Grapeseed oil has been growing in popularity over the past few decades.
It’s often promoted as healthy due to its high amounts of polyunsaturated fat and vitamin E.
Marketers claim it has all sorts of health benefits, including lowering your blood cholesterol levels and reducing your risk of heart disease.
This article takes a close look at the available research to separate the facts from the fiction.
Grape seed oil is processed from the seeds of grapes, which are a byproduct of winemaking.
From a business perspective, producing this oil is a brilliant idea. For thousands of years, wine manufacturers have been left with tons of this useless byproduct.
Due to technological advances, manufacturers can now extract the oil from the seeds and make a profit.
The oils are usually extracted in factories by crushing the seeds and using solvents, but the healthier types of seed- and vegetable oils are cold-pressed or expeller pressed.
Some people are concerned that traces of toxic solvents, such as hexane, could adversely affect people’s health.
However, virtually all solvents are removed from vegetable oils during the manufacturing process.
It’s currently unknown whether hexane traces in vegetable oils cause harm in people over time, but hexane’s adverse environmental effects are more worrying. Research now focuses on developing greener alternatives ().
If your oil doesn't explicitly state how it is processed, then you should assume that it was extracted using chemicals like hexane.
Summary Grape seed oil is extracted from grape seeds, a byproduct of winemaking. This process usually involves various chemicals, including the toxic solvent hexane.
The health claims for grape seed oil are based on its supposedly high amounts of nutrients, antioxidants and polyunsaturated fats ().
The fatty acid composition of grape seed oil is the following:
- Saturated: 10%
- Monounsaturated: 16%
- Polyunsaturated: 70%
It’s very high in polyunsaturated fats, mainly omega-6. Scientists have speculated that a high intake of omega-6 fats, relative to omega-3s, may increase inflammation in the body ().
This theory is supported by several observational studies that have associated a high intake of foods containing omega-6 fatty acids with an increased risk of chronic disease (, ).
However, controlled studies show that linoleic acid — the type of omega-6 fatty acid in grape seed oil — does not increase blood levels of inflammatory markers (, ).
Whether a high intake of omega-6 fatty acids promotes disease is currently unknown. High-quality studies examining the effects of omega-6 fatty acids on hard endpoints like heart disease are needed ().
Grape seed oil also contains significant amounts of vitamin E. One tablespoon provides 3.9 mg of vitamin E, which is 19% of the RDA ().
However, calorie for calorie, grape seed oil is not an impressive source of Vitamin E.
Virtually no other vitamins or minerals are found in grape seed oil.
Summary Grapeseed oil is high in vitamin E and phenolic antioxidants. It’s also a rich source of omega-6 polyunsaturated fats. Scientists have theorized that eating too much omega-6 may be harmful.
Very few studies have investigated the effects of grape seed oil on human health.
One two-month study in 44 overweight or obese women compared the health effects of taking either grape seed or sunflower oil daily.
Compared to taking sunflower oil, grape seed oil improved insulin resistance and reduced levels of C-reactive protein (CRP), a common inflammatory marker ().
It also seems to have anti-platelet effects, meaning it reduces your blood’s tendency to clot ().
However, some grape seed oils may contain potentially harmful levels of polycyclic aromatic hydrocarbons (PAHs), which are known to cause cancer in animals ().
It’s unknown how widespread this problem is or whether it’s a real cause for concern. Other vegetable oils, such as sunflower oil, may also be contaminated with PAHs ().
While there are some indications that high-quality grape seed oil may have some benefits, no strong claims can be made at this point.
Summary There’s a lack of research on the health effects of grape seed oil in humans. However, the current evidence suggests it may reduce blood clotting and decrease inflammation.
Grape seed oil has a moderately high smoking point.
For this reason, it’s advertised as a good choice for high-heat cooking like frying.
However, this may be bad advice, as grape seed oil is also high in polyunsaturated fatty acids. These fats tend to react with oxygen at high heat, forming harmful compounds and free radicals (, ).
Because grape seed oil is incredibly high in polyunsaturated fats, it really is one of the worst oils you could possibly use for frying.
The healthiest cooking oils for high-heat frying are those that contain mostly saturated fats or monounsaturated fats, such as olive oil, because they are less likely to react with oxygen when heated.
For this reason, you should avoid using grape seed oil for frying. Instead, you can use it as a salad dressing or an ingredient in mayonnaise and baked products.
Summary Grape seed oil is sensitive to high heat and should not be used for frying. However, it can be safely used as a salad dressing or in baked goods.
Grape seed oil is processed from grape seeds, which are an abundant byproduct of winemaking.
It’s relatively high in vitamin E and phenolic antioxidants, as well as a rich source of omega-6 fatty acids. Unfortunately, there is a lack of research on grape seed oil, so its health effects are not fully understood.
While there is nothing wrong with using grape seed oil in salad dressings or baked goods, its high levels of polyunsaturated fatty acids make it unsuitable for high-heat cooking, such as frying.
If you are looking for a healthy cooking oil, olive oil may be one of your best choices.