There is no “miracle food” that can cure all your problems. That’s not how human nutrition operates! When we consider nutrient density, real-life health outcomes, and sustainability, however, there are some clear winners when it comes to foods. The best diet isn’t a single food; it’s a lifestyle based on a few outstanding foods.
So here’s what the research actually shows – broken down by food, and the health you get per bite.
Leafy Greens: The Nutrient Density Champions
Dark leafy greens, such as kale, spinach, Swiss chard, collards and watercress are pretty much unbeatable when it comes to nutrients per calorie.
Why they win:
Vitamin K: plays an important role in blood clotting and in bone metabolism. 1 cup cooked kale = 6X your daily needs.
Folate: helps repair DNA; prevents neural tube defects.
Nitrates: Turn into nitric oxide, a substance that relaxes blood vessels, reducing blood pressure.
The macular carotenoids (lutein + zeaxanthin): These carotenoids are important in the retina for the prevention of macular degeneration.
People who consumed 1+ servings of leafy greens daily experienced slower rates of cognitive decline, which is similar to the equivalent of 11 years of age.
Uses: Add to salads, sauté with garlic, add to smoothies. Oxalates are diminished when cooked and bioavailability of some nutrients is increased during cooking.
Fatty Fish: Brain and Heart Insurance.
Long-chain omega-3 fats EPA and DHA are best found in dietary sources of fish like salmon, sardines, mackerel, herring and anchovies.
Why they matter:
DHA: Makes up 40% of the polyunsaturated fats in your brain and 60% in your retina. Low levels have been associated with depression and cognitive impairment.
EPA: High anti-inflammatory properties. Supports a healthy level of triglycerides and blood pressure.
Sardines with bones provide calcium, in addition to the complete protein + selenium + vitamin D.
However, the American Heart Association still states that consuming 1-2 servings of fatty fish per week will continue to reduce the risk of sudden cardiac death.
For those who do not consume fish, you can use the algal oil supplements that contain pre-formed DHA/EPA. Only flax and chia provide ALA, which is converted to DHA with less than 5% efficiency.
Legumes
The beans, lentils, chickpeas and peas appear in every Blue Zone diet: areas where people live the longest. They are the least well-known health food.
The case for legumes:
Once cooked 1 cup lentils = 15g fibre. This nourishes good bacteria in the gut which creates an anti-inflammatory compound called butyrate that will keep the lining of the colon healthy.
Resistant starch: Similars to fibre, but also increases insulin sensitivity.
Plant protein + minerals: Rich in minerals such as iron, magnesium, potassium and zinc – and contains no saturated fat like red meat.
Low glycemic effect: Even though they’re carbohydrates, they help to lessen blood sugar rises.
One meta-analysis of 26 studies showed a 5% reduction in LDL cholesterol when people consumed 130g of legumes a day, which is equivalent to 3/4 cup per day.
Give yourself a pat on the back: Canned works! Rinse them, and reduce sodium by 40%. If gas is an issue, start with 2 Tbsp/day and build up. Your microbiome adapts.
Berries
While blueberries, blackberries, strawberries, and raspberries are among the highest on the ORAC list, it is their unique compounds.
Key players:
Anthocyanins: These are pigments which give them a blue/red colour. Cross the blood brain barrier and enhance the communication of the neurons. Two servings or more per week are associated with an age equivalent delay in brain aging, according to Harvard studies.
The ellagic acid is present in raspberries and strawberries. Investigated for use in cancer.
Fiber + low sugar: One cup of raspberries contains 8g of fibre and just 5g of sugar, while a banana contains 23g of sugar.
Frozen berries have the same nutritional content as fresh, and are usually more affordable. In fact, the amount of anthocyanin is slightly higher after the freezing process.
Nuts and Seeds
On paper, walnuts, almonds, chia seeds, flaxseeds and pumpkin seeds are a bad idea: They’re high in fat and calories. In reality, though, they are associated with weight loss and life extension.
Why the paradox:
Unsaturated fats: Only walnuts have a high concentration of ALA omega-3. Almonds are high in monounsaturated fat, same as olive oil.
Fat in almonds and pistachios does not absorb: As much as 20% of the fat from almonds and pistachios passes through undigested as it’s stuck in the cell walls.
Protein + fibre + fat = satisfies you and leads to reduced eating later. Nuts were given to the patients in the PREDIMED study, and they lost some belly fat.
The ideal amount is 1-2 handfuls a day. That’s about 30g. More isn’t better — calories do still count.
Fermented foods – direct link to gut.
Live bacteria are added to yogurt, kefir, kimchi and sauerkraut, and also to tempeh and miso, to transiently colonize the gut and influence inflammation.
A 2021 Stanford study had people eat 6 servings/day of fermented foods for 10 weeks. Result: Improved diversity of gut microbes, reduced inflammation markers such as IL-6. The key is its diversity, and low diversity is linked to obesity, IBD and autoimmune diseases.
Look for: “Live active cultures” on the label. Pickles in vinegar that don’t require refrigeration are not fermented pickles.
What’s the One Healthiest Food then?
I would go with sardines if I could only choose one food that has the most properties — is dense in nutrients, protein, healthy fat, gut-healthy and has robust outcome data. While 200 calories per can, you’ll receive complete protein, omega-3s, calcium, vitamin D, B12 and selenium. Not only are they safe of mercury but they’re also short-lived and small.
Wait a second, this is a trick question! Sardines + leafy greens + Lentils + blueberries is better than any one.
The item is beat according to the pattern:
Fill 2/3 of your plate with plants: greens, legumes, berries, nuts.
Include 2-3 servings/week of fatty fish or algal oil.
If they’re not overly spicy, consume fermented foods every day.
Consistently consume those and you’ve taken 90% of the key points that nutrition science agrees upon. The other 10% is personal — your genes, gut flora, culture, and what you’re going to do.
The true answer is, of course, the healthiest food is the nourishing food you will eat on a regular basis for the next 30 years.
