An Apple a Day
Annual results and thoughts on fruit.
Another year, another diabetic check-up and chat with my doctor. My headline news is an HbA1c reading of 35mmol/ml (5.35%). Since I have had no medication at any time since diagnosis, that means my type-2 diabetes remains in remission.
My liver and kidney functions are fine. My total cholesterol is up but ratios are more or less where they should be. In particular my triglyceride/HDL ratio is 1 (where ‘ideal’ is defined as a ratio of 2 or less.)
I’m happy with that. The trick, as always, is to maintain it.
The one major difference between this year and last is a knee problem that has stopped me running since February. In 2023 I was running two or three 5Ks per week with a 10k most weekends. I’ve been to the swimming pool and the gym this year, but the physiological impacts aren’t the same as running. I have managed some short jogs on a treadmill without reaction, but I’m not ready for outdoors and harder surfaces yet.
Another difference this year, though maybe not so significant, is that I’ve relaxed my diet a little. I don’t mean that I’ve gone crazy, just that I’m not so strict on myself as I was when pushing the t2d into remission. As I’ve written here previously, having got to this position it’s now about maintenance. Having said that, I continue to avoid potatoes, pasta and rice, only having them very occasionally in, for example, restaurants. I’m just a bit more relaxed about the occasional LiDL almond croissant.
My weight has crept up though, so I’ve set myself a target to get back to last year’s average over the next couple of months.
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This week, I saw a video in Tiktok (I know) that referenced a study on t2d and consumption of fruit and vegetables. I normally scroll past that stuff but in this case the creator was a doctor in the UK. The thrust of the video, per the on-screen captions, was that certain fruit and vegetables were ‘preventative’ or ‘causative’ of t2d. For reasons that will become clear, I’m not linking to the Tiktok.
It was immediately apparent from a screenshot of the study that it was not about cause and effect at all but about association and therefore correlation. To that extent the video, even though it was by a doctor, was misleading. So I did what I often do: I went and read the study which is available online (links to an online pdf).
It's fair to say that the study, a metanalysis, was not written with a lay audience in mind and I skipped the denser statistical analysis.
The key finding was that intake of (i) fruit and vegetables and (ii) fruit alone is associated with a 7% reduction in t2d risk. There was also suggestive evidence that some of these foods were more associated with risk reduction than others while some were associated with increased risk. Note, it’s about risk not cause. I think the doctor on Tiktok should have explained this a lot better rather than jumping to the clickbait.
The specific fruits associated with reduced risk were apples, apples and pears together, blueberries, grapes and raisins.
The specific fruits and vegetables associated with increased risk were cantaloupe, fruit drinks, fruit juice, potatoes, brussels sprouts and cauliflower.
Note, the results were based on eating the foods at least three times per week.
A number of products had no significant statistical significance either way, including bananas.
The authors of the paper note a number of possible confounding variables that could skew the results. That being said, the general finding was a message to increase fruit consumption with a bias towards certain fruits, subject to further research.
I haven’t taken the time to do all the calculations, but I was immediately struck that, in the case of raisins and bananas, the results seem independent of their glycaemic load, which is to say their supposed impact on blood sugar (glycaemic load is the glycaemic index of the product as a percentage of total carbohydrate in it.) If that is accurate – and it is only an ‘if,’ then it raises questions about the proper understanding and use of glycaemic index and glycaemic load, both things that I paid attention to when putting my t2d into remission.
That would also resonate with Chris van Tulliken’s argument that, iirc, the method of delivery of sugars and nutrients into the body is as important as the chemical composition. There is, he says, something about the act of eating and the body’s physiological response to eating that is important and overlooked.
Now, to be clear, I’m not reaching any conclusions here except to be sceptical of doctors on Tiktok. But it lends weight to my general view that it is probably foolhardy to look for simple cause and effect in the operation of the metabolic system. Instead, it is about systems thinking in which outcomes depend on the interaction of several variables.
I don’t think that contradicts my view that we should all eat and cook from fresh ingredients as often as possible, have sensible portion sizes and avoid refined sugars and ultra-processed foods.
The thing is, though, eating fresh food as a staple is more than a nutritional issue: it is also economically dependent and specifically is deeply rooted in inequality (not to mention the impact of global heating.)
Access to affordable fresh food is a political issue, and so is type-2 diabetes.