If you a. are serious about wanting to live longer and b. don’t want to invest in a longevity strategy that might not pay off, you’ll be better off devoting your energy and money to increasing your vegetable intake, and leaving supplements alone. This is the conclusion we draw after reading the epidemiological study that researchers at University College London will publish soon in the Journal of Epidemiology and Community Health.
The advice that nutritionist give is that we should eat 5 portions of and vegetables daily. That’s the 5 a day guideline. Some supporters of the longevity movement say this is not enough: they add supplements to this that they believe delay aging.
Biochemists at the University of California at Riverside published in April 2014 in Age the results of an animal study in which they gave a number of these supplements – including Juvenon, Life Extension Mix and Ortho Core – to mice, but to little effect. [Age (Dordr). 2014 Apr;36(2):705-18. ] The same researchers reported in 2013 that tried and tested supplements such as blueberry, pomegranate, Pycnogenol and curcumin also did nothing to help extend the lifespan of the same kind of mice. [Rejuvenation Res. 2013 Apr;16(2):143-51.]
This may be because the researchers used a particularly robust type of lab mouse. After all, there are plenty of studies that show that supplements do extend the lifespan of lab animals. But maybe we should just conclude that there’s no hundred percent certainty that supplements extend lifespan.
The study that is about to be published in the Journal of Epidemiology and Community Health makes it clear that increasing your intake of vegetables is a strategy that extends life expectancy. If you already follow the 5 a day guideline to the letter, following this latest advice is likely to work. The more vegetables you eat, the better.
The researchers followed a group of 65,226 British people over the age of 35 for almost eight years, and examined the relationship between their diet and mortality.
The figure below shows the relationship between mortality and the average daily intake of fruit. The participants who ate more than 4 pieces of fruit a day had a 14 percent lower mortality rate than the participants who ate no fruit at all. That’s not such a huge amount.
The effect of eating vegetables was stronger. Consuming more than three portions of vegetables daily reduced the mortality risk by 32 percent compared with participants who ate no vegetables at all.
The joint effect of vegetables and fruit was not a lot stronger than eating just vegetables, as the table below shows [see ‘Population’]. The participants who ate vegetables and/or fruit more than 7 times a day had a 33 percent lower mortality rate than the participants who ate no fruit or vegetables at all.
The same figure also shows that lifestyle factors can strengthen the positive effects of eating vegetables. Among the participants who exercised a lot and the participants with a healthy weight, a high vegetable intake almost halved the mortality risk. And that’s definitely a worthwhile effect.
The researchers also looked at different types of fruit and vegetables, and discovered that the positive health effects of fruit juice were minimal. Tinned fruit actually had a negative health effect. [Table]
Fruit and vegetable consumption and all-cause, cancer and CVD mortality: analysis of Health Survey for England data.
Governments worldwide recommend daily consumption of fruit and vegetables. We examine whether this benefits health in the general population of England.
Cox regression was used to estimate HRs and 95% CI for an association between fruit and vegetable consumption and all-cause, cancer and cardiovascular mortality, adjusting for age, sex, social class, education, BMI, alcohol consumption and physical activity, in 65 226 participants aged 35+ years in the 2001-2008 Health Surveys for England, annual surveys of nationally representative random samples of the non-institutionalised population of England linked to mortality data (median follow-up: 7.7 years).
Fruit and vegetable consumption was associated with decreased all-cause mortality (adjusted HR for 7+ portions 0.67 (95% CI 0.58 to 0.78), reference category <1 portion). This association was more pronounced when excluding deaths within a year of baseline (0.58 (0.46 to 0.71)). Fruit and vegetable consumption was associated with reduced cancer (0.75 (0.59-0.96)) and cardiovascular mortality (0.69 (0.53 to 0.88)). Vegetables may have a stronger association with mortality than fruit (HR for 2 to 3 portions 0.81 (0.73 to 0.89) and 0.90 (0.82 to 0.98), respectively). Consumption of vegetables (0.85 (0.81 to 0.89) per portion) or salad (0.87 (0.82 to 0.92) per portion) were most protective, while frozen/canned fruit consumption was apparently associated with increased mortality (1.17 (1.07 to 1.28) per portion).
A robust inverse association exists between fruit and vegetable consumption and mortality, with benefits seen in up to 7+ portions daily. Further investigations into the effects of different types of fruit and vegetables are warranted.
PMID: 24687909 [PubMed – as supplied by publisher]