Reducing your intake of one particular food could help you ‘stay young’, according to a prominent expert. Dr Valter Longo, who heads the Longevity Institute at the University of Southern California, has dedicated his career to studying the biology of ageing and disease.
Although the average UK adult lives to around 80 years old, Dr Longo claims that you can indeed boost your life expectancy by following certain essential guidelines. While frequent exercise and a diet rich in vitamins are among the recommended necessities, he also advises keeping one thing to a minimum.
You may be surprised to hear this is fish, with Dr Longo suggesting that just ‘two or three’ portions each week is optimal for an adult’s ‘longevity diet’. “Eat mostly vegan, plus a little fish,” he wrote in a previous online blog.
“Choose fish, crustaceans, and molluscs with a high omega-3, omega-6, and vitamin B12 content (salmon, anchovies, sardines, cod, sea bream, trout, clams, shrimp. Pay attention to the quality of the fish, choosing those with low levels of mercury.”
As suggested by Dr Longo, fish rich in healthy fats- or omega-3s – are especially beneficial for our wellbeing. Studies suggest they play a number of key roles, not only enhancing cognitive function but also potentially reducing heart disease risk factors.
Albeit overwhelmingly positive, there are some potential drawbacks that are often overlooked. These are concerns explained by the NHS, with advice cautioning that oily varieties ‘usually have higher levels of pollutants than other types of seafood’.
Mercury, an element toxic to humans, is included in this. Although the threat of consuming fish is relatively low, high exposure to mercury may give rise to memory loss, seizures, numbness and other symptoms.
“We should eat at least one portion (around 140g when cooked) of oily fish a week,” the NHS states. “Oily fish usually have higher levels of pollutants than other types of seafood. For this reason, there are maximum recommendations for the number of portions some groups should be eating each week.”
It also adds: “[When pregnant] eating fish is good for your health and the development of your baby. However, pregnant and breastfeeding women should avoid some types of fish and limit the amount they eat of some others. This is because of the levels of mercury and pollutants that some fish can contain.”
Aside from this, Dr Longo recommends eating meals within a ‘twelve-hour period’ each day to maximise health benefits. Professor Tim Spector echoed similar sentiments on the ZOE podcast, suggesting it’s beneficial to avoid food for at least 12 hours overnight.
“There are a number of reasons for this,” he said. “One is that the body needs time to recover and that it’s part of our circadian rhythms, so all the cells in our body have the same 24-hour clock.”
Amidst the conversation, Dr Sarah Berry added: “There was a really interesting study that came out last year that I think really nicely illustrates what’s going on by eating late in the day. And in this study they gave people exactly the same food over exactly the same time period, but half of the people had the food slightly earlier in the day and the other half had the same food slightly later in the day.
“…Those people who were having it later in the day, despite eating late in the evening, woke up the next morning lots more hungry than the people who were finishing their food a lot earlier in the day.”