Intermittent fasting, which consists of going without or with minimal food for 16 hours up to 36 hours – more than that is “prolonged fasting” – could be one of the most potent anti-aging measures available, as potent or more so than exercise or dietary phytochemicals. One of its main mechanisms of action is through increasing autophagy, the cellular self-cleaning process that rids cells of junk organelles and macromolecules. Intermittent fasting can prevent heart disease too, and through the same mechanism, autophagy.
Aging is the number one correlate of increased risk for coronary heart disease (atherosclerosis), and aging also correlates strongly with a decline in natural levels of autophagy.
Dysfunction of the arterial walls plays a key role in coronary heart disease. This dysfunction is related to declining autophagy.
Some researchers decided to test the idea that declining autophagy is important to arterial dysfunction. They used human volunteers, mice, and cell culture in a three-pronged experiment.(1)
They showed that blood flow in the forearm in response to infusions of acetylcholine was only about half in healthy older humans, age 61 to 71, compared to that in healthy young people, age 20 to 31. The lower blood flow was shown to be due to lower production of nitric oxide, which mediates vasodilation.
Levels of autophagy in older people, as shown by protein markers, were about half those in younger people. The correlation between autophagy markers and forearm blood flow was high at 0.61.
The mouse segment of the experiment studied markers of autophagy in old and young mice. In the old mice, the markers showed about half the level of autophagy as in the young mice. Their arterial function was also much worse.
Then, they gave the old mice trehalose, a sugar (sic) which promotes autophagy, similarly to hydroxycitrate, resveratrol, curcumun, and EGCG.
Trehalose completely restored autophagy levels in old mice to those seen in young mice, and restored arterial function to the same degree.
Human cell cultures treated with trehalose responded with a restoration of nitric oxide production.
The scientists stated:
The present findings suggest that autophagy is reduced in arteries of older mice and humans and contributes to impaired vascular endothelial function, a clinically important expression of arterial ageing. Importantly, our parallel findings in mice and humans indicate that autophagy protects vascular endothelial function with ageing by reducing oxidative stress and inflammation and increasing NO bioavailability. These results provide a basis for translational research aimed at enhancing autophagy to reverse arterial ageing and reduce the risk of age-associated CVD in humans.
Declining autophagy is linked to increased oxidative stress, inflammation, and mitochondrial dysfunction, all of these being main physiological processes that accompany aging. In fact, they just are aging.
Reversing one of these means a reversal in the others. So increasing autophagy will lower these other markers. The result in this case is improved arterial health. As inflammation has been strongly implicated in coronary artery disease, increasing autophagy will lower inflammation and help prevent atherosclerosis.
Intermittent fasting strongly increases autophagy during the fasting window, so it has great potential in the prevention of coronary heart disease.
Other interventions already mentioned, curcumin, resveratrol, nicotinamide, etc. (you can see all of these on my supplements page) also increase autophagy – they have been called calorie restriction mimetics – and therefore have the same potential. Trehalose works in mice, though human data is lacking, and it’s cheap.