Saw this today on their website and had to take some photographic evidence. Talk about misinformation…
Wow, that isn’t even flubbing the facts, that’s straight up lying.
Ironically, glucose is highly toxic. Your body can only tolerate a couple tablespoons of it in your blood or it kills you.
Your irony is well-placed! 
As for safety and efficacy, the first point is usually attributed to the lack of evidence from longer-term randomised controlled trials, i.e. +12 months. Yet, the existing evidence from trials lasting 6-12 months shows that low carb (i.e. not necessarily keto but some form of diet with less than 130g CHO) is both safe AND effective. This came out in a recent paper published in the BMJ, titled ‘Efficacy and safety of low and very low carbohydrate diets for type 2 diabetes remission: systematic review and meta-analysis of published and unpublished randomized trial data’. Data here not only showed the low carb groups had superior weight loss, improved glucose tolerance and HBA1C levels, but on the safety aspect, the authors concluded ‘patients adhering to an LCD for six months may experience remission of diabetes without adverse consequences’. Similarly, also this year, the BMJ published another metanalysis titled ‘Low and very low carbohydrate diets for diabetes remission’ looking at the safety aspect. They concluded that for the low carb groups, there were ‘no statistically significant or clinically important increase in total or serious adverse events’.
So, this evidence suggests lower carb diets may not be only effective for treating diabetes but actually superior in this regard. As for safety, there simply is no evidence to show a low carb diet lasting +12 months ‘causes’ adverse health events. Intuitively, it seems like any eating regimen that has been shown in clinical trials to improve metabolic markers over 6-12 months cannot be detrimental to longer-term health. But that’s just my opinion.
Also the fact that for large portions of the human population (including those native to the UK) people practiced a very low carb diet for at least large portions of the year for the last several million years. I agree, there isn’t a lot of data, but the studies should be done to comparatively prove the safety of high carb year round diets, not the other way around.