To Live Longer, Replace Butter with Vegetable Oils!

A vast number of studies have clearly shown that replacing saturated fats—found mainly in animal-based foods—with unsaturated fats, especially those from plant sources, is strongly linked to a reduced risk of cardiovascular events and early mortality (see our article on this topic).

The current consensus is thus that lowering saturated fat intake, combined with increased intake of high-quality unsaturated fats (especially monounsaturated and omega-3 polyunsaturated fats), represents the optimal fat profile to enhance life expectancy.

This was recently confirmed by a large-scale study involving over 400,000 adults followed for 24 years. The study found that higher intake of animal fats was associated with a 15% increase in the risk of all-cause and cardiovascular mortality. In contrast, regular consumption of plant-based fats was linked to a 10–15% reduction in the risk of both types of death (Figure 1).

A more detailed analysis revealed that the increased risk of cardiovascular mortality from animal fats appears to be mainly due to fats from dairy products and eggs, whereas the reduction in mortality associated with plant-based fats is most pronounced for fats from vegetable oils and whole grains (Figure 2).

These opposing effects of animal vs. plant fat sources on mortality risk suggest that replacing animal fats with plant-based fats could have a positive impact on longevity. In this regard, when the authors modelled the effect of replacing 5% of calories from animal fats with an equivalent amount from plant fats, they observed up to a 24% reduction in all-cause mortality and a 30% reduction in cardiovascular mortality, especially when the plant fats came from vegetable oils and whole grains.

This finding aligns with several other studies showing that replacing saturated fats with unsaturated fats may reduce the relative risk of cardiovascular disease by about 30%—an effect comparable to that of statin medications.

Butter vs. Vegetable Oils

Another way to assess the impact of this fat substitution is by comparing butter and vegetable oils, two commonly used foods with completely opposite fat profiles (see Table 1).

• Butter, made from cream, contains about 62% saturated fats, which are associated with increased cardiovascular risk.
• Vegetable oils, on the other hand, are rich in polyunsaturated fats, which have been linked to lower cardiovascular risk.
• Olive oil, and to a lesser extent canola oil, stand out for their high content of monounsaturated fats, which are also considered beneficial for heart health.

Table 1. Fatty Acid Content of Butter and Various Vegetable Oils. The fat composition of coconut oil is included for comparison, to illustrate that tropical oils are not a valid alternative to butter when aiming to reduce saturated fat intake, as discussed earlier.

A recent large-scale study clearly illustrates the beneficial effects of replacing butter with vegetable oils. Conducted with 220,000 participants over a period of 33 years, the study found that individuals who consistently consumed the highest amounts of butter during that time (about 10 grams per day, or roughly 1 tablespoon) had a 15% higher risk of premature death from all causes (Figure 3).

In contrast, those who consumed the most vegetable oils (about 25 grams per day, or 5 teaspoons on average) had a 15% lower mortality risk, with the reduction reaching 20% among those who primarily used olive oil.

These opposing effects mean that simply replacing butter with an equivalent amount of vegetable oil is linked to a significant reduction in the risk of premature death—whether from all causes, cancer, or, to a lesser extent, cardiovascular disease (Figure 4).

In summary, this study clearly shows that small, simple changes in dietary habits—in this case, replacing butter with vegetable oils as the main source of fat—can have very positive impacts on health.