Growth hormone and IGF-1 during developmental years affect body size, but also longevity
You can see it in genetic conditions of excessive growth hormone production - Andre the Giant
As well as insufficient IGF-1 production - Laron's syndrome
Andre the Giant had acromegaly - excessive growth hormone and IGF-1 production, resulting in massive growth
Acromegaly is associated with a higher risk of cancer, heart disease, and overall mortality (PMID: 30197531)
People with acromegaly have a 2-fold higher mortality risk compared to the general population
Andre died at 46, but he also drank a lot of alcohol. Regardless, acromegaly is thought to be the reason he died so young
Laron syndrome, a condition of IGF-1 deficiency because of growth hormone insensitivity, results in shorter height
People with Laron syndrome live average lifespans (70-80 years), but they have a much lower risk of cancer and diabetes than the general population (PMID: 21325617)
1. Physical fitness is the single best predictor of life expectancy and healthspan. No increased risk was observed with extreme fitness (PMID: 35926933)
8 other key insights on training strategies for optimizing lifespan and cardiovascular health⬇️⬇️
From a 2023 review (PMID: 37091937)
2. Both moderate physical activity (MPA) and vigorous physical activity (VPA) are associated with reduced cardiovascular and all-cause mortality (PMID: 35876019)
More is better for moderate-intensity exercise with respect to cardiovascular health and life expectancy.
Vigorous exercise is also beneficial for optimizing life expectancy and healthspan, but maximal benefits are achieved at 150 minutes/week.
3. Cardiorespiratory fitness (CRF) is inversely associated with long-term mortality with no observed upper limit of benefit (PMID: 30646252)
Compared with the lowest tertile of CRF, those in the highest tertile of CRF had a 45% lower mortality (PMID: 35570068; PMID: 35926934)
Thiamine deficiency causes rapid insulin resistance and prediabetic symptoms.
Without thiamine, you're on the road to getting type 2 diabetes
Check out this thread to learn how to optimize your thiamine intake to improve resistance and blood sugar levels⬇️⬇️
What happens if you don't get thiamine
In 1939, four young healthy 21-29-year-old women were put on a thiamine-deficient diet (< 0.1 mg per day)(Williams et al 1939).
They all saw progressive impairment in glucose tolerance.
Injecting 1 mg of thiamine chloride subcutaneously for 4 days reversed that phenomenon.
Another 1940 study, on six healthy white women aged 21 to 46 saw that a low thiamine intake of 0.15 mg/day or less also caused diabetic blood sugar curves (Williams 1940).
In this case, as well, thiamine injections at doses of 1 mg reversed these symptoms
Some conclusions from the authors of the studies:
1. thiamine deficiency in as little as 15 days, but especially after 2-3 months, leads to impaired carbohydrate tolerance
2. thiamine supplementation improves glucose tolerance in those who are deficient
3. symptoms of thiamine deficiency are vague (lack of appetite and fatigue)
4. electrocardiogram changes can occur with thiamine deficiency
Benefits of thiamine for diabetes
Numerous studies show that thiamine or thiamine-related compounds (benfotiamine or thiamine tetrahydrofurfuryl disulfide) improve diabetic glucose control and diabetic symptoms (PMID: 21564442; PMID: 19057893; PMID: 18220605; PMID: 22446172; PMID: 23701274)
- Thiamine at 150 mg/day has been seen to significantly reduce blood glucose and leptin levels within one month in 24 drug naïve Type 2 diabetic patients (PMID: 20652275)
- Thiamine at 300 mg daily significantly improved microalbuminuria, A1C, and decreased protein kinase C (PKC) levels (a marker of inflammation) in Type 2 diabetic patients (Alam et al 2012)
- Thiamine administered as a one-time 100 mg IV dose improved endothelium-dependent vasodilation in 10 Type 2 diabetics during an acute glucose tolerance test (PMID: 16741654)
Exercise is known to be good for us, but how much exercise and is there something like too much exercise?
Exercise is often seen to have a J-shaped curve with mortality risk - not enough is bad but too much is also harmful (PMID: 26187713)
How much is optimal then?⬇️⬇️
The guidelines recommend adults get 150-300 min/week of moderate exercise or 75-150 min/week of vigorous exercise
Meeting that vs not is linked to a 36% lower odds of being overweight and 48% lower odds of being obese (PMID: 37773071)
However, exercising more than that is linked to a reduced risk of mortality
A 2022 study saw the lowest risk of mortality at 150-300 min/week of leisurely vigorous physical activity, 300-600 min/week of leisurely moderate physical activity, or a combination of both (PMID: 35876019)