Reducing consumption of a specific food might hold the key to preserving youthfulness, suggests a prominent expert in the field of aging. Dr. Valter Longo, who leads the Longevity Institute at the University of Southern California, has devoted his work to unraveling the mysteries of aging and disease progression.

While the average lifespan in the UK hovers around 80 years, Dr. Longo argues that longevity can be boosted by adhering to a few essential guidelines. Key among these are engaging in regular exercise and consuming a balanced, nutritious diet. However, he also stresses the importance of moderation when it comes to one particular food.

Interestingly, that food is fish. Dr. Longo has previously advised that adults should consume only ‘two or three’ servings of fish per week as part of a ‘longevity diet.’ “Adopt a primarily vegan diet, supplemented by small amounts of fish,” he mentioned in a past blog post dedicated to tips on ‘how to stay young.’

His advice emphasizes selecting fish, crustaceans, and mollusks that are high in omega-3, omega-6, and vitamin B12, such as salmon, anchovies, sardines, cod, sea bream, trout, clams, and shrimp. He also advises ensuring the fish are of good quality, with low mercury content.

Dr. Longo points out that fish rich in omega-3 fatty acids—often dubbed ‘healthy fats’—bring specific health benefits. Recent studies suggest these nutrients play crucial roles, not only in supporting brain health but also potentially reducing the risk factors for heart disease.

However, while this sounds beneficial, there are some drawbacks to consuming excessive amounts of fish. These concerns are echoed by the NHS, which cautions that oily fish types typically contain higher levels of pollutants than other seafood varieties.

This includes mercury, a toxic element that is harmful to humans. Although the danger from consuming fish is typically minimal, significant mercury exposure can trigger seizures, memory issues, numbness, and other complications.

“We should eat at least one portion (around 140g when cooked) of oily fish a week,” online NHS advice claims. “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.”

The NHS places particular emphasis on young girls, women considering pregnancy or hoping to conceive in future, pregnant women and those who are breastfeeding. These categories should consume no more than two portions of oily fish weekly as contaminants may impact the ‘future development of a baby in the womb’.

It adds: “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.

“When pregnant, you can reduce your risk of food poisoning by avoiding raw shellfish and making sure that any shellfish or smoked fish you eat is cooked thoroughly.”

In addition to this, Dr Longo advises dieters to confine their meals to a ‘twelve-hour period’ each day for optimal health benefits. Similar views are echoed by Professor Tim Spector, who previously suggested on the ZOE podcast that it’s beneficial to avoid eating for at least 12 hours overnight.

“There are a number of reasons for this,” he said, according to a previous Mirror report. “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.”

As part of the same 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.”