Nutrients Determine Health Inside and Out
The texture, strength, color, and sheen of skin, hair, and nails can all be an excellent indicator of overall health. Paying attention to our outer appearances can give us clues to the integrity of our nutrient status. Nutrient levels can determine the quality and health of our skin. Including healthy sources of fat into a balanced diet can contribute to that luster and glow in your skin.
Quality of Fat vs Caloric Counting
A healthy diet includes a balanced intake of essential macronutrients and micronutrients.
- Macronutrients include fat, protein, carbohydrates, and water
- Micronutrients include vitamins and minerals.
Of the macronutrients, fat has the highest caloric value per gram of food. For example, there are 9 kilocalories in 1 gram of fat in comparison to only 4 kilocalories in 1 gram of both carbohydrates and protein.
The fact that fat contains more calories often deters individuals from eating foods that are high in fat. Although, it is more important to remember that fat is essential and plays many vital roles in various biological processes (such as energy, absorption of fat-soluble vitamins [A, D, E, and K], skin structure, and more).[2,3] Therefore, rather than focusing on counting calories, the quality and type of fat should be considered.
What Is Considered a Healthy Fat?
There are several different types of fats:[2-4]
- Saturated: predominantly from animal sources
- Unsaturated (Monounsaturated and Polyunsaturated): predominantly from plant sources
- Trans: Unsaturated fats that have been processed to be made more stable (hydrogenated)
According to the 2015-2020 USDA Dietary Guidelines, saturated fat intake should be kept under 10% of total daily calories, and trans-fat intake is avoided as much as possible. The reason that saturated fat and trans fats are often deemed the ‘unhealthy fats’ is because they may increase bad LDL cholesterol levels and also increase the risk for cardiovascular disease. In contrast, the USDA Dietary Guidelines lists unsaturated fats (especially polyunsaturated fatty acids) as having the potential to lower the risk for cardiovascular disease. This is especially true for plant foods that are also composed of many beneficial antioxidants, fiber, and other plant constituents.
What’s in an Avocado?
Avocado is known for its high-fat content (predominantly monounsaturated fat). Its oil is commonly applied topically for various cosmetic reasons and has been found to have the following skin benefits: anti-inflammatory, promoting a healthy skin barrier, wound healing, and UV protection.[3,5,6]
Avocado is an excellent source of the following nutrients: Potassium, magnesium, dietary fiber, vitamins K, C, A, E, B6, folate, and carotenoids (lutein, zeaxanthin, and cryptoxanthin).
Like most food products avocado is composed of a mixture of the different types of fats, but It is primarily made up of oleic and palmitic fatty acids. Avocados are also a healthier option to include in a meal because they have a low glycemic index (meaning it will not spike blood sugar levels too high) due to its high water content and fiber content.
Avocado and Skin Health
There are a number of studies that look at the topical benefits of using avocado oils for health,[5,6,8] but a limited amount of research exists that looks into the direct relationship of avocado consumption and skin health.
One study compared the intake of dietary fat and anti-oxidant rich vegetables (particularly green and yellow vegetables) to skin aging amongst a number of Japanese women. The researchers measured skin hydration and elasticity on the face, backs of the hands, and the forearm. The participants filled out a questionnaire regarding diet and lifestyle habits (sun exposure, smoking, and environment). The researchers concluded that a higher intake of total fat was associated with an improvement in skin elasticity and that a higher intake of green and yellow vegetables was associated with decreased wrinkling. Although the vegetable-based skin benefits were thought to be due to the carotenoids (family of plant-based nutrients) in green and yellow vegetables, more research is needed to determine if other nutrients within the vegetable may also have skin benefits.
Avocados and Carotenoid Content
Avocados are a rich source of carotenoids. In fact, avocados are known to contain more lutein and zeaxanthin when compared to the most commonly consumed fruits and vegetables. According to one critical review, the National Health and Nutrition Examination Survey (NHANES) has determined the following nutrient amounts in one-half of a Hass avocado
Fat Soluble Vitamins & Carotenoids
Amount in ½ Fruit
Lutein & Zeaxanthin (mg)
The California Avocado Commission labels an avocado as a “nutrient booster.” This is a perfect description of an avocado due to its healthy fat and carotenoid content. Fatty acids are necessary to absorb all of the fat-soluble vitamins (vitamin A, vitamin D, vitamin E, and vitamin K).[9,10] Avocados have also been shown to enhance the absorption of carotenoids of other fruits and vegetables when eaten together. Topical and oral consumption of carotenoids may protect the skin from sun damage and radiation and the fatty acid content (oleic, linoleic, and linolenic acids) may possibly aid in wound healing.
Pick, Store, & Ripen Avocados for Maximum Benefits
The California Avocado Commission provides an excellent guide for selecting and handling avocados. Here are some helpful tips summarized:
- A perfectly ripe avocado will be firm, but soft enough to budge with a gentle squeeze.
- Know your variety: some avocados remain green when ripe, whereas others will turn slightly black when ripe.
- Choose a hard avocado if you need it in a few days!
- Put your avocado in a brown paper bag if you need to speed up the ripening process. Adding an apple or a kiwi also speeds up the process even more!
- Cut your avocado in half lengthwise, twist to break the halves apart, remove the seed, then cut the avocado in half one more time before peeling the skin off.
- Store the avocado in a refrigerator for up to 2-3 days in an airtight container, and squeeze some lemon juice on the cut avocado in order to avoid discoloration of the fruit.
An interesting fact to consider when consuming an avocado is that the carotenoid levels vary within the avocado flesh itself. A study on avocado pigments discovered that the total amount of carotenoids is higher in the dark green flesh (the portion of the fruit right below the skin) and lower in the pale yellow flesh of the avocado. Therefore, following the recommendations to peel an avocado will allow you to access the darker green flesh of the fruit with the highest concentration of carotenoids.[11,12]
A Closer Look at Dietary Intake and Skin Health
Topical application of avocado oils and extracts may increase collagen synthesis, decrease skin inflammation, help with wound healing, and improve the skin barrier. Although more research is warranted for the consumption of avocados and skin health, avocados can most definitely be included in the diet and contribute to a healthy skin glow. This may be due to the fact that avocado is a monounsaturated plant source of fat and contains a noticeable amount of water, fiber, carotenoids, antioxidants, and other essential nutrients.
The potential for future research to determine the nutrient status and dietary intake and a more direct effect on skin health are exciting.