Olive oil is the golden yellow natural oil extracted from the olive fruit. It is famous all over the world because of the local diet survey in the Mediterranean Sea decades ago. Scholars have found that local residents use a lot of olive oil and eat vegetables, grains and seafood as staple foods, which can greatly reduce the risk of chronic diseases such as cardiovascular diseases.
A large number of studies have found that the health benefits of olive oil come not only from high amounts of monounsaturated fatty acids, but also rich in plant antioxidants, including: carotenoids, tocopherols, squalene, sterols, etc., making it the most representative Non-toxic vegetable oil, not only stable but also not easy to oxidize.
In evidence-based medicine, what are the benefits of olive oil? Are there any side effects or contraindications? See text analysis for details.
What are the proven benefits of olive oil recommended?
1. Olive Oil for Pressure Ulcer Prevention
Pressure Ulcers are skin lesions secondary to ischemic processes that can appear anywhere on the body, often in bony prominences (sacrum, buttocks and heels), especially in patients with severe acute illness and neurological deficits Elderly patients with limited mobility. The International Acute Hospital Survey reports a prevalence of 12.3% to 13.5%.
Current clinical practice guidelines for pressure ulcer prevention include assessment and care of the skin. Dry skin is an important independent risk factor for flares, while smooth skin is more resistant to external stress. Recommended skin care measures include topical skin moisturizers, high oxygen fatty acids (HOFA) or silicone cream.
A systematic literature review and meta-analysis (Meta-Analysis, including 4 randomized controlled trials, a total of 1601 participants at risk of developing pressure ulcers) pointed out that topical olive oil has the effect of reducing the incidence of pressure ulcers, and may be associated with Longer time to ulcer development was associated with shorter hospital stay. Note 1
*Conclusion: For the prevention of pressure ulcers, topical application of olive oil may be an effective and safe preventive alternative therapy, but limited by the small number of samples, more research is still needed for further verification.
2. Olive Oil Benefits Cardiovascular Disease
Cardiovascular disease is the disease most related to aging. The effects of aging include cardiac hypertrophy, changes in ventricular diastolic function, decreased ventricular contractility, increased arteriosclerosis, and impaired endothelial function. Note 1
And by 2030, 20% of the world’s population will be over 65 years old, and cardiovascular disease will become the leading cause of death (accounting for 40%).
A systematic literature review and meta-analysis (meta-analysis, including 32 cohort studies, 841,211 participants) showed that a higher intake of monounsaturated fatty acids in the diet (especially virgin olive oil) was associated with a reduction in all-cause mortality Effects on Mortality, Cardiovascular Events, and Stroke. Note 2
The underlying mechanism may be related to the rich polyphenols contained in it, which have free radical scavenging, anti-inflammation, and improvement of endothelial cell dysfunction.
*Conclusion: Olive oil intake is associated with a lower incidence of cardiovascular disease, but limited by heterogeneity and confounding factors, the results still need further confirmation.
3. Olive Oil to Prevent and Manage Diabetes
The main pathological features of diabetes are hyperglycemia and hyperglycated hemoglobin caused by defective insulin secretion or poor function, and cause serious damage to large and small blood vessels. It is the main cause of cardiovascular disease, end-stage renal disease, vision loss, and amputation.
It is estimated that by 2040, 1 in 10 adults will suffer from diabetes, and every 0.1% reduction in glycosylated hemoglobin can reduce the risk of cardiovascular disease by about 7%. Note 3
A literature review and meta-analysis (meta-analysis, including 4 cohort studies, 29 randomized controlled trials) pointed out that compared with those who consumed the least olive oil, subjects who consumed more olive oil could reduce the risk of type 2 diabetes by about 16% Occurs at risk. Note 4
In addition, for subjects with type 2 diabetes, olive oil supplementation can reduce glycated hemoglobin (HbA1c) and fasting blood glucose
*Conclusion: Olive oil intake may have positive effects on preventing type 2 diabetes and controlling blood sugar values.
4. Olive Oil Reduces Cancer Rates
Due to medical advances, the overall 5-year relative cancer survival rate has increased from 58% in the 1970s to the current 68% to 84%. Note 5
However, the incidence of cancer in men is still higher than that in women, the increase can reach 20%, and the death rate is 40% higher. The difference behind the difference may be related to the type of cancer. For example, the most common liver cancer, the fatality rate of male patients is three times that of women.
A systematic literature review and meta-analysis (meta-analysis, including 19 case-control studies, 13,800 cancer cases) showed that, compared with the least intake, a higher amount of olive oil intake can reduce the risk of various types of cancer by about 34% Among them, breast cancer and digestive system cancer (colorectal, oral cavity, throat, esophagus, pancreas) are the most significant. Note 6
*Conclusion: Population observation studies have found that groups that consume more olive oil are associated with a lower incidence of cancer, but randomized controlled studies are still needed to further confirm whether there is a causal relationship.
5. Olive oil is good for blood lipid regulation
In a highly industrialized society, the intake of a Western-style diet (high in fat, sugar, and salt) is considered to be one of the main causes of hypercholesterolemia and atherosclerosis.
The atherogenic lipoproteins in blood vessels are mainly low-density lipoprotein cholesterol (LDL). When the level is too high, it may accumulate in blood vessels and cause inflammation, while high-density lipoprotein (HDL) can help reverse this process.
A systematic literature review and meta-analysis (meta-analysis, including 27 randomized controlled studies, with 1089 participants) pointed out that compared with other types of vegetable oils, olive oil has a more significant effect on raising high-density lipoprotein (but It is less obvious for reducing total cholesterol, low-density lipoprotein cholesterol, and triglyceride). Note 7
*Conclusion: The intake of olive oil may help regulate blood lipids, and the subjects who have used it for more than 30 days are more significant
Does olive oil have side effects?
Olive oil is very safe in moderation, about 14% of total daily calories (about 28 grams), and excess may cause diarrhea.
Some adverse reactions have been reported when applied directly to the skin, such as delayed allergic reactions and contact dermatitis.
Safety Precautions (Contraindications)
Olive oil (especially virgin) may have the effect of lowering blood sugar and blood pressure, please pay attention to those who take related drugs
Related diabetes drugs such as: glimepiride (Amaryl), glibenclamide (DiaBeta), pioglitazone (Actos), rosiglitazone (Avandia), chlorpropamide (Diabinese), glipizide (Glucotrol), Tolbutamide (Orinase)
Related blood pressure lowering drugs such as: Capoten, Enalapril (Vasotec), Cozaar, Valsartan (Diovan), Cardizem, Amlodipine (Norvasc), Hydrochlorothiazide (HydroDIURIL), furosemide (Lasix)
Note 1: https://pubmed.ncbi.nlm.nih.gov/36429639/
Note 2: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4198773/
Note 3: https://www.ncbi.nlm.nih.gov/pubmed/24668104/
Note 4: https://www.ncbi.nlm.nih.gov/pubmed/28394365
Note 5: https://www.ncbi.nlm.nih.gov/pubmed/28055103
Note 6: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3199852/
Note 7: https://www.ncbi.nlm.nih.gov/pubmed/29420053