Examining Possible Causes for Slower Wound Healing

Blueberries reduce inflammation, but do they affect wound healing? (Photo by a2gemma)

I'm not sure why, but during the past few months, I've noticed my wounds healing slower than usual. Even fairly minor scratches take more than a week to heal fully, and bigger cuts seem to take at least three weeks. The bleeding stops normally and everything, but after that, the healing process just takes longer than it used to.

This has had me wondering what the cause might be. I've ruled out most of the supplements I've taken, because the experiments have only lasted for a couple of months and haven't really coincided with the slower wound healing. The supplements I've been taking for several months are vitamin C (500 mg), vitamin D (2,000 IU), and AOR Ortho-Core multivitamin (2 capsules). None of these should interfere with wound healing; on the contrary.

The first thing that comes to mind besides supplements is intermittent fasting, which I've been doing for about nine months now. As it happens, there is a paper (here.) that says caloric restriction and intermittent fasting reduces cell proliferation in epidermal tissue, which would likely have an effect on wound healing as well.

Another possible reason could be a low level of inflammation. Low inflammation is of course generally a good thing, but there is some evidence suggesting it might interfere with the wound healing process. Intermittent fasting apparently reduces inflammation markers quite a bit, and green tea protects from arthritis by reducing inflammation in vivo and in vitro. As you may know, I drink several cups daily.

Other staples of my diet with possible inflammation-reducing properties include dark chocolate and my morning smoothie with a hefty dose blueberries, blackcurrants, strawberries and raspberries – all high in antioxidants and polyphenols, which are said to lower inflammation. Avoiding processed carbohydrates and starchy foods probably plays a part as well.

It was also pointed out to me that low levels of zinc may contribute to slow wound healing, so I looked around for some more information. One paper (here) suggests low levels of zinc delay wound healing during hip replacement, and another one (here) mentions correcting a zinc deficiency resulting in improved wound healing.

A zinc deficiency is rare, however, and it's less clear whether increasing zinc intake from less than optimal levels will speed up wound healing. Also, one paper (here) suggests very high doses may in fact negatively affect wound healing, similarly to a zinc deficiency. Nevertheless, zinc supplementation apparently stimulates healing of bone fractures (abstract available here).

The RDA for zinc in adult males is 11 mg. According to CRON-O-Meter, my typical daily menu contains only ~5 mg of zinc. My multivitamin gives me another ~4 mg, bringing me to 9 mg. On the days I replace the fish in my warm meal with meat, my zinc intake is higher, so I probably average pretty close to the RDA.

I'm not entirely convinced the RDA is the same as thing optimal (it certainly isn't for vitamin D), so as an experiment, I'll be taking 15 mg zinc as a supplement to see if it speeds wound healing. Meanwhile, I'll keep an eye out on other possible causes. And if you have a theory or personal experiences, feel free to drop a comment.

For more information on diets and health, see these posts:

Intermittent Fasting Improves Insulin Sensitivity Even without Weight Loss
Low-Carb vs. Low-Fat: Effects on Weight Loss and Cholesterol in Overweight Men
The Effects of a High-Fat Diet on Health and Weight - Experiment Conclusion
How the Accumulation of Minerals Might Cause Aging in Humans