It comes as no surprise that the foods we eat can have a major impact on our wellbeing. Some diets such as the Mediterranean diet are well-known to have beneficial effects on our health. But what foods do longevity diets have in common — what are the best foods for health and longevity?
Perhaps one of the most well-known pioneers in the field of longevity is Dan Buettner. In fact, Dan and his team coined the term Blue Zones to refer to geographical areas in the world which are home to the longest living populations on Earth. Through their work, the Blue Zones team analysed 150 dietary surveys from the world’s longest living populations to discover the keys to health and longevity.
Eat your greens
One of the main pillars of the Blue Zone diets is that they are heavily plant-based. In fact, people in the Blue Zones eat about 95 to 100% plant-based diets. The longest-living people eat a wide variety of seasonal vegetables and preserve the surplus for the off-season by pickling or drying the fresh produce. Moreover, leafy greens including kale, spinach, chard and collard greens are amongst the most popularly consumed vegetables.
In addition, cruciferous vegetables feature widely in longevity diets. Cruciferous vegetables such as broccoli, brussels sprouts, cauliflower and cabbage contain compounds called isothiocyanates. Cruciferous vegetables contain a compound called sulforaphane (SFN), a type of isothiocyanate. Broccoli contains particularly high amounts of SFN. Interestingly, research has found that SFN has chemoprotective properties in animal cancer models as well as anti-cancer properties.(1)
Greens and longevity
Moreover, increased intakes of leafy green and cruciferous vegetables are linked to longevity. In fact, a meta-analysis investigated the effects of green leafy and cruciferous vegetable intake on the incidence of cardiovascular disease. Overall, consumption of these vegetables significantly reduces the incidence of cardiovascular disease.(2)
In addition, cruciferous vegetable consumption is linked to a reduced incidence of multiple cancers. One study analysed data from thousands of case-control studies to determine the effect of cruciferous vegetables on cancer risk. The researchers found that consuming cruciferous vegetables at least once per week led to a significant reduction in risk of developing cancers of the oral cavity, oesophagus, colorectum, breast and kidney, compared to no or occasional consumption.(3)
Moreover, leafy greens contain fat-soluble phytochemicals including carotenoids which have powerful antioxidant properties. In order to maximise the health benefits, consuming fats with leafy greens is a great way to boost the absorption of fat-soluble phytochemicals. For example, you could make a salad dressing using extra virgin olive oil, or add some nuts or seeds to your salad.
Related reading
“People in the Blue Zones eat about 95 to 100% plant-based diets. The longest-living people eat a wide variety of seasonal vegetables[…]”
Go nuts for nuts
Nuts feature widely across all Blue Zones in the diets of the longest-living populations. Nuts are highly nutrient dense, they provide healthy fats along with plant protein, fibre, vitamins and minerals. In addition, nuts have a low glycemic index, so when added to a meal, they can reduce the total glycemic load. Thus, nuts can play an important role in regulating blood sugars and are especially important for individuals with diabetes.
A systematic review and meta-analysis of the literature analysed the relationship between nut consumption and risk of cardiovascular disease, total cancer and all-cause and cause-specific mortality. The study showed that higher nut intakes were associated with reduced risk of cardiovascular disease, total cancer, all-cause mortality and mortality due to diabetes, infections and respiratory disease.(4)
The fat profile of nuts makes them an ally against cholesterol. In fact, their low saturated fat content and high levels of unsaturated fatty acids favourably affect blood lipids. A number of studies support the hypothesis that tree nuts reduce LDL “bad” cholesterol by up to 19%.(5)
In addition to their healthy fat content, nuts contain other nutrients and compounds such as antioxidants, plant sterols and fibre which positively impact blood lipids. So next time you feel like a snack, grab a handful or a healthy snack containing nuts for some heart-healthy fats. You can also add nuts like chopped walnuts or almonds to garnish salads for an extra nutritious crunch.
Spilling the beans
Legumes come in different shapes and sizes, from kidney beans to lentils, chickpeas, black beans and cannellini beans, the variety is endless. You may be surprised to know just how nutritious legumes can be! Every longevity diet in the world contains legumes: from black beans in Nicoya, to lentils, chickpeas and cannellini beans in the Mediterranean and soybeans in Okinawa. Blue Zone inhabitants eat on average 4 times more legumes than the standard Western diet.
They are excellent sources of fibre, protein, carbohydrates, iron, phosphorus,manganese and zinc. They are naturally low in fat and of course, given they are plant foods, they are completely cholesterol free. In addition, legumes are low GI so they are the perfect food for diabetics and in general for anyone who wants to keep their blood sugar levels in check.
It is no surprise that legumes feature in the world’s healthiest diets including the Mediterranean diet and the DASH diet. Not only are legumes highly nutritious, they also play an important role in the prevention and management of several health conditions.
Legumes can lower blood sugars…
For example, one study looked at the effects of legume consumption in individuals with type 2 diabetes. The participants were divided into two groups, one was assigned a low GI diet highlighting legume consumption and the other group followed a low GI diet highlighting wheat fibre foods.
Blood sugar levels decreased in the low-GI legume group and they also recorded significant decreases in total cholesterol and triglyceride levels. Moreover, the participants in the legume group had decreased systolic and diastolic blood pressure readings compared to the low GI high wheat fibre group.(6)
…cholesterol and blood pressure
Moreover, regular legume consumption can help to lower total and LDL “bad” cholesterol levels. One meta-analysis looked at the effects of consuming legumes over a 3-week period. The results showed that there was a significant change in the cholesterol levels of the participants assigned to the legume group compared to the control group.(7)
Another study involving type 2 diabetics looked at the effects of a legume-free therapeutic diet for heart disease versus the same diet replacing 2 servings of red meat with legumes on 3 days per week. The group assigned to the diet including legumes had improved LDL and cholesterol levels as well as better fasting glucose and insulin levels compared to the legume-free group.(8)
Legumes contain fibre along with potassium and magnesium which are known to positively impact blood pressure. A systematic review and meta-analysis examined the reuslts of scientific trials involving over 500 people, 50% of whom were either overweight or obese. The study found a decrease in blood pressure in individuals who consumed legumes.(9)
Furthermore, an other study looked at the effects of replacing refined carbohydrates with legumes and whole grains every day for 18 months in an obese cohort. At the end of the study period, participants saw reductions in blood pressure, weight, waist circumference and triglyceride levels.(10)
Whole grains for the win
Most of the bread sold in stores today would barely be recognisable to our ancestors. In fact, bread eaten in the Blue Zones is significantly different to most commercially available breads sold in the UK and US. Most breads in supermarkets are made with bleached white flour which our body converts into sugar, thus spiking insulin levels.
In contrast, most of the bread consumed by the longest-living populations is either whole grain or sourdough. In Sardinia and Ikaria for example, breads are made from a multitude of whole grains including barley, wheat and rye. Each grain contributes its own unique nutritional value, for example barley is an excellent source of selenium and manganese and rye is rich in B vitamins.
Moreover, whole grains contain more fibre compared to commonly sold wheat flours, and fibre is an essential requirement for good gut health. Some traditional breads are made using lactobacilli, a type of bacteria that produces lactic acid, making the bread taste sour, thus the name “sourdough”.
The fermentation process involving these bacteria leads to bread that is lower in gluten compared to regular bread. Given that the fermentation process lowers the starch content in sourdough bread, it is also lower GI compared to standard bread. Thus it is a great option for keeping blood sugar levels under control.
Don’t skip the garlic
Allium vegetables include onion and garlic and are commonly consumed in many diets across the world. Since ancient times humans have been interested in the potential health benefits of these foods. Multiple epidemiological studies suggest an inverse relationship between allium vegetable consumption and the incidence of stomach, colorectal and prostate cancers.(11,12)
However, there is little evidence regarding the effects of allium vegetables on other types of cancers, especially in Western countries. In fact, most of the allium studies took place in China where dietary habits vary considerably from western diets.
In one study researchers analysed the data from a network of case-control studies to understand the relationship between onion and garlic consumption frequency and risk of cancer. Overall, there was an inverse relationship between frequency of allium vegetable consumption and the risk of developing several common cancers.(13)
Tomatoes…
Tomatoes contain a myriad of healthy nutrients, however the one nutrient that has attracted the most attention is lycopene. This compound is a carotenoid that gives the reddish colour to foods such as tomatoes and pink grapefruit. In the UK and the US, most of the dietary intake of lycopene comes from processed tomato products such as tomato sauce. Lycopene has gained a lot of attention due to its potential health benefits.
…and the benefits of lycopene
A review in the European Journal of Clinical Nutrition examined the effects of tomato products containing lycopene on oxidative stress and cancer in human clinical trials.(14)
It was found that consumption of tomato products containing lycopene can lower biomarkers of oxidative stress in healthy and type 2 diabeteic individuals and carcinogenesis in prostate cancer patients. Processed tomato foods include tomato sauce, paste, juice, puree and ketchup. Lycopene is a fat-soluble compound and therefore dietary fats should be consumed alongside food sources of lycopene in order to maximise its absorption.
There is limited data on the health benefits of lycopene alone. However most clinical trials involving tomato products suggest that lycopene alongside other nutrients naturally occurring in tomatoes can lower oxidative stress and the formation of cancer cells.
Overall, there are several foods which can contribute to health and longevity. This is by no means an exhaustive list. While there are many more healthy foods that you can include in your diet for a long and healthy life, these foods are a great place to start. Finally, if there’s one key takeaway that we can learn from the world’s longest living populations it’s that eating more plants is the foundation of longevity.
