Long life expectancy can be attributed to a person’s diet – a healthy, balanced diet has been proven to improve longevity. Experts recommend eating at least five portions of a variety of fruit and vegetables every day, basing meals on higher starchy foods like potatoes, bread and rice, having some dairy or dairy alternatives, eating some protein, choosing unsaturated oils and spreads, and drinking plenty of fluids.
But new research, published this week, has found the times of day a person eats holds the most benefits.
Dr Mark Mattson, a professor of neuroscience at John Hopkins University School of Medicine, in the US, has said “intermittent fasting could be part of a healthy lifestyle.”
Intermittent fasting diets usually involve daily time-restricted feeding, which narrows eating times to six to eight hours per day and so-called 5:2 intermittent fasting, in which people limit themselves to one moderate-sized meal two days each week.
A range of human and animal studies have shown that alternating between times of fasting and eating supports cellular health, probably by triggering an age-old adaptation to periods of food scarcity called metabolic switching.
Such a switch occurs when cells use up their stores of rapidly accessible, sugar-based fuel, and begin converting fat into energy in a slower metabolic process.
Dr Mattson says studies have shown that this switch improves blood sugar regulation, increases resistance to stress and suppresses inflammation.
Because most Americans eat three meals plus snacks each day, they do not experience the switch, or the suggested benefits.
In an article in the New England Journal of Medicine, Dr Mattson said four studies in both animals and people found intermittent fasting also decreased blood pressure, blood lipid levels and resting heart rates.
Evidence is also mounting that intermittent fasting can cut risk factors associated with obesity and diabetes.
Studies also suggest intermittent fasting could boost brain health too.
Experts say people adopting intermittent fasting regimes should gradually increase the duration and frequency of the fasting periods over the course of several months, instead of “going cold turkey.”
Other diets proven to increase life expectancy
Many studies have highlighted the benefits of a vegetarian diet.
The authors of a large, long-term study concluded vegetarianism is associated with a reduced risk of ischemic heart disease.
The study featured in the British Medical Journal looked specifically at plant based diets and their effect on the risk of ischemic heart disease and also stroke.
As part of the study, scientists took data from 48,188 people whom they followed for an average of 18.1 years.
The participants who had an average age of 45 years at the start of the study had no history of ischemic heart disease or stroke.
They were then assigned to one of three groups:
- Meat eaters – people who reported eating meat
- Fish eaters – those who ate fish but no meat
- Vegetarians and vegans – people who didn’t eat meat or fish
Using food questionnaires, the researchers assessed their overall food intake and nutrient levels.
They also collected information about factors such as body mass index (BMI), height and blood pressure.
During the 18.1 years of follow-up there were 2,820 cases of ischemic heart disease and 1,072 cases of stroke.
After adjusting for sociodemographic and lifestyle factors, the analysis revealed both positive and negative relationships between cardiovascular health and reduced meat intake.
The rate of ischemic heart disease among pescatarians was 13 per cent lower than that of meat eaters, while vegetarians had a rate that was 22 per cent lower.
Putting this into perspective, the authors of the study explained: “This difference was equivalent to 10 fewer cases of ischemic heart disease…in vegetarians than in meat eaters per 1,000 population over 10 years.”