A study which is currently still taking place in Kentucky, is showing promising results- suggesting that eating higher amounts of fibre could reduce levels of toxic PFAS or ‘forever’ chemicals.
Fibre has been shown to reduce PFOS and PFOA, which are among the most common and PFAS.
What are ‘forever’ chemicals?
‘Forever’ chemicals is the common name for a group of man-made chemicals known as PFAS.
PFAS are synthetic chemicals that were first used in 1950s and they are called ‘forever’ chemicals because they do not break down easily in the environment or the human body, meaning over time they can accumulate and persist for decades or longer.
They are used to keep food from sticking to packaging or cookware (like Teflon), to make clothes water repellent and carpets stain resistant, as well as in firefighting foams. They don’t degrade easily in the environment.
Why are they harmful?
Some PFAS have been linked to cancer (e.g. kidney and testicular), hormonal disruption, weakening the immune system, liver damage and developmental issues for infants and children.
PFAS can also contaminate soil, water and wildlife- and unfortunately have been found in drinking water systems around the world.
The US Environmental Protection Agency has found no level of exposure to PFOS or PFOA in drinking water safe as they have a half-life in human blood or anywhere from 2-5 years. It means that the body expels half the amount of the chemical that is blood during that time-frame.
What is a high fibre diet?
The study talks about a ‘fibre-rich’ diet, including soluble and insoluble fibre. Fibre comes from plant-based food and passes through our system undigested, but how much fibre do we need?
NHS guidelines suggest 30g per day, with most adults only eating an average of about 20g per day.
- 2 to 5 year-olds: ~15g fibre/ day
- 5 to 11 year-olds: ~20g fibre/ day
- 11 to 16 year olds: ~25 g fibre/ day
What’s the difference between soluble and insoluble fibre?
Soluble: this type of fibre dissolves in water, and helps to make a gel-like substance in your intestines. Soluble fibre is linked with lowering blood cholesterol and glucose levels. Foods include oats, barley, apples, citrus fruits, lentils and peas, beans and flaxseeds.
Insoluble: this type of fibre doesn’t dissolve in water and can promote bowel health and regularity. Foods include includes whole wheat and whole grains, nuts and seeds, vegetables such as cauliflower and green beans, corn (including popcorn), grapes and dark leafy greens.
Many foods contain both types of fibre, just in different ratios- for instance an apple has soluble fibre in its flesh and insoluble fibre in the skin.
How do I know what 30g/ fibre looks like?
- 2 slices of wholemeal bread 4g/ fibre
- ½ cup peas 4g/ fibre
- 1 medium carrot 2g/ fibre
- 50g raw porridge oats 4g
- Baked potato 5g/ fibre
- Banana 2.5g/ fibre
- Apple (with skin) 3.5g/ fibre
- 2-3 tablespoons chia seeds 9g/ fibre
- 1 teaspoon flax 1g/ fibre
- ½ cup broccoli 2.3g/ fibre
My top tips for increasing fibre in the diet
A diet high in fibre is associated with a lower risk of heart disease, stroke, type 2 diabetes and bowel cancer. Eating a range of dietary fibre can also improve the diversity of your microbiota and reduce inflammation in your gut.
Fibre can also help us feel fuller, aiding digestion and preventing constipation.
- Make sure your plate is made up of lots of vegetables at lunch and dinner time. I recommend people aim for half of their plate to be made up of veg, but this can take building up to- especially if you don’t eat a lot of vegetables currently.
- Snack on fruit such as apples and pears, when you’re wanting something sweet, even better if you can add in some nuts. Apple slices spread with nut butter are a great combination.
- Roast vegetables on a day when you have more time, you can use this to boost veg intake throughout the week.
- Adding nuts and seeds to your plate will boost intake of fibre, think of sprinkling over salads or your morning porridge/ yoghurt.
- Soups are another great way to boost veg intake, I recommend adding peas and beans to up the protein as well as the fibre content.
- When baking, use wholemeal flour and opt for wholegrain bread.
- Smoothies are better than juices when it comes to fibre, as juicing removes fibre- but smoothies retain fibre. Make sure to keep to the 1:1 ratio of veg: fruit, otherwise this can end up being fruit/ sugar-heavy. Add nuts and seeds for an extra boost.
References
High-fibre diet may protect against exposure to PFOS Environmental Factor – April 2023: High-fiber diet may protect against exposure to PFOS
Eating more fibre could reduce ‘forever chemicals’ in bodies, study suggests Eating more fiber could reduce ‘forever chemicals’ in bodies, study suggests | Pfas | The Guardian
NHS How to get more fibre into your diet – NHS
Fibre in Foods Chart https://www.med.umich.edu/mott/pdf/mott-fiber-chart.pdf
Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) | National Institute of Environmental Health Sciences
What are PFAS and how are they dangerous for my health? https://www.eea.europa.eu/en/about/contact-us/faqs/what-are-pfas-and-how-are-they-dangerous-for-my-health#:~:text=They%2520are%2520known%2520as%2520’forever,Europe%2520%E2%80%93%2520PFAS%2520for%2520further%2520information.
What’s the difference between soluble and insoluble fibre? Soluble vs. Insoluble Fiber: What’s the Difference?
Fibre Fibre – BDA