How To Boost Your Overall Health With Dietary Fibre: The Ultimate Guide

Even as a child, I was rather sensitive to what made for a good dinner table conversation. My beloved maternal grandfather, with whom I spent my childhood years, had no such filter for mealtime conversations. One of the recurring discussions we had during our meals was about how I should eat more veggies for "roughage" (one of his favourite words) to have a fighting fit digestive system. There was everyday reminder to chew your food well. Always the one to practice what he preached, he lived a fit and healthy life well into his early 90s.

As much as I would cringe over the de-romanticisation of food, calling it "roughage", here I am, glorifying the virtues of dietary fibre in a lifestyle column as it deserves to be. Dietary fibre is of utmost importance to our digestive health. It is not a nutrient by itself but a nutritional property of food.

Not all fibre is equal

Dietary fibre comes in two forms - soluble and insoluble. Together they form the total fibre in the food. Most good sources of fibre have a mix of soluble and insoluble fibre. They are the cleaners of the digestive system, with some extra services offered.

Dietary fibre is a type of carbohydrate the body cannot digest. Insoluble and soluble fibre are handled differently. Insoluble fibre leaves the body unchanged, adding bulk to stools and preventing constipation. Soluble fibre becomes a gel in the intestines and becomes food for the gut bacteria in the large intestine that ferment and break it down into beneficial metabolites and short-chain fatty acids (SCFA).

Think of soluble fibre like a sponge. It absorbs water in the intestines to form a gel, which is broken down by bacteria in the small intestine, providing some calories. It slows down digestion and glucose spikes. It keeps you full for longer. If you are a diabetic or pre-diabetic, foods with soluble fibre are your friends. Soluble fibre can be found in oats, beans, lentils, nuts, seeds, some fruits and vegetables (citrus, berries, apple, carrots).

Insoluble fibre is present in all the fibrous parts of vegetables, fruit and grains - the things that make you chew food for a long time. It does not dissolve in water and does not have any calories. It speeds up the passage of food through the intestine. Think of it like a power broom, sweeping through the intestines. Insoluble fibre can be found in wheat bran, bhindi, spinach, and all the plant-based foods with skins and leaves.

What are the health benefits of roughage?

Eating sufficient fibre has many more health benefits than just preventing constipation. Consumption of dietary fibre has been associated with lowered risk of cardiovascular disease, type 2 diabetes, obesity, colorectal cancer and reduced all-cause mortality.

A fibre-rich diet enables stable blood glucose levels, lowering total or LDL cholesterol or both, lowering blood pressure and better mineral absorption from the gut. Then there are the secondary benefits that arise from a well-fed gut microbiome.

The daily recommended intake of dietary fibre varies as per the country, age and general health condition. The acceptable level for most adults is 25-30 grams per day.

Fibre, prebiotics and SCFAs

Prebiotics and probiotics have become buzzwords in discussions on digestive health in the social media world. A good thumb rule to go by is that all prebiotics are fibre but all fibre is not prebiotic. Prebiotics are non-digestible fibre that go undigested in the upper part of the gastrointestinal tract but act as food for beneficial bacteria in the colon. These bacteria play a crucial role in maintaining gut health and supporting the immune system.

SCFAs, formed as a result of gut bacteria fermenting prebiotics, form the basis of good gut health. SCFAs such as acetates, propionates and n-butyrates not only fuel the lining of the gut but also get absorbed through the lining to have many health benefits. Some beneficial effects include regulating appetite, lowering cholesterol, improving mucosal secretion, boosting immunity and providing an anti-inflammatory effect.

Easy ways to up your daily dietary fibre

1. If you are a busy person and end up eating out of a box, don't forget to check the nutritional label to identify foods with higher dietary fibre. Foods with ≥3 g of fibre per 100 g or ≥10% of daily reference value per serving can be termed a "good source of fibre." If twice as much fibre is present, they can be called "high fibre."
2. Add a tablespoon of chia or flaxseed to your salads and smoothies.
3. Seed mix, roasted nuts, and seasonal fruit like apples or pear are high-fibre snacks that can be kept handy at your workplace or car.
4. Try to eat a salad on most days of the week.
5. Lentils and beans are not only good sources of vegetarian protein but also excellent sources of fibre and are very easy to incorporate into the everyday diet. Don't miss eating half to one cup of cooked lentils or beans every day.

Fibre supplements: yay or nay?

While fibre supplements can help fill a deficit, they are not the first choice for disease prevention and the variety of health benefits that come from eating fibre-rich foods. It's better to focus on getting your fibre intake from foods. There is limited evidence to support the use of isolated fibre supplements. It may be beneficial for older people who have overall reduced dietary intake.

For the rest of us, the fibre target is achievable through a balanced diet that provides both soluble and insoluble fibre along with other important nutrients for overall health.

Project High Fibre Salad

Let's build a big salad for one using fibre-rich ingredients and see for ourselves how much fibre that gets us! (in approximate values)

Ingredients:
1 cup thinly shredded cabbage ( 2g) OR 1 cup chopped salad greens (1g)
½ pear or apple (2.5g)
½ cup cooked whole masoor lentils (6.5g)
½ cup cooked quinoa (2.5g)
1 tbsp chia seeds (6g)
1 tbsp raisins (0.5g)

Dressing:
1 tbsp olive oil
1 tbsp lime juice
1 garlic clove, grated
Salt
Pepper

Method:
Whisk all the dressing ingredients using a fork in a small bowl or shake it in a glass jar with a lid on.

Mix the cabbage, pear, lentils and quinoa in a large bowl. Pour the dressing and toss well. Top with a sprinkle of chia seeds and raisins.

Using cabbage instead of lettuce makes the salad hearty and lunchbox friendly. Grain and lentil-based salads are great to refrigerate and eat later as these thirsty ingredients absorb all the liquid turning more flavourful with time.

As you can see, it is easy to get 20 grams of fibre from just one salad bowl meal, which is 60-80% of the daily fibre requirement. That said, it is good to spread out dietary fibre across meals for the least discomfort from bloating to keeping blood glucose levels steady. And make sure you increase your hydration with the increasing fibre intake.