49 Species a Week: What Britain's Most Diverse Diets Reveal About Longevity

New research from the University of Aberdeen's Rowett Institute has put a number on something nutritionists have long suspected: the average UK diet contains at least 49 different food species a week. Researchers analysed four-day food diaries from more than 3,500 people and found that those eating the widest range of species weren't following a single extreme regimen — they were simply meeting standard guidance on fibre, fruit and vegetables, and fish. Diversity, not restriction, was the marker of a better diet.

It's a quiet finding, but it lands at an interesting moment. Mintel's 2026 global food and drink predictions describe consumers stepping back from "nutrient maxxing" — the habit of chasing a single number, whether that's grams of protein or milligrams of a trending vitamin — in favour of balance and what the firm calls dietary diversity. After several years of supplement stacks and single-ingredient obsessions, the direction of travel is toward eating well across many foods, not maximising one.

The diversity shift

This isn't a rejection of nutrition science. It's a return to its original premise. Frank Hu, chair of nutrition at Harvard T.H. Chan School of Public Health, has made a similar point: there is no single diet that works best for everyone, but the patterns that consistently support long-term health share the same underlying logic — whole foods, healthier fats, fewer processed ingredients. "Basically," he says, "you want to eat whole foods." Not one whole food. Many.

This is where olive oil quietly earns its place — not as a single fix, but as one of the few foods that itself behaves like a diverse one. A fresh, cold-pressed extra virgin olive oil carries dozens of distinct phenolic compounds — oleocanthal, oleuropein, hydroxytyrosol, lignans — in proportions that shift with olive variety, soil, and harvest timing. The European Union has recognised the strongest of these compounds formally: under EU Regulation 432/2012, olive oil containing sufficient hydroxytyrosol and its derivatives may legally state that its polyphenols "contribute to the protection of blood lipids from oxidative stress" — one of the few food-based claims EFSA has ever formally approved. The British Heart Foundation points to the same pattern in its guidance on the Mediterranean diet, where olive oil replaces, rather than adds to, less beneficial fats.

What the science actually says

None of this is a claim that one spoonful of oil undoes a narrow diet. Researchers are careful, and so should we be: the evidence links regular, good-quality olive oil intake to measurable benefits, including support for heart and brain health, rather than guaranteeing them. What's notable is how consistently it shows up across the research Aberdeen, Harvard, and the EU's own regulators have each, separately, arrived at: variety at the level of the whole diet, and quality at the level of individual ingredients, matter more than any single number ever could.

A short list of what fresh, polyphenol-rich extra virgin olive oil is actually bringing to that variety:

• Oleocanthal — the compound responsible for that peppery catch at the back of the throat, with anti-inflammatory properties
• Hydroxytyrosol and oleuropein — antioxidants that decline measurably as oil ages or is refined
• Monounsaturated fats — the primary fat associated with cardiovascular benefit across Mediterranean diet research
• Vitamin E and chlorophyll — present in meaningful amounts only in early-harvest, unfiltered oils

The ritual that doesn't chase a number

This is precisely why Oliiv has never framed its oil as a supplement to be maximised. A spoonful each morning is a ritual, not a dose. It sits alongside a varied plate — not instead of one — which is the entire point the diversity research is making. Begin the day with one simple, repeatable habit, and let the rest of the week's variety take care of itself.

Rooted in provenance

That habit only holds up if the oil itself is honest. Every Oliiv harvest is dated, traceable to a single estate, and cold-pressed within hours of picking — because polyphenol content falls steadily from the moment an olive leaves the tree. We work with regenerative growers across single-origin groves, each with its own olive variety and terroir, which is also why no two harvests taste quite the same. Freshness, not formulation, is what keeps the diversity of compounds intact from grove to glass.

The research keeps pointing the same direction: fewer single-nutrient fixes, more whole, varied, well-sourced food. Fresh-pressed olive oil has always belonged in that picture. It simply took the data a little longer to catch up.

Sources: University of Aberdeen / Rowett Institute, "Diet diversity: average Brit eats at least 49 different species a week" (abdn.ac.uk), published in Public Health Nutrition, July 2025. Mintel, "2026 Global Food and Drink Predictions" (reported via Baking Business). Harvard T.H. Chan School of Public Health, "For a healthy diet, there's no one-size-fits-all" (hsph.harvard.edu). British Heart Foundation, guidance on the Mediterranean diet (bhf.org.uk). EU Regulation 432/2012 on the authorised olive oil polyphenol health claim, as reported by New Food Magazine.