FREMONT, Calif.  They gather five days a week at a mall called the Hub, sitting on concrete planters and sipping thermoses of chai. These elderly immigrants from India are members of an all-male group called The 100 Years Living Club. They talk about crime in nearby Oakland, the cheapest flights to Delhi and how to deal with recalcitrant daughters-in-law.

Together, they fend off the well of loneliness and isolation that so often accompany the move to this country late in life from distant places, some culturally light years away.

“If I don’t come here, I have sealed lips, nobody to talk to,” said Devendra Singh, a 79-year-old widower. Meeting beside the parking lot, the men were oblivious to their fellow mall rats, backpack-carrying teenagers swigging energy drinks.

In this country of twittering youth, Mr. Singh and his friends form a gathering force: the elderly, who now make up America’s fastest-growing immigrant group. Since 1990, the number of foreign-born people over 65 has grown from 2.7 million to 4.3 million  or about 11 percent of the country’s recently arrived immigrants. Their ranks are expected to swell to 16 million by 2050. In California, one in nearly three seniors is now foreign born, according to a 2007 census survey.