The common beverage green tea is highly effective at killing a specific oral bacteria, *Fusobacterium nucleotum*. This particular bacteria has been scientifically linked to accelerating tumor growth in colorectal and breast cancer, providing a specific mechanism for green tea's health benefits.

India has the world's lowest incidence of Alzheimer's disease. Researchers speculate this is linked to the high, lifelong consumption of turmeric, which Dr. Weil calls the most powerful natural anti-inflammatory agent known.

Instead of adhering to a strict diet label like vegan or pescatarian, Dr. Bolsiewicz advises focusing on nutrient quality. A gut-healthy, anti-inflammatory diet is achieved by consistently consuming these four "workhorses," which support the microbiome and calm the immune system, regardless of the diet's name.

The Omega-3 Index, a measure of omega-3 levels in red blood cells, is a powerful predictor of longevity. Observational data shows that individuals with an index of 8% have a five-year longer life expectancy compared to those with a 4% index, a level common among people on a standard American diet.

Dr. Patrick highlights the COSMOS trials, a series of three large, randomized controlled trials. They found that older adults (65+) taking a standard multivitamin (Centrum Silver) for a year experienced a reduction in global brain aging by ~2.1 years and episodic memory aging by ~4.9 years.

While effective for short-term weight loss, there is little scientific evidence that a long-term ketogenic diet promotes longevity. Sinclair expresses concern over the lack of plant-based polyphenols, which are crucial for activating the body's anti-aging pathways.

To significantly slow the progression of age-related macular degeneration, a leading cause of blindness, a surprisingly modest diet change is effective. Consuming just two servings of oily fish and 2.7 servings of green leafy vegetables per week reduces the risk of the disease advancing by 41%.

For brain health, vegetarians and vegans can get essential DHA omega-3 fatty acids from algae-based supplements, which provide the same preformed long-chain compounds found in fish like salmon and sardines.

Nutritional research shows that dietary diversity is a more critical health factor than simply eliminating animal products. People who consume 30 or more different kinds of plants and animals weekly are significantly freer from disease than even those on exclusively vegan or vegetarian diets.