Raspberries have long been established as a health food. But recent researches are even more encouraging regarding their health benefits. Though the studies are in their early stages, scientists have definitely found out that phytonutrients in raspberries increase our cellular metabolism, one of the most important among them being rheosmin which is also known as raspberry ketone. The action of phytonutrients in raspberry including rheosmin is to increase oxygen consumption, enzyme activity and heat production in particular kinds of fat cells, and reduce the risk of obesity and fatty liver. Moreover, rheosmin can also reduce the action of pancreatic lipase which is a fat-digesting enzyme produced by pancreas. Because of reduction in the activity of this enzyme, digestion and absorption of fat reduces greatly.
It has been seen in recent studies that organic raspberries are considerably higher in their antioxidant activity than non-organic raspberries. A series of trials were conducted on raspberries cultivated on the farms of Maryland and certified by the U.S. Department of Agriculture as organic. These organic raspberries showed free radical scavenging activity that outperformed that of their non-organic cousins. This higher antioxidant activity was accredited to the higher levels of total anthocyanins and total phenols found in the organic raspberries than the non-organic ones.
Fully Ripe Raspberries
Fully ripe raspberries show greater antioxidant activity than that of less ripe ones. In recent researches the total flavonoid content, total phenolic content and anthocyanin content of raspberries collected at various stages of ripeness (50%-100% maturity) were measured and it was found that greatest antioxidant activity was shown by fully ripe berries. Though raspberries can ripen after harvesting, they are highly perishable and can easily mold at room temperature. So, if you buy them in their fully ripened stage and keep them at temperatures ranging between 2° and 4° C (35°-39° F) all the time or consume them within 1 or 2 days of purchase, you will get the optimal antioxidant benefits from them.
Anticancer Benefits of Raspberries
Raspberries have long been proven to have anticancer benefits which are accredited to their phytonutrients which have antioxidant and anti-inflammatory properties. In animal studies which included cervical, esophageal, breast, colon and prostate cancers, phytonutrients in raspberries were found to play a very important role in reducing oxidative stress, thus lessening inflammation, and in turn, modifying the growth or reproduction of cancerous cells. However, newer research has revealed that the anticancer properties of raspberries are far extended beyond their primary antioxidant and anti-inflammatory properties. Raspberry phytonutrients can actually change the signals sent to existing or potential cancer cells. Ellagitannins are raspberry phytonutrients that are able to reduce the numbers of cancer cells by sending signals that promote cancer cells for being involved in a cycle of cell death (apoptosis). In case of cells that are potentially but not still cancerous, raspberry phytonutrients may activate signals that encourage them to remain non-cancerous.
Diversity in Phytonutrients in Raspberries
Raspberries have surprisingly diverse types of phytonutrients like anthocyanins (delphinidins, cyanidins, malvidins, pelargonidins), flavonols (kaempferol, quercetin), tannins (gallotannins, proanthocyanidins, ellagitannins), hydroxybenzoic acids (gallic acid, ellagic acid, vanillic acid, lambertianin, sanguiin), and many more. Raspberries contain not only these extremely varied phytonutrients, but also in amounts that are important for protecting us from oxidative stress and excessive inflammation. Because of the free radical scavenging and regulation of enzyme that could lead to unwanted inflammation, the raspberry phytonutrients cut down the risk of chronic ailments that are associated to chronic inflammation and chronic oxidative stress. These ailments include hypertension, type II diabetes, obesity and atherosclerosis.
A special mention is deserved by the ellagic acid in raspberries. This phytonutrient is an anti-inflammatory compound and has been found to help check excessive activity of specific pro-inflammatory enzymes (like cyclo-oxygenase (COX)-2) and also their excessive production. Animal studies have proved that intake of ellagic acid reduces various aspects of excessive and unwanted inflammation, such as aspects related to Crohn's disease.
Health Benefits of Raspberries for Obesity and Blood Sugar
New researches are being conducted on raspberries especially focusing on obesity and type II diabetes. For obesity, two nutrients in raspberries have attracted special attention of scientists and they are rheosmin (raspberry ketone) and tiliroside (a type of flavonoid).
Though its name is so, raspberry ketone is not exclusive to raspberries. It is an ingredient of an extensive range of plants, but in raspberries, it is found in quite sizable amount. Raspberry ketone or rheosmin has been included in the Generally Recognized As Safe (GRAS) list of the Food and Drug Administration (FDA) since 1965 as a permitted food additive. Thus it is added to foods for aroma and flavor.
As told earlier, rheosmin boosts up fat metabolism in our body and lessen fat deposition in fat cells. Because of improved fat metabolism our body can also lessen the amount of pro-inflammatory messaging molecules formed by our fat cells. Because of this, we may be less prone to undergo some inflammation-related problems that usually accompany obesity.
Also due to the reduced activity of pancreatic lipase brought about by rheosmin, body's fat absorption and digestion is reduced.
The second phytonutrient in raspberries – tiliroside – it is a flavonoid which is found in several plants belonging to rose family, like strawberries, rose hips and raspberries. This has been found to trigger a special hormone named adiponectin which is formed by our fat cells. Adiponectin is not sufficiently produced or if produced, remains inactive, in diabetes type II patients. This insufficiency in obese diabetes type II patients is a major problem for regulation of blood fats and blood sugar.
Tiliroside activates adiponectin and brings about blood fat balance, insulin balance and blood sugar balance. Though it has not been proven by studies so far that tiliroside in raspberries limits weight gain or fat accumulation, it may help prevent undesired consequences of excessive body fat and compromised regularization of blood fats, blood insulin and blood sugar.
One more aspect of phytonutrients in raspberry has attracted scientists' attention in the context of obesity and blood sugar problem and it is the capability of raspberry extracts to stop the activity of an enzyme known as alpha-glucosidase. This is a starch-digesting enzyme which increases the conversion of starches into sugars upon activation. These sugars are absorbed in the blood after meals and can lead to overly high levels of blood sugar. This is known as postprandial hyperglycemia.
Raspberry extracts block the activity of alpha-glucosidase and manage blood sugar levels better in type II diabetes individuals.
As one cup of fresh and fully ripe raspberries provide around 15g of total carbohydrates and just 5-6g of sugar, a moderate serving of fresh and ripe raspberries (such as ½ cup) can be an extremely beneficial content of most diets, even those focused on blood sugar stabilization.
Raspberry is a simple-looking food that can offer extraordinary health benefits. Include it in your daily meals and enjoy this wonderful fruit.