When we talk about nutrition and Sickle Cell Disease, antioxidants often come up. Vitamin C, vitamin E, colourful fruits and vegetables, berries, leafy greens and other antioxidant-rich foods are frequently described as being “good for us.” But what does that actually mean for someone living with SCD? The answer starts with something called oxidative stress.
What is oxidative stress?
Our bodies naturally produce substances called free radicals as part of normal metabolism. Usually, the body has antioxidant defence systems that help keep these reactive molecules under control.
Problems can arise when the balance shifts and oxidative activity exceeds the body’s ability to manage it. This is known as oxidative stress. SCD is associated with increased oxidative stress. The repeated sickling and breakdown of red blood cells, alongside inflammation and other biological processes, can contribute to an environment in which oxidative damage is increased. That matters because SCD isn’t only a disease of red blood cells. Blood vessels matter too.
Antioxidants and blood vessel health
The inner lining of our blood vessels is called the endothelium. It has an important job. Among other things, it helps regulate how blood vessels widen and narrow, influences blood flow and participates in inflammatory and clotting processes.
In SCD, haemolysis, the breakdown of red blood cells, releases substances into the circulation that can interfere with normal blood-vessel function. One important pathway involves nitric oxide. Nitric oxide helps blood vessels relax.
In SCD, haemolysis and oxidative stress can reduce nitric oxide availability and contribute to endothelial dysfunction.
Antioxidant defence is therefore relevant because it helps the body control oxidative damage. But this needs an important qualification. Antioxidants do not stop red blood cells from sickling, and antioxidant supplements should not be presented as a treatment for SCD. The biology is much more complicated than simply “take antioxidants, and your blood vessels will improve.”
Vitamin C, collagen and the body’s structure
There is another interesting connection between nutrition and health: collagen. Collagen is a structural protein found throughout the body, including in skin, bones, cartilage and blood-vessel walls.
Vitamin C has a particularly important role because the body needs it for normal collagen synthesis. This is one reason adequate vitamin C intake matters.
Foods containing vitamin C include peppers, oranges and other citrus fruits, berries, broccoli, tomatoes and many other fruits and vegetables. But again, more isn’t automatically better.
Getting sufficient vitamin C is important for normal physiology; taking very large doses does not mean the body will simply manufacture stronger blood vessels.
Antioxidants and inflammation
Inflammation is another important part of SCD. SCD is associated with chronic inflammatory activity, even outside an acute pain crisis. During vaso-occlusive events, complex interactions occur between sickled red blood cells, white blood cells, platelets and the endothelium.
Oxidative stress and inflammation can also influence each other. Antioxidant systems participate in regulating oxidative processes that can contribute to inflammatory signalling.
This is one reason researchers are interested in the relationship between oxidative stress, inflammation and SCD.
However, we need to resist turning an interesting biological mechanism into an exaggerated nutritional claim. Eating antioxidant-rich foods can form part of a nutritious diet. It does not mean that blueberries, vitamin tablets or a fashionable antioxidant supplement can switch off the inflammatory processes involved in SCD.
Food first
When possible, I prefer to think about antioxidants in terms of food rather than pills.
A varied diet can provide vitamin C, vitamin E, carotenoids, polyphenols and many other compounds alongside fibre, minerals and other nutrients.
Think about variety: berries, citrus fruits, peppers, tomatoes, leafy green vegetables, broccoli, beans, nuts, seeds and other colourful plant foods.
Rather than searching for one magical “superfood,” eating a variety of nutritious foods is a more sensible approach. And this connects with something else we need to acknowledge.
Telling people with SCD simply to “eat healthily” isn’t enough if healthier food is unaffordable or inaccessible. Nutrition doesn’t exist separately from the social determinants of health.
What about antioxidant supplements?
This is where I would be particularly cautious. A supplement labelled “antioxidant” is not automatically beneficial or harmless.
Supplements can contain doses far higher than those normally obtained from food. They may interact with medicines, be inappropriate for certain medical conditions, or provide little proven benefit despite impressive marketing.
People with SCD may also have complications affecting organs such as the kidneys or liver, which can change what is appropriate for an individual.
So, before taking high-dose antioxidant supplements, it is sensible to discuss them with your SCD specialist, doctor, pharmacist or dietitian, particularly if you take regular medication.
Supporting the whole body
There is an understandable desire when living with a chronic condition to find something we can do ourselves. Nutrition is one of those things.
And it matters. But I think we should approach nutrition in SCD without making promises that the science cannot support.
Antioxidants are part of the body’s defence against oxidative stress. Vitamin C contributes to normal collagen formation.
A nutritious diet provides antioxidant compounds and other nutrients needed for normal health. Oxidative stress and inflammation are important features of SCD biology.
But none of this means antioxidants are a cure for SCD or a replacement for established treatment. Perhaps the better question isn’t: “Which antioxidant should I take for sickle cell?” It is: “How can I give my body the nutrition it needs while continuing to manage my SCD properly?”
That turns the conversation away from miracle supplements and towards something much more useful: supporting the whole person living with sickle cell disease.
If you would like to get in touch with me about sickle cell, do so via my email address: [email protected]. And do check out my blog: www.dailylivingwithsicklecell.com.
My book on Sickle Cell – HOW TO LIVE WITH SICKLE CELL – and my other books are available for purchase on www.amazon.com.
