be understood. A recent study published in The Lancet1 analysed a wide range of research and found that a shortage of fibre in our diets is linked to greater risks of type-2 diabetes, bowel cancer, heart attacks and strokes. In addition people that eat more fibre tend to have lower weight, lower blood pressure and reduced cholesterol levels. Amazingly the research suggested that consuming a mere 30g (1oz) of fibre a day was sufficient to deliver the full range of health benefits. To put this into some kind of perspective the 30g target can be reached by consuming four slices of brown bread, eating a handful of nuts and seeds in addition to the regulation five portions of fruit and veg a day. In essence it is available to most of us with only a few small changes to our eating habits.
Fibre consumed through our diet can be divided into two types, soluble and insoluble. Soluble fiber is generally though of as a prebiotic, which means it supports communities of helpful bacteria in the gut microbiome. Insoluble fibre does not dissolve in water and typically passes through the digestive system aiding bowel movements. Most fibre rich foods contain soluble and insoluble elements, today food science is more concerned with the total amount of fibre rather than the different forms (cellulose, pectins and beta glucans) we eat.
In summary; fibre is an essential part of the human diet, strategic reviews of the available evidence strongly suggest that consuming 30g of fibre a day is correlated to reduced risk of colon cancer, type-2 diabetes, heart attacks and strokes. There is a growing body of evidence that fibre also plays an important role in maintaining helpful bacteria in the gut microbiome.
Eat more raw, to get the most from prebiotics and probiotics consider how you prepare your food.
As a fermentation fan and a non-strict vegan, eggs are not normally part of my diet. However a recent scientific study that came out of China got me thinking more generally about food preparation. In the UK eggs have enjoyed a love-hate relationship with food experts and nutritionists. In 1988 Health Minister Edwina Currie announced that UK egg production was badly affected by salmonella. Although she lost her job, uncertainty over the benefit of eating eggs remained. There has also been a long standing disquiet over the suffering experienced by hens in the ‘industrialised’ production of eggs. Scientists still suggest that there may be a correlation between egg consumption and a number of health problems.
Conversely a new large scale study from China has suggested eggs may actually reduce risk of stroke and heart disease. The current advice from the NHS is that the cholesterol found in eggs is less of a health problem than the effect of saturated fat from the cooking process. Indicating that boiled or poached eggs may be significantly better for you than fried. This is not an endorsement of eggs as a health food per se’ but it draws attention to the strong relationship between health and food preparation. So what has this got to do with fermentation, prebiotics and probiotics?
One of the reasons we cook food for a sustained period is to destroy potentially harmful bacteria. It follows then that if food, such as sauerkraut is cooked at a high temperature for a sustained period much of the helpful bacteria will be removed. People starting to think about gut-bacteria from scratch (like us), might be surprised to know that commercially available products thought to be ‘probiotic’ may in fact be pasturised (heat treated) or made from pasturised ingredients.
This is one of the reasons why home fermentation is taking off in such a big way. There are certain challenges to delivering high quality, probiotically rich foods, safely and at a competitive price. So if you are purchasing probiotics check the labels to ensure things are as they appear, in particular watch out for the word ‘pasturised’. This is not so say that you can’t cook ‘live’ yogurt in a curry or sauerkraut in a pork casserole. It’s just you may be loosing a lot of the bacterial benefit.
A quick word about prebiotics. Prebiotic is a blanket term for any food ingredients likely to enhance the growth and development of beneficial bacteria, typically (but not limited to) those found in the large intestine. In order to arrive at the large intestine, food needs to be structurally able to resist breakdown in the stomach. Foodstuffs in this group can (loosely) be thought of as ‘dietary fiber’. If you do a little research in this area you’ll find that many of the most useful prebiotics are in fact raw vegetables. That is because cooking can limit the probiotic benefit effect of certain foods.
There are many valid reasons why people may wish to cook fresh fruit, vegetables and dairy products. The take home point is that if you don’t already, you might wish to take a look at how you prepare your food and the extent to which you are maximizing your support for beneficial gut microorganisms.