I generally advise against eating refined sugar. I, personally, eat hardly any, but I do eat some. Practically all of this comes in the form of 85 per cent cocoa chocolate. I, for quite some time now, have been recommending dark chocolate as a sweet treat of choice. Firstly, dark chocolate is generally lower in sugar than milk or white varieties. Another boon, I think, that dark chocolate offers is that it lacks the morishness that other forms of chocolate tend to have. This is good news for individuals (such as I) who might to ensure that a little treat doesn’t turn into a big one. Dark chocolate is also relatively rich in plant substances known as ‘flavonols’ that have been linked with benefits for cardiovascular health.

However, if the results of a newly published study are to be believed, another benefit of eating dark chocolate might be protection from the potentially damaging effects of the sun’s rays [1]. I am a huge fan of sunshine, both in terms of psychological and physical benefits it brings, it is not entirely without risk. While I think the link between sunlight exposure and malignant melanoma has been generally overstated (see here for more about this), excess sunlight can burn the skin and damage it in a way that can cause visible ageing. In general terms, I advise seeking shade and donning appropriate clothing to protect against sun damage. But at the same time, it is possible to afford protection from the inside too (see here for some thoughts about this).

The study I’m writing about today tested the effect of dark chocolate rich in flavanols on the ability of the skin to withstand sunburn. There were 30 subjects in the study. Half of them ate 20 g of chocolate rich in flavanols each day. The other half ate the same amount of low-flavanol chocolate. The study lasted 12 weeks.

At the beginning and end of the study subjects had their skin exposed to UV light. The dose of light required to induce redness (known as the minimal erythema dose or MED) was assessed.

In those eating low-flavanol chocolate, there was no different in MED over the course of the study. On the other hand, the individuals eating high-flavanol chocolate saw their MEDs double on average. This study suggests that eating high-flavanol chocolate has some capacity to protect the skin from the potentially damaging effects of the sun’s rays.

I have no idea how one might ensure that the chocolate one eats is rich in flavanols. However, because the flavanols are found in cocoa, dark chocolate is going to offer up more in the flavanols than other varieties (and the darker the better).

References:

1. Williams S, et al. Eating chocolate can significantly protect the skin from UV light. Journal of Cosmetic Dermatology 2009;8(3):169-173

I make no secret of my leaning towards high-protein, relatively low-carb diets. I am well aware of the relatively unhealthy reputation that such diets have. However, when one looks at the research one generally finds that the criticisms of such diet are based on theoretical and ideological concerns. They are not, generally speaking, based on what the science shows.

For example, it has long been said that protein is generally not good news for the bone. One reason for this is that the metabolism of protein makes the blood more acidic, which might have detrimental effects on the bone, partly because it believed to cause calcium to be leached from the bone. I can see why this might give protein a bad name regarding bone health, but protein also promotes bone health, at least in part because amino acids (the building blocks of protein). In the end, it’s not important what effect a nutrient or foodstuff has theoretically or on some marker or other – the important thing is the impact it has on health.

So, if it’s bone health we’re interested in, it’s bone health we need to look at.

A group of British scientists recently performed a review of the available evidence regarding dietary protein and bone health, and this was published on-line in the American Journal of Clinical Nutrition [1]. To main types of study were used in this review; epidemiological and intervention. The epidemiological studies assessed the association between protein intake and bone mineral density (BMD) and/or bone mineral content (BMC). Some studies assessed the relationship between protein intake and risk of bone fracture.

The intervention studies involved giving individuals protein to see what effect this had on bone health. In this review, the outcome assessed was the BMD in the lumbar spine (lower back) and risk of hip fracture.

Taken as a whole, the epidemiological studies revealed that higher protein intakes were not associated with worse measures of bone health including BMD, BMC and risk of fracture. In fact, when amassed together, one type of epidemiological study (cross-sectional study) found higher protein intakes were associated with improved BMD.

The intervention studies followed suit – protein supplementation was found to be associated with enhanced BMD. However, this did not appear to manifest itself as reduced fracture risk.

All in all, what is clear about this study is that it provides no support for the commonly-wielded criticism of high-protein diets regarding bone health. If anything, the totality of evidence shows that proteins richer in protein have benefits for bone.

References:

1. Darling AL, et al. Dietary protein and bone health: a systematic review and meta-analysis. Am J Clin Nutr 4th November 2009 [epub ahead of print]