Antiaging creams and schemes are a multibillion-dollar business, but the only thing that has been scientifically proven to extend human lifespan is calorie restriction. Many well-documented and highly credible studies show that reducing the amount of calories you eat by 25 to 65 percent helps a number of processes in your body that can slow down aging and improve your overall health. 

Research shows that cutting calories can:

• Alter the actions of many key enzymes that control your body’s metabolism, helping you to lose weight.
• Influence genes that alter cell repair or death.
• Affect a protein/sugar cross-linking process called glycosylation that can damage your DNA.
• Reverse dysglycemia, an imbalance in sugar metabolism and energy production that accelerates aging in your cells. 
• Reduce chronic inflammation, which contributes to a variety of health conditions, including heart disease and diabetes.
• Limit the body’s free radical production, which is a factor in everything from wrinkled skin to creaky knees.
• Reduce blood pressure and LDL (bad) cholesterol.
• Improve insulin sensitivity and normalize blood glucose levels, which helps prevent obesity and diabetes. 
• Boost hormonal secretions, including DHEA and growth hormone, that tend to fall with age.
• Improve brain function, including memory, cognition and perhaps mood.

How to cut calories

Reducing your calories is not as simple as just eating less. Tests in mice show they actually age more quickly when they have a drastic cut in calories. The pioneer of calorie restriction, Roy Walford, MD, recommended gradually limiting your calories over a period of one to two years. Many people who follow the calorie-restriction diet eventually settle on a lifetime calorie goal of 30 percent less than the recommended daily intake of 2,500 calories for men and 2,000 for women.

According to the Calorie Restriction Society, you need to be vigilant about how you cut calories in order to avoid malnutrition. Here are some of the society’s recommendations:

• Avoid sugar and white flour. Both are high in calories but low in nutrition. They also have high glycemic indexes, which means your body absorbs them quickly and you become hungry faster. Choose fruit and whole grains instead.
• Eat lots of veggies. Vegetables give you the most nutrients for the fewest calories.
• Maintain protein consumption. Protein can be high in calories so it’s tempting to eat less, but make sure you get at least 1 to 1.5 ounces daily per 100 pounds of body weight. It’s also important that the proteins you eat are complete (meaning they contain all the essential amino acids) and balanced (with amino acids in ratios that are most useful to your body). Most animal proteins are both complete and balanced, as are the vegetarian combos of beans and whole grains; and brown rice and broccoli, cauliflower or spinach. Keep in mind that the number of grams of protein per ounce can vary depending on the source. For example, one ounce of cooked beef has about 7 grams of protein and three ounces of cooked chicken has about 21 grams of protein. To get 7 grams of protein from non-meat sources, you would need to eat about a ½ cup cooked beans, one ounce of cheese, one egg, two tablespoons of peanut butter or four ounces of tofu.
• Stay away from saturated fats. You need to consume some fat, but opt for foods rich in unsaturated fat, such as plant oils, nuts and avocados. It’s also a good idea to take an omega-3 fatty acid supplement.

That may all sound simple enough, but reducing calories is no easy task. Specialized nutrients may be able to help.

The memetics connection

If eating less were easy, there would be no need for the multibillion-dollar diet and antiaging industry. That’s why in the late 1990s, scientists started to propose the notion that there are certain substances that can mimic the effect of calorie restriction in the body. Known as mimetics, these substances are defined as pharmaceutical, chemical or natural agents that have the ability to reproduce one or more principal biological effects of calorie restriction. 

Mimetics are quite versatile—for instance, some may affect the genetic components of aging, whereas others may influence the glucose metabolism that contributes to obesity and diabetes. Many experts believe that combining mimetics with small reductions in overall calorie intake is as effective as larger reductions in calories alone. This approach seems to be deeply rooted in good scientific agreement, derived from almost eight decades of research.

8 ingredients that can help you live longer

Here are the safest natural calorie-restriction mimetics that have the most scientific backing:

• Resveratrol, a polyphenol found in grapes and red wine, is a potent antioxidant that helps reduce cell death and has proven anticancer and cardiovascular benefits.
• Leptin is a hormone that helps control appetite, stimulates fat metabolism and reduces body weight. Researchers believe it may be a key component of calorie restriction.
• Carnosine is an amino acid combo that helps reduce the cross-linking of proteins that can damage your DNA, and improves brain function and memory.
• Avocado improves insulin sensitivity and blood glucose levels, which can help prevent obesity and diabetes.
• Alpha lipoic acid is an antioxidant that improves insulin sensitivity.
• Cinnamon is another insulin sensitizer. 
• Gymnema, an Ayurvedic herb whose Indian name means “destroyer of sugar,” has glucose-regulating effects similar to avocado’s.
• Acetyl-L-carnitine is an antioxidant that helps protect the brain and boosts energy at the cellular level.

The Calorie Restriction Society recommends you get a blood test showing nutrient status for things like iron, vitamin D and other nutrients before beginning your new eating program. This will set a baseline to make sure you’re not becoming deficient in nutrients as you cut calories.